Bochs/bochs/cpu/paging.cc

2691 lines
95 KiB
C++

/////////////////////////////////////////////////////////////////////////
// $Id$
/////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2001-2019 The Bochs Project
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA B 02110-1301 USA
/////////////////////////////////////////////////////////////////////////
#define NEED_CPU_REG_SHORTCUTS 1
#include "bochs.h"
#include "cpu.h"
#include "msr.h"
#define LOG_THIS BX_CPU_THIS_PTR
// X86 Registers Which Affect Paging:
// ==================================
//
// CR0:
// bit 31: PG, Paging (386+)
// bit 16: WP, Write Protect (486+)
// 0: allow supervisor level writes into user level RO pages
// 1: inhibit supervisor level writes into user level RO pages
//
// CR3:
// bit 31..12: PDBR, Page Directory Base Register (386+)
// bit 4: PCD, Page level Cache Disable (486+)
// Controls caching of current page directory. Affects only the processor's
// internal caches (L1 and L2).
// This flag ignored if paging disabled (PG=0) or cache disabled (CD=1).
// Values:
// 0: Page Directory can be cached
// 1: Page Directory not cached
// bit 3: PWT, Page level Writes Transparent (486+)
// Controls write-through or write-back caching policy of current page
// directory. Affects only the processor's internal caches (L1 and L2).
// This flag ignored if paging disabled (PG=0) or cache disabled (CD=1).
// Values:
// 0: write-back caching enabled
// 1: write-through caching enabled
//
// CR4:
// bit 4: PSE, Page Size Extension (Pentium+)
// 0: 4KByte pages (typical)
// 1: 4MByte or 2MByte pages
// bit 5: PAE, Physical Address Extension (Pentium Pro+)
// 0: 32bit physical addresses
// 1: 36bit physical addresses
// bit 7: PGE, Page Global Enable (Pentium Pro+)
// The global page feature allows frequently used or shared pages
// to be marked as global (PDE or PTE bit 8). Global pages are
// not flushed from TLB on a task switch or write to CR3.
// Values:
// 0: disables global page feature
// 1: enables global page feature
//
// page size extention and physical address size extention matrix (legacy mode)
// ==============================================================================
// CR0.PG CR4.PAE CR4.PSE PDPE.PS PDE.PS | page size physical address size
// ==============================================================================
// 0 X X R X | -- paging disabled
// 1 0 0 R X | 4K 32bits
// 1 0 1 R 0 | 4K 32bits
// 1 0 1 R 1 | 4M 32bits
// 1 1 X R 0 | 4K 36bits
// 1 1 X R 1 | 2M 36bits
// page size extention and physical address size extention matrix (long mode)
// ==============================================================================
// CR0.PG CR4.PAE CR4.PSE PDPE.PS PDE.PS | page size physical address size
// ==============================================================================
// 1 1 X 0 0 | 4K 52bits
// 1 1 X 0 1 | 2M 52bits
// 1 1 X 1 - | 1G 52bits
// Page Directory/Table Entry Fields Defined:
// ==========================================
// NX: No Execute
// This bit controls the ability to execute code from all physical
// pages mapped by the table entry.
// 0: Code can be executed from the mapped physical pages
// 1: Code cannot be executed
// The NX bit can only be set when the no-execute page-protection
// feature is enabled by setting EFER.NXE=1, If EFER.NXE=0, the
// NX bit is treated as reserved. In this case, #PF occurs if the
// NX bit is not cleared to zero.
//
// G: Global flag
// Indiciates a global page when set. When a page is marked
// global and the PGE flag in CR4 is set, the page table or
// directory entry for the page is not invalidated in the TLB
// when CR3 is loaded or a task switch occurs. Only software
// clears and sets this flag. For page directory entries that
// point to page tables, this flag is ignored and the global
// characteristics of a page are set in the page table entries.
//
// PS: Page Size flag
// Only used in page directory entries. When PS=0, the page
// size is 4KBytes and the page directory entry points to a
// page table. When PS=1, the page size is 4MBytes for
// normal 32-bit addressing and 2MBytes if extended physical
// addressing.
//
// PAT: Page-Attribute Table
// This bit is only present in the lowest level of the page
// translation hierarchy. The PAT bit is the high-order bit
// of a 3-bit index into the PAT register. The other two
// bits involved in forming the index are the PCD and PWT
// bits.
//
// D: Dirty bit:
// Processor sets the Dirty bit in the 2nd-level page table before a
// write operation to an address mapped by that page table entry.
// Dirty bit in directory entries is undefined.
//
// A: Accessed bit:
// Processor sets the Accessed bits in both levels of page tables before
// a read/write operation to a page.
//
// PCD: Page level Cache Disable
// Controls caching of individual pages or page tables.
// This allows a per-page based mechanism to disable caching, for
// those pages which contained memory mapped IO, or otherwise
// should not be cached. Processor ignores this flag if paging
// is not used (CR0.PG=0) or the cache disable bit is set (CR0.CD=1).
// Values:
// 0: page or page table can be cached
// 1: page or page table is not cached (prevented)
//
// PWT: Page level Write Through
// Controls the write-through or write-back caching policy of individual
// pages or page tables. Processor ignores this flag if paging
// is not used (CR0.PG=0) or the cache disable bit is set (CR0.CD=1).
// Values:
// 0: write-back caching
// 1: write-through caching
//
// U/S: User/Supervisor level
// 0: Supervisor level - for the OS, drivers, etc.
// 1: User level - application code and data
//
// R/W: Read/Write access
// 0: read-only access
// 1: read/write access
//
// P: Present
// 0: Not present
// 1: Present
// ==========================================
// Combined page directory/page table protection:
// ==============================================
// There is one column for the combined effect on a 386
// and one column for the combined effect on a 486+ CPU.
// The 386 CPU behavior is not supported by Bochs.
//
// +----------------+-----------------+----------------+----------------+
// | Page Directory| Page Table | Combined 386 | Combined 486+ |
// |Privilege Type | Privilege Type | Privilege Type| Privilege Type|
// |----------------+-----------------+----------------+----------------|
// |User R | User R | User R | User R |
// |User R | User RW | User R | User R |
// |User RW | User R | User R | User R |
// |User RW | User RW | User RW | User RW |
// |User R | Supervisor R | User R | Supervisor RW |
// |User R | Supervisor RW | User R | Supervisor RW |
// |User RW | Supervisor R | User R | Supervisor RW |
// |User RW | Supervisor RW | User RW | Supervisor RW |
// |Supervisor R | User R | User R | Supervisor RW |
// |Supervisor R | User RW | User R | Supervisor RW |
// |Supervisor RW | User R | User R | Supervisor RW |
// |Supervisor RW | User RW | User RW | Supervisor RW |
// |Supervisor R | Supervisor R | Supervisor RW | Supervisor RW |
// |Supervisor R | Supervisor RW | Supervisor RW | Supervisor RW |
// |Supervisor RW | Supervisor R | Supervisor RW | Supervisor RW |
// |Supervisor RW | Supervisor RW | Supervisor RW | Supervisor RW |
// +----------------+-----------------+----------------+----------------+
// Page Fault Error Code Format:
// =============================
//
// bits 31..4: Reserved
// bit 3: RSVD (Pentium Pro+)
// 0: fault caused by reserved bits set to 1 in a page directory
// when the PSE or PAE flags in CR4 are set to 1
// 1: fault was not caused by reserved bit violation
// bit 2: U/S (386+)
// 0: fault originated when in supervior mode
// 1: fault originated when in user mode
// bit 1: R/W (386+)
// 0: access causing the fault was a read
// 1: access causing the fault was a write
// bit 0: P (386+)
// 0: fault caused by a nonpresent page
// 1: fault caused by a page level protection violation
// Some paging related notes:
// ==========================
//
// - When the processor is running in supervisor level, all pages are both
// readable and writable (write-protect ignored). When running at user
// level, only pages which belong to the user level are accessible;
// read/write & read-only are readable, read/write are writable.
//
// - If the Present bit is 0 in either level of page table, an
// access which uses these entries will generate a page fault.
//
// - (A)ccess bit is used to report read or write access to a page
// or 2nd level page table.
//
// - (D)irty bit is used to report write access to a page.
//
// - Processor running at CPL=0,1,2 maps to U/S=0
// Processor running at CPL=3 maps to U/S=1
// bit [11] of the TLB lpf used for TLB_NoHostPtr valid indication
#define TLB_LPFOf(laddr) AlignedAccessLPFOf(laddr, 0x7ff)
#if BX_CPU_LEVEL >= 4
# define BX_PRIV_CHECK_SIZE 32
#else
# define BX_PRIV_CHECK_SIZE 16
#endif
// The 'priv_check' array is used to decide if the current access
// has the proper paging permissions. An index is formed, based
// on parameters such as the access type and level, the write protect
// flag and values cached in the TLB. The format of the index into this
// array is:
//
// |4 |3 |2 |1 |0 |
// |wp|us|us|rw|rw|
// | | | | |
// | | | | +---> r/w of current access
// | | +--+------> u/s,r/w combined of page dir & table (cached)
// | +------------> u/s of current access
// +---------------> Current CR0.WP value
//
// CR0.WP = 0 CR0.WP = 1
// -----------------------------------------------------------------------------------------
// 0 0 0 0 | sys read from supervisor page | Allowed | Allowed
// 0 0 0 1 | sys write to read only supervisor page | Allowed | Not Allowed
// 0 0 1 0 | sys read from supervisor page | Allowed | Allowed
// 0 0 1 1 | sys write to supervisor page | Allowed | Allowed
// 0 1 0 0 | sys read from read only user page | Allowed | Allowed
// 0 1 0 1 | sys write to read only user page | Allowed | Not Allowed
// 0 1 1 0 | sys read from user page | Allowed | Allowed
// 0 1 1 1 | sys write to user page | Allowed | Allowed
// 1 0 0 0 | user read from read only supervisor page | Not Allowed | Not Allowed
// 1 0 0 1 | user write to read only supervisor page | Not Allowed | Not Allowed
// 1 0 1 0 | user read from supervisor page | Not Allowed | Not Allowed
// 1 0 1 1 | user write to supervisor page | Not Allowed | Not Allowed
// 1 1 0 0 | user read from read only user page | Allowed | Allowed
// 1 1 0 1 | user write to read only user page | Not Allowed | Not Allowed
// 1 1 1 0 | user read from user page | Allowed | Allowed
// 1 1 1 1 | user write to user page | Allowed | Allowed
//
/* 0xff0bbb0b */
static const Bit8u priv_check[BX_PRIV_CHECK_SIZE] =
{
1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1, 0, 1, 1,
#if BX_CPU_LEVEL >= 4
1, 0, 1, 1, 1, 0, 1, 1, 0, 0, 0, 0, 1, 0, 1, 1
#endif
};
// The 'priv_check' array for shadow stack accesses
//
// |3 |2 |1 |0 |
// |us|us|rw|rw|
// | | | |
// | | | +---> r/w of current access
// | +--+------> u/s,r/w combined of page dir & table (cached)
// +------------> u/s of current access
//
// -------------------------------------------------------------------
// 0 0 0 0 | sys read from supervisor page | Allowed
// 0 0 0 1 | sys write to read only supervisor page | Allowed : shadow stack page looks like read only page
// 0 0 1 0 | sys read from supervisor page | Allowed
// 0 0 1 1 | sys write to supervisor page | Allowed
// 0 1 0 0 | sys read from read only user page | Not Allowed : supervisor-mode shadow-stack access is not allowed to a user-mode page
// 0 1 0 1 | sys write to read only user page | Not Allowed : supervisor-mode shadow-stack access is not allowed to a user-mode page
// 0 1 1 0 | sys read from user page | Not Allowed : supervisor-mode shadow-stack access is not allowed to a user-mode page
// 0 1 1 1 | sys write to user page | Not Allowed : supervisor-mode shadow-stack access is not allowed to a user-mode page
// 1 0 0 0 | user read from read only supervisor page | Not Allowed : user-mode shadow-stack access is not allowed to a supervisor-mode page
// 1 0 0 1 | user write to read only supervisor page | Not Allowed : user-mode shadow-stack access is not allowed to a supervisor-mode page
// 1 0 1 0 | user read from supervisor page | Not Allowed : user-mode shadow-stack access is not allowed to a supervisor-mode page
// 1 0 1 1 | user write to supervisor page | Not Allowed : user-mode shadow-stack access is not allowed to a supervisor-mode page
// 1 1 0 0 | user read from read only user page | Allowed
// 1 1 0 1 | user write to read only user page | Allowed : shadow stack page looks like read only page
// 1 1 1 0 | user read from user page | Allowed
// 1 1 1 1 | user write to user page | Allowed
//
const Bit64u BX_PAGING_PHY_ADDRESS_RESERVED_BITS = BX_PHY_ADDRESS_RESERVED_BITS & BX_CONST64(0xfffffffffffff);
const Bit64u PAGE_DIRECTORY_NX_BIT = BX_CONST64(0x8000000000000000);
const Bit64u BX_CR3_PAGING_MASK = BX_CONST64(0x000ffffffffff000);
// Each entry in the TLB cache has 3 entries:
//
// lpf: Linear Page Frame (page aligned linear address of page)
// bits 32..12 Linear page frame
// bit 11 0: TLB HostPtr access allowed, 1: not allowed
// bit 10...0 Invalidate index
//
// ppf: Physical Page Frame (page aligned phy address of page)
//
// hostPageAddr:
// Host Page Frame address used for direct access to
// the mem.vector[] space allocated for the guest physical
// memory. If this is zero, it means that a pointer
// to the host space could not be generated, likely because
// that page of memory is not standard memory (it might
// be memory mapped IO, ROM, etc).
//
// accessBits:
//
// bit 31: Page is a global page.
//
// The following bits are used for a very efficient permissions
// check. The goal is to be able, using only the current privilege
// level and access type, to determine if the page tables allow the
// access to occur or at least should rewalk the page tables. On
// the first read access, permissions are set to only read, so a
// rewalk is necessary when a subsequent write fails the tests.
// This allows for the dirty bit to be set properly, but for the
// test to be efficient. Note that the CR0.WP flag is not present.
// The values in the following flags is based on the current CR0.WP
// value, necessitating a TLB flush when CR0.WP changes.
//
// The test bit:
// OK = 1 << ((S<<2) | (W<<1) | U)
//
// where S:1=Shadow Stack (CET)
// W:1=Write, 0=Read;
// U:1=CPL3, 0=CPL0-2
//
// Thus for reads, it is:
// OK = 0x01 << ( U )
// for writes:
// OK = 0x04 << ( U )
// for shadow stack reads:
// OK = 0x10 << ( U )
// for shadow stack writes:
// OK = 0x40 << ( U )
//
// bit 3: Write from User privilege is OK
// bit 2: Write from System privilege is OK
// bit 1: Read from User privilege is OK
// bit 0: Read from System privilege is OK
//
// Note, that the TLB should have TLB_NoHostPtr bit set in the lpf when
// direct access through host pointer is NOT allowed for the page.
// A memory operation asking for a direct access through host pointer
// will not set TLB_NoHostPtr bit in its lpf and thus get TLB miss
// result when the direct access is not allowed.
//
const Bit32u TLB_NoHostPtr = 0x800; /* set this bit when direct access is NOT allowed */
#include "cpustats.h"
// ==============================================================
void BX_CPU_C::TLB_flush(void)
{
INC_TLBFLUSH_STAT(tlbGlobalFlushes);
invalidate_prefetch_q();
invalidate_stack_cache();
BX_CPU_THIS_PTR DTLB.flush();
BX_CPU_THIS_PTR ITLB.flush();
#if BX_SUPPORT_MONITOR_MWAIT
// invalidating of the TLB might change translation for monitored page
// and cause subsequent MWAIT instruction to wait forever
BX_CPU_THIS_PTR monitor.reset_monitor();
#endif
// break all links bewteen traces
BX_CPU_THIS_PTR iCache.breakLinks();
}
#if BX_CPU_LEVEL >= 6
void BX_CPU_C::TLB_flushNonGlobal(void)
{
INC_TLBFLUSH_STAT(tlbNonGlobalFlushes);
invalidate_prefetch_q();
invalidate_stack_cache();
BX_CPU_THIS_PTR DTLB.flushNonGlobal();
BX_CPU_THIS_PTR ITLB.flushNonGlobal();
#if BX_SUPPORT_MONITOR_MWAIT
// invalidating of the TLB might change translation for monitored page
// and cause subsequent MWAIT instruction to wait forever
BX_CPU_THIS_PTR monitor.reset_monitor();
#endif
// break all links bewteen traces
BX_CPU_THIS_PTR iCache.breakLinks();
}
#endif
void BX_CPU_C::TLB_invlpg(bx_address laddr)
{
invalidate_prefetch_q();
invalidate_stack_cache();
BX_DEBUG(("TLB_invlpg(0x" FMT_ADDRX "): invalidate TLB entry", laddr));
BX_CPU_THIS_PTR DTLB.invlpg(laddr);
BX_CPU_THIS_PTR ITLB.invlpg(laddr);
#if BX_SUPPORT_MONITOR_MWAIT
// invalidating of the TLB entry might change translation for monitored
// page and cause subsequent MWAIT instruction to wait forever
BX_CPU_THIS_PTR monitor.reset_monitor();
#endif
// break all links bewteen traces
BX_CPU_THIS_PTR iCache.breakLinks();
}
void BX_CPP_AttrRegparmN(1) BX_CPU_C::INVLPG(bxInstruction_c* i)
{
// CPL is always 0 in real mode
if (/* !real_mode() && */ CPL!=0) {
BX_ERROR(("%s: priveledge check failed, generate #GP(0)", i->getIaOpcodeNameShort()));
exception(BX_GP_EXCEPTION, 0);
}
bx_address eaddr = BX_CPU_RESOLVE_ADDR(i);
bx_address laddr = get_laddr(i->seg(), eaddr);
#if BX_SUPPORT_VMX
if (BX_CPU_THIS_PTR in_vmx_guest) {
if (VMEXIT(VMX_VM_EXEC_CTRL2_INVLPG_VMEXIT)) VMexit(VMX_VMEXIT_INVLPG, laddr);
}
#endif
#if BX_SUPPORT_SVM
if (BX_CPU_THIS_PTR in_svm_guest) {
if (SVM_INTERCEPT(SVM_INTERCEPT0_INVLPG))
Svm_Vmexit(SVM_VMEXIT_INVLPG, BX_SUPPORT_SVM_EXTENSION(BX_CPUID_SVM_DECODE_ASSIST) ? laddr : 0);
}
#endif
#if BX_SUPPORT_X86_64
if (IsCanonical(laddr))
#endif
{
BX_INSTR_TLB_CNTRL(BX_CPU_ID, BX_INSTR_INVLPG, laddr);
TLB_invlpg(laddr);
}
BX_NEXT_TRACE(i);
}
// error checking order - page not present, reserved bits, protection
enum {
ERROR_NOT_PRESENT = 0x00,
ERROR_PROTECTION = 0x01,
ERROR_WRITE_ACCESS = 0x02,
ERROR_USER_ACCESS = 0x04,
ERROR_RESERVED = 0x08,
ERROR_CODE_ACCESS = 0x10,
ERROR_PKEY = 0x20,
ERROR_SHADOW_STACK = 0x40,
};
void BX_CPU_C::page_fault(unsigned fault, bx_address laddr, unsigned user, unsigned rw)
{
unsigned isWrite = rw & 1;
Bit32u error_code = fault | (user << 2) | (isWrite << 1);
#if BX_CPU_LEVEL >= 6
if (rw == BX_EXECUTE) {
if (BX_CPU_THIS_PTR cr4.get_SMEP())
error_code |= ERROR_CODE_ACCESS; // I/D = 1
if (BX_CPU_THIS_PTR cr4.get_PAE() && BX_CPU_THIS_PTR efer.get_NXE())
error_code |= ERROR_CODE_ACCESS;
}
#endif
#if BX_SUPPORT_CET
bx_bool is_shadow_stack = rw & 4;
if (is_shadow_stack)
error_code |= ERROR_SHADOW_STACK;
#endif
#if BX_SUPPORT_SVM
SvmInterceptException(BX_HARDWARE_EXCEPTION, BX_PF_EXCEPTION, error_code, 1, laddr); // before the CR2 was modified
#endif
#if BX_SUPPORT_VMX
VMexit_Event(BX_HARDWARE_EXCEPTION, BX_PF_EXCEPTION, error_code, 1, laddr); // before the CR2 was modified
#endif
BX_CPU_THIS_PTR cr2 = laddr;
#if BX_SUPPORT_X86_64
BX_DEBUG(("page fault for address %08x%08x @ %08x%08x",
GET32H(laddr), GET32L(laddr), GET32H(RIP), GET32L(RIP)));
#else
BX_DEBUG(("page fault for address %08x @ %08x", laddr, EIP));
#endif
exception(BX_PF_EXCEPTION, error_code);
}
enum {
BX_LEVEL_PML4 = 3,
BX_LEVEL_PDPTE = 2,
BX_LEVEL_PDE = 1,
BX_LEVEL_PTE = 0
};
static const char *bx_paging_level[4] = { "PTE", "PDE", "PDPE", "PML4" }; // keep it 4 letters
// combined_access legend:
// -----------------------
// 00 |
// 01 | R/W
// 02 | U/S
// 03 |
// 07 | Shadow Stack
// 08 | Global
// 11-09 | memtype (3 bits)
enum {
BX_COMBINED_ACCESS_WRITE = 0x2,
BX_COMBINED_ACCESS_USER = 0x4,
BX_COMBINED_SHADOW_STACK = 0x80,
BX_COMBINED_GLOBAL_PAGE = 0x100,
};
#if BX_CPU_LEVEL >= 6
// Format of a Long Mode Non-Leaf Entry
// -----------------------------------------------------------
// 00 | Present (P)
// 01 | R/W
// 02 | U/S
// 03 | Page-Level Write-Through (PWT)
// 04 | Page-Level Cache-Disable (PCD)
// 05 | Accessed (A)
// 06 | (ignored)
// 07 | Page Size (PS), must be 0 if no Large Page on the level
// 11-08 | (ignored)
// PA-12 | Physical address of 4-KByte aligned page-directory-pointer table
// 51-PA | Reserved (must be zero)
// 62-52 | (ignored)
// 63 | Execute-Disable (XD) (if EFER.NXE=1, reserved otherwise)
// -----------------------------------------------------------
const Bit64u PAGING_PAE_RESERVED_BITS = BX_PAGING_PHY_ADDRESS_RESERVED_BITS;
// in legacy PAE mode bits [62:52] are reserved. bit 63 is NXE
const Bit64u PAGING_LEGACY_PAE_RESERVED_BITS = BX_PAGING_PHY_ADDRESS_RESERVED_BITS | BX_CONST64(0x7ff0000000000000);
// Format of a PDPTE that References a 1-GByte Page
// -----------------------------------------------------------
// 00 | Present (P)
// 01 | R/W
// 02 | U/S
// 03 | Page-Level Write-Through (PWT)
// 04 | Page-Level Cache-Disable (PCD)
// 05 | Accessed (A)
// 06 | (ignored)
// 07 | Page Size, must be 1 to indicate a 1-GByte Page
// 08 | Global (G) (if CR4.PGE=1, ignored otherwise)
// 11-09 | (ignored)
// 12 | PAT (if PAT is supported, reserved otherwise)
// 29-13 | Reserved (must be zero)
// PA-30 | Physical address of the 1-Gbyte Page
// 51-PA | Reserved (must be zero)
// 62-52 | (ignored)
// 63 | Execute-Disable (XD) (if EFER.NXE=1, reserved otherwise)
// -----------------------------------------------------------
const Bit64u PAGING_PAE_PDPTE1G_RESERVED_BITS = BX_PAGING_PHY_ADDRESS_RESERVED_BITS | BX_CONST64(0x3FFFE000);
// Format of a PAE PDE that Maps a 2-MByte Page
// -----------------------------------------------------------
// 00 | Present (P)
// 01 | R/W
// 02 | U/S
// 03 | Page-Level Write-Through (PWT)
// 04 | Page-Level Cache-Disable (PCD)
// 05 | Accessed (A)
// 06 | Dirty (D)
// 07 | Page Size (PS), must be 1 to indicate a 2-MByte Page
// 08 | Global (G) (if CR4.PGE=1, ignored otherwise)
// 11-09 | (ignored)
// 12 | PAT (if PAT is supported, reserved otherwise)
// 20-13 | Reserved (must be zero)
// PA-21 | Physical address of the 2-MByte page
// 51-PA | Reserved (must be zero)
// 62-52 | ignored in long mode, reserved (must be 0) in legacy PAE mode
// 63 | Execute-Disable (XD) (if EFER.NXE=1, reserved otherwise)
// -----------------------------------------------------------
const Bit64u PAGING_PAE_PDE2M_RESERVED_BITS = BX_PAGING_PHY_ADDRESS_RESERVED_BITS | BX_CONST64(0x001FE000);
// Format of a PAE PTE that Maps a 4-KByte Page
// -----------------------------------------------------------
// 00 | Present (P)
// 01 | R/W
// 02 | U/S
// 03 | Page-Level Write-Through (PWT)
// 04 | Page-Level Cache-Disable (PCD)
// 05 | Accessed (A)
// 06 | Dirty (D)
// 07 | PAT (if PAT is supported, reserved otherwise)
// 08 | Global (G) (if CR4.PGE=1, ignored otherwise)
// 11-09 | (ignored)
// PA-12 | Physical address of the 4-KByte page
// 51-PA | Reserved (must be zero)
// 62-52 | ignored in long mode, reserved (must be 0) in legacy PAE mode
// 63 | Execute-Disable (XD) (if EFER.NXE=1, reserved otherwise)
// -----------------------------------------------------------
int BX_CPU_C::check_entry_PAE(const char *s, Bit64u entry, Bit64u reserved, unsigned rw, bx_bool *nx_fault)
{
if (!(entry & 0x1)) {
BX_DEBUG(("PAE %s: entry not present", s));
return ERROR_NOT_PRESENT;
}
if (entry & reserved) {
BX_DEBUG(("PAE %s: reserved bit is set 0x" FMT_ADDRX64, s, entry));
return ERROR_RESERVED | ERROR_PROTECTION;
}
if (entry & PAGE_DIRECTORY_NX_BIT) {
if (rw == BX_EXECUTE) {
BX_DEBUG(("PAE %s: non-executable page fault occurred", s));
*nx_fault = 1;
}
}
return -1;
}
#if BX_SUPPORT_MEMTYPE
BX_CPP_INLINE Bit32u calculate_pcd_pwt(Bit32u entry)
{
Bit32u pcd_pwt = (entry >> 3) & 0x3; // PCD, PWT are stored in bits 3 and 4
return pcd_pwt;
}
// extract PCD, PWT and PAT pat bits from page table entry
BX_CPP_INLINE Bit32u calculate_pat(Bit32u entry, Bit32u lpf_mask)
{
Bit32u pcd_pwt = calculate_pcd_pwt(entry);
// PAT is stored in bit 12 for large pages and in bit 7 for small pages
Bit32u pat = ((lpf_mask < 0x1000) ? (entry >> 7) : (entry >> 12)) & 0x1;
return pcd_pwt | (pat << 2);
}
#endif
#if BX_SUPPORT_X86_64
// Translate a linear address to a physical address in long mode
bx_phy_address BX_CPU_C::translate_linear_long_mode(bx_address laddr, Bit32u &lpf_mask, Bit32u &pkey, unsigned user, unsigned rw)
{
bx_phy_address ppf = BX_CPU_THIS_PTR cr3 & BX_CR3_PAGING_MASK;
bx_phy_address entry_addr[4];
Bit64u entry[4];
BxMemtype entry_memtype[4] = { 0 };
bx_bool nx_fault = 0;
int leaf;
Bit64u offset_mask = BX_CONST64(0x0000ffffffffffff);
lpf_mask = 0xfff;
Bit32u combined_access = (BX_COMBINED_ACCESS_WRITE | BX_COMBINED_ACCESS_USER);
Bit64u curr_entry = BX_CPU_THIS_PTR cr3;
Bit64u reserved = PAGING_PAE_RESERVED_BITS;
if (! BX_CPU_THIS_PTR efer.get_NXE())
reserved |= PAGE_DIRECTORY_NX_BIT;
for (leaf = BX_LEVEL_PML4;; --leaf) {
entry_addr[leaf] = ppf + ((laddr >> (9 + 9*leaf)) & 0xff8);
#if BX_SUPPORT_VMX >= 2
if (BX_CPU_THIS_PTR in_vmx_guest) {
if (SECONDARY_VMEXEC_CONTROL(VMX_VM_EXEC_CTRL3_EPT_ENABLE))
entry_addr[leaf] = translate_guest_physical(entry_addr[leaf], laddr, 1, 1, BX_READ);
}
#endif
#if BX_SUPPORT_SVM
if (BX_CPU_THIS_PTR in_svm_guest && SVM_NESTED_PAGING_ENABLED) {
entry_addr[leaf] = nested_walk(entry_addr[leaf], BX_RW, 1);
}
#endif
#if BX_SUPPORT_MEMTYPE
entry_memtype[leaf] = resolve_memtype(memtype_by_mtrr(entry_addr[leaf]), memtype_by_pat(calculate_pcd_pwt((Bit32u) curr_entry)));
#endif
access_read_physical(entry_addr[leaf], 8, &entry[leaf]);
BX_NOTIFY_PHY_MEMORY_ACCESS(entry_addr[leaf], 8, entry_memtype[leaf], BX_READ, (BX_PTE_ACCESS + leaf), (Bit8u*)(&entry[leaf]));
offset_mask >>= 9;
curr_entry = entry[leaf];
int fault = check_entry_PAE(bx_paging_level[leaf], curr_entry, reserved, rw, &nx_fault);
if (fault >= 0)
page_fault(fault, laddr, user, rw);
ppf = curr_entry & BX_CONST64(0x000ffffffffff000);
if (leaf == BX_LEVEL_PTE) break;
if (curr_entry & 0x80) {
if (leaf > (BX_LEVEL_PDE + !!is_cpu_extension_supported(BX_ISA_1G_PAGES))) {
BX_DEBUG(("long mode %s: PS bit set !", bx_paging_level[leaf]));
page_fault(ERROR_RESERVED | ERROR_PROTECTION, laddr, user, rw);
}
ppf &= BX_CONST64(0x000fffffffffe000);
if (ppf & offset_mask) {
BX_DEBUG(("long mode %s: reserved bit is set: 0x" FMT_ADDRX64, bx_paging_level[leaf], curr_entry));
page_fault(ERROR_RESERVED | ERROR_PROTECTION, laddr, user, rw);
}
lpf_mask = (Bit32u) offset_mask;
break;
}
combined_access &= curr_entry; // U/S and R/W
}
bx_bool isWrite = (rw & 1); // write or r-m-w
#if BX_SUPPORT_PKEYS
if (rw != BX_EXECUTE) {
if (BX_CPU_THIS_PTR cr4.get_PKE()) {
pkey = (entry[leaf] >> 59) & 0xf;
// check of accessDisable bit set
if (user) {
if (BX_CPU_THIS_PTR pkru & (1<<(pkey*2))) {
BX_ERROR(("protection key access not allowed PKRU=%x pkey=%d", BX_CPU_THIS_PTR pkru, pkey));
page_fault(ERROR_PROTECTION | ERROR_PKEY, laddr, user, rw);
}
}
// check of writeDisable bit set
if (BX_CPU_THIS_PTR pkru & (1<<(pkey*2+1))) {
if (isWrite && (user || BX_CPU_THIS_PTR cr0.get_WP())) {
BX_ERROR(("protection key write not allowed PKRU=%x pkey=%d", BX_CPU_THIS_PTR pkru, pkey));
page_fault(ERROR_PROTECTION | ERROR_PKEY, laddr, user, rw);
}
}
}
if (BX_CPU_THIS_PTR cr4.get_PKS() && !user) {
pkey = (entry[leaf] >> 59) & 0xf;
// check of accessDisable bit set
if (BX_CPU_THIS_PTR pkrs & (1<<(pkey*2))) {
BX_ERROR(("protection key access not allowed PKRS=%x pkey=%d", BX_CPU_THIS_PTR pkrs, pkey));
page_fault(ERROR_PROTECTION | ERROR_PKEY, laddr, user, rw);
}
// check of writeDisable bit set
if (BX_CPU_THIS_PTR pkrs & (1<<(pkey*2+1))) {
if (isWrite && BX_CPU_THIS_PTR cr0.get_WP()) {
BX_ERROR(("protection key write not allowed PKRS=%x pkey=%d", BX_CPU_THIS_PTR pkrs, pkey));
page_fault(ERROR_PROTECTION | ERROR_PKEY, laddr, user, rw);
}
}
}
}
#endif
#if BX_SUPPORT_CET
bx_bool shadow_stack = rw & 4;
if (shadow_stack) {
// shadow stack pages:
// - R/W bit=1 in every paging structure entry except the leaf
// - R/W bit=0 and Dirty=1 for leaf entry
bx_bool shadow_stack_page = ((combined_access & BX_COMBINED_ACCESS_WRITE) != 0) && ((entry[leaf] & 0x40) != 0) && ((entry[leaf] & 0x02) == 0);
if (!shadow_stack_page) {
BX_DEBUG(("shadow stack access to not shadow stack page CA=%x entry=%lx\n", combined_access, Bit32u(entry[leaf] & 0xfff)));
page_fault(ERROR_PROTECTION, laddr, user, rw);
}
combined_access &= entry[leaf]; // U/S and R/W
// must be to shadow stack page, check that U/S match
if ((combined_access & BX_COMBINED_ACCESS_USER) ^ (user << 2)) {
BX_DEBUG(("shadow stack U/S access mismatch"));
page_fault(ERROR_PROTECTION, laddr, user, rw);
}
combined_access |= BX_COMBINED_SHADOW_STACK;
}
else
#endif
{
combined_access &= entry[leaf]; // U/S and R/W
unsigned priv_index = (BX_CPU_THIS_PTR cr0.get_WP() << 4) | // bit 4
(user<<3) | // bit 3
(combined_access | isWrite); // bit 2,1,0
if (!priv_check[priv_index] || nx_fault)
page_fault(ERROR_PROTECTION, laddr, user, rw);
}
if (BX_CPU_THIS_PTR cr4.get_SMEP() && rw == BX_EXECUTE && !user) {
if (combined_access & BX_COMBINED_ACCESS_USER)
page_fault(ERROR_PROTECTION, laddr, user, rw);
}
// SMAP protections are disabled if EFLAGS.AC=1
if (BX_CPU_THIS_PTR cr4.get_SMAP() && ! BX_CPU_THIS_PTR get_AC() && rw != BX_EXECUTE && ! user) {
if (combined_access & BX_COMBINED_ACCESS_USER)
page_fault(ERROR_PROTECTION, laddr, user, rw);
}
if (BX_CPU_THIS_PTR cr4.get_PGE())
combined_access |= (entry[leaf] & BX_COMBINED_GLOBAL_PAGE);
#if BX_SUPPORT_MEMTYPE
combined_access |= (memtype_by_pat(calculate_pat((Bit32u) entry[leaf], lpf_mask)) << 9);
#endif
// Update A/D bits if needed
update_access_dirty_PAE(entry_addr, entry, entry_memtype, BX_LEVEL_PML4, leaf, isWrite);
return (ppf | combined_access);
}
#endif
void BX_CPU_C::update_access_dirty_PAE(bx_phy_address *entry_addr, Bit64u *entry, BxMemtype *entry_memtype, unsigned max_level, unsigned leaf, unsigned write)
{
// Update A bit if needed
for (unsigned level=max_level; level > leaf; level--) {
if (!(entry[level] & 0x20)) {
entry[level] |= 0x20;
access_write_physical(entry_addr[level], 8, &entry[level]);
BX_NOTIFY_PHY_MEMORY_ACCESS(entry_addr[level], 8, entry_memtype[level], BX_WRITE,
(BX_PTE_ACCESS + level), (Bit8u*)(&entry[level]));
}
}
// Update A/D bits if needed
if (!(entry[leaf] & 0x20) || (write && !(entry[leaf] & 0x40))) {
entry[leaf] |= (0x20 | (write<<6)); // Update A and possibly D bits
access_write_physical(entry_addr[leaf], 8, &entry[leaf]);
BX_NOTIFY_PHY_MEMORY_ACCESS(entry_addr[leaf], 8, entry_memtype[leaf], BX_WRITE,
(BX_PTE_ACCESS + leaf), (Bit8u*)(&entry[leaf]));
}
}
// Format of Legacy PAE PDPTR entry (PDPTE)
// -----------------------------------------------------------
// 00 | Present (P)
// 02-01 | Reserved (must be zero)
// 03 | Page-Level Write-Through (PWT) (486+), 0=reserved otherwise
// 04 | Page-Level Cache-Disable (PCD) (486+), 0=reserved otherwise
// 08-05 | Reserved (must be zero)
// 11-09 | (ignored)
// PA-12 | Physical address of 4-KByte aligned page directory
// 63-PA | Reserved (must be zero)
// -----------------------------------------------------------
const Bit64u PAGING_PAE_PDPTE_RESERVED_BITS = BX_PAGING_PHY_ADDRESS_RESERVED_BITS | BX_CONST64(0xFFF00000000001E6);
bx_bool BX_CPP_AttrRegparmN(1) BX_CPU_C::CheckPDPTR(bx_phy_address cr3_val)
{
// with Nested Paging PDPTRs are not loaded for guest page tables but
// accessed on demand as part of the guest page walk
#if BX_SUPPORT_SVM
if (BX_CPU_THIS_PTR in_svm_guest && SVM_NESTED_PAGING_ENABLED)
return 1;
#endif
cr3_val &= 0xffffffe0;
#if BX_SUPPORT_VMX >= 2
if (BX_CPU_THIS_PTR in_vmx_guest) {
if (SECONDARY_VMEXEC_CONTROL(VMX_VM_EXEC_CTRL3_EPT_ENABLE))
cr3_val = translate_guest_physical(cr3_val, 0, 0, 1, BX_READ);
}
#endif
Bit64u pdptr[4];
unsigned n;
for (n=0; n<4; n++) {
// read and check PDPTE entries
bx_phy_address pdpe_entry_addr = (bx_phy_address) (cr3_val | (n << 3));
access_read_physical(pdpe_entry_addr, 8, &(pdptr[n]));
BX_NOTIFY_PHY_MEMORY_ACCESS(pdpe_entry_addr, 8, BX_MEMTYPE_INVALID, BX_READ, (BX_PDPTR0_ACCESS + n), (Bit8u*) &(pdptr[n]));
if (pdptr[n] & 0x1) {
if (pdptr[n] & PAGING_PAE_PDPTE_RESERVED_BITS) return 0;
}
}
// load new PDPTRs
for (n=0; n<4; n++)
BX_CPU_THIS_PTR PDPTR_CACHE.entry[n] = pdptr[n];
return 1; /* PDPTRs are fine */
}
#if BX_SUPPORT_VMX >= 2
bx_bool BX_CPP_AttrRegparmN(1) BX_CPU_C::CheckPDPTR(Bit64u *pdptr)
{
for (unsigned n=0; n<4; n++) {
if (pdptr[n] & 0x1) {
if (pdptr[n] & PAGING_PAE_PDPTE_RESERVED_BITS) return 0;
}
}
return 1; /* PDPTRs are fine */
}
#endif
bx_phy_address BX_CPU_C::translate_linear_load_PDPTR(bx_address laddr, unsigned user, unsigned rw)
{
unsigned index = (laddr >> 30) & 0x3;
Bit64u pdptr;
#if BX_SUPPORT_SVM
if (BX_CPU_THIS_PTR in_svm_guest && SVM_NESTED_PAGING_ENABLED)
{
bx_phy_address cr3_val = BX_CPU_THIS_PTR cr3 & 0xffffffe0;
cr3_val = nested_walk(cr3_val, BX_RW, 1);
bx_phy_address pdpe_entry_addr = (bx_phy_address) (cr3_val | (index << 3));
access_read_physical(pdpe_entry_addr, 8, &pdptr);
BX_NOTIFY_PHY_MEMORY_ACCESS(pdpe_entry_addr, 8, BX_MEMTYPE_INVALID, BX_READ, (BX_PDPTR0_ACCESS + index), (Bit8u*) &pdptr);
if (pdptr & 0x1) {
if (pdptr & PAGING_PAE_PDPTE_RESERVED_BITS) {
BX_DEBUG(("PAE PDPTE%d entry reserved bits set: 0x" FMT_ADDRX64, index, pdptr));
page_fault(ERROR_RESERVED | ERROR_PROTECTION, laddr, user, rw);
}
}
}
else
#endif
{
pdptr = BX_CPU_THIS_PTR PDPTR_CACHE.entry[index];
}
if (! (pdptr & 0x1)) {
BX_DEBUG(("PAE PDPTE entry not present !"));
page_fault(ERROR_NOT_PRESENT, laddr, user, rw);
}
return pdptr;
}
// Translate a linear address to a physical address in PAE paging mode
bx_phy_address BX_CPU_C::translate_linear_PAE(bx_address laddr, Bit32u &lpf_mask, unsigned user, unsigned rw)
{
bx_phy_address entry_addr[2];
Bit64u entry[2];
BxMemtype entry_memtype[2] = { 0 };
bx_bool nx_fault = 0;
int leaf;
lpf_mask = 0xfff;
Bit32u combined_access = (BX_COMBINED_ACCESS_WRITE | BX_COMBINED_ACCESS_USER);
Bit64u reserved = PAGING_LEGACY_PAE_RESERVED_BITS;
if (! BX_CPU_THIS_PTR efer.get_NXE())
reserved |= PAGE_DIRECTORY_NX_BIT;
Bit64u pdpte = translate_linear_load_PDPTR(laddr, user, rw);
bx_phy_address ppf = pdpte & BX_CONST64(0x000ffffffffff000);
Bit64u curr_entry = pdpte;
for (leaf = BX_LEVEL_PDE;; --leaf) {
entry_addr[leaf] = ppf + ((laddr >> (9 + 9*leaf)) & 0xff8);
#if BX_SUPPORT_VMX >= 2
if (BX_CPU_THIS_PTR in_vmx_guest) {
if (SECONDARY_VMEXEC_CONTROL(VMX_VM_EXEC_CTRL3_EPT_ENABLE))
entry_addr[leaf] = translate_guest_physical(entry_addr[leaf], laddr, 1, 1, BX_READ);
}
#endif
#if BX_SUPPORT_SVM
if (BX_CPU_THIS_PTR in_svm_guest && SVM_NESTED_PAGING_ENABLED) {
entry_addr[leaf] = nested_walk(entry_addr[leaf], BX_RW, 1);
}
#endif
#if BX_SUPPORT_MEMTYPE
entry_memtype[leaf] = resolve_memtype(memtype_by_mtrr(entry_addr[leaf]), memtype_by_pat(calculate_pcd_pwt((Bit32u) curr_entry)));
#endif
access_read_physical(entry_addr[leaf], 8, &entry[leaf]);
BX_NOTIFY_PHY_MEMORY_ACCESS(entry_addr[leaf], 8, entry_memtype[leaf], BX_READ, (BX_PTE_ACCESS + leaf), (Bit8u*)(&entry[leaf]));
curr_entry = entry[leaf];
int fault = check_entry_PAE(bx_paging_level[leaf], curr_entry, reserved, rw, &nx_fault);
if (fault >= 0)
page_fault(fault, laddr, user, rw);
ppf = curr_entry & BX_CONST64(0x000ffffffffff000);
if (leaf == BX_LEVEL_PTE) break;
// Ignore CR4.PSE in PAE mode
if (curr_entry & 0x80) {
if (curr_entry & PAGING_PAE_PDE2M_RESERVED_BITS) {
BX_DEBUG(("PAE PDE2M: reserved bit is set PDE=0x" FMT_ADDRX64, curr_entry));
page_fault(ERROR_RESERVED | ERROR_PROTECTION, laddr, user, rw);
}
// Make up the physical page frame address
ppf = (bx_phy_address)(curr_entry & BX_CONST64(0x000fffffffe00000));
lpf_mask = 0x1fffff;
break;
}
combined_access &= curr_entry; // U/S and R/W
}
bx_bool isWrite = (rw & 1); // write or r-m-w
#if BX_SUPPORT_CET
bx_bool shadow_stack = rw & 4;
if (shadow_stack) {
// shadow stack pages:
// - R/W bit=1 in every paging structure entry except the leaf
// - R/W bit=0 and Dirty=1 for leaf entry
bx_bool shadow_stack_page = ((combined_access & BX_COMBINED_ACCESS_WRITE) != 0) && ((entry[leaf] & 0x40) != 0) && ((entry[leaf] & 0x02) == 0);
if (!shadow_stack_page)
page_fault(ERROR_PROTECTION, laddr, user, rw);
combined_access &= entry[leaf]; // U/S and R/W
// must be to shadow stack page, check that U/S match
if ((combined_access & BX_COMBINED_ACCESS_USER) ^ (user << 2)) {
BX_DEBUG(("shadow stack U/S access mismatch"));
page_fault(ERROR_PROTECTION, laddr, user, rw);
}
combined_access |= BX_COMBINED_SHADOW_STACK;
}
else
#endif
{
combined_access &= entry[leaf]; // U/S and R/W
unsigned priv_index = (BX_CPU_THIS_PTR cr0.get_WP() << 4) | // bit 4
(user<<3) | // bit 3
(combined_access | isWrite); // bit 2,1,0
if (!priv_check[priv_index] || nx_fault)
page_fault(ERROR_PROTECTION, laddr, user, rw);
}
if (BX_CPU_THIS_PTR cr4.get_SMEP() && rw == BX_EXECUTE && !user) {
if (combined_access & BX_COMBINED_ACCESS_USER)
page_fault(ERROR_PROTECTION, laddr, user, rw);
}
// SMAP protections are disabled if EFLAGS.AC=1
if (BX_CPU_THIS_PTR cr4.get_SMAP() && ! BX_CPU_THIS_PTR get_AC() && rw != BX_EXECUTE && ! user) {
if (combined_access & BX_COMBINED_ACCESS_USER)
page_fault(ERROR_PROTECTION, laddr, user, rw);
}
if (BX_CPU_THIS_PTR cr4.get_PGE())
combined_access |= (entry[leaf] & BX_COMBINED_GLOBAL_PAGE); // G
#if BX_SUPPORT_MEMTYPE
combined_access |= (memtype_by_pat(calculate_pat((Bit32u) entry[leaf], lpf_mask)) << 9);
#endif
// Update A/D bits if needed
update_access_dirty_PAE(entry_addr, entry, entry_memtype, BX_LEVEL_PDE, leaf, isWrite);
return (ppf | combined_access);
}
#endif
// Format of a PDE that Maps a 4-MByte Page
// -----------------------------------------------------------
// 00 | Present (P)
// 01 | R/W
// 02 | U/S
// 03 | Page-Level Write-Through (PWT)
// 04 | Page-Level Cache-Disable (PCD)
// 05 | Accessed (A)
// 06 | Dirty (D)
// 07 | Page size, must be 1 to indicate 4-Mbyte page
// 08 | Global (G) (if CR4.PGE=1, ignored otherwise)
// 11-09 | (ignored)
// 12 | PAT (if PAT is supported, reserved otherwise)
// PA-13 | Bits PA-32 of physical address of the 4-MByte page
// 21-PA | Reserved (must be zero)
// 31-22 | Bits 31-22 of physical address of the 4-MByte page
// -----------------------------------------------------------
#if BX_PHY_ADDRESS_WIDTH > 40
const Bit32u PAGING_PDE4M_RESERVED_BITS = 0; // there are no reserved bits in PDE4M when physical address is wider than 40 bit
#else
const Bit32u PAGING_PDE4M_RESERVED_BITS = ((1 << (41-BX_PHY_ADDRESS_WIDTH))-1) << (13 + BX_PHY_ADDRESS_WIDTH - 32);
#endif
// Translate a linear address to a physical address in legacy paging mode
bx_phy_address BX_CPU_C::translate_linear_legacy(bx_address laddr, Bit32u &lpf_mask, unsigned user, unsigned rw)
{
bx_phy_address entry_addr[2], ppf = (Bit32u) BX_CPU_THIS_PTR cr3 & BX_CR3_PAGING_MASK;
Bit32u entry[2];
BxMemtype entry_memtype[2] = { 0 };
int leaf;
lpf_mask = 0xfff;
Bit32u combined_access = (BX_COMBINED_ACCESS_WRITE | BX_COMBINED_ACCESS_USER);
Bit32u curr_entry = (Bit32u) BX_CPU_THIS_PTR cr3;
for (leaf = BX_LEVEL_PDE;; --leaf) {
entry_addr[leaf] = ppf + ((laddr >> (10 + 10*leaf)) & 0xffc);
#if BX_SUPPORT_VMX >= 2
if (BX_CPU_THIS_PTR in_vmx_guest) {
if (SECONDARY_VMEXEC_CONTROL(VMX_VM_EXEC_CTRL3_EPT_ENABLE))
entry_addr[leaf] = translate_guest_physical(entry_addr[leaf], laddr, 1, 1, BX_READ);
}
#endif
#if BX_SUPPORT_SVM
if (BX_CPU_THIS_PTR in_svm_guest && SVM_NESTED_PAGING_ENABLED) {
entry_addr[leaf] = nested_walk(entry_addr[leaf], BX_RW, 1);
}
#endif
#if BX_SUPPORT_MEMTYPE
entry_memtype[leaf] = resolve_memtype(memtype_by_mtrr(entry_addr[leaf]), memtype_by_pat(calculate_pcd_pwt(curr_entry)));
#endif
access_read_physical(entry_addr[leaf], 4, &entry[leaf]);
BX_NOTIFY_PHY_MEMORY_ACCESS(entry_addr[leaf], 4, entry_memtype[leaf], BX_READ, (BX_PTE_ACCESS + leaf), (Bit8u*)(&entry[leaf]));
curr_entry = entry[leaf];
if (!(curr_entry & 0x1)) {
BX_DEBUG(("%s: entry not present", bx_paging_level[leaf]));
page_fault(ERROR_NOT_PRESENT, laddr, user, rw);
}
ppf = curr_entry & 0xfffff000;
if (leaf == BX_LEVEL_PTE) break;
#if BX_CPU_LEVEL >= 5
if ((curr_entry & 0x80) != 0 && BX_CPU_THIS_PTR cr4.get_PSE()) {
// 4M paging, only if CR4.PSE enabled, ignore PDE.PS otherwise
if (curr_entry & PAGING_PDE4M_RESERVED_BITS) {
BX_DEBUG(("PSE PDE4M: reserved bit is set: PDE=0x%08x", entry[BX_LEVEL_PDE]));
page_fault(ERROR_RESERVED | ERROR_PROTECTION, laddr, user, rw);
}
// make up the physical frame number
ppf = (curr_entry & 0xffc00000);
#if BX_PHY_ADDRESS_WIDTH > 32
ppf |= ((bx_phy_address)(curr_entry & 0x003fe000)) << 19;
#endif
lpf_mask = 0x3fffff;
break;
}
#endif
combined_access &= curr_entry; // U/S and R/W
}
bx_bool isWrite = (rw & 1); // write or r-m-w
#if BX_SUPPORT_CET
bx_bool shadow_stack = rw & 4;
if (shadow_stack) {
// shadow stack pages:
// - R/W bit=1 in every paging structure entry except the leaf
// - R/W bit=0 and Dirty=1 for leaf entry
bx_bool shadow_stack_page = ((combined_access & BX_COMBINED_ACCESS_WRITE) != 0) && ((entry[leaf] & 0x40) != 0) && ((entry[leaf] & 0x02) == 0);
if (!shadow_stack_page)
page_fault(ERROR_PROTECTION, laddr, user, rw);
combined_access &= entry[leaf]; // U/S and R/W
// must be to shadow stack page, check that U/S match
if ((combined_access & BX_COMBINED_ACCESS_USER) ^ (user << 2)) {
BX_DEBUG(("shadow stack U/S access mismatch"));
page_fault(ERROR_PROTECTION, laddr, user, rw);
}
combined_access |= BX_COMBINED_SHADOW_STACK;
}
else
#endif
{
combined_access &= entry[leaf]; // U/S and R/W
unsigned priv_index =
#if BX_CPU_LEVEL >= 4
(BX_CPU_THIS_PTR cr0.get_WP() << 4) | // bit 4
#endif
(user<<3) | // bit 3
(combined_access | isWrite); // bit 2,1,0
if (!priv_check[priv_index])
page_fault(ERROR_PROTECTION, laddr, user, rw);
}
#if BX_CPU_LEVEL >= 6
if (BX_CPU_THIS_PTR cr4.get_SMEP() && rw == BX_EXECUTE && !user) {
if (combined_access & BX_COMBINED_ACCESS_USER)
page_fault(ERROR_PROTECTION, laddr, user, rw);
}
// SMAP protections are disabled if EFLAGS.AC=1
if (BX_CPU_THIS_PTR cr4.get_SMAP() && ! BX_CPU_THIS_PTR get_AC() && rw != BX_EXECUTE && ! user) {
if (combined_access & BX_COMBINED_ACCESS_USER)
page_fault(ERROR_PROTECTION, laddr, user, rw);
}
if (BX_CPU_THIS_PTR cr4.get_PGE())
combined_access |= (entry[leaf] & BX_COMBINED_GLOBAL_PAGE);
#if BX_SUPPORT_MEMTYPE
combined_access |= (memtype_by_pat(calculate_pat(entry[leaf], lpf_mask)) << 9);
#endif
#endif
update_access_dirty(entry_addr, entry, entry_memtype, leaf, isWrite);
return (ppf | combined_access);
}
void BX_CPU_C::update_access_dirty(bx_phy_address *entry_addr, Bit32u *entry, BxMemtype *entry_memtype, unsigned leaf, unsigned write)
{
if (leaf == BX_LEVEL_PTE) {
// Update PDE A bit if needed
if (!(entry[BX_LEVEL_PDE] & 0x20)) {
entry[BX_LEVEL_PDE] |= 0x20;
access_write_physical(entry_addr[BX_LEVEL_PDE], 4, &entry[BX_LEVEL_PDE]);
BX_NOTIFY_PHY_MEMORY_ACCESS(entry_addr[BX_LEVEL_PDE], 4, entry_memtype[BX_LEVEL_PDE], BX_WRITE, BX_PDE_ACCESS, (Bit8u*)(&entry[BX_LEVEL_PDE]));
}
}
// Update A/D bits if needed
if (!(entry[leaf] & 0x20) || (write && !(entry[leaf] & 0x40))) {
entry[leaf] |= (0x20 | (write<<6)); // Update A and possibly D bits
access_write_physical(entry_addr[leaf], 4, &entry[leaf]);
BX_NOTIFY_PHY_MEMORY_ACCESS(entry_addr[leaf], 4, entry_memtype[leaf], BX_WRITE, (BX_PTE_ACCESS + leaf), (Bit8u*)(&entry[leaf]));
}
}
// Translate a linear address to a physical address
bx_phy_address BX_CPU_C::translate_linear(bx_TLB_entry *tlbEntry, bx_address laddr, unsigned user, unsigned rw)
{
#if BX_SUPPORT_X86_64
if (! long_mode()) laddr &= 0xffffffff;
#endif
bx_phy_address paddress, ppf, poffset = PAGE_OFFSET(laddr);
unsigned isWrite = rw & 1; // write or r-m-w
unsigned isExecute = (rw == BX_EXECUTE);
unsigned isShadowStack = (rw & 4); // 4 if shadowstack and 0 otherwise
bx_address lpf = LPFOf(laddr);
INC_TLB_STAT(tlbLookups);
if (isExecute)
INC_TLB_STAT(tlbExecuteLookups);
if (isWrite)
INC_TLB_STAT(tlbWriteLookups);
// already looked up TLB for code access
if (! isExecute && TLB_LPFOf(tlbEntry->lpf) == lpf)
{
paddress = tlbEntry->ppf | poffset;
#if BX_SUPPORT_PKEYS
if (isWrite) {
if (tlbEntry->accessBits & (1 << (isShadowStack | (isWrite<<1) | user)) & BX_CPU_THIS_PTR wr_pkey[tlbEntry->pkey])
return paddress;
}
else {
if (tlbEntry->accessBits & (1 << (isShadowStack | user)) & BX_CPU_THIS_PTR rd_pkey[tlbEntry->pkey])
return paddress;
}
#else
if (tlbEntry->accessBits & (1 << (isShadowStack | (isWrite<<1) | user)))
return paddress;
#endif
// The current access does not have permission according to the info
// in our TLB cache entry. Re-walk the page tables, in case there is
// updated information in the memory image, and let the long path code
// generate an exception if one is warranted.
// Invalidate the TLB entry before re-walk as re-walk may end with paging fault.
// The entry will be reinitialized later if page walk succeeds.
tlbEntry->invalidate();
}
INC_TLB_STAT(tlbMisses);
if (isExecute)
INC_TLB_STAT(tlbExecuteMisses);
if (isWrite)
INC_TLB_STAT(tlbWriteMisses);
Bit32u lpf_mask = 0xfff; // 4K pages
Bit32u combined_access = BX_COMBINED_ACCESS_WRITE | BX_COMBINED_ACCESS_USER;
#if BX_SUPPORT_X86_64
Bit32u pkey = 0;
#endif
if(BX_CPU_THIS_PTR cr0.get_PG())
{
BX_DEBUG(("page walk for%s address 0x" FMT_LIN_ADDRX, isShadowStack ? " shadow stack" : "", laddr));
#if BX_CPU_LEVEL >= 6
#if BX_SUPPORT_X86_64
if (long_mode())
paddress = translate_linear_long_mode(laddr, lpf_mask, pkey, user, rw);
else
#endif
if (BX_CPU_THIS_PTR cr4.get_PAE())
paddress = translate_linear_PAE(laddr, lpf_mask, user, rw);
else
#endif
paddress = translate_linear_legacy(laddr, lpf_mask, user, rw);
// translate_linear functions return combined U/S, R/W bits, Global Page bit
// and also effective page tables memory type in lower 12 bits of the physical address.
// Bit 1 - R/W bit
// Bit 2 - U/S bit
// Bit 9,10,11 - Effective Memory Table from page tables
combined_access = paddress & lpf_mask;
paddress = (paddress & ~((Bit64u) lpf_mask)) | (laddr & lpf_mask);
#if BX_CPU_LEVEL >= 5
if (lpf_mask > 0xfff) {
if (isExecute)
BX_CPU_THIS_PTR ITLB.split_large = true;
else
BX_CPU_THIS_PTR DTLB.split_large = true;
}
#endif
}
else {
// no paging
paddress = (bx_phy_address) laddr;
combined_access |= (BX_MEMTYPE_WB << 9); // act as memory type by paging is WB
}
// Calculate physical memory address and fill in TLB cache entry
#if BX_SUPPORT_VMX >= 2
if (BX_CPU_THIS_PTR in_vmx_guest) {
if (SECONDARY_VMEXEC_CONTROL(VMX_VM_EXEC_CTRL3_EPT_ENABLE)) {
paddress = translate_guest_physical(paddress, laddr, 1, 0, rw, isShadowStack & !user);
}
}
#endif
#if BX_SUPPORT_SVM
if (BX_CPU_THIS_PTR in_svm_guest && SVM_NESTED_PAGING_ENABLED) {
paddress = nested_walk(paddress, rw, 0);
}
#endif
paddress = A20ADDR(paddress);
ppf = PPFOf(paddress);
// direct memory access is NOT allowed by default
tlbEntry->lpf = lpf | TLB_NoHostPtr;
tlbEntry->lpf_mask = lpf_mask;
#if BX_SUPPORT_PKEYS
tlbEntry->pkey = pkey;
#endif
tlbEntry->ppf = ppf;
tlbEntry->accessBits = 0;
if (isExecute) {
tlbEntry->accessBits |= TLB_SysExecuteOK;
}
else {
#if BX_SUPPORT_CET
if (isShadowStack) {
tlbEntry->accessBits |= TLB_SysReadOK | TLB_SysReadShadowStackOK;
if (isWrite)
tlbEntry->accessBits |= TLB_SysWriteShadowStackOK;
}
else
#endif
{
tlbEntry->accessBits |= TLB_SysReadOK;
if (isWrite)
tlbEntry->accessBits |= TLB_SysWriteOK;
}
}
if (! BX_CPU_THIS_PTR cr0.get_PG()
#if BX_SUPPORT_VMX >= 2
&& ! (BX_CPU_THIS_PTR in_vmx_guest && SECONDARY_VMEXEC_CONTROL(VMX_VM_EXEC_CTRL3_EPT_ENABLE))
#endif
#if BX_SUPPORT_SVM
&& ! (BX_CPU_THIS_PTR in_svm_guest && SVM_NESTED_PAGING_ENABLED)
#endif
) {
if (isExecute)
tlbEntry->accessBits |= TLB_UserExecuteOK;
else
tlbEntry->accessBits |= TLB_UserReadOK | TLB_UserWriteOK;
}
else {
if ((combined_access & BX_COMBINED_ACCESS_USER) != 0) {
if (user) {
if (isExecute) {
tlbEntry->accessBits |= TLB_UserExecuteOK;
}
else {
#if BX_SUPPORT_CET
if (isShadowStack) {
tlbEntry->accessBits |= TLB_UserReadOK | TLB_UserReadShadowStackOK;
if (isWrite)
tlbEntry->accessBits |= TLB_UserWriteShadowStackOK;
}
else
#endif
{
tlbEntry->accessBits |= TLB_UserReadOK;
if (isWrite)
tlbEntry->accessBits |= TLB_UserWriteOK;
}
}
}
#if BX_CPU_LEVEL >= 6
if (isExecute) {
if (BX_CPU_THIS_PTR cr4.get_SMEP())
tlbEntry->accessBits &= ~TLB_SysExecuteOK;
}
else {
if (BX_CPU_THIS_PTR cr4.get_SMAP())
tlbEntry->accessBits &= ~(TLB_SysReadOK | TLB_SysWriteOK);
}
#endif
#if BX_SUPPORT_CET
// system shadow stack accesses cannot access user pages
tlbEntry->accessBits &= ~(TLB_SysReadShadowStackOK | TLB_SysWriteShadowStackOK);
#endif
}
}
#if BX_CPU_LEVEL >= 6
if (combined_access & BX_COMBINED_GLOBAL_PAGE) // Global bit
tlbEntry->accessBits |= TLB_GlobalPage;
#endif
// Attempt to get a host pointer to this physical page. Put that
// pointer in the TLB cache. Note if the request is vetoed, NULL
// will be returned, and it's OK to OR zero in anyways.
tlbEntry->hostPageAddr = BX_CPU_THIS_PTR getHostMemAddr(ppf, rw);
if (tlbEntry->hostPageAddr) {
// All access allowed also via direct pointer
#if BX_X86_DEBUGGER
if (! hwbreakpoint_check(laddr, BX_HWDebugMemW, BX_HWDebugMemRW))
#endif
tlbEntry->lpf = lpf; // allow direct access with HostPtr
}
#if BX_SUPPORT_MEMTYPE
tlbEntry->memtype = resolve_memtype(memtype_by_mtrr(tlbEntry->ppf), combined_access >> 9 /* effective page tables memory type */);
#endif
return paddress;
}
const char *get_memtype_name(BxMemtype memtype)
{
static const char *mem_type_string[9] = { "UC", "WC", "RESERVED2", "RESERVED3", "WT", "WP", "WB", "UC-", "INVALID" };
if (memtype > BX_MEMTYPE_INVALID) memtype = BX_MEMTYPE_INVALID;
return mem_type_string[memtype];
}
#if BX_SUPPORT_MEMTYPE
BxMemtype BX_CPP_AttrRegparmN(1) BX_CPU_C::memtype_by_mtrr(bx_phy_address pAddr)
{
#if BX_CPU_LEVEL >= 6
if (is_cpu_extension_supported(BX_ISA_MTRR)) {
const Bit32u BX_MTRR_DEFTYPE_FIXED_MTRR_ENABLE_MASK = (1 << 10);
const Bit32u BX_MTRR_ENABLE_MASK = (1 << 11);
if (BX_CPU_THIS_PTR msr.mtrr_deftype & BX_MTRR_ENABLE_MASK) {
// fixed range MTRR take priority over variable range MTRR when enabled
if (pAddr < 0x100000 && (BX_CPU_THIS_PTR msr.mtrr_deftype & BX_MTRR_DEFTYPE_FIXED_MTRR_ENABLE_MASK)) {
if (pAddr < 0x80000) {
unsigned index = (pAddr >> 16) & 0x7;
return (BxMemtype) BX_CPU_THIS_PTR msr.mtrrfix64k.ubyte(index);
}
if (pAddr < 0xc0000) {
unsigned index = ((pAddr - 0x80000) >> 14) & 0xf;
return (BxMemtype) BX_CPU_THIS_PTR msr.mtrrfix16k[index >> 3].ubyte(index & 0x7);
}
else {
unsigned index = (pAddr - 0xc0000) >> 12;
return (BxMemtype) BX_CPU_THIS_PTR msr.mtrrfix4k [index >> 3].ubyte(index & 0x7);
}
}
int memtype = -1;
for (unsigned i=0; i < BX_NUM_VARIABLE_RANGE_MTRRS; i++) {
Bit64u base = BX_CPU_THIS_PTR msr.mtrrphys[i*2];
Bit64u mask = BX_CPU_THIS_PTR msr.mtrrphys[i*2 + 1];
if ((mask & BX_MTRR_ENABLE_MASK) == 0) continue;
mask = PPFOf(mask);
if ((pAddr & mask) == (base & mask)) {
//
// Matched variable MTRR, check overlap rules:
// - if two or more variable memory ranges match and the memory types are identical,
// then that memory type is used.
// - if two or more variable memory ranges match and one of the memory types is UC,
// the UC memory type used.
// - if two or more variable memory ranges match and the memory types are WT and WB,
// the WT memory type is used.
// - For overlaps not defined by the above rules, processor behavior is undefined.
//
BxMemtype curr_memtype = BxMemtype(base & 0xff);
if (curr_memtype == BX_MEMTYPE_UC)
return BX_MEMTYPE_UC;
if (memtype == -1) {
memtype = curr_memtype; // first match
}
else if (memtype != (int) curr_memtype) {
if (curr_memtype == BX_MEMTYPE_WT && memtype == BX_MEMTYPE_WB)
memtype = BX_MEMTYPE_WT;
else if (curr_memtype == BX_MEMTYPE_WB && memtype == BX_MEMTYPE_WT)
memtype = BX_MEMTYPE_WT;
else
memtype = BX_MEMTYPE_INVALID;
}
}
}
if (memtype != -1)
return BxMemtype(memtype);
// didn't match any variable range MTRR, return default memory type
return BxMemtype(BX_CPU_THIS_PTR msr.mtrr_deftype & 0xff);
}
// return UC memory type when MTRRs are not enabled
return BX_MEMTYPE_UC;
}
#endif
// return INVALID memory type when MTRRs are not supported
return BX_MEMTYPE_INVALID;
}
BxMemtype BX_CPP_AttrRegparmN(1) BX_CPU_C::memtype_by_pat(unsigned pat)
{
return (BxMemtype) BX_CPU_THIS_PTR msr.pat.ubyte(pat);
}
BxMemtype BX_CPP_AttrRegparmN(2) BX_CPU_C::resolve_memtype(BxMemtype mtrr_memtype, BxMemtype pat_memtype)
{
if (BX_CPU_THIS_PTR cr0.get_CD())
return BX_MEMTYPE_UC;
if (mtrr_memtype == BX_MEMTYPE_INVALID) // will result in ignore of MTRR memory type
mtrr_memtype = BX_MEMTYPE_WB;
switch(pat_memtype) {
case BX_MEMTYPE_UC:
case BX_MEMTYPE_WC:
return pat_memtype;
case BX_MEMTYPE_WT:
case BX_MEMTYPE_WP:
if (mtrr_memtype == BX_MEMTYPE_WC) return BX_MEMTYPE_UC;
return (mtrr_memtype < pat_memtype) ? mtrr_memtype : pat_memtype;
case BX_MEMTYPE_WB:
return mtrr_memtype;
case BX_MEMTYPE_UC_WEAK:
return (mtrr_memtype == BX_MEMTYPE_WC) ? BX_MEMTYPE_WC : BX_MEMTYPE_UC;
default:
BX_PANIC(("unexpected PAT memory type: %u", (unsigned) pat_memtype));
}
return BX_MEMTYPE_INVALID; // keep compiler happy
}
#endif
#if BX_SUPPORT_SVM
void BX_CPU_C::nested_page_fault(unsigned fault, bx_phy_address guest_paddr, unsigned rw, unsigned is_page_walk)
{
unsigned isWrite = rw & 1;
Bit64u error_code = fault | (1 << 2) | (isWrite << 1);
if (rw == BX_EXECUTE)
error_code |= ERROR_CODE_ACCESS; // I/D = 1
if (is_page_walk)
error_code |= BX_CONST64(1) << 32;
else
error_code |= BX_CONST64(1) << 33;
Svm_Vmexit(SVM_VMEXIT_NPF, error_code, guest_paddr);
}
bx_phy_address BX_CPU_C::nested_walk_long_mode(bx_phy_address guest_paddr, unsigned rw, bx_bool is_page_walk)
{
bx_phy_address entry_addr[4];
Bit64u entry[4];
BxMemtype entry_memtype[4] = { BX_MEMTYPE_INVALID };
bx_bool nx_fault = 0;
int leaf;
SVM_CONTROLS *ctrls = &BX_CPU_THIS_PTR vmcb.ctrls;
SVM_HOST_STATE *host_state = &BX_CPU_THIS_PTR vmcb.host_state;
bx_phy_address ppf = ctrls->ncr3 & BX_CR3_PAGING_MASK;
Bit64u offset_mask = BX_CONST64(0x0000ffffffffffff);
unsigned combined_access = BX_COMBINED_ACCESS_WRITE | BX_COMBINED_ACCESS_USER;
Bit64u reserved = PAGING_PAE_RESERVED_BITS;
if (! host_state->efer.get_NXE())
reserved |= PAGE_DIRECTORY_NX_BIT;
for (leaf = BX_LEVEL_PML4;; --leaf) {
entry_addr[leaf] = ppf + ((guest_paddr >> (9 + 9*leaf)) & 0xff8);
access_read_physical(entry_addr[leaf], 8, &entry[leaf]);
BX_NOTIFY_PHY_MEMORY_ACCESS(entry_addr[leaf], 8, BX_MEMTYPE_INVALID, BX_READ, (BX_PTE_ACCESS + leaf), (Bit8u*)(&entry[leaf]));
offset_mask >>= 9;
Bit64u curr_entry = entry[leaf];
int fault = check_entry_PAE(bx_paging_level[leaf], curr_entry, reserved, rw, &nx_fault);
if (fault >= 0)
nested_page_fault(fault, guest_paddr, rw, is_page_walk);
combined_access &= curr_entry; // U/S and R/W
ppf = curr_entry & BX_CONST64(0x000ffffffffff000);
if (leaf == BX_LEVEL_PTE) break;
if (curr_entry & 0x80) {
if (leaf > (BX_LEVEL_PDE + !!is_cpu_extension_supported(BX_ISA_1G_PAGES))) {
BX_DEBUG(("Nested PAE Walk %s: PS bit set !", bx_paging_level[leaf]));
nested_page_fault(ERROR_RESERVED | ERROR_PROTECTION, guest_paddr, rw, is_page_walk);
}
ppf &= BX_CONST64(0x000fffffffffe000);
if (ppf & offset_mask) {
BX_DEBUG(("Nested PAE Walk %s: reserved bit is set: 0x" FMT_ADDRX64, bx_paging_level[leaf], curr_entry));
nested_page_fault(ERROR_RESERVED | ERROR_PROTECTION, guest_paddr, rw, is_page_walk);
}
break;
}
}
bx_bool isWrite = (rw & 1); // write or r-m-w
unsigned priv_index = (1<<3) /* user */ | (combined_access | isWrite);
if (!priv_check[priv_index] || nx_fault)
nested_page_fault(ERROR_PROTECTION, guest_paddr, rw, is_page_walk);
// Update A/D bits if needed
update_access_dirty_PAE(entry_addr, entry, entry_memtype, BX_LEVEL_PML4, leaf, isWrite);
// Make up the physical page frame address
return ppf | (bx_phy_address)(guest_paddr & offset_mask);
}
bx_phy_address BX_CPU_C::nested_walk_PAE(bx_phy_address guest_paddr, unsigned rw, bx_bool is_page_walk)
{
bx_phy_address entry_addr[2];
Bit64u entry[2];
BxMemtype entry_memtype[2] = { BX_MEMTYPE_INVALID };
bx_bool nx_fault = 0;
int leaf;
unsigned combined_access = BX_COMBINED_ACCESS_WRITE | BX_COMBINED_ACCESS_USER;
SVM_CONTROLS *ctrls = &BX_CPU_THIS_PTR vmcb.ctrls;
SVM_HOST_STATE *host_state = &BX_CPU_THIS_PTR vmcb.host_state;
bx_phy_address ncr3 = ctrls->ncr3 & 0xffffffe0;
unsigned index = (guest_paddr >> 30) & 0x3;
Bit64u pdptr;
bx_phy_address pdpe_entry_addr = (bx_phy_address) (ncr3 | (index << 3));
access_read_physical(pdpe_entry_addr, 8, &pdptr);
BX_NOTIFY_PHY_MEMORY_ACCESS(pdpe_entry_addr, 8, BX_MEMTYPE_INVALID, BX_READ, (BX_PDPTR0_ACCESS + index), (Bit8u*) &pdptr);
if (! (pdptr & 0x1)) {
BX_DEBUG(("Nested PAE Walk PDPTE%d entry not present !", index));
nested_page_fault(ERROR_NOT_PRESENT, guest_paddr, rw, is_page_walk);
}
if (pdptr & PAGING_PAE_PDPTE_RESERVED_BITS) {
BX_DEBUG(("Nested PAE Walk PDPTE%d entry reserved bits set: 0x" FMT_ADDRX64, index, pdptr));
nested_page_fault(ERROR_RESERVED | ERROR_PROTECTION, guest_paddr, rw, is_page_walk);
}
Bit64u reserved = PAGING_LEGACY_PAE_RESERVED_BITS;
if (! host_state->efer.get_NXE())
reserved |= PAGE_DIRECTORY_NX_BIT;
bx_phy_address ppf = pdptr & BX_CONST64(0x000ffffffffff000);
for (leaf = BX_LEVEL_PDE;; --leaf) {
entry_addr[leaf] = ppf + ((guest_paddr >> (9 + 9*leaf)) & 0xff8);
access_read_physical(entry_addr[leaf], 8, &entry[leaf]);
BX_NOTIFY_PHY_MEMORY_ACCESS(entry_addr[leaf], 8, BX_MEMTYPE_INVALID, BX_READ, (BX_PTE_ACCESS + leaf), (Bit8u*)(&entry[leaf]));
Bit64u curr_entry = entry[leaf];
int fault = check_entry_PAE(bx_paging_level[leaf], curr_entry, reserved, rw, &nx_fault);
if (fault >= 0)
nested_page_fault(fault, guest_paddr, rw, is_page_walk);
combined_access &= curr_entry; // U/S and R/W
ppf = curr_entry & BX_CONST64(0x000ffffffffff000);
if (leaf == BX_LEVEL_PTE) break;
// Ignore CR4.PSE in PAE mode
if (curr_entry & 0x80) {
if (curr_entry & PAGING_PAE_PDE2M_RESERVED_BITS) {
BX_DEBUG(("PAE PDE2M: reserved bit is set PDE=0x" FMT_ADDRX64, curr_entry));
nested_page_fault(ERROR_RESERVED | ERROR_PROTECTION, guest_paddr, rw, is_page_walk);
}
// Make up the physical page frame address
ppf = (bx_phy_address)((curr_entry & BX_CONST64(0x000fffffffe00000)) | (guest_paddr & 0x001ff000));
break;
}
}
bx_bool isWrite = (rw & 1); // write or r-m-w
unsigned priv_index = (1<<3) /* user */ | (combined_access | isWrite);
if (!priv_check[priv_index] || nx_fault)
nested_page_fault(ERROR_PROTECTION, guest_paddr, rw, is_page_walk);
// Update A/D bits if needed
update_access_dirty_PAE(entry_addr, entry, entry_memtype, BX_LEVEL_PDE, leaf, isWrite);
Bit32u page_offset = PAGE_OFFSET(guest_paddr);
return ppf | page_offset;
}
bx_phy_address BX_CPU_C::nested_walk_legacy(bx_phy_address guest_paddr, unsigned rw, bx_bool is_page_walk)
{
bx_phy_address entry_addr[2];
Bit32u entry[2];
BxMemtype entry_memtype[2] = { BX_MEMTYPE_INVALID };
int leaf;
SVM_CONTROLS *ctrls = &BX_CPU_THIS_PTR vmcb.ctrls;
SVM_HOST_STATE *host_state = &BX_CPU_THIS_PTR vmcb.host_state;
bx_phy_address ppf = ctrls->ncr3 & BX_CR3_PAGING_MASK;
unsigned combined_access = BX_COMBINED_ACCESS_WRITE | BX_COMBINED_ACCESS_USER;
for (leaf = BX_LEVEL_PDE;; --leaf) {
entry_addr[leaf] = ppf + ((guest_paddr >> (10 + 10*leaf)) & 0xffc);
access_read_physical(entry_addr[leaf], 4, &entry[leaf]);
BX_NOTIFY_PHY_MEMORY_ACCESS(entry_addr[leaf], 4, BX_MEMTYPE_INVALID, BX_READ, (BX_PTE_ACCESS + leaf), (Bit8u*)(&entry[leaf]));
Bit32u curr_entry = entry[leaf];
if (!(curr_entry & 0x1)) {
BX_DEBUG(("Nested %s Walk: entry not present", bx_paging_level[leaf]));
nested_page_fault(ERROR_NOT_PRESENT, guest_paddr, rw, is_page_walk);
}
combined_access &= curr_entry; // U/S and R/W
ppf = curr_entry & 0xfffff000;
if (leaf == BX_LEVEL_PTE) break;
if ((curr_entry & 0x80) != 0 && host_state->cr4.get_PSE()) {
// 4M paging, only if CR4.PSE enabled, ignore PDE.PS otherwise
if (curr_entry & PAGING_PDE4M_RESERVED_BITS) {
BX_DEBUG(("Nested PSE Walk PDE4M: reserved bit is set: PDE=0x%08x", entry[BX_LEVEL_PDE]));
nested_page_fault(ERROR_RESERVED | ERROR_PROTECTION, guest_paddr, rw, is_page_walk);
}
// make up the physical frame number
ppf = (curr_entry & 0xffc00000) | (guest_paddr & 0x003ff000);
#if BX_PHY_ADDRESS_WIDTH > 32
ppf |= ((bx_phy_address)(curr_entry & 0x003fe000)) << 19;
#endif
break;
}
}
bx_bool isWrite = (rw & 1); // write or r-m-w
unsigned priv_index = (1<<3) /* user */ | (combined_access | isWrite);
if (!priv_check[priv_index])
nested_page_fault(ERROR_PROTECTION, guest_paddr, rw, is_page_walk);
update_access_dirty(entry_addr, entry, entry_memtype, leaf, isWrite);
Bit32u page_offset = PAGE_OFFSET(guest_paddr);
return ppf | page_offset;
}
bx_phy_address BX_CPU_C::nested_walk(bx_phy_address guest_paddr, unsigned rw, bx_bool is_page_walk)
{
SVM_HOST_STATE *host_state = &BX_CPU_THIS_PTR vmcb.host_state;
BX_DEBUG(("Nested walk for guest paddr 0x" FMT_PHY_ADDRX, guest_paddr));
if (host_state->efer.get_LMA())
return nested_walk_long_mode(guest_paddr, rw, is_page_walk);
else if (host_state->cr4.get_PAE())
return nested_walk_PAE(guest_paddr, rw, is_page_walk);
else
return nested_walk_legacy(guest_paddr, rw, is_page_walk);
}
#endif
#if BX_SUPPORT_VMX >= 2
/* EPT access type */
enum {
BX_EPT_READ = 0x01,
BX_EPT_WRITE = 0x02,
BX_EPT_EXECUTE = 0x04
};
/* EPT access mask */
enum {
BX_EPT_ENTRY_NOT_PRESENT = 0x00,
BX_EPT_ENTRY_READ_ONLY = 0x01,
BX_EPT_ENTRY_WRITE_ONLY = 0x02,
BX_EPT_ENTRY_READ_WRITE = 0x03,
BX_EPT_ENTRY_EXECUTE_ONLY = 0x04,
BX_EPT_ENTRY_READ_EXECUTE = 0x05,
BX_EPT_ENTRY_WRITE_EXECUTE = 0x06,
BX_EPT_ENTRY_READ_WRITE_EXECUTE = 0x07
};
#define BX_VMX_EPT_ACCESS_DIRTY_ENABLED (BX_CPU_THIS_PTR vmcs.eptptr & 0x40)
#define BX_VMX_EPT_SUPERVISOR_SHADOW_STACK_CTRL_ENABLED (BX_CPU_THIS_PTR vmcs.eptptr & 0x80)
// Format of a EPT Entry
// -----------------------------------------------------------
// 00 | Read access
// 01 | Write access
// 02 | Execute Access
// 05-03 | EPT Memory type (for leaf entries, reserved otherwise)
// 06 | Ignore PAT memory type (for leaf entries, reserved otherwise)
// 07 | Page Size, must be 1 to indicate a Large Page
// 08 | Accessed bit (if supported, ignored otherwise)
// 09 | Dirty bit (for leaf entries, if supported, ignored otherwise)
// 11-10 | (ignored)
// PA-12 | Physical address
// 51-PA | Reserved (must be zero)
// 61-52 | (ignored)
// 60 | Supervisor Shadow Stack Page (CET)
// 61 | Super Page Protected (SPP)
// 63 | Suppress #VE
// -----------------------------------------------------------
const Bit64u BX_SUPPRESS_EPT_VIOLATION_EXCEPTION = (BX_CONST64(1) << 63);
const Bit64u BX_SUB_PAGE_PROTECTED = (BX_CONST64(1) << 61);
const Bit64u BX_SUPERVISOR_SHADOW_STACK_PAGE = (BX_CONST64(1) << 60);
const Bit64u PAGING_EPT_RESERVED_BITS = BX_PAGING_PHY_ADDRESS_RESERVED_BITS;
bx_phy_address BX_CPU_C::translate_guest_physical(bx_phy_address guest_paddr, bx_address guest_laddr, bx_bool guest_laddr_valid, bx_bool is_page_walk, unsigned rw, bx_bool supervisor_shadow_stack)
{
VMCS_CACHE *vm = &BX_CPU_THIS_PTR vmcs;
bx_phy_address entry_addr[4], ppf = LPFOf(vm->eptptr);
Bit64u entry[4];
int leaf;
#if BX_SUPPORT_MEMTYPE
// The MTRRs have no effect on the memory type used for an access to an EPT paging structures.
BxMemtype eptptr_memtype = BX_CPU_THIS_PTR cr0.get_CD() ? (BX_MEMTYPE_UC) : BxMemtype(vm->eptptr & 0x7);
#endif
Bit32u combined_access = 0x7, access_mask = 0;
Bit64u offset_mask = BX_CONST64(0x0000ffffffffffff);
BX_DEBUG(("EPT walk for guest paddr 0x" FMT_PHY_ADDRX, guest_paddr));
// when EPT A/D enabled treat guest page table accesses as writes
if (BX_VMX_EPT_ACCESS_DIRTY_ENABLED && is_page_walk && guest_laddr_valid)
rw = BX_WRITE;
if (rw == BX_EXECUTE) access_mask |= BX_EPT_EXECUTE;
if (rw & 1) access_mask |= BX_EPT_WRITE; // write or r-m-w
if ((rw & 3) == BX_READ) access_mask |= BX_EPT_READ; // handle correctly shadow stack reads
Bit32u vmexit_reason = 0;
for (leaf = BX_LEVEL_PML4;; --leaf) {
entry_addr[leaf] = ppf + ((guest_paddr >> (9 + 9*leaf)) & 0xff8);
access_read_physical(entry_addr[leaf], 8, &entry[leaf]);
BX_NOTIFY_PHY_MEMORY_ACCESS(entry_addr[leaf], 8, MEMTYPE(eptptr_memtype), BX_READ, (BX_EPT_PTE_ACCESS + leaf), (Bit8u*)(&entry[leaf]));
offset_mask >>= 9;
Bit64u curr_entry = entry[leaf];
Bit32u curr_access_mask = curr_entry & 0x7;
if (curr_access_mask == BX_EPT_ENTRY_NOT_PRESENT) {
BX_DEBUG(("EPT %s: not present", bx_paging_level[leaf]));
vmexit_reason = VMX_VMEXIT_EPT_VIOLATION;
break;
}
if (curr_access_mask == BX_EPT_ENTRY_WRITE_ONLY || curr_access_mask == BX_EPT_ENTRY_WRITE_EXECUTE) {
BX_DEBUG(("EPT %s: EPT misconfiguration mask=%d", bx_paging_level[leaf], curr_access_mask));
vmexit_reason = VMX_VMEXIT_EPT_MISCONFIGURATION;
break;
}
extern bx_bool isMemTypeValidMTRR(unsigned memtype);
if (! isMemTypeValidMTRR((curr_entry >> 3) & 7)) {
BX_DEBUG(("EPT %s: EPT misconfiguration memtype=%d",
bx_paging_level[leaf], (unsigned)((curr_entry >> 3) & 7)));
vmexit_reason = VMX_VMEXIT_EPT_MISCONFIGURATION;
break;
}
if (curr_entry & PAGING_EPT_RESERVED_BITS) {
BX_DEBUG(("EPT %s: reserved bit is set 0x" FMT_ADDRX64, bx_paging_level[leaf], curr_entry));
vmexit_reason = VMX_VMEXIT_EPT_MISCONFIGURATION;
break;
}
ppf = curr_entry & BX_CONST64(0x000ffffffffff000);
if (leaf == BX_LEVEL_PTE) break;
if (curr_entry & 0x80) {
if (leaf > (BX_LEVEL_PDE + !!is_cpu_extension_supported(BX_ISA_1G_PAGES))) {
BX_DEBUG(("EPT %s: PS bit set !", bx_paging_level[leaf]));
vmexit_reason = VMX_VMEXIT_EPT_MISCONFIGURATION;
break;
}
ppf &= BX_CONST64(0x000fffffffffe000);
if (ppf & offset_mask) {
BX_DEBUG(("EPT %s: reserved bit is set: 0x" FMT_ADDRX64, bx_paging_level[leaf], curr_entry));
vmexit_reason = VMX_VMEXIT_EPT_MISCONFIGURATION;
break;
}
// Make up the physical page frame address
ppf += (bx_phy_address)(guest_paddr & offset_mask);
break;
}
// EPT non leaf entry, check for reserved bits
if ((curr_entry >> 3) & 0xf) {
BX_DEBUG(("EPT %s: EPT misconfiguration, reserved bits set for non-leaf entry", bx_paging_level[leaf]));
vmexit_reason = VMX_VMEXIT_EPT_MISCONFIGURATION;
break;
}
combined_access &= curr_access_mask;
}
// defer final combined_access calculation (with leaf entry) until CET is handled
if (!vmexit_reason) {
#if BX_SUPPORT_CET
if (BX_VMX_EPT_SUPERVISOR_SHADOW_STACK_CTRL_ENABLED && supervisor_shadow_stack) {
// The EPT.R bit is set in all EPT paging-structure entry controlling the translation
// The EPT.W bit is set in all EPT paging-structure entry controlling the translation except the leaf entry (allowed for shadow stack write access)
// The SSS bit (bit 60) is 1 in the EPT paging-structure entry maps the page
bx_bool supervisor_shadow_stack_page = ((combined_access & BX_EPT_ENTRY_READ_WRITE) == BX_EPT_ENTRY_READ_WRITE) &&
((entry[leaf] & BX_EPT_READ) != 0) &&
(((entry[leaf] & BX_EPT_WRITE) == 0) || !(access_mask & BX_EPT_WRITE)) &&
((entry[leaf] & BX_SUPERVISOR_SHADOW_STACK_PAGE) != 0);
if (!supervisor_shadow_stack_page) {
BX_ERROR(("VMEXIT: supervisor shadow stack access to non supervisor shadow stack page"));
vmexit_reason = VMX_VMEXIT_EPT_VIOLATION;
}
}
else
#endif
{
combined_access &= entry[leaf];
if ((access_mask & combined_access) != access_mask) {
vmexit_reason = VMX_VMEXIT_EPT_VIOLATION;
if (SECONDARY_VMEXEC_CONTROL(VMX_VM_EXEC_CTRL3_SUBPAGE_WR_PROTECT_CTRL) && (entry[leaf] & BX_SUB_PAGE_PROTECTED) != 0 && leaf == BX_LEVEL_PTE) {
if ((access_mask & BX_EPT_WRITE) != 0 && (combined_access & BX_EPT_WRITE) == 0 && guest_laddr_valid && ! is_page_walk)
if (spp_walk(guest_paddr, guest_laddr, MEMTYPE(eptptr_memtype)))
vmexit_reason = 0;
}
}
}
}
if (vmexit_reason) {
BX_ERROR(("VMEXIT: EPT %s for guest paddr 0x" FMT_PHY_ADDRX " laddr 0x" FMT_ADDRX,
(vmexit_reason == VMX_VMEXIT_EPT_VIOLATION) ? "violation" : "misconfig", guest_paddr, guest_laddr));
Bit32u vmexit_qualification = 0;
// no VMExit qualification for EPT Misconfiguration VMExit
if (vmexit_reason == VMX_VMEXIT_EPT_VIOLATION) {
combined_access &= entry[leaf];
vmexit_qualification = access_mask | (combined_access << 3);
if (guest_laddr_valid) {
vmexit_qualification |= (1<<7);
if (! is_page_walk) vmexit_qualification |= (1<<8);
}
if (BX_CPU_THIS_PTR nmi_unblocking_iret)
vmexit_qualification |= (1 << 12);
#if BX_SUPPORT_CET
if (rw & 4) // shadow stack access
vmexit_qualification |= (1 << 13);
if (BX_VMX_EPT_SUPERVISOR_SHADOW_STACK_CTRL_ENABLED && (entry[leaf] & BX_SUPERVISOR_SHADOW_STACK_PAGE) != 0)
vmexit_qualification |= (1 << 14);
#endif
if (SECONDARY_VMEXEC_CONTROL(VMX_VM_EXEC_CTRL3_EPT_VIOLATION_EXCEPTION)) {
if ((entry[leaf] & BX_SUPPRESS_EPT_VIOLATION_EXCEPTION) == 0)
Virtualization_Exception(vmexit_qualification, guest_paddr, guest_laddr);
}
}
VMwrite64(VMCS_64BIT_GUEST_PHYSICAL_ADDR, guest_paddr);
VMwrite_natural(VMCS_GUEST_LINEAR_ADDR, guest_laddr);
VMexit(vmexit_reason, vmexit_qualification);
}
if (BX_VMX_EPT_ACCESS_DIRTY_ENABLED) {
// write access and Dirty-bit is not set in the leaf entry
unsigned dirty_update = (rw & 1) && !(entry[leaf] & 0x200);
if (SECONDARY_VMEXEC_CONTROL(VMX_VM_EXEC_CTRL3_PML_ENABLE))
vmx_page_modification_logging(guest_paddr, dirty_update);
update_ept_access_dirty(entry_addr, entry, MEMTYPE(eptptr_memtype), leaf, rw & 1);
}
Bit32u page_offset = PAGE_OFFSET(guest_paddr);
return ppf | page_offset;
}
// Access bit 8, Dirty bit 9
void BX_CPU_C::update_ept_access_dirty(bx_phy_address *entry_addr, Bit64u *entry, BxMemtype eptptr_memtype, unsigned leaf, unsigned write)
{
// Update A bit if needed
for (unsigned level=BX_LEVEL_PML4; level > leaf; level--) {
if (!(entry[level] & 0x100)) {
entry[level] |= 0x100;
access_write_physical(entry_addr[level], 8, &entry[level]);
BX_NOTIFY_PHY_MEMORY_ACCESS(entry_addr[level], 8, MEMTYPE(eptptr_memtype), BX_WRITE, (BX_EPT_PTE_ACCESS + level), (Bit8u*)(&entry[level]));
}
}
// Update A/D bits if needed
if (!(entry[leaf] & 0x100) || (write && !(entry[leaf] & 0x200))) {
entry[leaf] |= (0x100 | (write<<9)); // Update A and possibly D bits
access_write_physical(entry_addr[leaf], 8, &entry[leaf]);
BX_NOTIFY_PHY_MEMORY_ACCESS(entry_addr[leaf], 8, MEMTYPE(eptptr_memtype), BX_WRITE, (BX_EPT_PTE_ACCESS + leaf), (Bit8u*)(&entry[leaf]));
}
}
const Bit64u PAGING_SPP_RESERVED_BITS = BX_PAGING_PHY_ADDRESS_RESERVED_BITS | BX_CONST64(0xFFF0000000000FFE);
const Bit32u VMX_SPP_NOT_PRESENT_QUALIFICATION = (1<<11);
bx_bool BX_CPU_C::spp_walk(bx_phy_address guest_paddr, bx_address guest_laddr, BxMemtype memtype)
{
VMCS_CACHE *vm = &BX_CPU_THIS_PTR vmcs;
bx_phy_address entry_addr[4], ppf = LPFOf(vm->spptp);
Bit64u entry[4];
int leaf;
BX_DEBUG(("SPP walk for guest paddr 0x" FMT_PHY_ADDRX, guest_paddr));
Bit32u vmexit_reason = 0;
Bit32u vmexit_qualification = 0;
for (leaf = BX_LEVEL_PML4;; --leaf) {
entry_addr[leaf] = ppf + ((guest_paddr >> (9 + 9*leaf)) & 0xff8);
access_read_physical(entry_addr[leaf], 8, &entry[leaf]);
BX_NOTIFY_PHY_MEMORY_ACCESS(entry_addr[leaf], 8, MEMTYPE(memtype), BX_READ, (BX_EPT_SPP_PTE_ACCESS + leaf), (Bit8u*)(&entry[leaf]));
if (leaf == BX_LEVEL_PTE) break;
Bit64u curr_entry = entry[leaf];
if (!(curr_entry & 1)) {
BX_DEBUG(("SPP %s: not present", bx_paging_level[leaf]));
vmexit_reason = VMX_VMEXIT_SPP;
vmexit_qualification = VMX_SPP_NOT_PRESENT_QUALIFICATION;
break;
}
if (curr_entry & PAGING_SPP_RESERVED_BITS) {
BX_DEBUG(("SPP %s: reserved bit is set 0x" FMT_ADDRX64, bx_paging_level[leaf], curr_entry));
vmexit_reason = VMX_VMEXIT_SPP;
break;
}
ppf = curr_entry & BX_CONST64(0x000ffffffffff000);
}
if (vmexit_reason) {
BX_ERROR(("VMEXIT: SPP %s for guest paddr 0x" FMT_PHY_ADDRX " laddr 0x" FMT_ADDRX,
(vmexit_qualification == VMX_SPP_NOT_PRESENT_QUALIFICATION) ? "violation" : "misconfig", guest_paddr, guest_laddr));
if (BX_CPU_THIS_PTR nmi_unblocking_iret)
vmexit_qualification |= (1 << 12);
VMwrite64(VMCS_64BIT_GUEST_PHYSICAL_ADDR, guest_paddr);
VMwrite_natural(VMCS_GUEST_LINEAR_ADDR, guest_laddr);
VMexit(vmexit_reason, vmexit_qualification);
}
Bit32u spp_bit = 2 * ((guest_paddr & 0xFFF) >> 7);
return (entry[BX_LEVEL_PTE] >> spp_bit) & 1;
}
#endif
#if BX_DEBUGGER || BX_DISASM || BX_INSTRUMENTATION || BX_GDBSTUB
#if BX_DEBUGGER
void dbg_print_paging_pte(int level, Bit64u entry)
{
dbg_printf("%4s: 0x%08x%08x", bx_paging_level[level], GET32H(entry), GET32L(entry));
if (entry & BX_CONST64(0x8000000000000000))
dbg_printf(" XD");
else
dbg_printf(" ");
if (level == BX_LEVEL_PTE) {
dbg_printf(" %s %s %s",
(entry & 0x0100) ? "G" : "g",
(entry & 0x0080) ? "PAT" : "pat",
(entry & 0x0040) ? "D" : "d");
}
else {
if (entry & 0x80) {
dbg_printf(" PS %s %s %s",
(entry & 0x0100) ? "G" : "g",
(entry & 0x1000) ? "PAT" : "pat",
(entry & 0x0040) ? "D" : "d");
}
else {
dbg_printf(" ps ");
}
}
dbg_printf(" %s %s %s %s %s %s\n",
(entry & 0x20) ? "A" : "a",
(entry & 0x10) ? "PCD" : "pcd",
(entry & 0x08) ? "PWT" : "pwt",
(entry & 0x04) ? "U" : "S",
(entry & 0x02) ? "W" : "R",
(entry & 0x01) ? "P" : "p");
}
#if BX_SUPPORT_VMX >= 2
void dbg_print_ept_paging_pte(int level, Bit64u entry)
{
dbg_printf("EPT %4s: 0x%08x%08x", bx_paging_level[level], GET32H(entry), GET32L(entry));
if (level != BX_LEVEL_PTE && (entry & 0x80))
dbg_printf(" PS");
else
dbg_printf(" ");
dbg_printf(" %s %s %s",
(entry & 0x04) ? "E" : "e",
(entry & 0x02) ? "W" : "w",
(entry & 0x01) ? "R" : "r");
if (level == BX_LEVEL_PTE || (entry & 0x80)) {
dbg_printf(" %s %s\n",
(entry & 0x40) ? "IGNORE_PAT" : "ignore_pat",
get_memtype_name(BxMemtype((entry >> 3) & 0x7)));
}
else {
dbg_printf("\n");
}
}
#endif
#endif // BX_DEBUGGER
#if BX_SUPPORT_VMX >= 2
bx_bool BX_CPU_C::dbg_translate_guest_physical(bx_phy_address guest_paddr, bx_phy_address *phy, bx_bool verbose)
{
VMCS_CACHE *vm = &BX_CPU_THIS_PTR vmcs;
bx_phy_address pt_address = LPFOf(vm->eptptr);
Bit64u offset_mask = BX_CONST64(0x0000ffffffffffff);
for (int level = 3; level >= 0; --level) {
Bit64u pte;
pt_address += ((guest_paddr >> (9 + 9*level)) & 0xff8);
offset_mask >>= 9;
BX_MEM(0)->readPhysicalPage(BX_CPU_THIS, pt_address, 8, &pte);
#if BX_DEBUGGER
if (verbose)
dbg_print_ept_paging_pte(level, pte);
#endif
switch(pte & 7) {
case BX_EPT_ENTRY_NOT_PRESENT:
case BX_EPT_ENTRY_WRITE_ONLY:
case BX_EPT_ENTRY_WRITE_EXECUTE:
return 0;
}
if (pte & BX_PAGING_PHY_ADDRESS_RESERVED_BITS)
return 0;
pt_address = bx_phy_address(pte & BX_CONST64(0x000ffffffffff000));
if (level == BX_LEVEL_PTE) break;
if (pte & 0x80) {
if (level > (BX_LEVEL_PDE + !!is_cpu_extension_supported(BX_ISA_1G_PAGES)))
return 0;
pt_address &= BX_CONST64(0x000fffffffffe000);
if (pt_address & offset_mask) return 0;
break;
}
}
*phy = pt_address + (bx_phy_address)(guest_paddr & offset_mask);
return 1;
}
#endif
bx_bool BX_CPU_C::dbg_xlate_linear2phy(bx_address laddr, bx_phy_address *phy, bx_address *lpf_mask, bx_bool verbose)
{
bx_phy_address paddress;
bx_address offset_mask = 0xfff;
#if BX_SUPPORT_X86_64
if (! long_mode()) laddr &= 0xffffffff;
#endif
if (! BX_CPU_THIS_PTR cr0.get_PG()) {
paddress = (bx_phy_address) laddr;
}
else {
bx_phy_address pt_address = BX_CPU_THIS_PTR cr3 & BX_CR3_PAGING_MASK;
#if BX_CPU_LEVEL >= 6
if (BX_CPU_THIS_PTR cr4.get_PAE()) {
offset_mask = BX_CONST64(0x0000ffffffffffff);
int level = 3;
if (! long_mode()) {
pt_address = BX_CPU_THIS_PTR PDPTR_CACHE.entry[(laddr >> 30) & 3];
if (! (pt_address & 0x1)) {
offset_mask = 0x3fffffff;
goto page_fault;
}
offset_mask >>= 18;
pt_address &= BX_CONST64(0x000ffffffffff000);
level = 1;
}
for (; level >= 0; --level) {
Bit64u pte;
pt_address += ((laddr >> (9 + 9*level)) & 0xff8);
offset_mask >>= 9;
#if BX_SUPPORT_VMX >= 2
if (BX_CPU_THIS_PTR in_vmx_guest) {
if (SECONDARY_VMEXEC_CONTROL(VMX_VM_EXEC_CTRL3_EPT_ENABLE)) {
if (! dbg_translate_guest_physical(pt_address, &pt_address, verbose))
goto page_fault;
}
}
#endif
BX_MEM(0)->readPhysicalPage(BX_CPU_THIS, pt_address, 8, &pte);
#if BX_DEBUGGER
if (verbose)
dbg_print_paging_pte(level, pte);
#endif
if(!(pte & 1))
goto page_fault;
if (pte & BX_PAGING_PHY_ADDRESS_RESERVED_BITS)
goto page_fault;
pt_address = bx_phy_address(pte & BX_CONST64(0x000ffffffffff000));
if (level == BX_LEVEL_PTE) break;
if (pte & 0x80) {
// large page
pt_address &= BX_CONST64(0x000fffffffffe000);
if (pt_address & offset_mask)
goto page_fault;
if (is_cpu_extension_supported(BX_ISA_1G_PAGES) && level == BX_LEVEL_PDPTE) break;
if (level == BX_LEVEL_PDE) break;
goto page_fault;
}
}
paddress = pt_address + (bx_phy_address)(laddr & offset_mask);
}
else // not PAE
#endif
{
offset_mask = 0xfff;
for (int level = 1; level >= 0; --level) {
Bit32u pte;
pt_address += ((laddr >> (10 + 10*level)) & 0xffc);
#if BX_SUPPORT_VMX >= 2
if (BX_CPU_THIS_PTR in_vmx_guest) {
if (SECONDARY_VMEXEC_CONTROL(VMX_VM_EXEC_CTRL3_EPT_ENABLE)) {
if (! dbg_translate_guest_physical(pt_address, &pt_address, verbose))
goto page_fault;
}
}
#endif
BX_MEM(0)->readPhysicalPage(BX_CPU_THIS, pt_address, 4, &pte);
#if BX_DEBUGGER
if (verbose)
dbg_print_paging_pte(level, pte);
#endif
if (!(pte & 1))
goto page_fault;
pt_address = pte & 0xfffff000;
#if BX_CPU_LEVEL >= 6
if (level == BX_LEVEL_PDE && (pte & 0x80) != 0 && BX_CPU_THIS_PTR cr4.get_PSE()) {
offset_mask = 0x3fffff;
pt_address = pte & 0xffc00000;
#if BX_PHY_ADDRESS_WIDTH > 32
pt_address += ((bx_phy_address)(pte & 0x003fe000)) << 19;
#endif
break;
}
#endif
}
paddress = pt_address + (bx_phy_address)(laddr & offset_mask);
}
}
#if BX_SUPPORT_VMX >= 2
if (BX_CPU_THIS_PTR in_vmx_guest) {
if (SECONDARY_VMEXEC_CONTROL(VMX_VM_EXEC_CTRL3_EPT_ENABLE)) {
if (! dbg_translate_guest_physical(paddress, &paddress, verbose))
goto page_fault;
}
}
#endif
if (lpf_mask)
*lpf_mask = offset_mask;
*phy = A20ADDR(paddress);
return 1;
page_fault:
if (lpf_mask)
*lpf_mask = offset_mask;
*phy = 0;
return 0;
}
#endif
int BX_CPU_C::access_write_linear(bx_address laddr, unsigned len, unsigned curr_pl, unsigned xlate_rw, Bit32u ac_mask, void *data)
{
#if BX_SUPPORT_CET
BX_ASSERT(xlate_rw == BX_WRITE || xlate_rw == BX_SHADOW_STACK_WRITE);
#else
BX_ASSERT(xlate_rw == BX_WRITE);
#endif
Bit32u pageOffset = PAGE_OFFSET(laddr);
bx_bool user = (curr_pl == 3);
bx_TLB_entry *tlbEntry = BX_DTLB_ENTRY_OF(laddr, 0);
#if BX_SUPPORT_X86_64
if (! IsCanonical(laddr)) {
BX_ERROR(("access_write_linear(): canonical failure"));
return -1;
}
#endif
#if BX_CPU_LEVEL >= 4 && BX_SUPPORT_ALIGNMENT_CHECK
if (BX_CPU_THIS_PTR alignment_check() && user) {
if (pageOffset & ac_mask) {
BX_ERROR(("access_write_linear(): #AC misaligned access"));
exception(BX_AC_EXCEPTION, 0);
}
}
#endif
/* check for reference across multiple pages */
if ((pageOffset + len) <= 4096) {
// Access within single page.
BX_CPU_THIS_PTR address_xlation.paddress1 = translate_linear(tlbEntry, laddr, user, xlate_rw);
BX_CPU_THIS_PTR address_xlation.pages = 1;
#if BX_SUPPORT_MEMTYPE
BX_CPU_THIS_PTR address_xlation.memtype1 = tlbEntry->get_memtype();
#endif
BX_NOTIFY_LIN_MEMORY_ACCESS(laddr, BX_CPU_THIS_PTR address_xlation.paddress1,
len, tlbEntry->get_memtype(), xlate_rw, (Bit8u*) data);
access_write_physical(BX_CPU_THIS_PTR address_xlation.paddress1, len, data);
#if BX_X86_DEBUGGER
hwbreakpoint_match(laddr, len, xlate_rw);
#endif
}
else {
// access across 2 pages
BX_CPU_THIS_PTR address_xlation.len1 = 4096 - pageOffset;
BX_CPU_THIS_PTR address_xlation.len2 = len - BX_CPU_THIS_PTR address_xlation.len1;
BX_CPU_THIS_PTR address_xlation.pages = 2;
bx_address laddr2 = laddr + BX_CPU_THIS_PTR address_xlation.len1;
#if BX_SUPPORT_X86_64
if (! long64_mode()) laddr2 &= 0xffffffff; /* handle linear address wrap in legacy mode */
else {
if (! IsCanonical(laddr2)) {
BX_ERROR(("access_write_linear(): canonical failure for second half of page split access"));
return -1;
}
}
#endif
bx_TLB_entry *tlbEntry2 = BX_DTLB_ENTRY_OF(laddr2, 0);
BX_CPU_THIS_PTR address_xlation.paddress1 = translate_linear(tlbEntry, laddr, user, xlate_rw);
BX_CPU_THIS_PTR address_xlation.paddress2 = translate_linear(tlbEntry2, laddr2, user, xlate_rw);
#if BX_SUPPORT_MEMTYPE
BX_CPU_THIS_PTR address_xlation.memtype1 = tlbEntry->get_memtype();
BX_CPU_THIS_PTR address_xlation.memtype2 = tlbEntry2->get_memtype();
#endif
#ifdef BX_LITTLE_ENDIAN
BX_NOTIFY_LIN_MEMORY_ACCESS(laddr, BX_CPU_THIS_PTR address_xlation.paddress1,
BX_CPU_THIS_PTR address_xlation.len1, tlbEntry->get_memtype(),
xlate_rw, (Bit8u*) data);
access_write_physical(BX_CPU_THIS_PTR address_xlation.paddress1,
BX_CPU_THIS_PTR address_xlation.len1, data);
BX_NOTIFY_LIN_MEMORY_ACCESS(laddr2, BX_CPU_THIS_PTR address_xlation.paddress2,
BX_CPU_THIS_PTR address_xlation.len2, tlbEntry2->get_memtype(),
xlate_rw, ((Bit8u*)data) + BX_CPU_THIS_PTR address_xlation.len1);
access_write_physical(BX_CPU_THIS_PTR address_xlation.paddress2,
BX_CPU_THIS_PTR address_xlation.len2,
((Bit8u*)data) + BX_CPU_THIS_PTR address_xlation.len1);
#else // BX_BIG_ENDIAN
BX_NOTIFY_LIN_MEMORY_ACCESS(laddr, BX_CPU_THIS_PTR address_xlation.paddress1,
BX_CPU_THIS_PTR address_xlation.len1, tlbEntry->get_memtype(),
xlate_rw, ((Bit8u*)data) + (len - BX_CPU_THIS_PTR address_xlation.len1));
access_write_physical(BX_CPU_THIS_PTR address_xlation.paddress1,
BX_CPU_THIS_PTR address_xlation.len1,
((Bit8u*)data) + (len - BX_CPU_THIS_PTR address_xlation.len1));
BX_NOTIFY_LIN_MEMORY_ACCESS(laddr2, BX_CPU_THIS_PTR address_xlation.paddress2,
BX_CPU_THIS_PTR address_xlation.len2, tlbEntry2->get_memtype(),
xlate_rw, (Bit8u*) data);
access_write_physical(BX_CPU_THIS_PTR address_xlation.paddress2,
BX_CPU_THIS_PTR address_xlation.len2, data);
#endif
#if BX_X86_DEBUGGER
hwbreakpoint_match(laddr, BX_CPU_THIS_PTR address_xlation.len1, xlate_rw);
hwbreakpoint_match(laddr2, BX_CPU_THIS_PTR address_xlation.len2, xlate_rw);
#endif
}
return 0;
}
int BX_CPU_C::access_read_linear(bx_address laddr, unsigned len, unsigned curr_pl, unsigned xlate_rw, Bit32u ac_mask, void *data)
{
#if BX_SUPPORT_CET
BX_ASSERT(xlate_rw == BX_READ || xlate_rw == BX_RW || xlate_rw == BX_SHADOW_STACK_READ || xlate_rw == BX_SHADOW_STACK_RW);
#else
BX_ASSERT(xlate_rw == BX_READ || xlate_rw == BX_RW);
#endif
Bit32u pageOffset = PAGE_OFFSET(laddr);
bx_bool user = (curr_pl == 3);
#if BX_SUPPORT_X86_64
if (! IsCanonical(laddr)) {
BX_ERROR(("access_read_linear(): canonical failure"));
return -1;
}
#endif
#if BX_CPU_LEVEL >= 4 && BX_SUPPORT_ALIGNMENT_CHECK
if (BX_CPU_THIS_PTR alignment_check() && user) {
if (pageOffset & ac_mask) {
BX_ERROR(("access_read_linear(): #AC misaligned access"));
exception(BX_AC_EXCEPTION, 0);
}
}
#endif
bx_TLB_entry *tlbEntry = BX_DTLB_ENTRY_OF(laddr, 0);
/* check for reference across multiple pages */
if ((pageOffset + len) <= 4096) {
// Access within single page.
BX_CPU_THIS_PTR address_xlation.paddress1 = translate_linear(tlbEntry, laddr, user, xlate_rw);
BX_CPU_THIS_PTR address_xlation.pages = 1;
#if BX_SUPPORT_MEMTYPE
BX_CPU_THIS_PTR address_xlation.memtype1 = tlbEntry->get_memtype();
#endif
access_read_physical(BX_CPU_THIS_PTR address_xlation.paddress1, len, data);
BX_NOTIFY_LIN_MEMORY_ACCESS(laddr, BX_CPU_THIS_PTR address_xlation.paddress1, len, tlbEntry->get_memtype(), xlate_rw, (Bit8u*) data);
#if BX_X86_DEBUGGER
hwbreakpoint_match(laddr, len, xlate_rw);
#endif
}
else {
// access across 2 pages
BX_CPU_THIS_PTR address_xlation.len1 = 4096 - pageOffset;
BX_CPU_THIS_PTR address_xlation.len2 = len - BX_CPU_THIS_PTR address_xlation.len1;
BX_CPU_THIS_PTR address_xlation.pages = 2;
bx_address laddr2 = laddr + BX_CPU_THIS_PTR address_xlation.len1;
#if BX_SUPPORT_X86_64
if (! long64_mode()) laddr2 &= 0xffffffff; /* handle linear address wrap in legacy mode */
else {
if (! IsCanonical(laddr2)) {
BX_ERROR(("access_read_linear(): canonical failure for second half of page split access"));
return -1;
}
}
#endif
bx_TLB_entry *tlbEntry2 = BX_DTLB_ENTRY_OF(laddr2, 0);
BX_CPU_THIS_PTR address_xlation.paddress1 = translate_linear(tlbEntry, laddr, user, xlate_rw);
BX_CPU_THIS_PTR address_xlation.paddress2 = translate_linear(tlbEntry2, laddr2, user, xlate_rw);
#if BX_SUPPORT_MEMTYPE
BX_CPU_THIS_PTR address_xlation.memtype1 = tlbEntry->get_memtype();
BX_CPU_THIS_PTR address_xlation.memtype2 = tlbEntry2->get_memtype();
#endif
#ifdef BX_LITTLE_ENDIAN
access_read_physical(BX_CPU_THIS_PTR address_xlation.paddress1,
BX_CPU_THIS_PTR address_xlation.len1, data);
BX_NOTIFY_LIN_MEMORY_ACCESS(laddr, BX_CPU_THIS_PTR address_xlation.paddress1,
BX_CPU_THIS_PTR address_xlation.len1, tlbEntry->get_memtype(),
xlate_rw, (Bit8u*) data);
access_read_physical(BX_CPU_THIS_PTR address_xlation.paddress2,
BX_CPU_THIS_PTR address_xlation.len2,
((Bit8u*)data) + BX_CPU_THIS_PTR address_xlation.len1);
BX_NOTIFY_LIN_MEMORY_ACCESS(laddr2, BX_CPU_THIS_PTR address_xlation.paddress2,
BX_CPU_THIS_PTR address_xlation.len2, tlbEntry2->get_memtype(),
xlate_rw, ((Bit8u*)data) + BX_CPU_THIS_PTR address_xlation.len1);
#else // BX_BIG_ENDIAN
access_read_physical(BX_CPU_THIS_PTR address_xlation.paddress1,
BX_CPU_THIS_PTR address_xlation.len1,
((Bit8u*)data) + (len - BX_CPU_THIS_PTR address_xlation.len1));
BX_NOTIFY_LIN_MEMORY_ACCESS(laddr, BX_CPU_THIS_PTR address_xlation.paddress1,
BX_CPU_THIS_PTR address_xlation.len1, tlbEntry->get_memtype(),
xlate_rw, ((Bit8u*)data) + (len - BX_CPU_THIS_PTR address_xlation.len1));
access_read_physical(BX_CPU_THIS_PTR address_xlation.paddress2,
BX_CPU_THIS_PTR address_xlation.len2, data);
BX_NOTIFY_LIN_MEMORY_ACCESS(laddr2, BX_CPU_THIS_PTR address_xlation.paddress2,
BX_CPU_THIS_PTR address_xlation.len2, tlbEntry2->get_memtype(),
xlate_rw, (Bit8u*) data);
#endif
#if BX_X86_DEBUGGER
hwbreakpoint_match(laddr, BX_CPU_THIS_PTR address_xlation.len1, xlate_rw);
hwbreakpoint_match(laddr2, BX_CPU_THIS_PTR address_xlation.len2, xlate_rw);
#endif
}
return 0;
}
void BX_CPU_C::access_write_physical(bx_phy_address paddr, unsigned len, void *data)
{
#if BX_SUPPORT_VMX && BX_SUPPORT_X86_64
if (is_virtual_apic_page(paddr)) {
VMX_Virtual_Apic_Write(paddr, len, data);
return;
}
#endif
#if BX_SUPPORT_APIC
if (BX_CPU_THIS_PTR lapic.is_selected(paddr)) {
BX_CPU_THIS_PTR lapic.write(paddr, data, len);
return;
}
#endif
BX_MEM(0)->writePhysicalPage(BX_CPU_THIS, paddr, len, data);
}
void BX_CPU_C::access_read_physical(bx_phy_address paddr, unsigned len, void *data)
{
#if BX_SUPPORT_VMX && BX_SUPPORT_X86_64
if (is_virtual_apic_page(paddr)) {
paddr = VMX_Virtual_Apic_Read(paddr, len, data);
}
#endif
#if BX_SUPPORT_APIC
if (BX_CPU_THIS_PTR lapic.is_selected(paddr)) {
BX_CPU_THIS_PTR lapic.read(paddr, data, len);
return;
}
#endif
BX_MEM(0)->readPhysicalPage(BX_CPU_THIS, paddr, len, data);
}
bx_hostpageaddr_t BX_CPU_C::getHostMemAddr(bx_phy_address paddr, unsigned rw)
{
#if BX_SUPPORT_VMX && BX_SUPPORT_X86_64
if (is_virtual_apic_page(paddr))
return 0; // Do not allow direct access to virtual apic page
#endif
#if BX_SUPPORT_APIC
if (BX_CPU_THIS_PTR lapic.is_selected(paddr))
return 0; // Vetoed! APIC address space
#endif
return (bx_hostpageaddr_t) BX_MEM(0)->getHostMemAddr(BX_CPU_THIS, paddr, rw);
}
#if BX_LARGE_RAMFILE
bx_bool BX_CPU_C::check_addr_in_tlb_buffers(const Bit8u *addr, const Bit8u *end)
{
#if BX_SUPPORT_VMX
if (BX_CPU_THIS_PTR vmcshostptr) {
if ((BX_CPU_THIS_PTR vmcshostptr >= (const bx_hostpageaddr_t)addr) &&
(BX_CPU_THIS_PTR vmcshostptr < (const bx_hostpageaddr_t)end)) return true;
}
#endif
#if BX_SUPPORT_SVM
if (BX_CPU_THIS_PTR vmcbhostptr) {
if ((BX_CPU_THIS_PTR vmcbhostptr >= (const bx_hostpageaddr_t)addr) &&
(BX_CPU_THIS_PTR vmcbhostptr < (const bx_hostpageaddr_t)end)) return true;
}
#endif
for (unsigned tlb_entry_num=0; tlb_entry_num < BX_DTLB_SIZE; tlb_entry_num++) {
bx_TLB_entry *tlbEntry = &BX_CPU_THIS_PTR DTLB.entry[tlb_entry_num];
if (tlbEntry->valid()) {
if ((tlbEntry->hostPageAddr >= (const bx_hostpageaddr_t)addr) &&
(tlbEntry->hostPageAddr < (const bx_hostpageaddr_t)end))
return true;
}
}
for (unsigned tlb_entry_num=0; tlb_entry_num < BX_ITLB_SIZE; tlb_entry_num++) {
bx_TLB_entry *tlbEntry = &BX_CPU_THIS_PTR ITLB.entry[tlb_entry_num];
if (tlbEntry->valid()) {
if ((tlbEntry->hostPageAddr >= (const bx_hostpageaddr_t)addr) &&
(tlbEntry->hostPageAddr < (const bx_hostpageaddr_t)end))
return true;
}
}
return false;
}
#endif