mirrors/qemu
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
0792e6c88d
qemu/target/i386/tcg/sysemu/excp_helper.c
Lara Lazier 52fb8ad37a target/i386: Added vVMLOAD and vVMSAVE feature 
The feature allows the VMSAVE and VMLOAD instructions to execute in guest mode without
causing a VMEXIT. (APM2 15.33.1)

Signed-off-by: Lara Lazier <laramglazier@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-13 13:56:26 +02:00

472 lines
15 KiB
C
Raw Blame History

/*
* x86 exception helpers - sysemu code
*
* Copyright (c) 2003 Fabrice Bellard
*
* 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 2.1 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, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
#include "cpu.h"
#include "tcg/helper-tcg.h"
int get_pg_mode(CPUX86State *env)
{
int pg_mode = 0;
if (env->cr[0] & CR0_WP_MASK) {
pg_mode |= PG_MODE_WP;
}
if (env->cr[4] & CR4_PAE_MASK) {
pg_mode |= PG_MODE_PAE;
}
if (env->cr[4] & CR4_PSE_MASK) {
pg_mode |= PG_MODE_PSE;
}
if (env->cr[4] & CR4_PKE_MASK) {
pg_mode |= PG_MODE_PKE;
}
if (env->cr[4] & CR4_PKS_MASK) {
pg_mode |= PG_MODE_PKS;
}
if (env->cr[4] & CR4_SMEP_MASK) {
pg_mode |= PG_MODE_SMEP;
}
if (env->cr[4] & CR4_LA57_MASK) {
pg_mode |= PG_MODE_LA57;
}
if (env->hflags & HF_LMA_MASK) {
pg_mode |= PG_MODE_LMA;
}
if (env->efer & MSR_EFER_NXE) {
pg_mode |= PG_MODE_NXE;
}
return pg_mode;
}
#define PG_ERROR_OK (-1)
typedef hwaddr (*MMUTranslateFunc)(CPUState *cs, hwaddr gphys, MMUAccessType access_type,
int *prot);
#define GET_HPHYS(cs, gpa, access_type, prot) \
(get_hphys_func ? get_hphys_func(cs, gpa, access_type, prot) : gpa)
static int mmu_translate(CPUState *cs, hwaddr addr, MMUTranslateFunc get_hphys_func,
uint64_t cr3, int is_write1, int mmu_idx, int pg_mode,
hwaddr *xlat, int *page_size, int *prot)
{
X86CPU *cpu = X86_CPU(cs);
CPUX86State *env = &cpu->env;
uint64_t ptep, pte;
int32_t a20_mask;
target_ulong pde_addr, pte_addr;
int error_code = 0;
int is_dirty, is_write, is_user;
uint64_t rsvd_mask = PG_ADDRESS_MASK & ~MAKE_64BIT_MASK(0, cpu->phys_bits);
uint32_t page_offset;
uint32_t pkr;
is_user = (mmu_idx == MMU_USER_IDX);
is_write = is_write1 & 1;
a20_mask = x86_get_a20_mask(env);
if (!(pg_mode & PG_MODE_NXE)) {
rsvd_mask |= PG_NX_MASK;
}
if (pg_mode & PG_MODE_PAE) {
uint64_t pde, pdpe;
target_ulong pdpe_addr;
#ifdef TARGET_X86_64
if (env->hflags & HF_LMA_MASK) {
bool la57 = pg_mode & PG_MODE_LA57;
uint64_t pml5e_addr, pml5e;
uint64_t pml4e_addr, pml4e;
int32_t sext;
/* test virtual address sign extension */
sext = la57 ? (int64_t)addr >> 56 : (int64_t)addr >> 47;
if (get_hphys_func && sext != 0 && sext != -1) {
env->error_code = 0;
cs->exception_index = EXCP0D_GPF;
return 1;
}
if (la57) {
pml5e_addr = ((cr3 & ~0xfff) +
(((addr >> 48) & 0x1ff) << 3)) & a20_mask;
pml5e_addr = GET_HPHYS(cs, pml5e_addr, MMU_DATA_STORE, NULL);
pml5e = x86_ldq_phys(cs, pml5e_addr);
if (!(pml5e & PG_PRESENT_MASK)) {
goto do_fault;
}
if (pml5e & (rsvd_mask | PG_PSE_MASK)) {
goto do_fault_rsvd;
}
if (!(pml5e & PG_ACCESSED_MASK)) {
pml5e |= PG_ACCESSED_MASK;
x86_stl_phys_notdirty(cs, pml5e_addr, pml5e);
}
ptep = pml5e ^ PG_NX_MASK;
} else {
pml5e = cr3;
ptep = PG_NX_MASK | PG_USER_MASK | PG_RW_MASK;
}
pml4e_addr = ((pml5e & PG_ADDRESS_MASK) +
(((addr >> 39) & 0x1ff) << 3)) & a20_mask;
pml4e_addr = GET_HPHYS(cs, pml4e_addr, MMU_DATA_STORE, NULL);
pml4e = x86_ldq_phys(cs, pml4e_addr);
if (!(pml4e & PG_PRESENT_MASK)) {
goto do_fault;
}
if (pml4e & (rsvd_mask | PG_PSE_MASK)) {
goto do_fault_rsvd;
}
if (!(pml4e & PG_ACCESSED_MASK)) {
pml4e |= PG_ACCESSED_MASK;
x86_stl_phys_notdirty(cs, pml4e_addr, pml4e);
}
ptep &= pml4e ^ PG_NX_MASK;
pdpe_addr = ((pml4e & PG_ADDRESS_MASK) + (((addr >> 30) & 0x1ff) << 3)) &
a20_mask;
pdpe_addr = GET_HPHYS(cs, pdpe_addr, MMU_DATA_STORE, NULL);
pdpe = x86_ldq_phys(cs, pdpe_addr);
if (!(pdpe & PG_PRESENT_MASK)) {
goto do_fault;
}
if (pdpe & rsvd_mask) {
goto do_fault_rsvd;
}
ptep &= pdpe ^ PG_NX_MASK;
if (!(pdpe & PG_ACCESSED_MASK)) {
pdpe |= PG_ACCESSED_MASK;
x86_stl_phys_notdirty(cs, pdpe_addr, pdpe);
}
if (pdpe & PG_PSE_MASK) {
/* 1 GB page */
*page_size = 1024 * 1024 * 1024;
pte_addr = pdpe_addr;
pte = pdpe;
goto do_check_protect;
}
} else
#endif
{
/* XXX: load them when cr3 is loaded ? */
pdpe_addr = ((cr3 & ~0x1f) + ((addr >> 27) & 0x18)) &
a20_mask;
pdpe_addr = GET_HPHYS(cs, pdpe_addr, MMU_DATA_STORE, NULL);
pdpe = x86_ldq_phys(cs, pdpe_addr);
if (!(pdpe & PG_PRESENT_MASK)) {
goto do_fault;
}
rsvd_mask |= PG_HI_USER_MASK;
if (pdpe & (rsvd_mask | PG_NX_MASK)) {
goto do_fault_rsvd;
}
ptep = PG_NX_MASK | PG_USER_MASK | PG_RW_MASK;
}
pde_addr = ((pdpe & PG_ADDRESS_MASK) + (((addr >> 21) & 0x1ff) << 3)) &
a20_mask;
pde_addr = GET_HPHYS(cs, pde_addr, MMU_DATA_STORE, NULL);
pde = x86_ldq_phys(cs, pde_addr);
if (!(pde & PG_PRESENT_MASK)) {
goto do_fault;
}
if (pde & rsvd_mask) {
goto do_fault_rsvd;
}
ptep &= pde ^ PG_NX_MASK;
if (pde & PG_PSE_MASK) {
/* 2 MB page */
*page_size = 2048 * 1024;
pte_addr = pde_addr;
pte = pde;
goto do_check_protect;
}
/* 4 KB page */
if (!(pde & PG_ACCESSED_MASK)) {
pde |= PG_ACCESSED_MASK;
x86_stl_phys_notdirty(cs, pde_addr, pde);
}
pte_addr = ((pde & PG_ADDRESS_MASK) + (((addr >> 12) & 0x1ff) << 3)) &
a20_mask;
pte_addr = GET_HPHYS(cs, pte_addr, MMU_DATA_STORE, NULL);
pte = x86_ldq_phys(cs, pte_addr);
if (!(pte & PG_PRESENT_MASK)) {
goto do_fault;
}
if (pte & rsvd_mask) {
goto do_fault_rsvd;
}
/* combine pde and pte nx, user and rw protections */
ptep &= pte ^ PG_NX_MASK;
*page_size = 4096;
} else {
uint32_t pde;
/* page directory entry */
pde_addr = ((cr3 & ~0xfff) + ((addr >> 20) & 0xffc)) &
a20_mask;
pde_addr = GET_HPHYS(cs, pde_addr, MMU_DATA_STORE, NULL);
pde = x86_ldl_phys(cs, pde_addr);
if (!(pde & PG_PRESENT_MASK)) {
goto do_fault;
}
ptep = pde | PG_NX_MASK;
/* if PSE bit is set, then we use a 4MB page */
if ((pde & PG_PSE_MASK) && (pg_mode & PG_MODE_PSE)) {
*page_size = 4096 * 1024;
pte_addr = pde_addr;
/* Bits 20-13 provide bits 39-32 of the address, bit 21 is reserved.
* Leave bits 20-13 in place for setting accessed/dirty bits below.
*/
pte = pde | ((pde & 0x1fe000LL) << (32 - 13));
rsvd_mask = 0x200000;
goto do_check_protect_pse36;
}
if (!(pde & PG_ACCESSED_MASK)) {
pde |= PG_ACCESSED_MASK;
x86_stl_phys_notdirty(cs, pde_addr, pde);
}
/* page directory entry */
pte_addr = ((pde & ~0xfff) + ((addr >> 10) & 0xffc)) &
a20_mask;
pte_addr = GET_HPHYS(cs, pte_addr, MMU_DATA_STORE, NULL);
pte = x86_ldl_phys(cs, pte_addr);
if (!(pte & PG_PRESENT_MASK)) {
goto do_fault;
}
/* combine pde and pte user and rw protections */
ptep &= pte | PG_NX_MASK;
*page_size = 4096;
rsvd_mask = 0;
}
do_check_protect:
rsvd_mask |= (*page_size - 1) & PG_ADDRESS_MASK & ~PG_PSE_PAT_MASK;
do_check_protect_pse36:
if (pte & rsvd_mask) {
goto do_fault_rsvd;
}
ptep ^= PG_NX_MASK;
/* can the page can be put in the TLB? prot will tell us */
if (is_user && !(ptep & PG_USER_MASK)) {
goto do_fault_protect;
}
*prot = 0;
if (mmu_idx != MMU_KSMAP_IDX || !(ptep & PG_USER_MASK)) {
*prot |= PAGE_READ;
if ((ptep & PG_RW_MASK) || !(is_user || (pg_mode & PG_MODE_WP))) {
*prot |= PAGE_WRITE;
}
}
if (!(ptep & PG_NX_MASK) &&
(mmu_idx == MMU_USER_IDX ||
!((pg_mode & PG_MODE_SMEP) && (ptep & PG_USER_MASK)))) {
*prot |= PAGE_EXEC;
}
if (!(env->hflags & HF_LMA_MASK)) {
pkr = 0;
} else if (ptep & PG_USER_MASK) {
pkr = pg_mode & PG_MODE_PKE ? env->pkru : 0;
} else {
pkr = pg_mode & PG_MODE_PKS ? env->pkrs : 0;
}
if (pkr) {
uint32_t pk = (pte & PG_PKRU_MASK) >> PG_PKRU_BIT;
uint32_t pkr_ad = (pkr >> pk * 2) & 1;
uint32_t pkr_wd = (pkr >> pk * 2) & 2;
uint32_t pkr_prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
if (pkr_ad) {
pkr_prot &= ~(PAGE_READ | PAGE_WRITE);
} else if (pkr_wd && (is_user || (pg_mode & PG_MODE_WP))) {
pkr_prot &= ~PAGE_WRITE;
}
*prot &= pkr_prot;
if ((pkr_prot & (1 << is_write1)) == 0) {
assert(is_write1 != 2);
error_code |= PG_ERROR_PK_MASK;
goto do_fault_protect;
}
}
if ((*prot & (1 << is_write1)) == 0) {
goto do_fault_protect;
}
/* yes, it can! */
is_dirty = is_write && !(pte & PG_DIRTY_MASK);
if (!(pte & PG_ACCESSED_MASK) || is_dirty) {
pte |= PG_ACCESSED_MASK;
if (is_dirty) {
pte |= PG_DIRTY_MASK;
}
x86_stl_phys_notdirty(cs, pte_addr, pte);
}
if (!(pte & PG_DIRTY_MASK)) {
/* only set write access if already dirty... otherwise wait
for dirty access */
assert(!is_write);
*prot &= ~PAGE_WRITE;
}
pte = pte & a20_mask;
/* align to page_size */
pte &= PG_ADDRESS_MASK & ~(*page_size - 1);
page_offset = addr & (*page_size - 1);
*xlat = GET_HPHYS(cs, pte + page_offset, is_write1, prot);
return PG_ERROR_OK;
do_fault_rsvd:
error_code |= PG_ERROR_RSVD_MASK;
do_fault_protect:
error_code |= PG_ERROR_P_MASK;
do_fault:
error_code |= (is_write << PG_ERROR_W_BIT);
if (is_user)
error_code |= PG_ERROR_U_MASK;
if (is_write1 == 2 &&
(((pg_mode & PG_MODE_NXE) && (pg_mode & PG_MODE_PAE)) ||
(pg_mode & PG_MODE_SMEP)))
error_code |= PG_ERROR_I_D_MASK;
return error_code;
}
hwaddr get_hphys(CPUState *cs, hwaddr gphys, MMUAccessType access_type,
int *prot)
{
CPUX86State *env = &X86_CPU(cs)->env;
uint64_t exit_info_1;
int page_size;
int next_prot;
hwaddr hphys;
if (likely(!(env->hflags2 & HF2_NPT_MASK))) {
return gphys;
}
exit_info_1 = mmu_translate(cs, gphys, NULL, env->nested_cr3,
access_type, MMU_USER_IDX, env->nested_pg_mode,
&hphys, &page_size, &next_prot);
if (exit_info_1 == PG_ERROR_OK) {
if (prot) {
*prot &= next_prot;
}
return hphys;
}
x86_stq_phys(cs, env->vm_vmcb + offsetof(struct vmcb, control.exit_info_2),
gphys);
if (prot) {
exit_info_1 |= SVM_NPTEXIT_GPA;
} else { /* page table access */
exit_info_1 |= SVM_NPTEXIT_GPT;
}
cpu_vmexit(env, SVM_EXIT_NPF, exit_info_1, env->retaddr);
}
/* return value:
* -1 = cannot handle fault
* 0 = nothing more to do
* 1 = generate PF fault
*/
static int handle_mmu_fault(CPUState *cs, vaddr addr, int size,
int is_write1, int mmu_idx)
{
X86CPU *cpu = X86_CPU(cs);
CPUX86State *env = &cpu->env;
int error_code = PG_ERROR_OK;
int pg_mode, prot, page_size;
hwaddr paddr;
hwaddr vaddr;
#if defined(DEBUG_MMU)
printf("MMU fault: addr=%" VADDR_PRIx " w=%d mmu=%d eip=" TARGET_FMT_lx "\n",
addr, is_write1, mmu_idx, env->eip);
#endif
if (!(env->cr[0] & CR0_PG_MASK)) {
paddr = addr;
#ifdef TARGET_X86_64
if (!(env->hflags & HF_LMA_MASK)) {
/* Without long mode we can only address 32bits in real mode */
paddr = (uint32_t)paddr;
}
#endif
prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
page_size = 4096;
} else {
pg_mode = get_pg_mode(env);
error_code = mmu_translate(cs, addr, get_hphys, env->cr[3], is_write1,
mmu_idx, pg_mode,
&paddr, &page_size, &prot);
}
if (error_code == PG_ERROR_OK) {
/* Even if 4MB pages, we map only one 4KB page in the cache to
avoid filling it too fast */
vaddr = addr & TARGET_PAGE_MASK;
paddr &= TARGET_PAGE_MASK;
assert(prot & (1 << is_write1));
tlb_set_page_with_attrs(cs, vaddr, paddr, cpu_get_mem_attrs(env),
prot, mmu_idx, page_size);
return 0;
} else {
if (env->intercept_exceptions & (1 << EXCP0E_PAGE)) {
/* cr2 is not modified in case of exceptions */
x86_stq_phys(cs,
env->vm_vmcb + offsetof(struct vmcb, control.exit_info_2),
addr);
} else {
env->cr[2] = addr;
}
env->error_code = error_code;
cs->exception_index = EXCP0E_PAGE;
return 1;
}
}
bool x86_cpu_tlb_fill(CPUState *cs, vaddr addr, int size,
MMUAccessType access_type, int mmu_idx,
bool probe, uintptr_t retaddr)
{
X86CPU *cpu = X86_CPU(cs);
CPUX86State *env = &cpu->env;
env->retaddr = retaddr;
if (handle_mmu_fault(cs, addr, size, access_type, mmu_idx)) {
/* FIXME: On error in get_hphys we have already jumped out. */
g_assert(!probe);
raise_exception_err_ra(env, cs->exception_index,
env->error_code, retaddr);
}
return true;
}
Reference in New Issue View Git Blame Copy Permalink