mirrors/qemu
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
0fd7432533
qemu/target/riscv/cpu_helper.c
Georg Kotheimer ec352d0cab target/riscv: Add proper two-stage lookup exception detection 
The current two-stage lookup detection in riscv_cpu_do_interrupt falls
short of its purpose, as all it checks is whether two-stage address
translation either via the hypervisor-load store instructions or the
MPRV feature would be allowed.

What we really need instead is whether two-stage address translation was
active when the exception was raised. However, in riscv_cpu_do_interrupt
we do not have the information to reliably detect this. Therefore, when
we raise a memory fault exception we have to record whether two-stage
address translation is active.

Signed-off-by: Georg Kotheimer <georg.kotheimer@kernkonzept.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20210319141459.1196741-1-georg.kotheimer@kernkonzept.com
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
2021-03-22 21:54:40 -04:00

1074 lines
36 KiB
C
Raw Blame History

/*
* RISC-V CPU helpers for qemu.
*
* Copyright (c) 2016-2017 Sagar Karandikar, sagark@eecs.berkeley.edu
* Copyright (c) 2017-2018 SiFive, Inc.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2 or later, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
#include "qemu/log.h"
#include "qemu/main-loop.h"
#include "cpu.h"
#include "exec/exec-all.h"
#include "tcg/tcg-op.h"
#include "trace.h"
#include "semihosting/common-semi.h"
int riscv_cpu_mmu_index(CPURISCVState *env, bool ifetch)
{
#ifdef CONFIG_USER_ONLY
return 0;
#else
return env->priv;
#endif
}
#ifndef CONFIG_USER_ONLY
static int riscv_cpu_local_irq_pending(CPURISCVState *env)
{
target_ulong irqs;
target_ulong mstatus_mie = get_field(env->mstatus, MSTATUS_MIE);
target_ulong mstatus_sie = get_field(env->mstatus, MSTATUS_SIE);
target_ulong hs_mstatus_sie = get_field(env->mstatus_hs, MSTATUS_SIE);
target_ulong pending = env->mip & env->mie &
~(MIP_VSSIP | MIP_VSTIP | MIP_VSEIP);
target_ulong vspending = (env->mip & env->mie &
(MIP_VSSIP | MIP_VSTIP | MIP_VSEIP));
target_ulong mie = env->priv < PRV_M ||
(env->priv == PRV_M && mstatus_mie);
target_ulong sie = env->priv < PRV_S ||
(env->priv == PRV_S && mstatus_sie);
target_ulong hs_sie = env->priv < PRV_S ||
(env->priv == PRV_S && hs_mstatus_sie);
if (riscv_cpu_virt_enabled(env)) {
target_ulong pending_hs_irq = pending & -hs_sie;
if (pending_hs_irq) {
riscv_cpu_set_force_hs_excep(env, FORCE_HS_EXCEP);
return ctz64(pending_hs_irq);
}
pending = vspending;
}
irqs = (pending & ~env->mideleg & -mie) | (pending & env->mideleg & -sie);
if (irqs) {
return ctz64(irqs); /* since non-zero */
} else {
return EXCP_NONE; /* indicates no pending interrupt */
}
}
#endif
bool riscv_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
{
#if !defined(CONFIG_USER_ONLY)
if (interrupt_request & CPU_INTERRUPT_HARD) {
RISCVCPU *cpu = RISCV_CPU(cs);
CPURISCVState *env = &cpu->env;
int interruptno = riscv_cpu_local_irq_pending(env);
if (interruptno >= 0) {
cs->exception_index = RISCV_EXCP_INT_FLAG | interruptno;
riscv_cpu_do_interrupt(cs);
return true;
}
}
#endif
return false;
}
#if !defined(CONFIG_USER_ONLY)
/* Return true is floating point support is currently enabled */
bool riscv_cpu_fp_enabled(CPURISCVState *env)
{
if (env->mstatus & MSTATUS_FS) {
if (riscv_cpu_virt_enabled(env) && !(env->mstatus_hs & MSTATUS_FS)) {
return false;
}
return true;
}
return false;
}
void riscv_cpu_swap_hypervisor_regs(CPURISCVState *env)
{
uint64_t mstatus_mask = MSTATUS_MXR | MSTATUS_SUM | MSTATUS_FS |
MSTATUS_SPP | MSTATUS_SPIE | MSTATUS_SIE |
MSTATUS64_UXL;
bool current_virt = riscv_cpu_virt_enabled(env);
g_assert(riscv_has_ext(env, RVH));
if (current_virt) {
/* Current V=1 and we are about to change to V=0 */
env->vsstatus = env->mstatus & mstatus_mask;
env->mstatus &= ~mstatus_mask;
env->mstatus |= env->mstatus_hs;
env->vstvec = env->stvec;
env->stvec = env->stvec_hs;
env->vsscratch = env->sscratch;
env->sscratch = env->sscratch_hs;
env->vsepc = env->sepc;
env->sepc = env->sepc_hs;
env->vscause = env->scause;
env->scause = env->scause_hs;
env->vstval = env->sbadaddr;
env->sbadaddr = env->stval_hs;
env->vsatp = env->satp;
env->satp = env->satp_hs;
} else {
/* Current V=0 and we are about to change to V=1 */
env->mstatus_hs = env->mstatus & mstatus_mask;
env->mstatus &= ~mstatus_mask;
env->mstatus |= env->vsstatus;
env->stvec_hs = env->stvec;
env->stvec = env->vstvec;
env->sscratch_hs = env->sscratch;
env->sscratch = env->vsscratch;
env->sepc_hs = env->sepc;
env->sepc = env->vsepc;
env->scause_hs = env->scause;
env->scause = env->vscause;
env->stval_hs = env->sbadaddr;
env->sbadaddr = env->vstval;
env->satp_hs = env->satp;
env->satp = env->vsatp;
}
}
bool riscv_cpu_virt_enabled(CPURISCVState *env)
{
if (!riscv_has_ext(env, RVH)) {
return false;
}
return get_field(env->virt, VIRT_ONOFF);
}
void riscv_cpu_set_virt_enabled(CPURISCVState *env, bool enable)
{
if (!riscv_has_ext(env, RVH)) {
return;
}
/* Flush the TLB on all virt mode changes. */
if (get_field(env->virt, VIRT_ONOFF) != enable) {
tlb_flush(env_cpu(env));
}
env->virt = set_field(env->virt, VIRT_ONOFF, enable);
}
bool riscv_cpu_force_hs_excep_enabled(CPURISCVState *env)
{
if (!riscv_has_ext(env, RVH)) {
return false;
}
return get_field(env->virt, FORCE_HS_EXCEP);
}
void riscv_cpu_set_force_hs_excep(CPURISCVState *env, bool enable)
{
if (!riscv_has_ext(env, RVH)) {
return;
}
env->virt = set_field(env->virt, FORCE_HS_EXCEP, enable);
}
bool riscv_cpu_two_stage_lookup(int mmu_idx)
{
return mmu_idx & TB_FLAGS_PRIV_HYP_ACCESS_MASK;
}
int riscv_cpu_claim_interrupts(RISCVCPU *cpu, uint32_t interrupts)
{
CPURISCVState *env = &cpu->env;
if (env->miclaim & interrupts) {
return -1;
} else {
env->miclaim |= interrupts;
return 0;
}
}
uint32_t riscv_cpu_update_mip(RISCVCPU *cpu, uint32_t mask, uint32_t value)
{
CPURISCVState *env = &cpu->env;
CPUState *cs = CPU(cpu);
uint32_t old = env->mip;
bool locked = false;
if (!qemu_mutex_iothread_locked()) {
locked = true;
qemu_mutex_lock_iothread();
}
env->mip = (env->mip & ~mask) | (value & mask);
if (env->mip) {
cpu_interrupt(cs, CPU_INTERRUPT_HARD);
} else {
cpu_reset_interrupt(cs, CPU_INTERRUPT_HARD);
}
if (locked) {
qemu_mutex_unlock_iothread();
}
return old;
}
void riscv_cpu_set_rdtime_fn(CPURISCVState *env, uint64_t (*fn)(uint32_t),
uint32_t arg)
{
env->rdtime_fn = fn;
env->rdtime_fn_arg = arg;
}
void riscv_cpu_set_mode(CPURISCVState *env, target_ulong newpriv)
{
if (newpriv > PRV_M) {
g_assert_not_reached();
}
if (newpriv == PRV_H) {
newpriv = PRV_U;
}
/* tlb_flush is unnecessary as mode is contained in mmu_idx */
env->priv = newpriv;
/*
* Clear the load reservation - otherwise a reservation placed in one
* context/process can be used by another, resulting in an SC succeeding
* incorrectly. Version 2.2 of the ISA specification explicitly requires
* this behaviour, while later revisions say that the kernel "should" use
* an SC instruction to force the yielding of a load reservation on a
* preemptive context switch. As a result, do both.
*/
env->load_res = -1;
}
/*
* get_physical_address_pmp - check PMP permission for this physical address
*
* Match the PMP region and check permission for this physical address and it's
* TLB page. Returns 0 if the permission checking was successful
*
* @env: CPURISCVState
* @prot: The returned protection attributes
* @tlb_size: TLB page size containing addr. It could be modified after PMP
* permission checking. NULL if not set TLB page for addr.
* @addr: The physical address to be checked permission
* @access_type: The type of MMU access
* @mode: Indicates current privilege level.
*/
static int get_physical_address_pmp(CPURISCVState *env, int *prot,
target_ulong *tlb_size, hwaddr addr,
int size, MMUAccessType access_type,
int mode)
{
pmp_priv_t pmp_priv;
target_ulong tlb_size_pmp = 0;
if (!riscv_feature(env, RISCV_FEATURE_PMP)) {
*prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
return TRANSLATE_SUCCESS;
}
if (!pmp_hart_has_privs(env, addr, size, 1 << access_type, &pmp_priv,
mode)) {
*prot = 0;
return TRANSLATE_PMP_FAIL;
}
*prot = pmp_priv_to_page_prot(pmp_priv);
if (tlb_size != NULL) {
if (pmp_is_range_in_tlb(env, addr & ~(*tlb_size - 1), &tlb_size_pmp)) {
*tlb_size = tlb_size_pmp;
}
}
return TRANSLATE_SUCCESS;
}
/* get_physical_address - get the physical address for this virtual address
*
* Do a page table walk to obtain the physical address corresponding to a
* virtual address. Returns 0 if the translation was successful
*
* Adapted from Spike's mmu_t::translate and mmu_t::walk
*
* @env: CPURISCVState
* @physical: This will be set to the calculated physical address
* @prot: The returned protection attributes
* @addr: The virtual address to be translated
* @fault_pte_addr: If not NULL, this will be set to fault pte address
* when a error occurs on pte address translation.
* This will already be shifted to match htval.
* @access_type: The type of MMU access
* @mmu_idx: Indicates current privilege level
* @first_stage: Are we in first stage translation?
* Second stage is used for hypervisor guest translation
* @two_stage: Are we going to perform two stage translation
*/
static int get_physical_address(CPURISCVState *env, hwaddr *physical,
int *prot, target_ulong addr,
target_ulong *fault_pte_addr,
int access_type, int mmu_idx,
bool first_stage, bool two_stage)
{
/* NOTE: the env->pc value visible here will not be
* correct, but the value visible to the exception handler
* (riscv_cpu_do_interrupt) is correct */
MemTxResult res;
MemTxAttrs attrs = MEMTXATTRS_UNSPECIFIED;
int mode = mmu_idx & TB_FLAGS_PRIV_MMU_MASK;
bool use_background = false;
/*
* Check if we should use the background registers for the two
* stage translation. We don't need to check if we actually need
* two stage translation as that happened before this function
* was called. Background registers will be used if the guest has
* forced a two stage translation to be on (in HS or M mode).
*/
if (!riscv_cpu_virt_enabled(env) && two_stage) {
use_background = true;
}
/* MPRV does not affect the virtual-machine load/store
instructions, HLV, HLVX, and HSV. */
if (riscv_cpu_two_stage_lookup(mmu_idx)) {
mode = get_field(env->hstatus, HSTATUS_SPVP);
} else if (mode == PRV_M && access_type != MMU_INST_FETCH) {
if (get_field(env->mstatus, MSTATUS_MPRV)) {
mode = get_field(env->mstatus, MSTATUS_MPP);
}
}
if (first_stage == false) {
/* We are in stage 2 translation, this is similar to stage 1. */
/* Stage 2 is always taken as U-mode */
mode = PRV_U;
}
if (mode == PRV_M || !riscv_feature(env, RISCV_FEATURE_MMU)) {
*physical = addr;
*prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
return TRANSLATE_SUCCESS;
}
*prot = 0;
hwaddr base;
int levels, ptidxbits, ptesize, vm, sum, mxr, widened;
if (first_stage == true) {
mxr = get_field(env->mstatus, MSTATUS_MXR);
} else {
mxr = get_field(env->vsstatus, MSTATUS_MXR);
}
if (first_stage == true) {
if (use_background) {
base = (hwaddr)get_field(env->vsatp, SATP_PPN) << PGSHIFT;
vm = get_field(env->vsatp, SATP_MODE);
} else {
base = (hwaddr)get_field(env->satp, SATP_PPN) << PGSHIFT;
vm = get_field(env->satp, SATP_MODE);
}
widened = 0;
} else {
base = (hwaddr)get_field(env->hgatp, HGATP_PPN) << PGSHIFT;
vm = get_field(env->hgatp, HGATP_MODE);
widened = 2;
}
/* status.SUM will be ignored if execute on background */
sum = get_field(env->mstatus, MSTATUS_SUM) || use_background;
switch (vm) {
case VM_1_10_SV32:
levels = 2; ptidxbits = 10; ptesize = 4; break;
case VM_1_10_SV39:
levels = 3; ptidxbits = 9; ptesize = 8; break;
case VM_1_10_SV48:
levels = 4; ptidxbits = 9; ptesize = 8; break;
case VM_1_10_SV57:
levels = 5; ptidxbits = 9; ptesize = 8; break;
case VM_1_10_MBARE:
*physical = addr;
*prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
return TRANSLATE_SUCCESS;
default:
g_assert_not_reached();
}
CPUState *cs = env_cpu(env);
int va_bits = PGSHIFT + levels * ptidxbits + widened;
target_ulong mask, masked_msbs;
if (TARGET_LONG_BITS > (va_bits - 1)) {
mask = (1L << (TARGET_LONG_BITS - (va_bits - 1))) - 1;
} else {
mask = 0;
}
masked_msbs = (addr >> (va_bits - 1)) & mask;
if (masked_msbs != 0 && masked_msbs != mask) {
return TRANSLATE_FAIL;
}
int ptshift = (levels - 1) * ptidxbits;
int i;
#if !TCG_OVERSIZED_GUEST
restart:
#endif
for (i = 0; i < levels; i++, ptshift -= ptidxbits) {
target_ulong idx;
if (i == 0) {
idx = (addr >> (PGSHIFT + ptshift)) &
((1 << (ptidxbits + widened)) - 1);
} else {
idx = (addr >> (PGSHIFT + ptshift)) &
((1 << ptidxbits) - 1);
}
/* check that physical address of PTE is legal */
hwaddr pte_addr;
if (two_stage && first_stage) {
int vbase_prot;
hwaddr vbase;
/* Do the second stage translation on the base PTE address. */
int vbase_ret = get_physical_address(env, &vbase, &vbase_prot,
base, NULL, MMU_DATA_LOAD,
mmu_idx, false, true);
if (vbase_ret != TRANSLATE_SUCCESS) {
if (fault_pte_addr) {
*fault_pte_addr = (base + idx * ptesize) >> 2;
}
return TRANSLATE_G_STAGE_FAIL;
}
pte_addr = vbase + idx * ptesize;
} else {
pte_addr = base + idx * ptesize;
}
int pmp_prot;
int pmp_ret = get_physical_address_pmp(env, &pmp_prot, NULL, pte_addr,
sizeof(target_ulong),
MMU_DATA_LOAD, PRV_S);
if (pmp_ret != TRANSLATE_SUCCESS) {
return TRANSLATE_PMP_FAIL;
}
target_ulong pte;
if (riscv_cpu_is_32bit(env)) {
pte = address_space_ldl(cs->as, pte_addr, attrs, &res);
} else {
pte = address_space_ldq(cs->as, pte_addr, attrs, &res);
}
if (res != MEMTX_OK) {
return TRANSLATE_FAIL;
}
hwaddr ppn = pte >> PTE_PPN_SHIFT;
if (!(pte & PTE_V)) {
/* Invalid PTE */
return TRANSLATE_FAIL;
} else if (!(pte & (PTE_R | PTE_W | PTE_X))) {
/* Inner PTE, continue walking */
base = ppn << PGSHIFT;
} else if ((pte & (PTE_R | PTE_W | PTE_X)) == PTE_W) {
/* Reserved leaf PTE flags: PTE_W */
return TRANSLATE_FAIL;
} else if ((pte & (PTE_R | PTE_W | PTE_X)) == (PTE_W | PTE_X)) {
/* Reserved leaf PTE flags: PTE_W + PTE_X */
return TRANSLATE_FAIL;
} else if ((pte & PTE_U) && ((mode != PRV_U) &&
(!sum || access_type == MMU_INST_FETCH))) {
/* User PTE flags when not U mode and mstatus.SUM is not set,
or the access type is an instruction fetch */
return TRANSLATE_FAIL;
} else if (!(pte & PTE_U) && (mode != PRV_S)) {
/* Supervisor PTE flags when not S mode */
return TRANSLATE_FAIL;
} else if (ppn & ((1ULL << ptshift) - 1)) {
/* Misaligned PPN */
return TRANSLATE_FAIL;
} else if (access_type == MMU_DATA_LOAD && !((pte & PTE_R) ||
((pte & PTE_X) && mxr))) {
/* Read access check failed */
return TRANSLATE_FAIL;
} else if (access_type == MMU_DATA_STORE && !(pte & PTE_W)) {
/* Write access check failed */
return TRANSLATE_FAIL;
} else if (access_type == MMU_INST_FETCH && !(pte & PTE_X)) {
/* Fetch access check failed */
return TRANSLATE_FAIL;
} else {
/* if necessary, set accessed and dirty bits. */
target_ulong updated_pte = pte | PTE_A |
(access_type == MMU_DATA_STORE ? PTE_D : 0);
/* Page table updates need to be atomic with MTTCG enabled */
if (updated_pte != pte) {
/*
* - if accessed or dirty bits need updating, and the PTE is
* in RAM, then we do so atomically with a compare and swap.
* - if the PTE is in IO space or ROM, then it can't be updated
* and we return TRANSLATE_FAIL.
* - if the PTE changed by the time we went to update it, then
* it is no longer valid and we must re-walk the page table.
*/
MemoryRegion *mr;
hwaddr l = sizeof(target_ulong), addr1;
mr = address_space_translate(cs->as, pte_addr,
&addr1, &l, false, MEMTXATTRS_UNSPECIFIED);
if (memory_region_is_ram(mr)) {
target_ulong *pte_pa =
qemu_map_ram_ptr(mr->ram_block, addr1);
#if TCG_OVERSIZED_GUEST
/* MTTCG is not enabled on oversized TCG guests so
* page table updates do not need to be atomic */
*pte_pa = pte = updated_pte;
#else
target_ulong old_pte =
qatomic_cmpxchg(pte_pa, pte, updated_pte);
if (old_pte != pte) {
goto restart;
} else {
pte = updated_pte;
}
#endif
} else {
/* misconfigured PTE in ROM (AD bits are not preset) or
* PTE is in IO space and can't be updated atomically */
return TRANSLATE_FAIL;
}
}
/* for superpage mappings, make a fake leaf PTE for the TLB's
benefit. */
target_ulong vpn = addr >> PGSHIFT;
*physical = ((ppn | (vpn & ((1L << ptshift) - 1))) << PGSHIFT) |
(addr & ~TARGET_PAGE_MASK);
/* set permissions on the TLB entry */
if ((pte & PTE_R) || ((pte & PTE_X) && mxr)) {
*prot |= PAGE_READ;
}
if ((pte & PTE_X)) {
*prot |= PAGE_EXEC;
}
/* add write permission on stores or if the page is already dirty,
so that we TLB miss on later writes to update the dirty bit */
if ((pte & PTE_W) &&
(access_type == MMU_DATA_STORE || (pte & PTE_D))) {
*prot |= PAGE_WRITE;
}
return TRANSLATE_SUCCESS;
}
}
return TRANSLATE_FAIL;
}
static void raise_mmu_exception(CPURISCVState *env, target_ulong address,
MMUAccessType access_type, bool pmp_violation,
bool first_stage, bool two_stage)
{
CPUState *cs = env_cpu(env);
int page_fault_exceptions;
if (first_stage) {
page_fault_exceptions =
get_field(env->satp, SATP_MODE) != VM_1_10_MBARE &&
!pmp_violation;
} else {
page_fault_exceptions =
get_field(env->hgatp, HGATP_MODE) != VM_1_10_MBARE &&
!pmp_violation;
}
switch (access_type) {
case MMU_INST_FETCH:
if (riscv_cpu_virt_enabled(env) && !first_stage) {
cs->exception_index = RISCV_EXCP_INST_GUEST_PAGE_FAULT;
} else {
cs->exception_index = page_fault_exceptions ?
RISCV_EXCP_INST_PAGE_FAULT : RISCV_EXCP_INST_ACCESS_FAULT;
}
break;
case MMU_DATA_LOAD:
if (two_stage && !first_stage) {
cs->exception_index = RISCV_EXCP_LOAD_GUEST_ACCESS_FAULT;
} else {
cs->exception_index = page_fault_exceptions ?
RISCV_EXCP_LOAD_PAGE_FAULT : RISCV_EXCP_LOAD_ACCESS_FAULT;
}
break;
case MMU_DATA_STORE:
if (two_stage && !first_stage) {
cs->exception_index = RISCV_EXCP_STORE_GUEST_AMO_ACCESS_FAULT;
} else {
cs->exception_index = page_fault_exceptions ?
RISCV_EXCP_STORE_PAGE_FAULT : RISCV_EXCP_STORE_AMO_ACCESS_FAULT;
}
break;
default:
g_assert_not_reached();
}
env->badaddr = address;
env->two_stage_lookup = two_stage;
}
hwaddr riscv_cpu_get_phys_page_debug(CPUState *cs, vaddr addr)
{
RISCVCPU *cpu = RISCV_CPU(cs);
CPURISCVState *env = &cpu->env;
hwaddr phys_addr;
int prot;
int mmu_idx = cpu_mmu_index(&cpu->env, false);
if (get_physical_address(env, &phys_addr, &prot, addr, NULL, 0, mmu_idx,
true, riscv_cpu_virt_enabled(env))) {
return -1;
}
if (riscv_cpu_virt_enabled(env)) {
if (get_physical_address(env, &phys_addr, &prot, phys_addr, NULL,
0, mmu_idx, false, true)) {
return -1;
}
}
return phys_addr & TARGET_PAGE_MASK;
}
void riscv_cpu_do_transaction_failed(CPUState *cs, hwaddr physaddr,
vaddr addr, unsigned size,
MMUAccessType access_type,
int mmu_idx, MemTxAttrs attrs,
MemTxResult response, uintptr_t retaddr)
{
RISCVCPU *cpu = RISCV_CPU(cs);
CPURISCVState *env = &cpu->env;
if (access_type == MMU_DATA_STORE) {
cs->exception_index = RISCV_EXCP_STORE_AMO_ACCESS_FAULT;
} else {
cs->exception_index = RISCV_EXCP_LOAD_ACCESS_FAULT;
}
env->badaddr = addr;
env->two_stage_lookup = riscv_cpu_virt_enabled(env) ||
riscv_cpu_two_stage_lookup(mmu_idx);
riscv_raise_exception(&cpu->env, cs->exception_index, retaddr);
}
void riscv_cpu_do_unaligned_access(CPUState *cs, vaddr addr,
MMUAccessType access_type, int mmu_idx,
uintptr_t retaddr)
{
RISCVCPU *cpu = RISCV_CPU(cs);
CPURISCVState *env = &cpu->env;
switch (access_type) {
case MMU_INST_FETCH:
cs->exception_index = RISCV_EXCP_INST_ADDR_MIS;
break;
case MMU_DATA_LOAD:
cs->exception_index = RISCV_EXCP_LOAD_ADDR_MIS;
break;
case MMU_DATA_STORE:
cs->exception_index = RISCV_EXCP_STORE_AMO_ADDR_MIS;
break;
default:
g_assert_not_reached();
}
env->badaddr = addr;
env->two_stage_lookup = riscv_cpu_virt_enabled(env) ||
riscv_cpu_two_stage_lookup(mmu_idx);
riscv_raise_exception(env, cs->exception_index, retaddr);
}
#endif /* !CONFIG_USER_ONLY */
bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
MMUAccessType access_type, int mmu_idx,
bool probe, uintptr_t retaddr)
{
RISCVCPU *cpu = RISCV_CPU(cs);
CPURISCVState *env = &cpu->env;
#ifndef CONFIG_USER_ONLY
vaddr im_address;
hwaddr pa = 0;
int prot, prot2, prot_pmp;
bool pmp_violation = false;
bool first_stage_error = true;
bool two_stage_lookup = false;
int ret = TRANSLATE_FAIL;
int mode = mmu_idx;
/* default TLB page size */
target_ulong tlb_size = TARGET_PAGE_SIZE;
env->guest_phys_fault_addr = 0;
qemu_log_mask(CPU_LOG_MMU, "%s ad %" VADDR_PRIx " rw %d mmu_idx %d\n",
__func__, address, access_type, mmu_idx);
/* MPRV does not affect the virtual-machine load/store
instructions, HLV, HLVX, and HSV. */
if (riscv_cpu_two_stage_lookup(mmu_idx)) {
mode = get_field(env->hstatus, HSTATUS_SPVP);
} else if (mode == PRV_M && access_type != MMU_INST_FETCH &&
get_field(env->mstatus, MSTATUS_MPRV)) {
mode = get_field(env->mstatus, MSTATUS_MPP);
if (riscv_has_ext(env, RVH) && get_field(env->mstatus, MSTATUS_MPV)) {
two_stage_lookup = true;
}
}
if (riscv_cpu_virt_enabled(env) ||
((riscv_cpu_two_stage_lookup(mmu_idx) || two_stage_lookup) &&
access_type != MMU_INST_FETCH)) {
/* Two stage lookup */
ret = get_physical_address(env, &pa, &prot, address,
&env->guest_phys_fault_addr, access_type,
mmu_idx, true, true);
/*
* A G-stage exception may be triggered during two state lookup.
* And the env->guest_phys_fault_addr has already been set in
* get_physical_address().
*/
if (ret == TRANSLATE_G_STAGE_FAIL) {
first_stage_error = false;
access_type = MMU_DATA_LOAD;
}
qemu_log_mask(CPU_LOG_MMU,
"%s 1st-stage address=%" VADDR_PRIx " ret %d physical "
TARGET_FMT_plx " prot %d\n",
__func__, address, ret, pa, prot);
if (ret == TRANSLATE_SUCCESS) {
/* Second stage lookup */
im_address = pa;
ret = get_physical_address(env, &pa, &prot2, im_address, NULL,
access_type, mmu_idx, false, true);
qemu_log_mask(CPU_LOG_MMU,
"%s 2nd-stage address=%" VADDR_PRIx " ret %d physical "
TARGET_FMT_plx " prot %d\n",
__func__, im_address, ret, pa, prot2);
prot &= prot2;
if (ret == TRANSLATE_SUCCESS) {
ret = get_physical_address_pmp(env, &prot_pmp, &tlb_size, pa,
size, access_type, mode);
qemu_log_mask(CPU_LOG_MMU,
"%s PMP address=" TARGET_FMT_plx " ret %d prot"
" %d tlb_size " TARGET_FMT_lu "\n",
__func__, pa, ret, prot_pmp, tlb_size);
prot &= prot_pmp;
}
if (ret != TRANSLATE_SUCCESS) {
/*
* Guest physical address translation failed, this is a HS
* level exception
*/
first_stage_error = false;
env->guest_phys_fault_addr = (im_address |
(address &
(TARGET_PAGE_SIZE - 1))) >> 2;
}
}
} else {
/* Single stage lookup */
ret = get_physical_address(env, &pa, &prot, address, NULL,
access_type, mmu_idx, true, false);
qemu_log_mask(CPU_LOG_MMU,
"%s address=%" VADDR_PRIx " ret %d physical "
TARGET_FMT_plx " prot %d\n",
__func__, address, ret, pa, prot);
if (ret == TRANSLATE_SUCCESS) {
ret = get_physical_address_pmp(env, &prot_pmp, &tlb_size, pa,
size, access_type, mode);
qemu_log_mask(CPU_LOG_MMU,
"%s PMP address=" TARGET_FMT_plx " ret %d prot"
" %d tlb_size " TARGET_FMT_lu "\n",
__func__, pa, ret, prot_pmp, tlb_size);
prot &= prot_pmp;
}
}
if (ret == TRANSLATE_PMP_FAIL) {
pmp_violation = true;
}
if (ret == TRANSLATE_SUCCESS) {
tlb_set_page(cs, address & ~(tlb_size - 1), pa & ~(tlb_size - 1),
prot, mmu_idx, tlb_size);
return true;
} else if (probe) {
return false;
} else {
raise_mmu_exception(env, address, access_type, pmp_violation,
first_stage_error,
riscv_cpu_virt_enabled(env) ||
riscv_cpu_two_stage_lookup(mmu_idx));
riscv_raise_exception(env, cs->exception_index, retaddr);
}
return true;
#else
switch (access_type) {
case MMU_INST_FETCH:
cs->exception_index = RISCV_EXCP_INST_PAGE_FAULT;
break;
case MMU_DATA_LOAD:
cs->exception_index = RISCV_EXCP_LOAD_PAGE_FAULT;
break;
case MMU_DATA_STORE:
cs->exception_index = RISCV_EXCP_STORE_PAGE_FAULT;
break;
default:
g_assert_not_reached();
}
env->badaddr = address;
cpu_loop_exit_restore(cs, retaddr);
#endif
}
/*
* Handle Traps
*
* Adapted from Spike's processor_t::take_trap.
*
*/
void riscv_cpu_do_interrupt(CPUState *cs)
{
#if !defined(CONFIG_USER_ONLY)
RISCVCPU *cpu = RISCV_CPU(cs);
CPURISCVState *env = &cpu->env;
bool force_hs_execp = riscv_cpu_force_hs_excep_enabled(env);
uint64_t s;
/* cs->exception is 32-bits wide unlike mcause which is XLEN-bits wide
* so we mask off the MSB and separate into trap type and cause.
*/
bool async = !!(cs->exception_index & RISCV_EXCP_INT_FLAG);
target_ulong cause = cs->exception_index & RISCV_EXCP_INT_MASK;
target_ulong deleg = async ? env->mideleg : env->medeleg;
bool write_tval = false;
target_ulong tval = 0;
target_ulong htval = 0;
target_ulong mtval2 = 0;
if (cause == RISCV_EXCP_SEMIHOST) {
if (env->priv >= PRV_S) {
env->gpr[xA0] = do_common_semihosting(cs);
env->pc += 4;
return;
}
cause = RISCV_EXCP_BREAKPOINT;
}
if (!async) {
/* set tval to badaddr for traps with address information */
switch (cause) {
case RISCV_EXCP_INST_GUEST_PAGE_FAULT:
case RISCV_EXCP_LOAD_GUEST_ACCESS_FAULT:
case RISCV_EXCP_STORE_GUEST_AMO_ACCESS_FAULT:
force_hs_execp = true;
/* fallthrough */
case RISCV_EXCP_INST_ADDR_MIS:
case RISCV_EXCP_INST_ACCESS_FAULT:
case RISCV_EXCP_LOAD_ADDR_MIS:
case RISCV_EXCP_STORE_AMO_ADDR_MIS:
case RISCV_EXCP_LOAD_ACCESS_FAULT:
case RISCV_EXCP_STORE_AMO_ACCESS_FAULT:
case RISCV_EXCP_INST_PAGE_FAULT:
case RISCV_EXCP_LOAD_PAGE_FAULT:
case RISCV_EXCP_STORE_PAGE_FAULT:
write_tval = true;
tval = env->badaddr;
break;
default:
break;
}
/* ecall is dispatched as one cause so translate based on mode */
if (cause == RISCV_EXCP_U_ECALL) {
assert(env->priv <= 3);
if (env->priv == PRV_M) {
cause = RISCV_EXCP_M_ECALL;
} else if (env->priv == PRV_S && riscv_cpu_virt_enabled(env)) {
cause = RISCV_EXCP_VS_ECALL;
} else if (env->priv == PRV_S && !riscv_cpu_virt_enabled(env)) {
cause = RISCV_EXCP_S_ECALL;
} else if (env->priv == PRV_U) {
cause = RISCV_EXCP_U_ECALL;
}
}
}
trace_riscv_trap(env->mhartid, async, cause, env->pc, tval,
riscv_cpu_get_trap_name(cause, async));
qemu_log_mask(CPU_LOG_INT,
"%s: hart:"TARGET_FMT_ld", async:%d, cause:"TARGET_FMT_lx", "
"epc:0x"TARGET_FMT_lx", tval:0x"TARGET_FMT_lx", desc=%s\n",
__func__, env->mhartid, async, cause, env->pc, tval,
riscv_cpu_get_trap_name(cause, async));
if (env->priv <= PRV_S &&
cause < TARGET_LONG_BITS && ((deleg >> cause) & 1)) {
/* handle the trap in S-mode */
if (riscv_has_ext(env, RVH)) {
target_ulong hdeleg = async ? env->hideleg : env->hedeleg;
if (env->two_stage_lookup && write_tval) {
/*
* If we are writing a guest virtual address to stval, set
* this to 1. If we are trapping to VS we will set this to 0
* later.
*/
env->hstatus = set_field(env->hstatus, HSTATUS_GVA, 1);
} else {
/* For other HS-mode traps, we set this to 0. */
env->hstatus = set_field(env->hstatus, HSTATUS_GVA, 0);
}
if (riscv_cpu_virt_enabled(env) && ((hdeleg >> cause) & 1) &&
!force_hs_execp) {
/* Trap to VS mode */
/*
* See if we need to adjust cause. Yes if its VS mode interrupt
* no if hypervisor has delegated one of hs mode's interrupt
*/
if (cause == IRQ_VS_TIMER || cause == IRQ_VS_SOFT ||
cause == IRQ_VS_EXT) {
cause = cause - 1;
}
env->hstatus = set_field(env->hstatus, HSTATUS_GVA, 0);
} else if (riscv_cpu_virt_enabled(env)) {
/* Trap into HS mode, from virt */
riscv_cpu_swap_hypervisor_regs(env);
env->hstatus = set_field(env->hstatus, HSTATUS_SPVP,
env->priv);
env->hstatus = set_field(env->hstatus, HSTATUS_SPV,
riscv_cpu_virt_enabled(env));
htval = env->guest_phys_fault_addr;
riscv_cpu_set_virt_enabled(env, 0);
riscv_cpu_set_force_hs_excep(env, 0);
} else {
/* Trap into HS mode */
env->hstatus = set_field(env->hstatus, HSTATUS_SPV, false);
htval = env->guest_phys_fault_addr;
}
}
s = env->mstatus;
s = set_field(s, MSTATUS_SPIE, get_field(s, MSTATUS_SIE));
s = set_field(s, MSTATUS_SPP, env->priv);
s = set_field(s, MSTATUS_SIE, 0);
env->mstatus = s;
env->scause = cause | ((target_ulong)async << (TARGET_LONG_BITS - 1));
env->sepc = env->pc;
env->sbadaddr = tval;
env->htval = htval;
env->pc = (env->stvec >> 2 << 2) +
((async && (env->stvec & 3) == 1) ? cause * 4 : 0);
riscv_cpu_set_mode(env, PRV_S);
} else {
/* handle the trap in M-mode */
if (riscv_has_ext(env, RVH)) {
if (riscv_cpu_virt_enabled(env)) {
riscv_cpu_swap_hypervisor_regs(env);
}
env->mstatus = set_field(env->mstatus, MSTATUS_MPV,
riscv_cpu_virt_enabled(env));
if (riscv_cpu_virt_enabled(env) && tval) {
env->mstatus = set_field(env->mstatus, MSTATUS_GVA, 1);
}
mtval2 = env->guest_phys_fault_addr;
/* Trapping to M mode, virt is disabled */
riscv_cpu_set_virt_enabled(env, 0);
riscv_cpu_set_force_hs_excep(env, 0);
}
s = env->mstatus;
s = set_field(s, MSTATUS_MPIE, get_field(s, MSTATUS_MIE));
s = set_field(s, MSTATUS_MPP, env->priv);
s = set_field(s, MSTATUS_MIE, 0);
env->mstatus = s;
env->mcause = cause | ~(((target_ulong)-1) >> async);
env->mepc = env->pc;
env->mbadaddr = tval;
env->mtval2 = mtval2;
env->pc = (env->mtvec >> 2 << 2) +
((async && (env->mtvec & 3) == 1) ? cause * 4 : 0);
riscv_cpu_set_mode(env, PRV_M);
}
/* NOTE: it is not necessary to yield load reservations here. It is only
* necessary for an SC from "another hart" to cause a load reservation
* to be yielded. Refer to the memory consistency model section of the
* RISC-V ISA Specification.
*/
env->two_stage_lookup = false;
#endif
cs->exception_index = EXCP_NONE; /* mark handled to qemu */
}
Reference in New Issue View Git Blame Copy Permalink