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target/riscv: Implement second stage MMU 

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
This commit is contained in:
Alistair Francis 2020-01-31 17:02:56 -08:00 committed by Palmer Dabbelt
parent 1448689c7b
commit 36a18664ba
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GPG Key ID: 2E1319F35FBB1889
2 changed files with 175 additions and 19 deletions
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1
target/riscv/cpu.h
View File

@ -104,6 +104,7 @@ struct CPURISCVState {
target_ulong frm;
target_ulong badaddr;
target_ulong guest_phys_fault_addr;
target_ulong priv_ver;
target_ulong misa;

193
target/riscv/cpu_helper.c
View File

@ -285,11 +285,12 @@ void riscv_cpu_set_mode(CPURISCVState *env, target_ulong newpriv)
* @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,
int access_type, int mmu_idx,
bool first_stage)
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
@ -297,13 +298,40 @@ static int get_physical_address(CPURISCVState *env, hwaddr *physical,
MemTxResult res;
MemTxAttrs attrs = MEMTXATTRS_UNSPECIFIED;
int mode = mmu_idx;
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 (mode == PRV_M && access_type != MMU_INST_FETCH) {
if (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)) {
use_background = true;
}
}
}
if (mode == PRV_S && access_type != MMU_INST_FETCH &&
riscv_has_ext(env, RVH) && !riscv_cpu_virt_enabled(env)) {
if (get_field(env->hstatus, HSTATUS_SPRV)) {
mode = get_field(env->mstatus, SSTATUS_SPP);
use_background = true;
}
}
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;
@ -313,13 +341,30 @@ static int get_physical_address(CPURISCVState *env, hwaddr *physical,
*prot = 0;
hwaddr base;
int levels, ptidxbits, ptesize, vm, sum;
int mxr = get_field(env->mstatus, MSTATUS_MXR);
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 (env->priv_ver >= PRIV_VERSION_1_10_0) {
base = (hwaddr)get_field(env->satp, SATP_PPN) << PGSHIFT;
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;
}
sum = get_field(env->mstatus, MSTATUS_SUM);
vm = get_field(env->satp, SATP_MODE);
switch (vm) {
case VM_1_10_SV32:
levels = 2; ptidxbits = 10; ptesize = 4; break;
@ -337,6 +382,7 @@ static int get_physical_address(CPURISCVState *env, hwaddr *physical,
g_assert_not_reached();
}
} else {
widened = 0;
base = (hwaddr)(env->sptbr) << PGSHIFT;
sum = !get_field(env->mstatus, MSTATUS_PUM);
vm = get_field(env->mstatus, MSTATUS_VM);
@ -357,9 +403,16 @@ static int get_physical_address(CPURISCVState *env, hwaddr *physical,
}
CPUState *cs = env_cpu(env);
int va_bits = PGSHIFT + levels * ptidxbits;
target_ulong mask = (1L << (TARGET_LONG_BITS - (va_bits - 1))) - 1;
target_ulong masked_msbs = (addr >> (va_bits - 1)) & mask;
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;
}
@ -371,11 +424,29 @@ static int get_physical_address(CPURISCVState *env, hwaddr *physical,
restart:
#endif
for (i = 0; i < levels; i++, ptshift -= ptidxbits) {
target_ulong idx = (addr >> (PGSHIFT + ptshift)) &
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 = base + idx * ptesize;
hwaddr pte_addr;
if (two_stage && first_stage) {
hwaddr vbase;
/* Do the second stage translation on the base PTE address. */
get_physical_address(env, &vbase, prot, base, access_type,
mmu_idx, false, true);
pte_addr = vbase + idx * ptesize;
} else {
pte_addr = base + idx * ptesize;
}
if (riscv_feature(env, RISCV_FEATURE_PMP) &&
!pmp_hart_has_privs(env, pte_addr, sizeof(target_ulong),
@ -472,7 +543,12 @@ restart:
/* 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;
if (i == 0) {
*physical = (ppn | (vpn & ((1L << (ptshift + widened)) - 1))) <<
PGSHIFT;
} else {
*physical = (ppn | (vpn & ((1L << ptshift) - 1))) << PGSHIFT;
}
/* set permissions on the TLB entry */
if ((pte & PTE_R) || ((pte & PTE_X) && mxr)) {
@ -531,14 +607,23 @@ static void raise_mmu_exception(CPURISCVState *env, target_ulong address,
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(&cpu->env, &phys_addr, &prot, addr, 0, mmu_idx,
true)) {
if (get_physical_address(env, &phys_addr, &prot, addr, 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,
0, mmu_idx, false, true)) {
return -1;
}
}
return phys_addr;
}
@ -592,17 +677,37 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
RISCVCPU *cpu = RISCV_CPU(cs);
CPURISCVState *env = &cpu->env;
#ifndef CONFIG_USER_ONLY
vaddr im_address;
hwaddr pa = 0;
int prot;
bool pmp_violation = false;
bool m_mode_two_stage = false;
bool hs_mode_two_stage = false;
bool first_stage_error = true;
int ret = TRANSLATE_FAIL;
int mode = mmu_idx;
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);
ret = get_physical_address(env, &pa, &prot, address, access_type, mmu_idx,
true);
/*
* Determine if we are in M mode and MPRV is set or in HS mode and SPRV is
* set and we want to access a virtulisation address.
*/
if (riscv_has_ext(env, RVH)) {
m_mode_two_stage = env->priv == PRV_M &&
access_type != MMU_INST_FETCH &&
get_field(env->mstatus, MSTATUS_MPRV) &&
get_field(env->mstatus, MSTATUS_MPV);
hs_mode_two_stage = env->priv == PRV_S &&
!riscv_cpu_virt_enabled(env) &&
access_type != MMU_INST_FETCH &&
get_field(env->hstatus, HSTATUS_SPRV) &&
get_field(env->hstatus, HSTATUS_SPV);
}
if (mode == PRV_M && access_type != MMU_INST_FETCH) {
if (get_field(env->mstatus, MSTATUS_MPRV)) {
@ -610,9 +715,55 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
}
}
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 (riscv_cpu_virt_enabled(env) || m_mode_two_stage || hs_mode_two_stage) {
/* Two stage lookup */
ret = get_physical_address(env, &pa, &prot, address, access_type,
mmu_idx, true, true);
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_FAIL) {
/* Second stage lookup */
im_address = pa;
ret = get_physical_address(env, &pa, &prot, im_address,
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, prot);
if (riscv_feature(env, RISCV_FEATURE_PMP) &&
(ret == TRANSLATE_SUCCESS) &&
!pmp_hart_has_privs(env, pa, size, 1 << access_type, mode)) {
ret = TRANSLATE_PMP_FAIL;
}
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, 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 (riscv_feature(env, RISCV_FEATURE_PMP) &&
(ret == TRANSLATE_SUCCESS) &&
@ -622,6 +773,7 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
if (ret == TRANSLATE_PMP_FAIL) {
pmp_violation = true;
}
if (ret == TRANSLATE_SUCCESS) {
tlb_set_page(cs, address & TARGET_PAGE_MASK, pa & TARGET_PAGE_MASK,
prot, mmu_idx, TARGET_PAGE_SIZE);
@ -629,9 +781,12 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
} else if (probe) {
return false;
} else {
raise_mmu_exception(env, address, access_type, pmp_violation, true);
raise_mmu_exception(env, address, access_type, pmp_violation, first_stage_error);
riscv_raise_exception(env, cs->exception_index, retaddr);
}
return true;
#else
switch (access_type) {
case MMU_INST_FETCH: