From 9bbcf372193a2064743461aea5bf59cc83e37aa9 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Sun, 2 Oct 2022 10:29:51 -0700 Subject: [PATCH] target/i386: Reorg GET_HPHYS Replace with PTE_HPHYS for the page table walk, and a direct call to mmu_translate for the final stage2 translation. Hoist the check for HF2_NPT_MASK out to get_physical_address, which avoids the recursive call when stage2 is disabled. We can now return all the way out to x86_cpu_tlb_fill before raising an exception, which means probe works. Signed-off-by: Richard Henderson Message-Id: <20221002172956.265735-5-richard.henderson@linaro.org> Signed-off-by: Paolo Bonzini --- target/i386/tcg/sysemu/excp_helper.c | 123 +++++++++++++++++++++------ 1 file changed, 95 insertions(+), 28 deletions(-) diff --git a/target/i386/tcg/sysemu/excp_helper.c b/target/i386/tcg/sysemu/excp_helper.c index 00ce4cf253..816b307547 100644 --- a/target/i386/tcg/sysemu/excp_helper.c +++ b/target/i386/tcg/sysemu/excp_helper.c @@ -37,18 +37,43 @@ typedef struct TranslateResult { int page_size; } TranslateResult; +typedef enum TranslateFaultStage2 { + S2_NONE, + S2_GPA, + S2_GPT, +} TranslateFaultStage2; + typedef struct TranslateFault { int exception_index; int error_code; target_ulong cr2; + TranslateFaultStage2 stage2; } TranslateFault; -#define GET_HPHYS(cs, gpa, access_type, prot) \ - (in->use_stage2 ? get_hphys(cs, gpa, access_type, prot) : gpa) +#define PTE_HPHYS(ADDR) \ + do { \ + if (in->use_stage2) { \ + nested_in.addr = (ADDR); \ + if (!mmu_translate(env, &nested_in, out, err)) { \ + err->stage2 = S2_GPT; \ + return false; \ + } \ + (ADDR) = out->paddr; \ + } \ + } while (0) static bool mmu_translate(CPUX86State *env, const TranslateParams *in, TranslateResult *out, TranslateFault *err) { + TranslateParams nested_in = { + /* Use store for page table entries, to allow A/D flag updates. */ + .access_type = MMU_DATA_STORE, + .cr3 = env->nested_cr3, + .pg_mode = env->nested_pg_mode, + .mmu_idx = MMU_USER_IDX, + .use_stage2 = false, + }; + CPUState *cs = env_cpu(env); X86CPU *cpu = env_archcpu(env); const int32_t a20_mask = x86_get_a20_mask(env); @@ -79,7 +104,7 @@ static bool mmu_translate(CPUX86State *env, const TranslateParams *in, if (la57) { pml5e_addr = ((in->cr3 & ~0xfff) + (((addr >> 48) & 0x1ff) << 3)) & a20_mask; - pml5e_addr = GET_HPHYS(cs, pml5e_addr, MMU_DATA_STORE, NULL); + PTE_HPHYS(pml5e_addr); pml5e = x86_ldq_phys(cs, pml5e_addr); if (!(pml5e & PG_PRESENT_MASK)) { goto do_fault; @@ -99,7 +124,7 @@ static bool mmu_translate(CPUX86State *env, const TranslateParams *in, pml4e_addr = ((pml5e & PG_ADDRESS_MASK) + (((addr >> 39) & 0x1ff) << 3)) & a20_mask; - pml4e_addr = GET_HPHYS(cs, pml4e_addr, MMU_DATA_STORE, NULL); + PTE_HPHYS(pml4e_addr); pml4e = x86_ldq_phys(cs, pml4e_addr); if (!(pml4e & PG_PRESENT_MASK)) { goto do_fault; @@ -114,7 +139,7 @@ static bool mmu_translate(CPUX86State *env, const TranslateParams *in, 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); + PTE_HPHYS(pdpe_addr); pdpe = x86_ldq_phys(cs, pdpe_addr); if (!(pdpe & PG_PRESENT_MASK)) { goto do_fault; @@ -140,7 +165,7 @@ static bool mmu_translate(CPUX86State *env, const TranslateParams *in, /* XXX: load them when cr3 is loaded ? */ pdpe_addr = ((in->cr3 & ~0x1f) + ((addr >> 27) & 0x18)) & a20_mask; - pdpe_addr = GET_HPHYS(cs, pdpe_addr, MMU_DATA_STORE, NULL); + PTE_HPHYS(pdpe_addr); pdpe = x86_ldq_phys(cs, pdpe_addr); if (!(pdpe & PG_PRESENT_MASK)) { goto do_fault; @@ -154,7 +179,7 @@ static bool mmu_translate(CPUX86State *env, const TranslateParams *in, pde_addr = ((pdpe & PG_ADDRESS_MASK) + (((addr >> 21) & 0x1ff) << 3)) & a20_mask; - pde_addr = GET_HPHYS(cs, pde_addr, MMU_DATA_STORE, NULL); + PTE_HPHYS(pde_addr); pde = x86_ldq_phys(cs, pde_addr); if (!(pde & PG_PRESENT_MASK)) { goto do_fault; @@ -177,7 +202,7 @@ static bool mmu_translate(CPUX86State *env, const TranslateParams *in, } pte_addr = ((pde & PG_ADDRESS_MASK) + (((addr >> 12) & 0x1ff) << 3)) & a20_mask; - pte_addr = GET_HPHYS(cs, pte_addr, MMU_DATA_STORE, NULL); + PTE_HPHYS(pte_addr); pte = x86_ldq_phys(cs, pte_addr); if (!(pte & PG_PRESENT_MASK)) { goto do_fault; @@ -194,7 +219,7 @@ static bool mmu_translate(CPUX86State *env, const TranslateParams *in, /* page directory entry */ pde_addr = ((in->cr3 & ~0xfff) + ((addr >> 20) & 0xffc)) & a20_mask; - pde_addr = GET_HPHYS(cs, pde_addr, MMU_DATA_STORE, NULL); + PTE_HPHYS(pde_addr); pde = x86_ldl_phys(cs, pde_addr); if (!(pde & PG_PRESENT_MASK)) { goto do_fault; @@ -222,7 +247,7 @@ static bool mmu_translate(CPUX86State *env, const TranslateParams *in, /* page directory entry */ pte_addr = ((pde & ~0xfff) + ((addr >> 10) & 0xffc)) & a20_mask; - pte_addr = GET_HPHYS(cs, pte_addr, MMU_DATA_STORE, NULL); + PTE_HPHYS(pte_addr); pte = x86_ldl_phys(cs, pte_addr); if (!(pte & PG_PRESENT_MASK)) { goto do_fault; @@ -303,13 +328,31 @@ do_check_protect_pse36: assert(access_type != MMU_DATA_STORE); prot &= ~PAGE_WRITE; } - out->prot = prot; - out->page_size = page_size; /* align to page_size */ out->paddr = (pte & a20_mask & PG_ADDRESS_MASK & ~(page_size - 1)) | (addr & (page_size - 1)); - out->paddr = GET_HPHYS(cs, out->paddr, access_type, &out->prot); + + if (in->use_stage2) { + nested_in.addr = out->paddr; + nested_in.access_type = access_type; + + if (!mmu_translate(env, &nested_in, out, err)) { + err->stage2 = S2_GPA; + return false; + } + + /* Merge stage1 & stage2 protection bits. */ + prot &= out->prot; + + /* Re-verify resulting protection. */ + if ((prot & (1 << access_type)) == 0) { + goto do_fault_protect; + } + } + + out->prot = prot; + out->page_size = page_size; return true; int error_code; @@ -344,13 +387,36 @@ do_check_protect_pse36: err->exception_index = EXCP0E_PAGE; err->error_code = error_code; err->cr2 = addr; + err->stage2 = S2_NONE; return false; } +static G_NORETURN void raise_stage2(CPUX86State *env, TranslateFault *err, + uintptr_t retaddr) +{ + uint64_t exit_info_1 = err->error_code; + + switch (err->stage2) { + case S2_GPT: + exit_info_1 |= SVM_NPTEXIT_GPT; + break; + case S2_GPA: + exit_info_1 |= SVM_NPTEXIT_GPA; + break; + default: + g_assert_not_reached(); + } + + x86_stq_phys(env_cpu(env), + env->vm_vmcb + offsetof(struct vmcb, control.exit_info_2), + err->cr2); + cpu_vmexit(env, SVM_EXIT_NPF, exit_info_1, retaddr); +} + hwaddr get_hphys(CPUState *cs, hwaddr gphys, MMUAccessType access_type, int *prot) { - CPUX86State *env = &X86_CPU(cs)->env; + CPUX86State *env = cs->env_ptr; if (likely(!(env->hflags2 & HF2_NPT_MASK))) { return gphys; @@ -365,20 +431,16 @@ hwaddr get_hphys(CPUState *cs, hwaddr gphys, MMUAccessType access_type, }; TranslateResult out; TranslateFault err; - uint64_t exit_info_1; - if (mmu_translate(env, &in, &out, &err)) { - if (prot) { - *prot &= out.prot; - } - return out.paddr; + if (!mmu_translate(env, &in, &out, &err)) { + err.stage2 = prot ? SVM_NPTEXIT_GPA : SVM_NPTEXIT_GPT; + raise_stage2(env, &err, env->retaddr); } - x86_stq_phys(cs, env->vm_vmcb + - offsetof(struct vmcb, control.exit_info_2), gphys); - exit_info_1 = err.error_code - | (prot ? SVM_NPTEXIT_GPA : SVM_NPTEXIT_GPT); - cpu_vmexit(env, SVM_EXIT_NPF, exit_info_1, env->retaddr); + if (prot) { + *prot &= out.prot; + } + return out.paddr; } } @@ -405,7 +467,7 @@ static bool get_physical_address(CPUX86State *env, vaddr addr, .pg_mode = get_pg_mode(env), .mmu_idx = mmu_idx, .access_type = access_type, - .use_stage2 = true + .use_stage2 = env->hflags2 & HF2_NPT_MASK, }; if (in.pg_mode & PG_MODE_LMA) { @@ -444,8 +506,13 @@ bool x86_cpu_tlb_fill(CPUState *cs, vaddr addr, int size, return true; } - /* FIXME: On error in get_hphys we have already jumped out. */ - g_assert(!probe); + if (probe) { + return false; + } + + if (err.stage2 != S2_NONE) { + raise_stage2(env, &err, retaddr); + } if (env->intercept_exceptions & (1 << err.exception_index)) { /* cr2 is not modified in case of exceptions */