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target-i386: Add NPT support 

This implements NPT suport for SVM by hooking into
x86_cpu_handle_mmu_fault where it reads the stage-1 page table. Whether
we need to perform this 2nd stage translation, and how, is decided
during vmrun and stored in hflags2, along with nested_cr3 and
nested_pg_mode.

As get_hphys performs a direct cpu_vmexit in case of NPT faults, we need
retaddr in that function. To avoid changing the signature of
cpu_handle_mmu_fault, this passes the value from tlb_fill to get_hphys
via the CPU state.

This was tested successfully via the Jailhouse hypervisor.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Message-Id: <567473a0-6005-5843-4c73-951f476085ca@web.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Jan Kiszka 2018-06-30 08:08:23 +02:00 committed by Paolo Bonzini
parent 76b004d10d
commit fe441054bb
7 changed files with 281 additions and 6 deletions
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2
target/i386/cpu.c
View File

@ -749,7 +749,7 @@ static void x86_cpu_vendor_words2str(char *dst, uint32_t vendor1,
#define TCG_EXT3_FEATURES (CPUID_EXT3_LAHF_LM | CPUID_EXT3_SVM | \
CPUID_EXT3_CR8LEG | CPUID_EXT3_ABM | CPUID_EXT3_SSE4A)
#define TCG_EXT4_FEATURES 0
#define TCG_SVM_FEATURES 0
#define TCG_SVM_FEATURES CPUID_SVM_NPT
#define TCG_KVM_FEATURES 0
#define TCG_7_0_EBX_FEATURES (CPUID_7_0_EBX_SMEP | CPUID_7_0_EBX_SMAP | \
CPUID_7_0_EBX_BMI1 | CPUID_7_0_EBX_BMI2 | CPUID_7_0_EBX_ADX | \

6
target/i386/cpu.h
View File

@ -211,6 +211,7 @@ typedef enum X86Seg {
#define HF2_VINTR_SHIFT 3 /* value of V_INTR_MASKING bit */
#define HF2_SMM_INSIDE_NMI_SHIFT 4 /* CPU serving SMI nested inside NMI */
#define HF2_MPX_PR_SHIFT 5 /* BNDCFGx.BNDPRESERVE */
#define HF2_NPT_SHIFT 6 /* Nested Paging enabled */
#define HF2_GIF_MASK (1 << HF2_GIF_SHIFT)
#define HF2_HIF_MASK (1 << HF2_HIF_SHIFT)
@ -218,6 +219,7 @@ typedef enum X86Seg {
#define HF2_VINTR_MASK (1 << HF2_VINTR_SHIFT)
#define HF2_SMM_INSIDE_NMI_MASK (1 << HF2_SMM_INSIDE_NMI_SHIFT)
#define HF2_MPX_PR_MASK (1 << HF2_MPX_PR_SHIFT)
#define HF2_NPT_MASK (1 << HF2_NPT_SHIFT)
#define CR0_PE_SHIFT 0
#define CR0_MP_SHIFT 1
@ -1265,12 +1267,16 @@ typedef struct CPUX86State {
uint16_t intercept_dr_read;
uint16_t intercept_dr_write;
uint32_t intercept_exceptions;
uint64_t nested_cr3;
uint32_t nested_pg_mode;
uint8_t v_tpr;
/* KVM states, automatically cleared on reset */
uint8_t nmi_injected;
uint8_t nmi_pending;
uintptr_t retaddr;
/* Fields up to this point are cleared by a CPU reset */
struct {} end_reset_fields;

216
target/i386/excp_helper.c
View File

@ -157,6 +157,209 @@ int x86_cpu_handle_mmu_fault(CPUState *cs, vaddr addr, int size,
#else
static hwaddr get_hphys(CPUState *cs, hwaddr gphys, MMUAccessType access_type,
int *prot)
{
CPUX86State *env = &X86_CPU(cs)->env;
uint64_t rsvd_mask = PG_HI_RSVD_MASK;
uint64_t ptep, pte;
uint64_t exit_info_1 = 0;
target_ulong pde_addr, pte_addr;
uint32_t page_offset;
int page_size;
if (likely(!(env->hflags2 & HF2_NPT_MASK))) {
return gphys;
}
if (!(env->nested_pg_mode & SVM_NPT_NXE)) {
rsvd_mask |= PG_NX_MASK;
}
if (env->nested_pg_mode & SVM_NPT_PAE) {
uint64_t pde, pdpe;
target_ulong pdpe_addr;
#ifdef TARGET_X86_64
if (env->nested_pg_mode & SVM_NPT_LMA) {
uint64_t pml5e;
uint64_t pml4e_addr, pml4e;
pml5e = env->nested_cr3;
ptep = PG_NX_MASK | PG_USER_MASK | PG_RW_MASK;
pml4e_addr = (pml5e & PG_ADDRESS_MASK) +
(((gphys >> 39) & 0x1ff) << 3);
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) +
(((gphys >> 30) & 0x1ff) << 3);
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
{
pdpe_addr = (env->nested_cr3 & ~0x1f) + ((gphys >> 27) & 0x18);
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) + (((gphys >> 21) & 0x1ff) << 3);
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) + (((gphys >> 12) & 0x1ff) << 3);
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 = (env->nested_cr3 & ~0xfff) + ((gphys >> 20) & 0xffc);
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) && (env->cr[4] & CR4_PSE_MASK)) {
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) + ((gphys >> 10) & 0xffc);
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;
if (!(ptep & PG_USER_MASK)) {
goto do_fault_protect;
}
if (ptep & PG_NX_MASK) {
if (access_type == MMU_INST_FETCH) {
goto do_fault_protect;
}
*prot &= ~PAGE_EXEC;
}
if (!(ptep & PG_RW_MASK)) {
if (access_type == MMU_DATA_STORE) {
goto do_fault_protect;
}
*prot &= ~PAGE_WRITE;
}
pte &= PG_ADDRESS_MASK & ~(page_size - 1);
page_offset = gphys & (page_size - 1);
return pte + page_offset;
do_fault_rsvd:
exit_info_1 |= SVM_NPTEXIT_RSVD;
do_fault_protect:
exit_info_1 |= SVM_NPTEXIT_P;
do_fault:
x86_stq_phys(cs, env->vm_vmcb + offsetof(struct vmcb, control.exit_info_2),
gphys);
exit_info_1 |= SVM_NPTEXIT_US;
if (access_type == MMU_DATA_STORE) {
exit_info_1 |= SVM_NPTEXIT_RW;
} else if (access_type == MMU_INST_FETCH) {
exit_info_1 |= SVM_NPTEXIT_ID;
}
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
@ -224,6 +427,7 @@ int x86_cpu_handle_mmu_fault(CPUState *cs, vaddr addr, int size,
if (la57) {
pml5e_addr = ((env->cr[3] & ~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;
@ -243,6 +447,7 @@ int x86_cpu_handle_mmu_fault(CPUState *cs, vaddr addr, int size,
pml4e_addr = ((pml5e & PG_ADDRESS_MASK) +
(((addr >> 39) & 0x1ff) << 3)) & a20_mask;
pml4e_addr = get_hphys(cs, pml4e_addr, MMU_DATA_STORE, false);
pml4e = x86_ldq_phys(cs, pml4e_addr);
if (!(pml4e & PG_PRESENT_MASK)) {
goto do_fault;
@ -257,6 +462,7 @@ int x86_cpu_handle_mmu_fault(CPUState *cs, vaddr addr, int size,
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;
@ -282,6 +488,7 @@ int x86_cpu_handle_mmu_fault(CPUState *cs, vaddr addr, int size,
/* XXX: load them when cr3 is loaded ? */
pdpe_addr = ((env->cr[3] & ~0x1f) + ((addr >> 27) & 0x18)) &
a20_mask;
pdpe_addr = get_hphys(cs, pdpe_addr, MMU_DATA_STORE, false);
pdpe = x86_ldq_phys(cs, pdpe_addr);
if (!(pdpe & PG_PRESENT_MASK)) {
goto do_fault;
@ -295,6 +502,7 @@ int x86_cpu_handle_mmu_fault(CPUState *cs, vaddr addr, int size,
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;
@ -317,6 +525,7 @@ int x86_cpu_handle_mmu_fault(CPUState *cs, vaddr addr, int size,
}
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;
@ -333,6 +542,7 @@ int x86_cpu_handle_mmu_fault(CPUState *cs, vaddr addr, int size,
/* page directory entry */
pde_addr = ((env->cr[3] & ~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;
@ -360,6 +570,7 @@ int x86_cpu_handle_mmu_fault(CPUState *cs, vaddr addr, int size,
/* 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;
@ -442,12 +653,13 @@ do_check_protect_pse36:
/* align to page_size */
pte &= PG_ADDRESS_MASK & ~(page_size - 1);
page_offset = addr & (page_size - 1);
paddr = get_hphys(cs, pte + page_offset, is_write1, &prot);
/* Even if 4MB pages, we map only one 4KB page in the cache to
avoid filling it too fast */
vaddr = addr & TARGET_PAGE_MASK;
page_offset = vaddr & (page_size - 1);
paddr = pte + page_offset;
paddr &= TARGET_PAGE_MASK;
assert(prot & (1 << is_write1));
tlb_set_page_with_attrs(cs, vaddr, paddr, cpu_get_mem_attrs(env),

21
target/i386/machine.c
View File

@ -935,6 +935,26 @@ static const VMStateDescription vmstate_msr_virt_ssbd = {
}
};
static bool svm_npt_needed(void *opaque)
{
X86CPU *cpu = opaque;
CPUX86State *env = &cpu->env;
return !!(env->hflags2 & HF2_NPT_MASK);
}
static const VMStateDescription vmstate_svm_npt = {
.name = "cpu/svn_npt",
.version_id = 1,
.minimum_version_id = 1,
.needed = svm_npt_needed,
.fields = (VMStateField[]){
VMSTATE_UINT64(env.nested_cr3, X86CPU),
VMSTATE_UINT32(env.nested_pg_mode, X86CPU),
VMSTATE_END_OF_LIST()
}
};
VMStateDescription vmstate_x86_cpu = {
.name = "cpu",
.version_id = 12,
@ -1059,6 +1079,7 @@ VMStateDescription vmstate_x86_cpu = {
&vmstate_mcg_ext_ctl,
&vmstate_msr_intel_pt,
&vmstate_msr_virt_ssbd,
&vmstate_svm_npt,
NULL
}
};

6
target/i386/mem_helper.c
View File

@ -202,13 +202,13 @@ void helper_boundl(CPUX86State *env, target_ulong a0, int v)
void tlb_fill(CPUState *cs, target_ulong addr, int size,
MMUAccessType access_type, int mmu_idx, uintptr_t retaddr)
{
X86CPU *cpu = X86_CPU(cs);
CPUX86State *env = &cpu->env;
int ret;
env->retaddr = retaddr;
ret = x86_cpu_handle_mmu_fault(cs, addr, size, access_type, mmu_idx);
if (ret) {
X86CPU *cpu = X86_CPU(cs);
CPUX86State *env = &cpu->env;
raise_exception_err_ra(env, cs->exception_index, env->error_code, retaddr);
}
}

14
target/i386/svm.h
View File

@ -130,6 +130,20 @@
#define SVM_CR0_SELECTIVE_MASK (1 << 3 | 1) /* TS and MP */
#define SVM_NPT_ENABLED (1 << 0)
#define SVM_NPT_PAE (1 << 0)
#define SVM_NPT_LMA (1 << 1)
#define SVM_NPT_NXE (1 << 2)
#define SVM_NPTEXIT_P (1ULL << 0)
#define SVM_NPTEXIT_RW (1ULL << 1)
#define SVM_NPTEXIT_US (1ULL << 2)
#define SVM_NPTEXIT_RSVD (1ULL << 3)
#define SVM_NPTEXIT_ID (1ULL << 4)
#define SVM_NPTEXIT_GPA (1ULL << 32)
#define SVM_NPTEXIT_GPT (1ULL << 33)
struct QEMU_PACKED vmcb_control_area {
uint16_t intercept_cr_read;
uint16_t intercept_cr_write;

22
target/i386/svm_helper.c
View File

@ -124,6 +124,7 @@ void helper_vmrun(CPUX86State *env, int aflag, int next_eip_addend)
{
CPUState *cs = CPU(x86_env_get_cpu(env));
target_ulong addr;
uint64_t nested_ctl;
uint32_t event_inj;
uint32_t int_ctl;
@ -206,6 +207,26 @@ void helper_vmrun(CPUX86State *env, int aflag, int next_eip_addend)
control.intercept_exceptions
));
nested_ctl = x86_ldq_phys(cs, env->vm_vmcb + offsetof(struct vmcb,
control.nested_ctl));
if (nested_ctl & SVM_NPT_ENABLED) {
env->nested_cr3 = x86_ldq_phys(cs,
env->vm_vmcb + offsetof(struct vmcb,
control.nested_cr3));
env->hflags2 |= HF2_NPT_MASK;
env->nested_pg_mode = 0;
if (env->cr[4] & CR4_PAE_MASK) {
env->nested_pg_mode |= SVM_NPT_PAE;
}
if (env->hflags & HF_LMA_MASK) {
env->nested_pg_mode |= SVM_NPT_LMA;
}
if (env->efer & MSR_EFER_NXE) {
env->nested_pg_mode |= SVM_NPT_NXE;
}
}
/* enable intercepts */
env->hflags |= HF_SVMI_MASK;
@ -616,6 +637,7 @@ void do_vmexit(CPUX86State *env, uint32_t exit_code, uint64_t exit_info_1)
x86_stl_phys(cs,
env->vm_vmcb + offsetof(struct vmcb, control.int_state), 0);
}
env->hflags2 &= ~HF2_NPT_MASK;
/* Save the VM state in the vmcb */
svm_save_seg(env, env->vm_vmcb + offsetof(struct vmcb, save.es),