Commit 25d92081 authored by Yang Zhang's avatar Yang Zhang Committed by Paolo Bonzini

nEPT: Add nEPT violation/misconfigration support

Inject nEPT fault to L1 guest. This patch is original from Xinhao.
Reviewed-by: default avatarXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: default avatarJun Nakajima <jun.nakajima@intel.com>
Signed-off-by: default avatarXinhao Xu <xinhao.xu@intel.com>
Signed-off-by: default avatarYang Zhang <yang.z.zhang@Intel.com>
Signed-off-by: default avatarGleb Natapov <gleb@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 53166229
...@@ -286,6 +286,7 @@ struct kvm_mmu { ...@@ -286,6 +286,7 @@ struct kvm_mmu {
u64 *pae_root; u64 *pae_root;
u64 *lm_root; u64 *lm_root;
u64 rsvd_bits_mask[2][4]; u64 rsvd_bits_mask[2][4];
u64 bad_mt_xwr;
/* /*
* Bitmap: bit set = last pte in walk * Bitmap: bit set = last pte in walk
...@@ -512,6 +513,9 @@ struct kvm_vcpu_arch { ...@@ -512,6 +513,9 @@ struct kvm_vcpu_arch {
* instruction. * instruction.
*/ */
bool write_fault_to_shadow_pgtable; bool write_fault_to_shadow_pgtable;
/* set at EPT violation at this point */
unsigned long exit_qualification;
}; };
struct kvm_lpage_info { struct kvm_lpage_info {
......
...@@ -3519,6 +3519,8 @@ static void reset_rsvds_bits_mask(struct kvm_vcpu *vcpu, ...@@ -3519,6 +3519,8 @@ static void reset_rsvds_bits_mask(struct kvm_vcpu *vcpu,
int maxphyaddr = cpuid_maxphyaddr(vcpu); int maxphyaddr = cpuid_maxphyaddr(vcpu);
u64 exb_bit_rsvd = 0; u64 exb_bit_rsvd = 0;
context->bad_mt_xwr = 0;
if (!context->nx) if (!context->nx)
exb_bit_rsvd = rsvd_bits(63, 63); exb_bit_rsvd = rsvd_bits(63, 63);
switch (context->root_level) { switch (context->root_level) {
...@@ -3574,7 +3576,40 @@ static void reset_rsvds_bits_mask(struct kvm_vcpu *vcpu, ...@@ -3574,7 +3576,40 @@ static void reset_rsvds_bits_mask(struct kvm_vcpu *vcpu,
} }
} }
static void update_permission_bitmask(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu) static void reset_rsvds_bits_mask_ept(struct kvm_vcpu *vcpu,
struct kvm_mmu *context, bool execonly)
{
int maxphyaddr = cpuid_maxphyaddr(vcpu);
int pte;
context->rsvd_bits_mask[0][3] =
rsvd_bits(maxphyaddr, 51) | rsvd_bits(3, 7);
context->rsvd_bits_mask[0][2] =
rsvd_bits(maxphyaddr, 51) | rsvd_bits(3, 6);
context->rsvd_bits_mask[0][1] =
rsvd_bits(maxphyaddr, 51) | rsvd_bits(3, 6);
context->rsvd_bits_mask[0][0] = rsvd_bits(maxphyaddr, 51);
/* large page */
context->rsvd_bits_mask[1][3] = context->rsvd_bits_mask[0][3];
context->rsvd_bits_mask[1][2] =
rsvd_bits(maxphyaddr, 51) | rsvd_bits(12, 29);
context->rsvd_bits_mask[1][1] =
rsvd_bits(maxphyaddr, 51) | rsvd_bits(12, 20);
context->rsvd_bits_mask[1][0] = context->rsvd_bits_mask[0][0];
for (pte = 0; pte < 64; pte++) {
int rwx_bits = pte & 7;
int mt = pte >> 3;
if (mt == 0x2 || mt == 0x3 || mt == 0x7 ||
rwx_bits == 0x2 || rwx_bits == 0x6 ||
(rwx_bits == 0x4 && !execonly))
context->bad_mt_xwr |= (1ull << pte);
}
}
static void update_permission_bitmask(struct kvm_vcpu *vcpu,
struct kvm_mmu *mmu, bool ept)
{ {
unsigned bit, byte, pfec; unsigned bit, byte, pfec;
u8 map; u8 map;
...@@ -3592,12 +3627,16 @@ static void update_permission_bitmask(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu ...@@ -3592,12 +3627,16 @@ static void update_permission_bitmask(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu
w = bit & ACC_WRITE_MASK; w = bit & ACC_WRITE_MASK;
u = bit & ACC_USER_MASK; u = bit & ACC_USER_MASK;
/* Not really needed: !nx will cause pte.nx to fault */ if (!ept) {
x |= !mmu->nx; /* Not really needed: !nx will cause pte.nx to fault */
/* Allow supervisor writes if !cr0.wp */ x |= !mmu->nx;
w |= !is_write_protection(vcpu) && !uf; /* Allow supervisor writes if !cr0.wp */
/* Disallow supervisor fetches of user code if cr4.smep */ w |= !is_write_protection(vcpu) && !uf;
x &= !(smep && u && !uf); /* Disallow supervisor fetches of user code if cr4.smep */
x &= !(smep && u && !uf);
} else
/* Not really needed: no U/S accesses on ept */
u = 1;
fault = (ff && !x) || (uf && !u) || (wf && !w); fault = (ff && !x) || (uf && !u) || (wf && !w);
map |= fault << bit; map |= fault << bit;
...@@ -3632,7 +3671,7 @@ static int paging64_init_context_common(struct kvm_vcpu *vcpu, ...@@ -3632,7 +3671,7 @@ static int paging64_init_context_common(struct kvm_vcpu *vcpu,
context->root_level = level; context->root_level = level;
reset_rsvds_bits_mask(vcpu, context); reset_rsvds_bits_mask(vcpu, context);
update_permission_bitmask(vcpu, context); update_permission_bitmask(vcpu, context, false);
update_last_pte_bitmap(vcpu, context); update_last_pte_bitmap(vcpu, context);
ASSERT(is_pae(vcpu)); ASSERT(is_pae(vcpu));
...@@ -3662,7 +3701,7 @@ static int paging32_init_context(struct kvm_vcpu *vcpu, ...@@ -3662,7 +3701,7 @@ static int paging32_init_context(struct kvm_vcpu *vcpu,
context->root_level = PT32_ROOT_LEVEL; context->root_level = PT32_ROOT_LEVEL;
reset_rsvds_bits_mask(vcpu, context); reset_rsvds_bits_mask(vcpu, context);
update_permission_bitmask(vcpu, context); update_permission_bitmask(vcpu, context, false);
update_last_pte_bitmap(vcpu, context); update_last_pte_bitmap(vcpu, context);
context->new_cr3 = paging_new_cr3; context->new_cr3 = paging_new_cr3;
...@@ -3724,7 +3763,7 @@ static int init_kvm_tdp_mmu(struct kvm_vcpu *vcpu) ...@@ -3724,7 +3763,7 @@ static int init_kvm_tdp_mmu(struct kvm_vcpu *vcpu)
context->gva_to_gpa = paging32_gva_to_gpa; context->gva_to_gpa = paging32_gva_to_gpa;
} }
update_permission_bitmask(vcpu, context); update_permission_bitmask(vcpu, context, false);
update_last_pte_bitmap(vcpu, context); update_last_pte_bitmap(vcpu, context);
return 0; return 0;
...@@ -3803,7 +3842,7 @@ static int init_kvm_nested_mmu(struct kvm_vcpu *vcpu) ...@@ -3803,7 +3842,7 @@ static int init_kvm_nested_mmu(struct kvm_vcpu *vcpu)
g_context->gva_to_gpa = paging32_gva_to_gpa_nested; g_context->gva_to_gpa = paging32_gva_to_gpa_nested;
} }
update_permission_bitmask(vcpu, g_context); update_permission_bitmask(vcpu, g_context, false);
update_last_pte_bitmap(vcpu, g_context); update_last_pte_bitmap(vcpu, g_context);
return 0; return 0;
......
...@@ -129,10 +129,10 @@ static inline void FNAME(protect_clean_gpte)(unsigned *access, unsigned gpte) ...@@ -129,10 +129,10 @@ static inline void FNAME(protect_clean_gpte)(unsigned *access, unsigned gpte)
static bool FNAME(is_rsvd_bits_set)(struct kvm_mmu *mmu, u64 gpte, int level) static bool FNAME(is_rsvd_bits_set)(struct kvm_mmu *mmu, u64 gpte, int level)
{ {
int bit7; int bit7 = (gpte >> 7) & 1, low6 = gpte & 0x3f;
bit7 = (gpte >> 7) & 1; return (gpte & mmu->rsvd_bits_mask[bit7][level-1]) |
return (gpte & mmu->rsvd_bits_mask[bit7][level-1]) != 0; ((mmu->bad_mt_xwr & (1ull << low6)) != 0);
} }
static inline int FNAME(is_present_gpte)(unsigned long pte) static inline int FNAME(is_present_gpte)(unsigned long pte)
...@@ -386,6 +386,25 @@ static int FNAME(walk_addr_generic)(struct guest_walker *walker, ...@@ -386,6 +386,25 @@ static int FNAME(walk_addr_generic)(struct guest_walker *walker,
walker->fault.vector = PF_VECTOR; walker->fault.vector = PF_VECTOR;
walker->fault.error_code_valid = true; walker->fault.error_code_valid = true;
walker->fault.error_code = errcode; walker->fault.error_code = errcode;
#if PTTYPE == PTTYPE_EPT
/*
* Use PFERR_RSVD_MASK in error_code to to tell if EPT
* misconfiguration requires to be injected. The detection is
* done by is_rsvd_bits_set() above.
*
* We set up the value of exit_qualification to inject:
* [2:0] - Derive from [2:0] of real exit_qualification at EPT violation
* [5:3] - Calculated by the page walk of the guest EPT page tables
* [7:8] - Derived from [7:8] of real exit_qualification
*
* The other bits are set to 0.
*/
if (!(errcode & PFERR_RSVD_MASK)) {
vcpu->arch.exit_qualification &= 0x187;
vcpu->arch.exit_qualification |= ((pt_access & pte) & 0x7) << 3;
}
#endif
walker->fault.address = addr; walker->fault.address = addr;
walker->fault.nested_page_fault = mmu != vcpu->arch.walk_mmu; walker->fault.nested_page_fault = mmu != vcpu->arch.walk_mmu;
......
...@@ -5317,9 +5317,13 @@ static int handle_ept_violation(struct kvm_vcpu *vcpu) ...@@ -5317,9 +5317,13 @@ static int handle_ept_violation(struct kvm_vcpu *vcpu)
/* It is a write fault? */ /* It is a write fault? */
error_code = exit_qualification & (1U << 1); error_code = exit_qualification & (1U << 1);
/* It is a fetch fault? */
error_code |= (exit_qualification & (1U << 2)) << 2;
/* ept page table is present? */ /* ept page table is present? */
error_code |= (exit_qualification >> 3) & 0x1; error_code |= (exit_qualification >> 3) & 0x1;
vcpu->arch.exit_qualification = exit_qualification;
return kvm_mmu_page_fault(vcpu, gpa, error_code, NULL, 0); return kvm_mmu_page_fault(vcpu, gpa, error_code, NULL, 0);
} }
...@@ -7348,6 +7352,21 @@ static void vmx_set_supported_cpuid(u32 func, struct kvm_cpuid_entry2 *entry) ...@@ -7348,6 +7352,21 @@ static void vmx_set_supported_cpuid(u32 func, struct kvm_cpuid_entry2 *entry)
entry->ecx |= bit(X86_FEATURE_VMX); entry->ecx |= bit(X86_FEATURE_VMX);
} }
static void nested_ept_inject_page_fault(struct kvm_vcpu *vcpu,
struct x86_exception *fault)
{
struct vmcs12 *vmcs12;
nested_vmx_vmexit(vcpu);
vmcs12 = get_vmcs12(vcpu);
if (fault->error_code & PFERR_RSVD_MASK)
vmcs12->vm_exit_reason = EXIT_REASON_EPT_MISCONFIG;
else
vmcs12->vm_exit_reason = EXIT_REASON_EPT_VIOLATION;
vmcs12->exit_qualification = vcpu->arch.exit_qualification;
vmcs12->guest_physical_address = fault->address;
}
/* /*
* prepare_vmcs02 is called when the L1 guest hypervisor runs its nested * prepare_vmcs02 is called when the L1 guest hypervisor runs its nested
* L2 guest. L1 has a vmcs for L2 (vmcs12), and this function "merges" it * L2 guest. L1 has a vmcs for L2 (vmcs12), and this function "merges" it
......
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