KVM: x86: propagate exception from permission checks on the nested page fault
Currently, if a permission error happens during the translation of
the final GPA to HPA, walk_addr_generic returns 0 but does not fill
in walker->fault. To avoid this, add an x86_exception* argument
to the translate_gpa function, and let it fill in walker->fault.
The nested_page_fault field will be true, since the walk_mmu is the
nested_mmu and translate_gpu instead operates on the "outer" (NPT)
instance.
Reported-by: Valentine Sinitsyn <valentine.sinitsyn@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index c989651..2dbde3b 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -262,7 +262,8 @@
struct x86_exception *fault);
gpa_t (*gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t gva, u32 access,
struct x86_exception *exception);
- gpa_t (*translate_gpa)(struct kvm_vcpu *vcpu, gpa_t gpa, u32 access);
+ gpa_t (*translate_gpa)(struct kvm_vcpu *vcpu, gpa_t gpa, u32 access,
+ struct x86_exception *exception);
int (*sync_page)(struct kvm_vcpu *vcpu,
struct kvm_mmu_page *sp);
void (*invlpg)(struct kvm_vcpu *vcpu, gva_t gva);
@@ -923,7 +924,8 @@
int kvm_mmu_load(struct kvm_vcpu *vcpu);
void kvm_mmu_unload(struct kvm_vcpu *vcpu);
void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu);
-gpa_t translate_nested_gpa(struct kvm_vcpu *vcpu, gpa_t gpa, u32 access);
+gpa_t translate_nested_gpa(struct kvm_vcpu *vcpu, gpa_t gpa, u32 access,
+ struct x86_exception *exception);
gpa_t kvm_mmu_gva_to_gpa_read(struct kvm_vcpu *vcpu, gva_t gva,
struct x86_exception *exception);
gpa_t kvm_mmu_gva_to_gpa_fetch(struct kvm_vcpu *vcpu, gva_t gva,
@@ -943,7 +945,8 @@
void kvm_enable_tdp(void);
void kvm_disable_tdp(void);
-static inline gpa_t translate_gpa(struct kvm_vcpu *vcpu, gpa_t gpa, u32 access)
+static inline gpa_t translate_gpa(struct kvm_vcpu *vcpu, gpa_t gpa, u32 access,
+ struct x86_exception *exception)
{
return gpa;
}
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 5b93a59..76398fe 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -3200,7 +3200,7 @@
{
if (exception)
exception->error_code = 0;
- return vcpu->arch.nested_mmu.translate_gpa(vcpu, vaddr, access);
+ return vcpu->arch.nested_mmu.translate_gpa(vcpu, vaddr, access, exception);
}
static bool quickly_check_mmio_pf(struct kvm_vcpu *vcpu, u64 addr, bool direct)
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index df1a044..0ab6c65a 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -321,7 +321,8 @@
walker->pte_gpa[walker->level - 1] = pte_gpa;
real_gfn = mmu->translate_gpa(vcpu, gfn_to_gpa(table_gfn),
- PFERR_USER_MASK|PFERR_WRITE_MASK);
+ PFERR_USER_MASK|PFERR_WRITE_MASK,
+ &walker->fault);
/*
* FIXME: This can happen if emulation (for of an INS/OUTS
@@ -334,7 +335,7 @@
* fields.
*/
if (unlikely(real_gfn == UNMAPPED_GVA))
- goto error;
+ return 0;
real_gfn = gpa_to_gfn(real_gfn);
@@ -376,7 +377,7 @@
if (PTTYPE == 32 && walker->level == PT_DIRECTORY_LEVEL && is_cpuid_PSE36())
gfn += pse36_gfn_delta(pte);
- real_gpa = mmu->translate_gpa(vcpu, gfn_to_gpa(gfn), access);
+ real_gpa = mmu->translate_gpa(vcpu, gfn_to_gpa(gfn), access, &walker->fault);
if (real_gpa == UNMAPPED_GVA)
return 0;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 3541946..7b25aa2 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -459,11 +459,12 @@
gfn_t ngfn, void *data, int offset, int len,
u32 access)
{
+ struct x86_exception exception;
gfn_t real_gfn;
gpa_t ngpa;
ngpa = gfn_to_gpa(ngfn);
- real_gfn = mmu->translate_gpa(vcpu, ngpa, access);
+ real_gfn = mmu->translate_gpa(vcpu, ngpa, access, &exception);
if (real_gfn == UNMAPPED_GVA)
return -EFAULT;
@@ -4065,16 +4066,16 @@
kvm_x86_ops->get_segment(vcpu, var, seg);
}
-gpa_t translate_nested_gpa(struct kvm_vcpu *vcpu, gpa_t gpa, u32 access)
+gpa_t translate_nested_gpa(struct kvm_vcpu *vcpu, gpa_t gpa, u32 access,
+ struct x86_exception *exception)
{
gpa_t t_gpa;
- struct x86_exception exception;
BUG_ON(!mmu_is_nested(vcpu));
/* NPT walks are always user-walks */
access |= PFERR_USER_MASK;
- t_gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, gpa, access, &exception);
+ t_gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, gpa, access, exception);
return t_gpa;
}