This is required for the following patch to work correctly. If a nested page
fault happens during emulation, we must inject a vmexit, not a page fault.
Luckily we already have the required machinery: it is enough to return
X86EMUL_INTERCEPTED instead of X86EMUL_PROPAGATE_FAULT.
Reported-by: Valentine Sinitsyn <valentine.sinitsyn@xxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
arch/x86/kvm/x86.c | 18 ++++++++++++++----
1 file changed, 14 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index e4ed85e07a01..9e3b74c044ed 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -416,6 +416,16 @@ void kvm_propagate_fault(struct kvm_vcpu *vcpu, struct x86_exception *fault)
vcpu->arch.mmu.inject_page_fault(vcpu, fault);
}
+static inline int kvm_propagate_or_intercept(struct kvm_vcpu *vcpu,
+ struct x86_exception *exception)
+{
+ if (likely(!exception->nested_page_fault))
+ return X86EMUL_PROPAGATE_FAULT;
+
+ vcpu->arch.mmu.inject_page_fault(vcpu, exception);
+ return X86EMUL_INTERCEPTED;
+}
+
void kvm_inject_nmi(struct kvm_vcpu *vcpu)
{
atomic_inc(&vcpu->arch.nmi_queued);
@@ -4122,7 +4132,7 @@ static int kvm_read_guest_virt_helper(gva_t addr, void *val, unsigned int bytes,
int ret;
if (gpa == UNMAPPED_GVA)
- return X86EMUL_PROPAGATE_FAULT;
+ return kvm_propagate_or_intercept(vcpu, exception);
ret = kvm_read_guest_page(vcpu->kvm, gpa >> PAGE_SHIFT, data,
offset, toread);
if (ret < 0) {
@@ -4152,7 +4162,7 @@ static int kvm_fetch_guest_virt(struct x86_emulate_ctxt *ctxt,
gpa_t gpa = vcpu->arch.walk_mmu->gva_to_gpa(vcpu, addr, access|PFERR_FETCH_MASK,
exception);
if (unlikely(gpa == UNMAPPED_GVA))
- return X86EMUL_PROPAGATE_FAULT;
+ return kvm_propagate_or_intercept(vcpu, exception);
offset = addr & (PAGE_SIZE-1);
if (WARN_ON(offset + bytes > PAGE_SIZE))
@@ -4203,7 +4213,7 @@ int kvm_write_guest_virt_system(struct x86_emulate_ctxt *ctxt,
int ret;
if (gpa == UNMAPPED_GVA)
- return X86EMUL_PROPAGATE_FAULT;
+ return kvm_propagate_or_intercept(vcpu, exception);
ret = kvm_write_guest(vcpu->kvm, gpa, data, towrite);
if (ret < 0) {
r = X86EMUL_IO_NEEDED;
@@ -4350,7 +4360,7 @@ static int emulator_read_write_onepage(unsigned long addr, void *val,
ret = vcpu_mmio_gva_to_gpa(vcpu, addr, &gpa, exception, write);
if (ret < 0)
- return X86EMUL_PROPAGATE_FAULT;
+ return kvm_propagate_or_intercept(vcpu, exception);
/* For APIC access vmexit */
if (ret)
--
1.8.3.1
--
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