summaryrefslogtreecommitdiffstats
path: root/arch/x86
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kvm/mmu.c10
-rw-r--r--arch/x86/kvm/svm.c6
2 files changed, 14 insertions, 2 deletions
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index e5e66e5..d5e5dbd 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -4950,6 +4950,16 @@ int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u64 error_code,
if (mmio_info_in_cache(vcpu, cr2, direct))
emulation_type = 0;
emulate:
+ /*
+ * On AMD platforms, under certain conditions insn_len may be zero on #NPF.
+ * This can happen if a guest gets a page-fault on data access but the HW
+ * table walker is not able to read the instruction page (e.g instruction
+ * page is not present in memory). In those cases we simply restart the
+ * guest.
+ */
+ if (unlikely(insn && !insn_len))
+ return 1;
+
er = x86_emulate_instruction(vcpu, cr2, emulation_type, insn, insn_len);
switch (er) {
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 3e848f9..ec5df57 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -2436,7 +2436,8 @@ static int pf_interception(struct vcpu_svm *svm)
u64 error_code = svm->vmcb->control.exit_info_1;
return kvm_handle_page_fault(&svm->vcpu, error_code, fault_address,
- svm->vmcb->control.insn_bytes,
+ static_cpu_has(X86_FEATURE_DECODEASSISTS) ?
+ svm->vmcb->control.insn_bytes : NULL,
svm->vmcb->control.insn_len);
}
@@ -2447,7 +2448,8 @@ static int npf_interception(struct vcpu_svm *svm)
trace_kvm_page_fault(fault_address, error_code);
return kvm_mmu_page_fault(&svm->vcpu, fault_address, error_code,
- svm->vmcb->control.insn_bytes,
+ static_cpu_has(X86_FEATURE_DECODEASSISTS) ?
+ svm->vmcb->control.insn_bytes : NULL,
svm->vmcb->control.insn_len);
}
OpenPOWER on IntegriCloud