According to section "VM-entry Failures During or After Loading Guest State"
in Intel SDM vol 3C,
"No MSRs are saved into the VM-exit MSR-store area."
when bit 31 of the exit reason is set.
Reported-by: Krish Sadhukhan <krish.sadhukhan@xxxxxxxxxx>
Suggested-by: Jim Mattson <jmattson@xxxxxxxxxx>
Signed-off-by: Krish Sadhukhan <krish.sadhukhan@xxxxxxxxxx>
Reviewed-by: Darren Kenny <darren.kenny@xxxxxxxxxx>
---
arch/x86/kvm/vmx.c | 17 +++++++++++++----
1 file changed, 13 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 4555077..9e1a640 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -13827,6 +13827,19 @@ static void prepare_vmcs12(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
* L2 to IDT_VECTORING_INFO_FIELD.
*/
vmcs12_save_pending_event(vcpu, vmcs12);
+
+ /*
+ * There's no need to store the guest's MSRs if we exit
+ * due to a VM-entry failure that occurs during or after
+ * loading the guest state, because the guest has not
+ * executed any instruction in that case. However, here we
+ * are past that point. So we need to save the MSRs.
+ */
+ if (nested_vmx_store_msr(vcpu,
+ vmcs12->vm_exit_msr_store_addr,
+ vmcs12->vm_exit_msr_store_count))
+ nested_vmx_abort(vcpu,
+ VMX_ABORT_SAVE_GUEST_MSR_FAIL);
}
/*
@@ -14159,10 +14172,6 @@ static void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 exit_reason,
* immutable.
*/
nested_flush_cached_shadow_vmcs12(vcpu, vmcs12);
-
- if (nested_vmx_store_msr(vcpu, vmcs12->vm_exit_msr_store_addr,
- vmcs12->vm_exit_msr_store_count))
- nested_vmx_abort(vcpu, VMX_ABORT_SAVE_GUEST_MSR_FAIL);
} else {
/*
* The only expected VM-instruction error is "VM entry with
--
2.9.5
