redonkable/alistair23-linux
redonkable/alistair23-linux
1
0
Fork 0
Code Releases Activity

KVM: nSVM: cancel KVM_REQ_GET_NESTED_STATE_PAGES on nested vmexit

Browse source 
It is possible to exit the nested guest mode, entered by
svm_set_nested_state prior to first vm entry to it (e.g due to pending event)
if the nested run was not pending during the migration.

In this case we must not switch to the nested msr permission bitmap.
Also add a warning to catch similar cases in the future.

Fixes: a7d5c7ce41 ("KVM: nSVM: delay MSR permission processing to first nested VM run")

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20210107093854.882483-2-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Maxim Levitsky 2021-01-07 11:38:51 +02:00 committed by Paolo Bonzini
parent 56fe28de8c
commit f2c7ef3ba9
3 changed files with 8 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

3
arch/x86/kvm/svm/nested.c
View file

@ -199,6 +199,7 @@ static bool nested_svm_vmrun_msrpm(struct vcpu_svm *svm)
static bool svm_get_nested_state_pages(struct kvm_vcpu *vcpu)
{
struct vcpu_svm *svm = to_svm(vcpu);
if (!nested_svm_vmrun_msrpm(svm)) {
vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
vcpu->run->internal.suberror =
@ -595,6 +596,8 @@ int nested_svm_vmexit(struct vcpu_svm *svm)
svm->nested.vmcb12_gpa = 0;
WARN_ON_ONCE(svm->nested.nested_run_pending);
kvm_clear_request(KVM_REQ_GET_NESTED_STATE_PAGES, &svm->vcpu);
/* in case we halted in L2 */
svm->vcpu.arch.mp_state = KVM_MP_STATE_RUNNABLE;

2
arch/x86/kvm/vmx/nested.c
View file

@ -4442,6 +4442,8 @@ void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 vm_exit_reason,
/* trying to cancel vmlaunch/vmresume is a bug */
WARN_ON_ONCE(vmx->nested.nested_run_pending);
kvm_clear_request(KVM_REQ_GET_NESTED_STATE_PAGES, vcpu);
/* Service the TLB flush request for L2 before switching to L1. */
if (kvm_check_request(KVM_REQ_TLB_FLUSH_CURRENT, vcpu))
kvm_vcpu_flush_tlb_current(vcpu);

4
arch/x86/kvm/x86.c
View file

@ -8789,7 +8789,9 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
if (kvm_request_pending(vcpu)) {
if (kvm_check_request(KVM_REQ_GET_NESTED_STATE_PAGES, vcpu)) {
if (unlikely(!kvm_x86_ops.nested_ops->get_nested_state_pages(vcpu))) {
if (WARN_ON_ONCE(!is_guest_mode(vcpu)))
;
else if (unlikely(!kvm_x86_ops.nested_ops->get_nested_state_pages(vcpu))) {
r = 0;
goto out;
}