The shadow vmcs12 cannot be flushed on KVM_GET_NESTED_STATE,
because at that point guest memory is assumed by userspace to
be immutable. Capture the cache in vmx_get_nested_state, adding
another page at the end if there is an active shadow vmcs12.
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
arch/x86/kvm/vmx.c | 31 ++++++++++++++++++++++++++++++-
1 file changed, 30 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index b5ee9e08bb48..ce8c0c759a19 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -13167,9 +13167,15 @@ static int vmx_get_nested_state(struct kvm_vcpu *vcpu,
kvm_state.vmx.vmxon_pa = vmx->nested.vmxon_ptr;
kvm_state.vmx.vmcs_pa = vmx->nested.current_vmptr;
- if (vmx->nested.current_vmptr != -1ull)
+ if (vmx->nested.current_vmptr != -1ull) {
kvm_state.size += VMCS12_SIZE;
+ if (is_guest_mode(vcpu) &&
+ nested_cpu_has_shadow_vmcs(vmcs12) &&
+ vmcs12->vmcs_link_pointer != -1ull)
+ kvm_state.size += VMCS12_SIZE;
+ }
+
if (vmx->nested.smm.vmxon)
kvm_state.vmx.smm.flags |= KVM_STATE_NESTED_SMM_VMXON;
@@ -13208,6 +13214,13 @@ static int vmx_get_nested_state(struct kvm_vcpu *vcpu,
if (copy_to_user(user_kvm_nested_state->data, vmcs12, sizeof(*vmcs12)))
return -EFAULT;
+ if (nested_cpu_has_shadow_vmcs(vmcs12) &&
+ vmcs12->vmcs_link_pointer != -1ull) {
+ if (copy_to_user(user_kvm_nested_state->data + VMCS12_SIZE,
+ get_shadow_vmcs12(vcpu), sizeof(*vmcs12)))
+ return -EFAULT;
+ }
+
out:
return kvm_state.size;
}
@@ -13288,6 +13301,22 @@ static int vmx_set_nested_state(struct kvm_vcpu *vcpu,
vmx->nested.nested_run_pending =
!!(kvm_state->flags & KVM_STATE_NESTED_RUN_PENDING);
+ if (nested_cpu_has_shadow_vmcs(vmcs12) &&
+ vmcs12->vmcs_link_pointer != -1ull) {
+ struct vmcs12 *shadow_vmcs12 = get_shadow_vmcs12(vcpu);
+ if (kvm_state->size < sizeof(kvm_state) + 2 * sizeof(*vmcs12))
+ return -EINVAL;
+
+ if (copy_from_user(shadow_vmcs12,
+ user_kvm_nested_state->data + VMCS12_SIZE,
+ sizeof(*vmcs12)))
+ return -EFAULT;
+
+ if (shadow_vmcs12->hdr.revision_id != VMCS12_REVISION ||
+ !shadow_vmcs12->hdr.shadow_vmcs)
+ return -EINVAL;
+ }
+
if (check_vmentry_prereqs(vcpu, vmcs12) ||
check_vmentry_postreqs(vcpu, vmcs12, &exit_qual))
return -EINVAL;
--
1.8.3.1
