kvm: nVMX: VMCLEAR should not cause the vCPU to shut down

VMCLEAR should silently ignore a failure to clear the launch state of
the VMCS referenced by the operand.

Signed-off-by: Jim Mattson <jmattson@google.com>
[Changed "kvm_write_guest(vcpu->kvm" to "kvm_vcpu_write_guest(vcpu".]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 283aa86..3b626d6 100644 (file)
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -7258,9 +7258,8 @@ static int handle_vmoff(struct kvm_vcpu *vcpu)
 static int handle_vmclear(struct kvm_vcpu *vcpu)
 {
        struct vcpu_vmx *vmx = to_vmx(vcpu);
+       u32 zero = 0;
        gpa_t vmptr;
-       struct vmcs12 *vmcs12;
-       struct page *page;
 
        if (!nested_vmx_check_permission(vcpu))
                return 1;
@@ -7271,22 +7270,9 @@ static int handle_vmclear(struct kvm_vcpu *vcpu)
        if (vmptr == vmx->nested.current_vmptr)
                nested_release_vmcs12(vmx);
 
-       page = nested_get_page(vcpu, vmptr);
-       if (page == NULL) {
-               /*
-                * For accurate processor emulation, VMCLEAR beyond available
-                * physical memory should do nothing at all. However, it is
-                * possible that a nested vmx bug, not a guest hypervisor bug,
-                * resulted in this case, so let's shut down before doing any
-                * more damage:
-                */
-               kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu);
-               return 1;
-       }
-       vmcs12 = kmap(page);
-       vmcs12->launch_state = 0;
-       kunmap(page);
-       nested_release_page(page);
+       kvm_vcpu_write_guest(vcpu,
+                       vmptr + offsetof(struct vmcs12, launch_state),
+                       &zero, sizeof(zero));
 
        nested_free_vmcs02(vmx, vmptr);