[PATCH 3.16 74/83] KVM: nVMX: handle page fault in vmread

[Ben Hutchings]

3.16.78-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Paolo Bonzini <pbonzini@xxxxxxxxxx>

commit f7eea636c3d505fe6f1d1066234f1aaf7171b681 upstream.

The implementation of vmread to memory is still incomplete, as it
lacks the ability to do vmread to I/O memory just like vmptrst.

Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 arch/x86/kvm/vmx.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -6426,6 +6426,7 @@ static int handle_vmread(struct kvm_vcpu
 	unsigned long exit_qualification = vmcs_readl(EXIT_QUALIFICATION);
 	u32 vmx_instruction_info = vmcs_read32(VMX_INSTRUCTION_INFO);
 	gva_t gva = 0;
+	struct x86_exception e;
 
 	if (!nested_vmx_check_permission(vcpu) ||
 	    !nested_vmx_check_vmcs12(vcpu))
@@ -6452,8 +6453,10 @@ static int handle_vmread(struct kvm_vcpu
 				vmx_instruction_info, &gva))
 			return 1;
 		/* _system ok, as nested_vmx_check_permission verified cpl=0 */
-		kvm_write_guest_virt_system(vcpu, gva, &field_value,
-					    (is_long_mode(vcpu) ? 8 : 4), NULL);
+		if (kvm_write_guest_virt_system(vcpu, gva, &field_value,
+						(is_long_mode(vcpu) ? 8 : 4),
+						&e))
+			kvm_inject_page_fault(vcpu, &e);
 	}
 
 	nested_vmx_succeed(vcpu);