Patch "kvm: nVMX: VMCLEAR should not cause the vCPU to shut down" has been added to the 4.9-stable tree

This is a note to let you know that I've just added the patch titled

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

to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
kvm-nvmx-vmclear-should-not-cause-the-vcpu-to-shut-down.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Jim Mattson <[email protected]>
Date: Thu, 2 Mar 2017 12:41:48 -0800
Subject: kvm: nVMX: VMCLEAR should not cause the vCPU to shut down

From: Jim Mattson <[email protected]>

[ Upstream commit 587d7e72aedca91cee80c0a56811649c3efab765 ]

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

---
 arch/x86/kvm/vmx.c |   22 ++++------------------
 1 file changed, 4 insertions(+), 18 deletions(-)

@@ -7203,9 +7203,8 @@ static int handle_vmoff(struct kvm_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;

@@ -7216,22 +7215,9 @@ static int handle_vmclear(struct kvm_vcp
 	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);
 

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/kvm-nvmx-reset-nested_run_pending-if-the-vcpu-is-going-to-be-reset.patch queue-4.9/kvm-nvmx-vmclear-should-not-cause-the-vcpu-to-shut-down.patch queue-4.9/kvm-vmx-remove-i-o-port-0x80-bypass-on-intel-hosts.patch