[3.16.y-ckt stable] Patch "KVM: vmx: fix VPID is 0000H in non-root operation" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    KVM: vmx: fix VPID is 0000H in non-root operation

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue

This patch is scheduled to be released in version 3.19.8-ckt9.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

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>From 7fb7dfcbbd19556dfb532ba05b96033877417fe9 Mon Sep 17 00:00:00 2001
From: Wanpeng Li <wanpeng.li at hotmail.com>
Date: Wed, 16 Sep 2015 19:31:11 +0800
Subject: KVM: vmx: fix VPID is 0000H in non-root operation
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

commit 04bb92e4b4cf06a66889d37b892b78f926faa9d4 upstream.

Reference SDM 28.1:

The current VPID is 0000H in the following situations:
- Outside VMX operation. (This includes operation in system-management
  mode under the default treatment of SMIs and SMM with VMX operation;
  see Section 34.14.)
- In VMX root operation.
- In VMX non-root operation when the “enable VPID” VM-execution control
  is 0.

The VPID should never be 0000H in non-root operation when "enable VPID"
VM-execution control is 1. However, commit 34a1cd60 ("kvm: x86: vmx:
move some vmx setting from vmx_init() to hardware_setup()") remove the
codes which reserve 0000H for VMX root operation.

This patch fix it by again reserving 0000H for VMX root operation.

Fixes: 34a1cd60d17f62c1f077c1478a6c2ca8c3d17af4
Reported-by: Wincy Van <fanwenyi0529 at gmail.com>
Signed-off-by: Wanpeng Li <wanpeng.li at hotmail.com>
Signed-off-by: Paolo Bonzini <pbonzini at redhat.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 arch/x86/kvm/vmx.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index bde6bd1..ba2ba0f 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -5918,6 +5918,8 @@ static __init int hardware_setup(void)
 	memcpy(vmx_msr_bitmap_longmode_x2apic,
 			vmx_msr_bitmap_longmode, PAGE_SIZE);

+	set_bit(0, vmx_vpid_bitmap); /* 0 is reserved for host */
+
 	if (enable_apicv) {
 		for (msr = 0x800; msr <= 0x8ff; msr++)
 			vmx_disable_intercept_msr_read_x2apic(msr);
--
1.9.1