[PATCH 3.19.y-ckt 32/86] KVM: vmx: fix VPID is 0000H in non-root operation

From: Kamal Mostafa
Date: Tue Oct 27 2015 - 18:09:04 EST

3.19.8-ckt9 -stable review patch. If anyone has any objections, please let me know.


From: Wanpeng Li <wanpeng.li@xxxxxxxxxxx>

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 âenable VPIDâ 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@xxxxxxxxx>
Signed-off-by: Wanpeng Li <wanpeng.li@xxxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
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)
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++)

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