Patch "KVM: x86: mask CPUID(0xD,0x1).EAX against host value" has been added to the 4.5-stable tree

Patch "KVM: x86: mask CPUID(0xD,0x1).EAX against host value" has been added to the 4.5-stable tree

[gregkh]

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

    KVM: x86: mask CPUID(0xD,0x1).EAX against host value

to the 4.5-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-x86-mask-cpuid-0xd-0x1-.eax-against-host-value.patch
and it can be found in the queue-4.5 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 316314cae15fb0e3869b76b468f59a0c83ac3d4e Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonzini@redhat.com>
Date: Mon, 21 Mar 2016 12:33:00 +0100
Subject: KVM: x86: mask CPUID(0xD,0x1).EAX against host value
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

From: Paolo Bonzini <pbonzini@redhat.com>

commit 316314cae15fb0e3869b76b468f59a0c83ac3d4e upstream.

This ensures that the guest doesn't see XSAVE extensions
(e.g. xgetbv1 or xsavec) that the host lacks.

Cc: stable@vger.kernel.org
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
[4.5 does have CPUID_D_1_EAX, but earlier kernels don't, so use
 the numeric value.  This is consistent with other occurrences
 of cpuid_mask in arch/x86/kvm/cpuid.c - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/x86/kvm/cpuid.c |    1 +
 1 file changed, 1 insertion(+)

--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -509,6 +509,7 @@ static inline int __do_cpuid_ent(struct
 			do_cpuid_1_ent(&entry[i], function, idx);
 			if (idx == 1) {
 				entry[i].eax &= kvm_supported_word10_x86_features;
+				cpuid_mask(&entry[i].eax, 10);
 				entry[i].ebx = 0;
 				if (entry[i].eax & (F(XSAVES)|F(XSAVEC)))
 					entry[i].ebx =


Patches currently in stable-queue which might be from pbonzini@redhat.com are

queue-4.5/kvm-mtrr-remove-msr-0x2f8.patch
queue-4.5/kvm-x86-mask-cpuid-0xd-0x1-.eax-against-host-value.patch
queue-4.5/mips-kvm-fix-timer-irq-race-when-writing-cp0_compare.patch
queue-4.5/mips-kvm-fix-timer-irq-race-when-freezing-timer.patch