This is a note to let you know that I've just added the patch titled
kvm: fix wrong address when writing Hyper-V tsc page
to the 3.15-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-fix-wrong-address-when-writing-hyper-v-tsc-page.patch
and it can be found in the queue-3.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From e1fa108d24697b78348fd4e5a531029a50d0d36d Mon Sep 17 00:00:00 2001
From: Xiaoming Gao <newtongao@xxxxxxxxxxx>
Date: Thu, 19 Jun 2014 19:14:57 +0800
Subject: kvm: fix wrong address when writing Hyper-V tsc page
From: Xiaoming Gao <newtongao@xxxxxxxxxxx>
commit e1fa108d24697b78348fd4e5a531029a50d0d36d upstream.
When kvm_write_guest writes the tsc_ref structure to the guest, or it will lead
the low HV_X64_MSR_TSC_REFERENCE_ADDRESS_SHIFT bits of the TSC page address
must be cleared, or the guest can see a non-zero sequence number.
Otherwise Windows guests would not be able to get a correct clocksource
(QueryPerformanceCounter will always return 0) which causes serious chaos.
Signed-off-by: Xiaoming Gao <newtongao@xxxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/kvm/x86.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1912,7 +1912,7 @@ static int set_msr_hyperv_pw(struct kvm_
if (!(data & HV_X64_MSR_TSC_REFERENCE_ENABLE))
break;
gfn = data >> HV_X64_MSR_TSC_REFERENCE_ADDRESS_SHIFT;
- if (kvm_write_guest(kvm, data,
+ if (kvm_write_guest(kvm, gfn << HV_X64_MSR_TSC_REFERENCE_ADDRESS_SHIFT,
&tsc_ref, sizeof(tsc_ref)))
return 1;
mark_page_dirty(kvm, gfn);
Patches currently in stable-queue which might be from newtongao@xxxxxxxxxxx are
queue-3.15/kvm-fix-wrong-address-when-writing-hyper-v-tsc-page.patch
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