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Groups > linux.kernel > #1267668
| From | "Denis V. Lunev" <den@openvz.org> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH 1/1] drivers/hv: correct tsc page sequence invalid value |
| Date | 2015-11-12 08:20 +0100 |
| Message-ID | <qtUkO-5Od-5@gated-at.bofh.it> (permalink) |
| References | <qqlCW-4Kt-21@gated-at.bofh.it> <qquGf-1YL-25@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On 11/02/2015 10:42 PM, KY Srinivasan wrote:
>
>> -----Original Message-----
>> From: Denis V. Lunev [mailto:den@openvz.org]
>> Sent: Monday, November 2, 2015 3:34 AM
>> Cc: rkagan@virtuozzo.com; devel@linuxdriverproject.org; linux-
>> kernel@vger.kernel.org; Andrey Smetanin <asmetanin@virtuozzo.com>; KY
>> Srinivasan <kys@microsoft.com>; Haiyang Zhang
>> <haiyangz@microsoft.com>; Vitaly Kuznetsov <vkuznets@redhat.com>;
>> Denis V. Lunev <den@openvz.org>
>> Subject: [PATCH 1/1] drivers/hv: correct tsc page sequence invalid value
>>
>> From: Andrey Smetanin <asmetanin@virtuozzo.com>
>>
>> Hypervisor Top Level Functional Specification v3/4 says
>> that TSC page sequence value = -1(0xFFFFFFFF) is used to
>> indicate that TSC page no longer reliable source of reference
>> timer. Unfortunately, we found that Windows Hyper-V guest
>> side implementation uses sequence value = 0 to indicate
>> that Tsc page no longer valid. This is clearly visible
>> inside Windows 2012R2 ntoskrnl.exe HvlGetReferenceTime()
>> function dissassembly:
>>
>> HvlGetReferenceTime proc near
>> xchg ax, ax
>> loc_1401C3132:
>> mov rax, cs:HvlpReferenceTscPage
>> mov r9d, [rax]
>> test r9d, r9d
>> jz short loc_1401C3176
>> rdtsc
>> mov rcx, cs:HvlpReferenceTscPage
>> shl rdx, 20h
>> or rdx, rax
>> mov rax, [rcx+8]
>> mov rcx, cs:HvlpReferenceTscPage
>> mov r8, [rcx+10h]
>> mul rdx
>> mov rax, cs:HvlpReferenceTscPage
>> add rdx, r8
>> mov ecx, [rax]
>> cmp ecx, r9d
>> jnz short loc_1401C3132
>> jmp short loc_1401C3184
>> loc_1401C3176:
>> mov ecx, 40000020h
>> rdmsr
>> shl rdx, 20h
>> or rdx, rax
>> loc_1401C3184:
>> mov rax, rdx
>> retn
>> HvlGetReferenceTime endp
>>
>> This patch aligns Tsc page invalid sequence value with
>> Windows Hyper-V guest implementation which is more
>> compatible with both Hyper-V hypervisor and KVM hypervisor.
>>
>> Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
>> CC: "K. Y. Srinivasan" <kys@microsoft.com>
> Thanks Andrey; the Hyper-V team will be updating the Hyper-V documentation.
>
> Acked-by: K. Y. Srinivasan <kys@microsoft.com>
>
> Regards,
>
> K. Y
K.Y.,
can you pls clarify the state of this patch? It is a bit unclear
to me whether it is applied or not.
By the way, I also do not see the following patch
"drivers/hv: cleanup synic msrs if vmbus connect failed"
as applied in the Linux-next. You have promised to resend
it will correct author.
Thank you in advance,
Den
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[PATCH 1/1] drivers/hv: correct tsc page sequence invalid value "Denis V. Lunev" <den@openvz.org> - 2015-11-02 12:40 +0100
RE: [PATCH 1/1] drivers/hv: correct tsc page sequence invalid value KY Srinivasan <kys@microsoft.com> - 2015-11-02 22:20 +0100
Re: [PATCH 1/1] drivers/hv: correct tsc page sequence invalid value "Denis V. Lunev" <den@openvz.org> - 2015-11-12 08:20 +0100
RE: [PATCH 1/1] drivers/hv: correct tsc page sequence invalid value KY Srinivasan <kys@microsoft.com> - 2015-11-12 18:40 +0100
Re: [PATCH 1/1] drivers/hv: correct tsc page sequence invalid value "Denis V. Lunev" <den@openvz.org> - 2015-11-12 20:00 +0100
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