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Groups > linux.kernel > #1291637
| From | "K. Y. Srinivasan" <kys@microsoft.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH RESEND 24/27] drivers/hv: correct tsc page sequence invalid value |
| Date | 2015-12-14 23:40 +0100 |
| Message-ID | <qFJWH-3Ss-49@gated-at.bofh.it> (permalink) |
| References | <qFJN1-3NK-19@gated-at.bofh.it> <qFJN1-3NK-17@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
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that Tsc page no longer valid.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>
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: "K. Y. Srinivasan" <kys@microsoft.com>
CC: Haiyang Zhang <haiyangz@microsoft.com>
CC: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
---
drivers/hv/hv.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index 7a06933..1db9556 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -140,7 +140,7 @@ static cycle_t read_hv_clock_tsc(struct clocksource *arg)
cycle_t current_tick;
struct ms_hyperv_tsc_page *tsc_pg = hv_context.tsc_page;
- if (tsc_pg->tsc_sequence != -1) {
+ if (tsc_pg->tsc_sequence != 0) {
/*
* Use the tsc page to compute the value.
*/
@@ -162,7 +162,7 @@ static cycle_t read_hv_clock_tsc(struct clocksource *arg)
if (tsc_pg->tsc_sequence == sequence)
return current_tick;
- if (tsc_pg->tsc_sequence != -1)
+ if (tsc_pg->tsc_sequence != 0)
continue;
/*
* Fallback using MSR method.
--
1.7.4.1
--
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[PATCH RESEND 01/27] Drivers: hv: util: Increase the timeout for util services "K. Y. Srinivasan" <kys@microsoft.com> - 2015-12-14 23:30 +0100
[PATCH RESEND 02/27] Drivers: hv: utils: run polling callback always in interrupt context "K. Y. Srinivasan" <kys@microsoft.com> - 2015-12-14 23:30 +0100
[PATCH RESEND 03/27] tools: hv: report ENOSPC errors in hv_fcopy_daemon "K. Y. Srinivasan" <kys@microsoft.com> - 2015-12-14 23:30 +0100
[PATCH RESEND 06/27] Drivers: hv: utils: use memdup_user in hvt_op_write "K. Y. Srinivasan" <kys@microsoft.com> - 2015-12-14 23:30 +0100
[PATCH RESEND 04/27] tools: hv: remove repeated HV_FCOPY string "K. Y. Srinivasan" <kys@microsoft.com> - 2015-12-14 23:30 +0100
[PATCH RESEND 10/27] drivers:hv: Define the channel type for Hyper-V PCI Express pass-through "K. Y. Srinivasan" <kys@microsoft.com> - 2015-12-14 23:40 +0100
[PATCH RESEND 09/27] drivers:hv: Export the API to invoke a hypercall on Hyper-V "K. Y. Srinivasan" <kys@microsoft.com> - 2015-12-14 23:40 +0100
Re: [PATCH RESEND 09/27] drivers:hv: Export the API to invoke a hypercall on Hyper-V Greg KH <gregkh@linuxfoundation.org> - 2015-12-15 04:10 +0100
RE: [PATCH RESEND 09/27] drivers:hv: Export the API to invoke a hypercall on Hyper-V KY Srinivasan <kys@microsoft.com> - 2015-12-15 05:20 +0100
[PATCH RESEND 14/27] Drivers: hv: vmbus: Get rid of the unused macro "K. Y. Srinivasan" <kys@microsoft.com> - 2015-12-14 23:40 +0100
[PATCH RESEND 20/27] Drivers: hv: vmbus: channge vmbus_connection.channel_lock to mutex "K. Y. Srinivasan" <kys@microsoft.com> - 2015-12-14 23:40 +0100
[PATCH RESEND 26/27] Drivers: hv: utils: Invoke the poll function after handshake "K. Y. Srinivasan" <kys@microsoft.com> - 2015-12-14 23:40 +0100
[PATCH RESEND 05/27] Drivers: hv: util: catch allocation errors "K. Y. Srinivasan" <kys@microsoft.com> - 2015-12-14 23:40 +0100
[PATCH RESEND 08/27] drivers:hv: Export a function that maps Linux CPU num onto Hyper-V proc num "K. Y. Srinivasan" <kys@microsoft.com> - 2015-12-14 23:40 +0100
[PATCH RESEND 07/27] drivers/hv: cleanup synic msrs if vmbus connect failed "K. Y. Srinivasan" <kys@microsoft.com> - 2015-12-14 23:40 +0100
[PATCH RESEND 22/27] tools/hv: Use include/uapi with __EXPORTED_HEADERS__ "K. Y. Srinivasan" <kys@microsoft.com> - 2015-12-14 23:40 +0100
Re: [PATCH RESEND 22/27] tools/hv: Use include/uapi with __EXPORTED_HEADERS__ Greg KH <gregkh@linuxfoundation.org> - 2015-12-15 04:20 +0100
Re: [PATCH RESEND 22/27] tools/hv: Use include/uapi with __EXPORTED_HEADERS__ Kamal Mostafa <kamal@canonical.com> - 2015-12-15 19:20 +0100
[PATCH v2] tools/hv: Use include/uapi with __EXPORTED_HEADERS__ Kamal Mostafa <kamal@canonical.com> - 2015-12-15 19:30 +0100
Re: [PATCH v2] tools/hv: Use include/uapi with __EXPORTED_HEADERS__ Greg KH <gregkh@linuxfoundation.org> - 2015-12-15 19:50 +0100
[PATCH RESEND 25/27] Drivers: hv: vmbus: Force all channel messages to be delivered on CPU 0 "K. Y. Srinivasan" <kys@microsoft.com> - 2015-12-14 23:40 +0100
[PATCH RESEND 21/27] drivers:hv: Allow for MMIO claims that span ACPI _CRS records "K. Y. Srinivasan" <kys@microsoft.com> - 2015-12-14 23:40 +0100
[PATCH RESEND 24/27] drivers/hv: correct tsc page sequence invalid value "K. Y. Srinivasan" <kys@microsoft.com> - 2015-12-14 23:40 +0100
[PATCH RESEND 11/27] Drivers: hv: vss: run only on supported host versions "K. Y. Srinivasan" <kys@microsoft.com> - 2015-12-14 23:40 +0100
[PATCH RESEND 27/27] tools: hv: vss: fix the write()'s argument: error -> vss_msg "K. Y. Srinivasan" <kys@microsoft.com> - 2015-12-14 23:40 +0100
[PATCH RESEND 16/27] Drivers: hv: vmbus: serialize process_chn_event() and vmbus_close_internal() "K. Y. Srinivasan" <kys@microsoft.com> - 2015-12-14 23:40 +0100
[PATCH RESEND 18/27] Drivers: hv: vmbus: fix rescind-offer handling for device without a driver "K. Y. Srinivasan" <kys@microsoft.com> - 2015-12-14 23:40 +0100
[PATCH RESEND 19/27] Drivers: hv: vmbus: release relid on error in vmbus_process_offer() "K. Y. Srinivasan" <kys@microsoft.com> - 2015-12-14 23:40 +0100
[PATCH RESEND 23/27] Drivers: hv: vmbus: Fix a Host signaling bug "K. Y. Srinivasan" <kys@microsoft.com> - 2015-12-14 23:40 +0100
[PATCH RESEND 17/27] Drivers: hv: vmbus: do sanity check of channel state in vmbus_close_internal() "K. Y. Srinivasan" <kys@microsoft.com> - 2015-12-14 23:50 +0100
[PATCH RESEND 13/27] Drivers: hv: vmbus: Use uuid_le_cmp() for comparing GUIDs "K. Y. Srinivasan" <kys@microsoft.com> - 2015-12-14 23:50 +0100
[PATCH RESEND 12/27] Drivers: hv: vmbus: Use uuid_le type consistently "K. Y. Srinivasan" <kys@microsoft.com> - 2015-12-14 23:50 +0100
[PATCH RESEND 15/27] Drivers: hv: vmbus: Get rid of the unused irq variable "K. Y. Srinivasan" <kys@microsoft.com> - 2015-12-14 23:50 +0100
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