linux/drivers/hv
Andrey Smetanin c35b82ef02 drivers/hv: correct tsc page sequence invalid value
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that Tsc page no longer valid.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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-14 19:15:05 -08:00
..
channel_mgmt.c Drivers: hv: vmbus: channge vmbus_connection.channel_lock to mutex 2015-12-14 19:15:05 -08:00
channel.c Drivers: hv: vmbus: Fix a Host signaling bug 2015-12-14 19:15:05 -08:00
connection.c Drivers: hv: vmbus: channge vmbus_connection.channel_lock to mutex 2015-12-14 19:15:05 -08:00
hv_balloon.c Drivers: hv: balloon: Enable dynamic memory protocol negotiation with Windows 10 hosts 2015-08-04 22:28:39 -07:00
hv_fcopy.c Drivers: hv: utils: run polling callback always in interrupt context 2015-12-14 19:12:21 -08:00
hv_kvp.c Drivers: hv: utils: run polling callback always in interrupt context 2015-12-14 19:12:21 -08:00
hv_snapshot.c Drivers: hv: vss: run only on supported host versions 2015-12-14 19:15:05 -08:00
hv_util.c Drivers: hv: util: On device remove, close the channel after de-initializing the service 2015-03-01 19:31:02 -08:00
hv_utils_transport.c Drivers: hv: utils: use memdup_user in hvt_op_write 2015-12-14 19:12:21 -08:00
hv_utils_transport.h Drivers: hv: util: introduce hv_utils_transport abstraction 2015-05-24 12:17:41 -07:00
hv.c drivers/hv: correct tsc page sequence invalid value 2015-12-14 19:15:05 -08:00
hyperv_vmbus.h Drivers: hv: vmbus: channge vmbus_connection.channel_lock to mutex 2015-12-14 19:15:05 -08:00
Kconfig x86: Make Linux guest support optional 2013-03-04 13:14:25 -08:00
Makefile Drivers: hv: util: introduce hv_utils_transport abstraction 2015-05-24 12:17:41 -07:00
ring_buffer.c Drivers: hv_vmbus: Fix signal to host condition 2015-08-05 11:44:29 -07:00
vmbus_drv.c drivers:hv: Allow for MMIO claims that span ACPI _CRS records 2015-12-14 19:15:05 -08:00