From: "Fernando Luis Vázquez Cao" <fernando@oss.ntt.co.jp>
To: Yoshiaki Tamura <tamura.yoshiaki@lab.ntt.co.jp>
Cc: dlaor@redhat.com, ohmura.kei@lab.ntt.co.jp, kvm@vger.kernel.org,
mtosatti@redhat.com, aliguori@us.ibm.com, qemu-devel@nongnu.org,
yoshikawa.takuya@oss.ntt.co.jp, avi@redhat.com
Subject: Re: [Qemu-devel] [RFC PATCH 00/20] Kemari for KVM v0.1
Date: Fri, 23 Apr 2010 16:36:44 +0900 [thread overview]
Message-ID: <4BD14E0C.9010902@oss.ntt.co.jp> (raw)
In-Reply-To: <4BD12D54.2020304@lab.ntt.co.jp>
On 04/23/2010 02:17 PM, Yoshiaki Tamura wrote:
> Dor Laor wrote:
[...]
>> Second, even if it wasn't the case, the tsc delta and kvmclock are
>> synchronized as part of the VM state so there is no use of trapping it
>> in the middle.
>
> I should study the clock in KVM, but won't tsc get updated by the HW
> after migration?
> I was wondering the following case for example:
>
> 1. The application on the guest calls rdtsc on host A.
> 2. The application uses rdtsc value for something.
> 3. Failover to host B.
> 4. The application on the guest replays the rdtsc call on host B.
> 5. If the rdtsc value is different between A and B, the application may
> get into trouble because of it.
Regarding the TSC, we need to guarantee that the guest sees a monotonic
TSC after migration, which can be achieved by adjusting the TSC offset properly.
Besides, we also need a trapping TSC, so that we can tackle the case where the
primary node and the standby node have different TSC frequencies.
WARNING: multiple messages have this Message-ID (diff)
From: "Fernando Luis Vázquez Cao" <fernando@oss.ntt.co.jp>
To: Yoshiaki Tamura <tamura.yoshiaki@lab.ntt.co.jp>
Cc: ohmura.kei@lab.ntt.co.jp, mtosatti@redhat.com,
kvm@vger.kernel.org, dlaor@redhat.com, qemu-devel@nongnu.org,
yoshikawa.takuya@oss.ntt.co.jp, aliguori@us.ibm.com,
avi@redhat.com
Subject: Re: [Qemu-devel] [RFC PATCH 00/20] Kemari for KVM v0.1
Date: Fri, 23 Apr 2010 16:36:44 +0900 [thread overview]
Message-ID: <4BD14E0C.9010902@oss.ntt.co.jp> (raw)
In-Reply-To: <4BD12D54.2020304@lab.ntt.co.jp>
On 04/23/2010 02:17 PM, Yoshiaki Tamura wrote:
> Dor Laor wrote:
[...]
>> Second, even if it wasn't the case, the tsc delta and kvmclock are
>> synchronized as part of the VM state so there is no use of trapping it
>> in the middle.
>
> I should study the clock in KVM, but won't tsc get updated by the HW
> after migration?
> I was wondering the following case for example:
>
> 1. The application on the guest calls rdtsc on host A.
> 2. The application uses rdtsc value for something.
> 3. Failover to host B.
> 4. The application on the guest replays the rdtsc call on host B.
> 5. If the rdtsc value is different between A and B, the application may
> get into trouble because of it.
Regarding the TSC, we need to guarantee that the guest sees a monotonic
TSC after migration, which can be achieved by adjusting the TSC offset properly.
Besides, we also need a trapping TSC, so that we can tackle the case where the
primary node and the standby node have different TSC frequencies.
next prev parent reply other threads:[~2010-04-23 7:36 UTC|newest]
Thread overview: 144+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-04-21 5:57 [RFC PATCH 00/20] Kemari for KVM v0.1 Yoshiaki Tamura
2010-04-21 5:57 ` [Qemu-devel] " Yoshiaki Tamura
2010-04-21 5:57 ` [RFC PATCH 01/20] Modify DIRTY_FLAG value and introduce DIRTY_IDX to use as indexes of bit-based phys_ram_dirty Yoshiaki Tamura
2010-04-21 5:57 ` [Qemu-devel] " Yoshiaki Tamura
2010-04-22 19:26 ` Anthony Liguori
2010-04-22 19:26 ` [Qemu-devel] " Anthony Liguori
2010-04-23 2:09 ` Yoshiaki Tamura
2010-04-23 2:09 ` [Qemu-devel] " Yoshiaki Tamura
2010-04-21 5:57 ` [RFC PATCH 02/20] Introduce cpu_physical_memory_get_dirty_range() Yoshiaki Tamura
2010-04-21 5:57 ` [Qemu-devel] " Yoshiaki Tamura
2010-04-21 5:57 ` [RFC PATCH 03/20] Use cpu_physical_memory_set_dirty_range() to update phys_ram_dirty Yoshiaki Tamura
2010-04-21 5:57 ` [Qemu-devel] " Yoshiaki Tamura
2010-04-21 5:57 ` [RFC PATCH 04/20] Make QEMUFile buf expandable, and introduce qemu_realloc_buffer() and qemu_clear_buffer() Yoshiaki Tamura
2010-04-21 5:57 ` [Qemu-devel] " Yoshiaki Tamura
2010-04-21 8:03 ` Stefan Hajnoczi
2010-04-21 8:03 ` [Qemu-devel] " Stefan Hajnoczi
2010-04-21 8:27 ` Yoshiaki Tamura
2010-04-21 8:27 ` [Qemu-devel] " Yoshiaki Tamura
2010-04-23 9:53 ` Avi Kivity
2010-04-23 9:53 ` [Qemu-devel] " Avi Kivity
2010-04-23 9:59 ` Yoshiaki Tamura
2010-04-23 9:59 ` [Qemu-devel] " Yoshiaki Tamura
2010-04-23 13:14 ` Avi Kivity
2010-04-23 13:14 ` [Qemu-devel] " Avi Kivity
2010-04-26 10:43 ` Yoshiaki Tamura
2010-04-26 10:43 ` [Qemu-devel] " Yoshiaki Tamura
2010-04-23 13:26 ` Anthony Liguori
2010-04-23 13:26 ` [Qemu-devel] " Anthony Liguori
2010-04-21 5:57 ` [RFC PATCH 05/20] Introduce put_vector() and get_vector to QEMUFile and qemu_fopen_ops() Yoshiaki Tamura
2010-04-21 5:57 ` [Qemu-devel] " Yoshiaki Tamura
2010-04-22 19:28 ` Anthony Liguori
2010-04-22 19:28 ` [Qemu-devel] " Anthony Liguori
2010-04-23 3:37 ` Yoshiaki Tamura
2010-04-23 3:37 ` [Qemu-devel] " Yoshiaki Tamura
2010-04-23 13:22 ` Anthony Liguori
2010-04-23 13:22 ` [Qemu-devel] " Anthony Liguori
2010-04-23 13:48 ` Avi Kivity
2010-04-23 13:48 ` [Qemu-devel] " Avi Kivity
2010-05-03 9:32 ` Yoshiaki Tamura
2010-05-03 9:32 ` [Qemu-devel] " Yoshiaki Tamura
2010-05-03 12:05 ` Anthony Liguori
2010-05-03 12:05 ` [Qemu-devel] " Anthony Liguori
2010-05-03 15:36 ` Yoshiaki Tamura
2010-05-03 15:36 ` [Qemu-devel] " Yoshiaki Tamura
2010-05-03 16:07 ` Anthony Liguori
2010-05-03 16:07 ` [Qemu-devel] " Anthony Liguori
2010-04-26 10:43 ` Yoshiaki Tamura
2010-04-26 10:43 ` [Qemu-devel] " Yoshiaki Tamura
2010-04-21 5:57 ` [RFC PATCH 06/20] Introduce iovec util functions, qemu_iovec_to_vector() and qemu_iovec_to_size() Yoshiaki Tamura
2010-04-21 5:57 ` [Qemu-devel] " Yoshiaki Tamura
2010-04-21 5:57 ` [RFC PATCH 07/20] Introduce qemu_put_vector() and qemu_put_vector_prepare() to use put_vector() in QEMUFile Yoshiaki Tamura
2010-04-21 5:57 ` [Qemu-devel] " Yoshiaki Tamura
2010-04-22 19:29 ` Anthony Liguori
2010-04-22 19:29 ` [Qemu-devel] " Anthony Liguori
2010-04-23 4:02 ` Yoshiaki Tamura
2010-04-23 4:02 ` [Qemu-devel] " Yoshiaki Tamura
2010-04-23 13:23 ` Anthony Liguori
2010-04-23 13:23 ` [Qemu-devel] " Anthony Liguori
2010-04-26 10:43 ` Yoshiaki Tamura
2010-04-26 10:43 ` [Qemu-devel] " Yoshiaki Tamura
2010-04-21 5:57 ` [RFC PATCH 08/20] Introduce RAMSaveIO and use cpu_physical_memory_get_dirty_range() to check multiple dirty pages Yoshiaki Tamura
2010-04-21 5:57 ` [Qemu-devel] " Yoshiaki Tamura
2010-04-22 19:31 ` Anthony Liguori
2010-04-22 19:31 ` [Qemu-devel] " Anthony Liguori
2010-04-21 5:57 ` [RFC PATCH 09/20] Introduce writev and read to FdMigrationState Yoshiaki Tamura
2010-04-21 5:57 ` [Qemu-devel] " Yoshiaki Tamura
2010-04-21 5:57 ` [RFC PATCH 10/20] Introduce skip_header parameter to qemu_loadvm_state() so that it can be called iteratively without reading the header Yoshiaki Tamura
2010-04-21 5:57 ` [Qemu-devel] " Yoshiaki Tamura
2010-04-22 19:34 ` Anthony Liguori
2010-04-22 19:34 ` [Qemu-devel] " Anthony Liguori
2010-04-23 4:25 ` Yoshiaki Tamura
2010-04-23 4:25 ` [Qemu-devel] " Yoshiaki Tamura
2010-04-21 5:57 ` [RFC PATCH 11/20] Introduce some socket util functions Yoshiaki Tamura
2010-04-21 5:57 ` [Qemu-devel] " Yoshiaki Tamura
2010-04-21 5:57 ` [RFC PATCH 12/20] Introduce fault tolerant VM transaction QEMUFile and ft_mode Yoshiaki Tamura
2010-04-21 5:57 ` [Qemu-devel] " Yoshiaki Tamura
2010-04-21 5:57 ` [RFC PATCH 13/20] Introduce util functions to control ft_transaction from savevm layer Yoshiaki Tamura
2010-04-21 5:57 ` [Qemu-devel] " Yoshiaki Tamura
2010-04-21 5:57 ` [RFC PATCH 14/20] Upgrade QEMU_FILE_VERSION from 3 to 4, and introduce qemu_savevm_state_all() Yoshiaki Tamura
2010-04-21 5:57 ` [Qemu-devel] " Yoshiaki Tamura
2010-04-22 19:37 ` Anthony Liguori
2010-04-22 19:37 ` [Qemu-devel] " Anthony Liguori
2010-04-23 3:29 ` Yoshiaki Tamura
2010-04-23 3:29 ` [Qemu-devel] " Yoshiaki Tamura
2010-04-21 5:57 ` [RFC PATCH 15/20] Introduce FT mode support to configure Yoshiaki Tamura
2010-04-21 5:57 ` [Qemu-devel] " Yoshiaki Tamura
2010-04-22 19:38 ` Anthony Liguori
2010-04-22 19:38 ` [Qemu-devel] " Anthony Liguori
2010-04-23 3:09 ` Yoshiaki Tamura
2010-04-23 3:09 ` [Qemu-devel] " Yoshiaki Tamura
2010-04-21 5:57 ` [RFC PATCH 16/20] Introduce event_tap fucntions and ft_tranx_ready() Yoshiaki Tamura
2010-04-21 5:57 ` [Qemu-devel] " Yoshiaki Tamura
2010-04-21 5:57 ` [RFC PATCH 17/20] Modify migrate_fd_put_ready() when ft_mode is on Yoshiaki Tamura
2010-04-21 5:57 ` [Qemu-devel] " Yoshiaki Tamura
2010-04-21 5:57 ` [RFC PATCH 18/20] Modify tcp_accept_incoming_migration() to handle ft_mode, and add a hack not to close fd when ft_mode is enabled Yoshiaki Tamura
2010-04-21 5:57 ` [Qemu-devel] " Yoshiaki Tamura
2010-04-21 5:57 ` [RFC PATCH 19/20] Insert do_event_tap() to virtio-{blk,net}, comment out assert() on cpu_single_env temporally Yoshiaki Tamura
2010-04-21 5:57 ` [Qemu-devel] [RFC PATCH 19/20] Insert do_event_tap() to virtio-{blk, net}, " Yoshiaki Tamura
2010-04-22 19:39 ` Anthony Liguori
2010-04-22 19:39 ` [Qemu-devel] " Anthony Liguori
2010-04-23 4:51 ` Yoshiaki Tamura
2010-04-23 4:51 ` [Qemu-devel] " Yoshiaki Tamura
2010-04-21 5:57 ` [RFC PATCH 20/20] Introduce -k option to enable FT migration mode (Kemari) Yoshiaki Tamura
2010-04-21 5:57 ` [Qemu-devel] " Yoshiaki Tamura
2010-04-22 8:58 ` [Qemu-devel] [RFC PATCH 00/20] Kemari for KVM v0.1 Dor Laor
2010-04-22 8:58 ` Dor Laor
2010-04-22 10:35 ` Yoshiaki Tamura
2010-04-22 10:35 ` Yoshiaki Tamura
2010-04-22 11:36 ` Takuya Yoshikawa
2010-04-22 11:36 ` Takuya Yoshikawa
2010-04-22 12:35 ` Yoshiaki Tamura
2010-04-22 12:35 ` Yoshiaki Tamura
2010-04-22 12:19 ` Dor Laor
2010-04-22 13:16 ` Yoshiaki Tamura
2010-04-22 20:33 ` Anthony Liguori
2010-04-22 20:33 ` Anthony Liguori
2010-04-23 1:53 ` Yoshiaki Tamura
2010-04-23 1:53 ` Yoshiaki Tamura
2010-04-23 13:20 ` Anthony Liguori
2010-04-23 13:20 ` Anthony Liguori
2010-04-26 10:44 ` Yoshiaki Tamura
2010-04-26 10:44 ` Yoshiaki Tamura
2010-04-22 20:38 ` Dor Laor
2010-04-23 5:17 ` Yoshiaki Tamura
2010-04-23 7:36 ` Fernando Luis Vázquez Cao [this message]
2010-04-23 7:36 ` Fernando Luis Vázquez Cao
2010-04-25 21:52 ` Dor Laor
2010-04-25 21:52 ` Dor Laor
2010-04-22 16:15 ` Jamie Lokier
2010-04-22 16:15 ` Jamie Lokier
2010-04-23 0:20 ` Yoshiaki Tamura
2010-04-23 0:20 ` Yoshiaki Tamura
2010-04-23 15:07 ` Jamie Lokier
2010-04-23 15:07 ` Jamie Lokier
2010-04-22 19:42 ` Anthony Liguori
2010-04-22 19:42 ` [Qemu-devel] " Anthony Liguori
2010-04-23 0:45 ` Yoshiaki Tamura
2010-04-23 0:45 ` [Qemu-devel] " Yoshiaki Tamura
2010-04-23 13:10 ` Anthony Liguori
2010-04-23 13:10 ` [Qemu-devel] " Anthony Liguori
2010-04-23 13:24 ` Avi Kivity
2010-04-23 13:24 ` [Qemu-devel] " Avi Kivity
2010-04-26 10:44 ` Yoshiaki Tamura
2010-04-26 10:44 ` [Qemu-devel] " Yoshiaki Tamura
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