From: Xiongzi Ge <gexxx132@umn.edu>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] The first function called after migration for a block device
Date: Fri, 27 Jun 2014 18:54:09 -0400 [thread overview]
Message-ID: <CACtCCo-QTDp72ZNDvk2rWUaA7bAv+6tTCo2jFqvFYKDObOVGqQ@mail.gmail.com> (raw)
In-Reply-To: <53ADE6F8.1070303@redhat.com>
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Hi Paolo,
Thanks. I found a function called bdrv_invalidate_cache() in qcow2.c. After
migration, it will be called to invalidate the cache of the block device?
On Fri, Jun 27, 2014 at 5:49 PM, Paolo Bonzini <pbonzini@redhat.com> wrote:
> Il 27/06/2014 21:41, Xiongzi Ge ha scritto:
>
>
>> When I studied the code, I found in migration.c,
>> bdrv_clear_incoming_migration_all();
>>
>> the cache of the bdrv devices will be deleted.
>>
>> Is this the one for the functions to be called after migration?
>>
>> Does the bdrv device need to be reopen or load state in block.c?
>>
>> I would like to find this function to add my new code.
>>
>
> This function is not going to do anything if your code is in "raw" format.
> In particular, it has *nothing* to do with the guest OS's cache. That
> cache is managed by the guest OS and, as I have already told you multiple
> times, there is *nothing* that QEMU can do about it.
>
> All you can do is use O_DIRECT in the guest.
>
> Paolo
>
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next prev parent reply other threads:[~2014-06-27 22:54 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-27 19:41 [Qemu-devel] The first function called after migration for a block device Xiongzi Ge
2014-06-27 21:49 ` Paolo Bonzini
2014-06-27 22:54 ` Xiongzi Ge [this message]
2014-06-30 10:48 ` Paolo Bonzini
2014-06-30 14:03 ` Xiongzi Ge
2014-06-30 14:35 ` Paolo Bonzini
2014-06-30 14:47 ` Xiongzi Ge
2014-06-30 15:13 ` Paolo Bonzini
2014-06-30 15:17 ` Xiongzi Ge
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