From: Peter Xu <peterx@redhat.com>
To: Leonardo Bras <leobras@redhat.com>
Cc: "Daniel P. Berrangé" <berrange@redhat.com>,
"Juan Quintela" <quintela@redhat.com>,
"Dr. David Alan Gilbert" <dgilbert@redhat.com>,
"Eric Blake" <eblake@redhat.com>,
"Markus Armbruster" <armbru@redhat.com>,
徐闯 <xuchuangxclwt@bytedance.com>,
qemu-devel@nongnu.org
Subject: Re: [PATCH v4 2/4] QIOChannelSocket: Fix zero-copy send so socket flush works
Date: Mon, 20 Jun 2022 11:27:47 -0400 [thread overview]
Message-ID: <YrCR89nDyzDitcv8@xz-m1.local> (raw)
In-Reply-To: <20220620053944.257547-3-leobras@redhat.com>
On Mon, Jun 20, 2022 at 02:39:43AM -0300, Leonardo Bras wrote:
> Somewhere between v6 and v7 the of the zero-copy-send patchset a crucial
> part of the flushing mechanism got missing: incrementing zero_copy_queued.
>
> Without that, the flushing interface becomes a no-op, and there is no
> guarantee the buffer is really sent.
>
> This can go as bad as causing a corruption in RAM during migration.
>
> Fixes: 2bc58ffc2926 ("QIOChannelSocket: Implement io_writev zero copy flag & io_flush for CONFIG_LINUX")
> Reported-by: 徐闯 <xuchuangxclwt@bytedance.com>
> Signed-off-by: Leonardo Bras <leobras@redhat.com>
> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
--
Peter Xu
next prev parent reply other threads:[~2022-06-20 15:32 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-20 5:39 [PATCH v4 0/4] MSG_ZEROCOPY fixes & improvements Leonardo Bras
2022-06-20 5:39 ` [PATCH v4 1/4] QIOChannelSocket: Introduce assert and reduce ifdefs to improve readability Leonardo Bras
2022-06-20 8:47 ` Juan Quintela
2022-06-20 15:27 ` Peter Xu
2022-06-20 5:39 ` [PATCH v4 2/4] QIOChannelSocket: Fix zero-copy send so socket flush works Leonardo Bras
2022-06-20 8:48 ` Juan Quintela
2022-06-20 15:27 ` Peter Xu [this message]
2022-06-20 5:39 ` [PATCH v4 3/4] migration: zero-copy flush only at the end of bitmap scanning Leonardo Bras
2022-06-20 9:23 ` Juan Quintela
2022-06-20 15:44 ` Peter Xu
2022-06-21 3:35 ` Leonardo Brás
2022-06-21 14:51 ` Juan Quintela
2022-06-21 15:09 ` Peter Xu
2022-06-21 15:04 ` Peter Xu
2022-06-21 3:26 ` Leonardo Brás
2022-06-20 5:39 ` [PATCH v4 4/4] migration: Change zero_copy_send from migration parameter to migration capability Leonardo Bras
2022-06-20 5:46 ` Leonardo Bras Soares Passos
2022-06-20 9:34 ` Juan Quintela
2022-06-20 15:31 ` Peter Xu
2022-06-20 15:51 ` Juan Quintela
2022-06-21 12:34 ` Markus Armbruster
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