From: Kevin Wolf <kwolf@redhat.com>
To: Sergio Lopez <slp@redhat.com>
Cc: qemu-devel@nongnu.org, qemu-block@nongnu.org,
Max Reitz <mreitz@redhat.com>
Subject: Re: [PATCH v4 0/2] nbd/server: Quiesce coroutines on context switch
Date: Mon, 1 Feb 2021 16:31:34 +0100 [thread overview]
Message-ID: <20210201153134.GE13157@merkur.fritz.box> (raw)
In-Reply-To: <20210201125032.44713-1-slp@redhat.com>
Am 01.02.2021 um 13:50 hat Sergio Lopez geschrieben:
> This series allows the NBD server to properly switch between AIO contexts,
> having quiesced recv_coroutine and send_coroutine before doing the transition.
>
> We need this because we send back devices running in IO Thread owned contexts
> to the main context when stopping the data plane, something that can happen
> multiple times during the lifetime of a VM (usually during the boot sequence or
> on a reboot), and we drag the NBD server of the correspoing export with it.
>
> While there, fix also a problem caused by a cross-dependency between
> closing the export's client connections and draining the block
> layer. The visible effect of this problem was QEMU getting hung when
> the guest request a power off while there's an active NBD client.
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
prev parent reply other threads:[~2021-02-01 15:33 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-01 12:50 [PATCH v4 0/2] nbd/server: Quiesce coroutines on context switch Sergio Lopez
2021-02-01 12:50 ` [PATCH v4 1/2] block: Avoid processing BDS twice in bdrv_set_aio_context_ignore() Sergio Lopez
2021-02-01 12:50 ` [PATCH v4 2/2] block: move blk_exp_close_all() to qemu_cleanup() Sergio Lopez
2021-02-01 15:31 ` Kevin Wolf [this message]
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