From: Stefan Hajnoczi <stefanha@gmail.com>
To: Kevin Wolf <kwolf@redhat.com>
Cc: pbonzini@redhat.com, qemu-devel@nongnu.org, stefanha@redhat.com,
armbru@redhat.com
Subject: Re: [Qemu-devel] [RFC PATCH 00/19] block: Support for 512b-on-4k emulation
Date: Mon, 9 Dec 2013 13:51:48 +0100 [thread overview]
Message-ID: <20131209125148.GD9611@stefanha-thinkpad.redhat.com> (raw)
In-Reply-To: <1386350580-5666-1-git-send-email-kwolf@redhat.com>
On Fri, Dec 06, 2013 at 06:22:41PM +0100, Kevin Wolf wrote:
> This series does not cover 4k guests on a 512 byte host, and I'm not
> sure yet what to do with this case. Paolos series contained a patch to
> protect against "torn reads" (i.e. reads running in parallel with
> writes, which return old data for one half of a sector and new data for
> the other half) by serialising requests if the guest block size was
> greater than the host block size.
>
> One problem with this approach is that it assumes that a single host
> block size even exists and can be compared against on the top level.
> Different backing files can be stored on different storage, though, with
> different block sizes.
As long as the backing file is read-only you won't get torn reads.
next prev parent reply other threads:[~2013-12-09 12:52 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-12-06 17:22 [Qemu-devel] [RFC PATCH 00/19] block: Support for 512b-on-4k emulation Kevin Wolf
2013-12-06 17:22 ` [Qemu-devel] [RFC PATCH 01/19] qemu_memalign: Allow small alignments Kevin Wolf
2013-12-06 17:22 ` [Qemu-devel] [RFC PATCH 02/19] block: Detect unaligned length in bdrv_qiov_is_aligned() Kevin Wolf
2013-12-06 19:12 ` Eric Blake
2013-12-06 17:22 ` [Qemu-devel] [RFC PATCH 03/19] block: Don't use guest sector size for qemu_blockalign() Kevin Wolf
2013-12-10 3:18 ` Wenchao Xia
2013-12-10 9:42 ` Kevin Wolf
2013-12-11 2:43 ` Wenchao Xia
2013-12-06 17:22 ` [Qemu-devel] [RFC PATCH 04/19] block: rename buffer_alignment to guest_block_size Kevin Wolf
2013-12-10 3:25 ` Wenchao Xia
2013-12-06 17:22 ` [Qemu-devel] [RFC PATCH 05/19] raw: Probe required direct I/O alignment Kevin Wolf
2013-12-06 17:53 ` Paolo Bonzini
2013-12-09 12:58 ` Kevin Wolf
2013-12-09 13:40 ` Paolo Bonzini
2013-12-06 17:22 ` [Qemu-devel] [RFC PATCH 06/19] block: Introduce bdrv_aligned_preadv() Kevin Wolf
2013-12-06 17:22 ` [Qemu-devel] [RFC PATCH 07/19] block: Introduce bdrv_co_do_preadv() Kevin Wolf
2013-12-06 17:22 ` [Qemu-devel] [RFC PATCH 08/19] block: Introduce bdrv_aligned_pwritev() Kevin Wolf
2013-12-06 17:22 ` [Qemu-devel] [RFC PATCH 09/19] block: write: Handle COR dependency after I/O throttling Kevin Wolf
2013-12-06 17:22 ` [Qemu-devel] [RFC PATCH 10/19] block: Introduce bdrv_co_do_pwritev() Kevin Wolf
2013-12-06 17:22 ` [Qemu-devel] [RFC PATCH 11/19] block: Switch BdrvTrackedRequest to byte granularity Kevin Wolf
2013-12-06 17:22 ` [Qemu-devel] [RFC PATCH 12/19] block: Allow waiting for overlapping requests between begin/end Kevin Wolf
2013-12-06 17:22 ` [Qemu-devel] [RFC PATCH 13/19] block: Make zero-after-EOF work with larger alignment Kevin Wolf
2013-12-06 17:22 ` [Qemu-devel] [RFC PATCH 14/19] block: Generalise and optimise COR serialisation Kevin Wolf
2013-12-06 17:22 ` [Qemu-devel] [RFC PATCH 15/19] block: Make overlap range for serialisation dynamic Kevin Wolf
2013-12-06 17:22 ` [Qemu-devel] [RFC PATCH 16/19] block: Align requests in bdrv_co_do_pwritev() Kevin Wolf
2013-12-06 17:22 ` [Qemu-devel] [RFC PATCH 17/19] block: Change coroutine wrapper to byte granularity Kevin Wolf
2013-12-06 17:22 ` [Qemu-devel] [RFC PATCH 18/19] block: Make bdrv_pread() a bdrv_prwv_co() wrapper Kevin Wolf
2013-12-06 17:23 ` [Qemu-devel] [RFC PATCH 19/19] block: Make bdrv_pwrite() " Kevin Wolf
2013-12-06 17:55 ` [Qemu-devel] [RFC PATCH 00/19] block: Support for 512b-on-4k emulation Paolo Bonzini
2013-12-09 11:16 ` Kevin Wolf
2013-12-09 12:51 ` Stefan Hajnoczi [this message]
2013-12-09 13:02 ` Kevin Wolf
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