From: Stefan Hajnoczi <stefanha@redhat.com>
To: John Snow <jsnow@redhat.com>
Cc: kwolf@redhat.com, qemu-devel@nongnu.org, qemu-block@nongnu.org
Subject: Re: [Qemu-devel] [PATCH] ide: remove hardcoded 2GiB transactional limit
Date: Tue, 27 Oct 2015 16:50:15 +0000 [thread overview]
Message-ID: <20151027165015.GA9986@stefanha-x1.localdomain> (raw)
In-Reply-To: <1445902682-20051-1-git-send-email-jsnow@redhat.com>
On Mon, Oct 26, 2015 at 07:38:02PM -0400, John Snow wrote:
> Not that you can request a >2GiB transaction, but that's why checking
> for it makes no sense anymore.
>
> With the newer 'limit' parameter to prepare_buf, we no longer need a
> static limit. The maximum limit is still 2GiB, but the limit parameter
> is set to the current transaction size, which cannot surpass 32MiB
> (512 * 65536). If the PRDT surpasses the transactional size, then,
> we'll just carry out the normative underflow handling pathways instead
> of needing an extra, strange pathway that worries about hitting some
> logistical cap for the largest sglist we can support -- we'll never
> even attempt to build one that big anymore.
>
> Reported-by: Kevin Wolf <kwolf@redhat.com>
> Signed-off-by: John Snow <jsnow@redhat.com>
> ---
> hw/ide/ahci.c | 30 ++++++++++++++----------------
> hw/ide/internal.h | 2 +-
> hw/ide/pci.c | 7 -------
> 3 files changed, 15 insertions(+), 24 deletions(-)
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
next prev parent reply other threads:[~2015-10-27 16:50 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-26 23:38 [Qemu-devel] [PATCH] ide: remove hardcoded 2GiB transactional limit John Snow
2015-10-27 16:50 ` Stefan Hajnoczi [this message]
2015-11-02 19:54 ` John Snow
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