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From: Jason Wang <jasowang@redhat.com>
To: Greg Kurz <gkurz@linux.vnet.ibm.com>,
	Peter Maydell <peter.maydell@linaro.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
	QEMU Developers <qemu-devel@nongnu.org>,
	"Michael S. Tsirkin" <mst@redhat.com>
Subject: Re: [Qemu-devel] [PATCH 1/2] memory: allow zero size for adjust_endianness()
Date: Thu, 27 Aug 2015 12:50:19 +0800	[thread overview]
Message-ID: <55DE970B.6040807@redhat.com> (raw)
In-Reply-To: <20150826165140.6bab7d28@bahia.local>



On 08/26/2015 10:51 PM, Greg Kurz wrote:
> On Wed, 26 Aug 2015 15:21:59 +0100
> Peter Maydell <peter.maydell@linaro.org> wrote:
>
>> On 26 August 2015 at 11:04, Jason Wang <jasowang@redhat.com> wrote:
>>> Wildcard mmio eventfd use zero size, but it will lead abort() since it
>>> was illegal in adjust_endianness(). Fix this by allowing zero size.
>>>
>>> Cc: Greg Kurz <gkurz@linux.vnet.ibm.com>
>>> Cc: Paolo Bonzini <pbonzini@redhat.com>
>>> Signed-off-by: Jason Wang <jasowang@redhat.com>
>> This seems to me like a bug in the caller. Why would anything
>> try to call into the memory subsystem to do a zero-size
>> transaction?
>>
>> thanks
>> -- PMM
>>
> Here's the patch which needs zero-size eventfd:
>
> http://patchwork.ozlabs.org/patch/509428/
>
> Cheers.
>
> --
> Greg
>

Yes, this is because we want to use wildcard mmio eventfd (which
requires size to be zero) to speed up virtio 1.0 mmio.

  reply	other threads:[~2015-08-27  4:50 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-08-26 10:04 [Qemu-devel] [PATCH 1/2] memory: allow zero size for adjust_endianness() Jason Wang
2015-08-26 10:04 ` [Qemu-devel] [PATCH 2/2] pci: test-dev: try to test fast mmio bus for wildcard mmio event Jason Wang
2015-08-27 10:28   ` Michael S. Tsirkin
2015-08-26 14:21 ` [Qemu-devel] [PATCH 1/2] memory: allow zero size for adjust_endianness() Peter Maydell
2015-08-26 14:51   ` Greg Kurz
2015-08-27  4:50     ` Jason Wang [this message]
2015-08-27 10:49       ` Peter Maydell
2015-08-27 10:53         ` Michael S. Tsirkin
2015-08-27 11:04           ` Peter Maydell
2015-08-27 11:08             ` Michael S. Tsirkin
2015-08-27 12:12               ` Peter Maydell
2015-08-27 12:17                 ` Michael S. Tsirkin
2015-08-27 12:20                   ` Peter Maydell
2015-08-27 12:25                     ` Michael S. Tsirkin
2015-08-27 12:27                       ` Peter Maydell
2015-08-27 12:30                         ` Michael S. Tsirkin
2015-08-27 13:10                           ` Greg Kurz
2015-08-28  2:23                             ` Jason Wang

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