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Date: Tue, 29 Aug 2017 11:08:06 +0100
From: Stefan Hajnoczi <stefanha@gmail.com>
Message-ID: <20170829100806.GO25960@stefanha-x1.localdomain>
References: <8c62454c-828b-0f16-76dd-227d9c52af1d@erigones.com>
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In-Reply-To: <8c62454c-828b-0f16-76dd-227d9c52af1d@erigones.com>
Subject: Re: [Qemu-devel] wrong ioctl error handling on dirty pages sync?
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To: =?iso-8859-1?B?SuFu?= Poctavek <jan.poctavek@erigones.com>
Cc: qemu-devel@nongnu.org

On Fri, Aug 25, 2017 at 01:42:55PM +0200, Ján Poctavek wrote:
> Hi guys,
> 
> Maybe it is just my lack of understanding, this seems like a bug to me:
> 
> To get list of dirty pages, qemu calls kvm_vm_ioctl() with
> KVM_GET_DIRTY_LOG:
> https://github.com/qemu/qemu/blob/v2.10.0-rc4/accel/kvm/kvm-all.c#L494
> 
> and considers the ioctl call failed when -1 is returned.
> 
> But the kvm_vm_ioctl() itself returns -errno, not the -1 on error:
> https://github.com/qemu/qemu/blob/v2.10.0-rc4/accel/kvm/kvm-all.c#L2142
> 
> Thanks in advance for sheding some light into this for me.

Looks like a bug to me.  Do you want to send a patch?

Guidelines on how to submit a patch are here:
http://wiki.qemu.org/Contribute/SubmitAPatch

Stefan