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From: =?UTF-8?B?TWFyYy1BbmRyw6kgTHVyZWF1?= <marcandre.lureau@redhat.com>
Date: Wed, 28 Feb 2018 18:22:29 +0100
Message-ID: <CAMxuvayJD1O4gz-E0B--E1VMXqbb3u10D8W=CAtOaQPeoYuvuQ@mail.gmail.com>
Subject: Re: [PATCH v15 11/11] RFC: fw_cfg: do DMA read operation
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Sergio Lopez Pascual <slp@redhat.com>, Baoquan He <bhe@redhat.com>,
        "Somlo, Gabriel" <somlo@cmu.edu>, xiaolong.ye@intel.com
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Hi

On Wed, Feb 28, 2018 at 6:17 PM, Michael S. Tsirkin <mst@redhat.com> wrote:
> On Wed, Feb 28, 2018 at 04:41:51PM +0100, Marc-André Lureau wrote:
>> I don't know if it's always safe to enable dma in read_raw(), how
>> could we know? Is there a check we could use to choose one or ther
>> other (and thus avoiding explicit dma/readfn argument)?
>
> IMHO the way to go is not to try to do zero copy.
> Allocate a buffer and DMA there, then copy.

Sounds fine to me, I'll resend this patch separately if the rest from
v16 is applied.

thanks