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From: Paolo Bonzini <pbonzini@redhat.com>
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Date: Thu, 2 Jul 2015 15:47:34 +0200
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Subject: Re: [Qemu-devel] [PATCH] raw-posix.c: remove raw device access for
	cdrom
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To: Laurent Vivier <lvivier@redhat.com>, Stefan Hajnoczi <stefanha@gmail.com>, Programmingkid <programmingkidx@gmail.com>
Cc: Kevin Wolf <kwolf@redhat.com>, Peter Maydell <peter.maydell@linaro.org>, John Snow <jsnow@redhat.com>, qemu-devel qemu-devel <qemu-devel@nongnu.org>, Qemu-block <qemu-block@nongnu.org>



On 02/07/2015 14:24, Laurent Vivier wrote:
> 
> #ifdef __FreeBSD__
>     if (S_ISCHR(st.st_mode)) {
>         /*
>          * The file is a char device (disk), which on FreeBSD isn't behind
>          * a pager, so force all requests to be aligned. This is needed
>          * so QEMU makes sure all IO operations on the device are aligned
>          * to sector size, or else FreeBSD will reject them with EINVAL.
>          */
>         s->needs_alignment = true;
>     }
> #endif

So on FreeBSD and Apple /dev/r* is the equivalent of BDRV_O_NO_CACHE?

Paolo