RE: [PATCH v2 01/22] block: add eMMC block device type

[Sai Pavan Boddu]

Hi Stefan

> -----Original Message-----
> From: Stefan Hajnoczi <stefanha@redhat.com>
> Sent: Wednesday, February 24, 2021 5:10 PM
> To: Sai Pavan Boddu <saipava@xilinx.com>
> Cc: Philippe Mathieu-Daudé <philmd@redhat.com>; Markus Armbruster
> <armbru@redhat.com>; Kevin Wolf <kwolf@redhat.com>; Max Reitz
> <mreitz@redhat.com>; Vladimir Sementsov-Ogievskiy
> <vsementsov@virtuozzo.com>; Eric Blake <eblake@redhat.com>; Joel Stanley
> <joel@jms.id.au>; Cédric Le Goater <clg@kaod.org>; Vincent Palatin
> <vpalatin@chromium.org>; Dr. David Alan Gilbert <dgilbert@redhat.com>;
> Thomas Huth <thuth@redhat.com>; Peter Maydell
> <peter.maydell@linaro.org>; Alistair Francis <alistair.francis@wdc.com>; Edgar
> Iglesias <edgari@xilinx.com>; Luc Michel <luc.michel@greensocs.com>; Paolo
> Bonzini <pbonzini@redhat.com>; qemu-devel@nongnu.org; qemu-
> block@nongnu.org
> Subject: Re: [PATCH v2 01/22] block: add eMMC block device type
> 
> On Tue, Feb 23, 2021 at 05:35:20PM +0000, Sai Pavan Boddu wrote:
> > Hi Philippe,
> >
> > > -----Original Message-----
> > > From: Philippe Mathieu-Daudé <philmd@redhat.com>
> > > Sent: Monday, February 22, 2021 5:34 PM
> > > To: Sai Pavan Boddu <saipava@xilinx.com>; Markus Armbruster
> > > <armbru@redhat.com>; Kevin Wolf <kwolf@redhat.com>; Max Reitz
> > > <mreitz@redhat.com>; Vladimir Sementsov-Ogievskiy
> > > <vsementsov@virtuozzo.com>; Eric Blake <eblake@redhat.com>; Joel
> > > Stanley <joel@jms.id.au>; Cédric Le Goater <clg@kaod.org>; Vincent
> > > Palatin <vpalatin@chromium.org>; Dr. David Alan Gilbert
> > > <dgilbert@redhat.com>; Thomas Huth <thuth@redhat.com>; Stefan
> > > Hajnoczi <stefanha@redhat.com>; Peter Maydell
> > > <peter.maydell@linaro.org>; Alistair Francis
> > > <alistair.francis@wdc.com>; Edgar Iglesias <edgari@xilinx.com>; Luc
> > > Michel <luc.michel@greensocs.com>; Paolo Bonzini
> > > <pbonzini@redhat.com>
> > > Cc: Sai Pavan Boddu <saipava@xilinx.com>; qemu-devel@nongnu.org;
> > > qemu- block@nongnu.org
> > > Subject: Re: [PATCH v2 01/22] block: add eMMC block device type
> > >
> > > On 2/22/21 9:20 AM, Sai Pavan Boddu wrote:
> > > > From: Vincent Palatin <vpalatin@chromium.org>
> > > >
> > > > Add new block device type.
> > > >
> > > > Signed-off-by: Vincent Palatin <vpalatin@chromium.org>
> > > > [SPB: Rebased over 5.1 version]
> > > > Signed-off-by: Sai Pavan Boddu <sai.pavan.boddu@xilinx.com>
> > > > Signed-off-by: Joel Stanley <joel@jms.id.au>
> > > > Signed-off-by: Cédric Le Goater <clg@kaod.org>
> > > > Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
> > > > ---
> > > >  include/sysemu/blockdev.h | 1 +
> > > >  blockdev.c                | 1 +
> > > >  2 files changed, 2 insertions(+)
> > > >
> > > > diff --git a/include/sysemu/blockdev.h b/include/sysemu/blockdev.h
> > > > index 3b5fcda..eefae9f 100644
> > > > --- a/include/sysemu/blockdev.h
> > > > +++ b/include/sysemu/blockdev.h
> > > > @@ -24,6 +24,7 @@ typedef enum {
> > > >       */
> > > >      IF_NONE = 0,
> > > >      IF_IDE, IF_SCSI, IF_FLOPPY, IF_PFLASH, IF_MTD, IF_SD,
> > > > IF_VIRTIO, IF_XEN,
> > > > +    IF_EMMC,
> > > >      IF_COUNT
> > > >  } BlockInterfaceType;
> > > >
> > > > diff --git a/blockdev.c b/blockdev.c index cd438e6..390d43c 100644
> > > > --- a/blockdev.c
> > > > +++ b/blockdev.c
> > > > @@ -83,6 +83,7 @@ static const char *const if_name[IF_COUNT] = {
> > > >      [IF_SD] = "sd",
> > > >      [IF_VIRTIO] = "virtio",
> > > >      [IF_XEN] = "xen",
> > > > +    [IF_EMMC] = "emmc",
> > > >  };
> > >
> > > We don't need to introduce support for the legacy -drive magic.
> > >
> > > -device should be enough for this device, right?
> > [Sai Pavan Boddu] I was seeing to use -device for emmc. But I see we anyway
> need blockdev support for this, which would require us the use -drive.
> >
> > Can you give some pointers, how to approach this ?
> 
> It is probably not necessary to add a new IF_ constant. Would this work:
> 
>   -drive if=none,id=emmc0,file=test.img,format=raw
>   -device emmc,...,drive=emmc0
[Sai Pavan Boddu] Great, this works for me.
> 
> Or the more modern:
> 
>   -blockdev node-name=emmc0,driver=file,filename=test.img
>   -device emmc,...,drive=emmc0
[Sai Pavan Boddu] Thanks, I would try to follow the modern approach then!

Regards,
Sai Pavan
> 
> ?
> 
> (The syntax might need small tweaks but is shows the general idea.)
> 
> Stefan