Re: [Qemu-devel] [RESEND PATCH] virtio-scsi: forward scsibus for virtio-scsi-pci.

[Frederic Konrad]

On 12/06/2013 13:21, Alexey Kardashevskiy wrote:
> On 06/12/2013 07:16 PM, Michael S. Tsirkin wrote:
> > On Wed, Jun 12, 2013 at 07:04:48PM +1000, Alexey Kardashevskiy wrote:
> > > On 06/12/2013 07:03 PM, Michael S. Tsirkin wrote:
> > > > On Wed, Jun 12, 2013 at 08:15:17AM +0200, address@hidden wrote:
> > > > > From: KONRAD Frederic <address@hidden>
> > > > >
> > > > > This fix a bug with scsi hotplug on virtio-scsi-pci:
> > > > >
> > > > > As virtio-scsi-pci doesn't have any scsi bus, we need to forward scsi-hot-add
> > > > > to the virtio-scsi-device plugged on the virtio-bus.
> > > > >
> > > > > Cc: address@hidden
> > > > > Reported-by: Alexey Kardashevskiy <address@hidden>
> > > > > Reviewed-by: Andreas Färber <address@hidden>
> > > > > Signed-off-by: KONRAD Frederic <address@hidden>
> > > > Acked-by: Michael S. Tsirkin <address@hidden>
> > > >
> > > > Note: we don't seem to have any decent way to
> > > > add disks to devices: no QMP interface,
> > > > pci address is required instead of using an id ...
> > > >
> > > > Anyone can be bothered to fix this?
> > >
> > > Actually PCI address is not always required, this field (we are talking
> > > about "drive_add"?) is ignored when "if=none".
> > Then documentation in hmp-commands.hx is wrong, isn't it?
> > Add that to the list.
> >
> > if=none can't be actually used to hot-add
> > a disk to a device, can it? It creates a disc and assumes you will
> > use it by a device created later.
>
> Yep. I run QEMU with -device "virtio-scsi-pci,id=device0" and then do in
> console:
> drive_add auto file=virtimg/fc18guest,if=none,id=bar1
> device_add scsi-disk,bus=device0.0,drive=bar1
>
> Pretty hot plug :)

I thought you use drive_add 0 if=scsi?
> > > > > ---
> > > > >   hw/pci/pci-hotplug.c | 19 +++++++++++++++++--
> > > > >   1 file changed, 17 insertions(+), 2 deletions(-)
> > > > >
> > > > > diff --git a/hw/pci/pci-hotplug.c b/hw/pci/pci-hotplug.c
> > > > > index 12287d1..c708752 100644
> > > > > --- a/hw/pci/pci-hotplug.c
> > > > > +++ b/hw/pci/pci-hotplug.c
> > > > > @@ -30,6 +30,8 @@
> > > > >   #include "monitor/monitor.h"
> > > > >   #include "hw/scsi/scsi.h"
> > > > >   #include "hw/virtio/virtio-blk.h"
> > > > > +#include "hw/virtio/virtio-scsi.h"
> > > > > +#include "hw/virtio/virtio-pci.h"
> > > > >   #include "qemu/config-file.h"
> > > > >   #include "sysemu/blockdev.h"
> > > > >   #include "qapi/error.h"
> > > > > @@ -79,13 +81,26 @@ static int scsi_hot_add(Monitor *mon, DeviceState *adapter,
> > > > >   {
> > > > >       SCSIBus *scsibus;
> > > > >       SCSIDevice *scsidev;
> > > > > +    VirtIOPCIProxy *virtio_proxy;
> > > > >   
> > > > >       scsibus = (SCSIBus *)
> > > > >           object_dynamic_cast(OBJECT(QLIST_FIRST(&adapter->child_bus)),
> > > > >                               TYPE_SCSI_BUS);
> > > > >       if (!scsibus) {
> > > > > -       error_report("Device is not a SCSI adapter");
> > > > > -       return -1;
> > > > > +        /*
> > > > > +         * Check if the adapter is a virtio-scsi-pci, and forward scsi_hot_add
> > > > > +         * to the virtio-scsi-device.
> > > > > +         */
> > > > > +        if (!object_dynamic_cast(OBJECT(adapter), TYPE_VIRTIO_SCSI_PCI)) {
> > > > > +            error_report("Device is not a SCSI adapter");
> > > > > +            return -1;
> > > > > +        }
> > > > > +        virtio_proxy = VIRTIO_PCI(adapter);
> > > > > +        adapter = DEVICE(virtio_proxy->bus.vdev);
> > > > > +        scsibus = (SCSIBus *)
> > > > > +                  object_dynamic_cast(OBJECT(QLIST_FIRST(&adapter->child_bus)),
> > > > > +                            TYPE_SCSI_BUS);
> > > > > +        assert(scsibus);
> > > > >       }
> > > > >   
> > > > >       /*