Re: [Qemu-devel] [PATCH v3] Add remove_boot_device_path() function for hot-unplug device

["Michael S. Tsirkin" <mst@redhat.com>]

On Mon, May 19, 2014 at 05:31:43PM +0200, Andreas Färber wrote:
> Hi,
> 
> Am 19.05.2014 17:03, schrieb Jun Li:
> > Add remove_boot_device_path() function to remove bootindex when hot-unplug
> > a device. This patch fixed virtio-blk/virtio-net/scsi-disk/scsi-generic device.
> > 
> > Signed-off-by: Jun Li <junmuzi@gmail.com>
> > ---
> > This patch also fixed bug1086603, ref:
> > https://bugzilla.redhat.com/show_bug.cgi?id=1086603
> > 
> > This version of patch delete dev and suffix parameter from function remove_boot_device_path().
> > ---
> >  hw/block/virtio-blk.c   |  1 +
> >  hw/net/virtio-net.c     |  1 +
> >  hw/scsi/scsi-disk.c     |  1 +
> >  hw/scsi/scsi-generic.c  |  1 +
> 
> On v1 I believe I reminded you of spapr_llan. Your patch is adding a new
> remove_*() function, but is using it only for roughly half of the
> devices that currently call add_boot_device_path(). Why? I can
> understand that ISA devices will not be hot-unpluggable, but all PCI and
> USB devices are.

Can we remove the device from boot path automatically
when it's going away?


> hw/block/fdc.c:    add_boot_device_path(isa->bootindexA, dev, "/floppy@0");
> hw/block/fdc.c:    add_boot_device_path(isa->bootindexB, dev, "/floppy@1");
> hw/block/virtio-blk.c:    add_boot_device_path(s->conf->bootindex, dev,
> "/disk@0,0");
> hw/core/loader.c:    add_boot_device_path(bootindex, NULL, devpath);
> hw/i386/kvm/pci-assign.c:    add_boot_device_path(dev->bootindex,
> &pci_dev->qdev, NULL);
> hw/ide/qdev.c:    add_boot_device_path(dev->conf.bootindex, &dev->qdev,
> hw/misc/vfio.c:    add_boot_device_path(vdev->bootindex, &pdev->qdev, NULL);
> hw/net/e1000.c:    add_boot_device_path(d->conf.bootindex, dev,
> "/ethernet-phy@0");
> hw/net/eepro100.c:    add_boot_device_path(s->conf.bootindex,
> &pci_dev->qdev, "/ethernet-phy@0");
> hw/net/ne2000.c:    add_boot_device_path(s->c.bootindex, &pci_dev->qdev,
> "/ethernet-phy@0");
> hw/net/pcnet.c:    add_boot_device_path(s->conf.bootindex, dev,
> "/ethernet-phy@0");
> hw/net/rtl8139.c:    add_boot_device_path(s->conf.bootindex, d,
> "/ethernet-phy@0");
> hw/net/spapr_llan.c:    add_boot_device_path(dev->nicconf.bootindex,
> DEVICE(dev), "");
> hw/net/virtio-net.c:    add_boot_device_path(n->nic_conf.bootindex, dev,
> "/ethernet-phy@0");
> hw/net/vmxnet3.c:    add_boot_device_path(s->conf.bootindex, dev,
> "/ethernet-phy@0");
> hw/scsi/scsi-disk.c:    add_boot_device_path(s->qdev.conf.bootindex,
> &dev->qdev, NULL);
> hw/scsi/scsi-generic.c:        add_boot_device_path(s->conf.bootindex,
> &s->qdev, NULL);
> hw/usb/dev-network.c:    add_boot_device_path(s->conf.bootindex,
> &dev->qdev, "/ethernet@0");
> hw/usb/host-libusb.c:    add_boot_device_path(s->bootindex, &udev->qdev,
> NULL);
> hw/usb/redirect.c:    add_boot_device_path(dev->bootindex, &udev->qdev,
> NULL);
> 
> >  include/sysemu/sysemu.h |  1 +
> >  vl.c                    | 15 +++++++++++++++
> >  6 files changed, 20 insertions(+)
> > 
> > diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
> > index 8a568e5..497eb40 100644
> > --- a/hw/block/virtio-blk.c
> > +++ b/hw/block/virtio-blk.c
> > @@ -752,6 +752,7 @@ static void virtio_blk_device_unrealize(DeviceState *dev, Error **errp)
> >      unregister_savevm(dev, "virtio-blk", s);
> >      blockdev_mark_auto_del(s->bs);
> >      virtio_cleanup(vdev);
> > +    remove_boot_device_path(s->conf->bootindex);
> >  }
> >  
> >  static Property virtio_blk_properties[] = {
> > diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
> > index 940a7cf..6afb1ca 100644
> > --- a/hw/net/virtio-net.c
> > +++ b/hw/net/virtio-net.c
> > @@ -1645,6 +1645,7 @@ static void virtio_net_device_unrealize(DeviceState *dev, Error **errp)
> >      g_free(n->vqs);
> >      qemu_del_nic(n->nic);
> >      virtio_cleanup(vdev);
> > +    remove_boot_device_path(n->nic_conf.bootindex);
> >  }
> >  
> >  static void virtio_net_instance_init(Object *obj)
> > diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c
> > index 4bcef55..d33df2e 100644
> > --- a/hw/scsi/scsi-disk.c
> > +++ b/hw/scsi/scsi-disk.c
> > @@ -2156,6 +2156,7 @@ static void scsi_destroy(SCSIDevice *dev)
> >  
> >      scsi_device_purge_requests(&s->qdev, SENSE_CODE(NO_SENSE));
> >      blockdev_mark_auto_del(s->qdev.conf.bs);
> > +    remove_boot_device_path(s->qdev.conf.bootindex);
> 
> Didn't I previously ask that you use dev->config.bootindex here?
> Pointers to parent's struct shouldn't be accessed anywhere except
> VMStateDescription.
> 
> >  }
> >  
> >  static void scsi_disk_resize_cb(void *opaque)
> > diff --git a/hw/scsi/scsi-generic.c b/hw/scsi/scsi-generic.c
> > index 3733d2c..d387f3e 100644
> > --- a/hw/scsi/scsi-generic.c
> > +++ b/hw/scsi/scsi-generic.c
> > @@ -390,6 +390,7 @@ static void scsi_destroy(SCSIDevice *s)
> >  {
> >      scsi_device_purge_requests(s, SENSE_CODE(NO_SENSE));
> >      blockdev_mark_auto_del(s->conf.bs);
> > +    remove_boot_device_path(s->conf.bootindex);
> >  }
> >  
> >  static int scsi_generic_initfn(SCSIDevice *s)
> > diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
> > index ba5c7f8..2510e3b 100644
> > --- a/include/sysemu/sysemu.h
> > +++ b/include/sysemu/sysemu.h
> > @@ -193,6 +193,7 @@ void rtc_change_mon_event(struct tm *tm);
> >  
> >  void add_boot_device_path(int32_t bootindex, DeviceState *dev,
> >                            const char *suffix);
> > +void remove_boot_device_path(int32_t bootindex);
> >  char *get_boot_devices_list(size_t *size, bool ignore_suffixes);
> >  
> >  DeviceState *get_boot_device(uint32_t position);
> > diff --git a/vl.c b/vl.c
> > index 709d8cd..f31d008 100644
> > --- a/vl.c
> > +++ b/vl.c
> > @@ -1189,6 +1189,21 @@ void add_boot_device_path(int32_t bootindex, DeviceState *dev,
> >      QTAILQ_INSERT_TAIL(&fw_boot_order, node, link);
> >  }
> >  
> > +void remove_boot_device_path(int32_t bootindex)
> > +{
> > +    FWBootEntry *node, *next_node;
> > +
> > +    if (bootindex == -1) {
> > +        return;
> > +    }
> > +
> > +    QTAILQ_FOREACH_SAFE(node, &fw_boot_order, link, next_node)
> 
> Coding Style requires braces around the below single-statement if.
> 
> > +        if (node->bootindex == bootindex) {
> > +            QTAILQ_REMOVE(&fw_boot_order, node, link);
> > +            return;
> > +        }
> > +}
> > +
> >  DeviceState *get_boot_device(uint32_t position)
> >  {
> >      uint32_t counter = 0;
> 
> Regards,
> Andreas
> 
> -- 
> SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
> GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg