Re: [Qemu-devel] [PATCH 05/11] virtio-blk: support VIRTIO_BLK_F_CONFIG_WCE

[Anthony Liguori <anthony@codemonkey.ws>]

Kevin Wolf <kwolf@redhat.com> writes:

> From: Paolo Bonzini <pbonzini@redhat.com>
>
> Also rename VIRTIO_BLK_F_WCACHE to VIRTIO_BLK_F_WCE for consistency with
> the spec.
>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>

This broke qemu-test because it changed the pc-1.0 machine type:

Setting guest RANDOM seed to 47167
*** Running tests ***
Running test /tests/finger-print.sh...		OK
--- fingerprints/pc-1.0.x86_64	2011-12-18 13:08:40.000000000 -0600
+++ fingerprint.txt	2012-08-12 13:30:48.000000000 -0500
@@ -55,7 +55,7 @@
 /sys/bus/pci/devices/0000:00:06.0/subsystem_device=0x0002
 /sys/bus/pci/devices/0000:00:06.0/class=0x010000
 /sys/bus/pci/devices/0000:00:06.0/revision=0x00
-/sys/bus/pci/devices/0000:00:06.0/virtio/host-features=0x710006d4
+/sys/bus/pci/devices/0000:00:06.0/virtio/host-features=0x71000ed4
 /sys/class/dmi/id/bios_vendor=Bochs
 /sys/class/dmi/id/bios_date=01/01/2007
 /sys/class/dmi/id/bios_version=Bochs
Guest fingerprint changed for pc-1.0!

Need to make this a qdev-visible feature and then add compatibility
properties for all of the old machine types.

Regards,

Anthony Liguori

> ---
>  hw/virtio-blk.c |   16 ++++++++++++++--
>  hw/virtio-blk.h |    4 +++-
>  2 files changed, 17 insertions(+), 3 deletions(-)
>
> diff --git a/hw/virtio-blk.c b/hw/virtio-blk.c
> index 552b3b6..97bb4bd 100644
> --- a/hw/virtio-blk.c
> +++ b/hw/virtio-blk.c
> @@ -510,9 +510,19 @@ static void virtio_blk_update_config(VirtIODevice *vdev, uint8_t *config)
>      blkcfg.size_max = 0;
>      blkcfg.physical_block_exp = get_physical_block_exp(s->conf);
>      blkcfg.alignment_offset = 0;
> +    blkcfg.wce = bdrv_enable_write_cache(s->bs);
>      memcpy(config, &blkcfg, sizeof(struct virtio_blk_config));
>  }
>  
> +static void virtio_blk_set_config(VirtIODevice *vdev, const uint8_t *config)
> +{
> +    VirtIOBlock *s = to_virtio_blk(vdev);
> +    struct virtio_blk_config blkcfg;
> +
> +    memcpy(&blkcfg, config, sizeof(blkcfg));
> +    bdrv_set_enable_write_cache(s->bs, blkcfg.wce != 0);
> +}
> +
>  static uint32_t virtio_blk_get_features(VirtIODevice *vdev, uint32_t features)
>  {
>      VirtIOBlock *s = to_virtio_blk(vdev);
> @@ -523,9 +533,10 @@ static uint32_t virtio_blk_get_features(VirtIODevice *vdev, uint32_t features)
>      features |= (1 << VIRTIO_BLK_F_BLK_SIZE);
>      features |= (1 << VIRTIO_BLK_F_SCSI);
>  
> +    features |= (1 << VIRTIO_BLK_F_CONFIG_WCE);
>      if (bdrv_enable_write_cache(s->bs))
> -        features |= (1 << VIRTIO_BLK_F_WCACHE);
> -    
> +        features |= (1 << VIRTIO_BLK_F_WCE);
> +
>      if (bdrv_is_read_only(s->bs))
>          features |= 1 << VIRTIO_BLK_F_RO;
>  
> @@ -610,6 +621,7 @@ VirtIODevice *virtio_blk_init(DeviceState *dev, VirtIOBlkConf *blk)
>                                            sizeof(VirtIOBlock));
>  
>      s->vdev.get_config = virtio_blk_update_config;
> +    s->vdev.set_config = virtio_blk_set_config;
>      s->vdev.get_features = virtio_blk_get_features;
>      s->vdev.reset = virtio_blk_reset;
>      s->bs = blk->conf.bs;
> diff --git a/hw/virtio-blk.h b/hw/virtio-blk.h
> index 79ebccc..35834cf 100644
> --- a/hw/virtio-blk.h
> +++ b/hw/virtio-blk.h
> @@ -31,8 +31,9 @@
>  #define VIRTIO_BLK_F_BLK_SIZE   6       /* Block size of disk is available*/
>  #define VIRTIO_BLK_F_SCSI       7       /* Supports scsi command passthru */
>  /* #define VIRTIO_BLK_F_IDENTIFY   8       ATA IDENTIFY supported, DEPRECATED */
> -#define VIRTIO_BLK_F_WCACHE     9       /* write cache enabled */
> +#define VIRTIO_BLK_F_WCE        9       /* write cache enabled */
>  #define VIRTIO_BLK_F_TOPOLOGY   10      /* Topology information is available */
> +#define VIRTIO_BLK_F_CONFIG_WCE 11      /* write cache configurable */
>  
>  #define VIRTIO_BLK_ID_BYTES     20      /* ID string length */
>  
> @@ -49,6 +50,7 @@ struct virtio_blk_config
>      uint8_t alignment_offset;
>      uint16_t min_io_size;
>      uint32_t opt_io_size;
> +    uint8_t wce;
>  } QEMU_PACKED;
>  
>  /* These two define direction. */
> -- 
> 1.7.6.5