Add feature bits as properties to virtio. This makes it possible to e.g. define
machine without indirect buffer support, which is required for 0.10
compatibility, or without hardware checksum support, which is required for 0.11
compatibility. Since default values for optional features are now set by qdev,
get_features callback has been modified: it sets non-optional bits, and clears
bits not supported by host.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Add a new VIRTIO_BLK_F_WCACHE feature to virtio-blk to indicate that we have
a volatile write cache that needs controlled flushing. Implement a
VIRTIO_BLK_T_FLUSH operation to flush it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
[brought forward to current qemu-kvm.git]
This patch implements the missing qemu logic to
interpret a '-drive .. serial=XYZ ..' flag for
a virtio_blk device.
The serial number string is contained in a
skeletal IDENTIFY DEVICE data structure and
this structure is made available to the guest
virtio_blk driver via pci i/o region 0.
Signed-off-by: john cooper <john.cooper@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
The inhdr is at the end of the S/G list, not the beginning.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
[had the qemu list address wrong the first time, reply to this message,
not the previous if you were on Cc]
Add support for SG_IO passthru (packet commands) to the virtio-blk
backend. Conceptually based on an older patch from Hannes Reinecke
but largely rewritten to match the code structure and layering in
virtio-blk.
Note that currently we issue the hose SG_IO synchronously. We could
easily switch to async I/O, but that would required either bloating
the VirtIOBlockReq by the size of struct sg_io_hdr or an additional
memory allocation for each SG_IO request.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Use the defines added by the previous patch in the virtio drivers.
Also remove the pointless vendor and device args from the
virtio_blk_init() function.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5987 c046a42c-6fe2-441c-8c8c-71466251a162
Virtio-blk is a paravirtual block device based on VirtIO. It can be used by
specifying the if=virtio parameter to the -drive parameter.
When using -enable-kvm, it can achieve very good performance compared to IDE or
SCSI.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5870 c046a42c-6fe2-441c-8c8c-71466251a162
