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path: root/drivers/scsi/virtio_scsi.c
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2012-07-20[SCSI] virtio-scsi: Add vdrv->scan for post VIRTIO_CONFIG_S_DRIVER_OK LUN ↵Nicholas Bellinger
scanning This patch changes virtio-scsi to use a new virtio_driver->scan() callback so that scsi_scan_host() can be properly invoked once virtio_dev_probe() has set add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK) to signal active virtio-ring operation, instead of from within virtscsi_probe(). This fixes a bug where SCSI LUN scanning for both virtio-scsi-raw and virtio-scsi/tcm_vhost setups was happening before VIRTIO_CONFIG_S_DRIVER_OK had been set, causing VIRTIO_SCSI_S_BAD_TARGET to occur. This fixes a bug with virtio-scsi/tcm_vhost where LUN scan was not detecting LUNs. Tested with virtio-scsi-raw + virtio-scsi/tcm_vhost w/ IBLOCK on 3.5-rc2 code. Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-07-20[SCSI] virtio-scsi: hotplug support for virtio-scsiCong Meng
This patch implements the hotplug support for virtio-scsi. When there is a device attached/detached, the virtio-scsi driver will be signaled via event virtual queue and it will add/remove the scsi device in question automatically. Signed-off-by: Sen Wang <senwang@linux.vnet.ibm.com> Signed-off-by: Cong Meng <mc@linux.vnet.ibm.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-07-20[SCSI] virtio-scsi: split scatterlist per targetPaolo Bonzini
To improve performance for I/O to different targets, add a separate scatterlist for each of them. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-07-20[SCSI] virtio-scsi: release sg_lock after add_bufPaolo Bonzini
We do not need the sglist after calling virtqueue_add_buf. Hence we can "pipeline" the locked operations and start preparing the sglist for the next request while we kick the virtqueue. Together with the previous two patches, this improves performance as follows. For a simple "if=/dev/sda of=/dev/null bs=128M iflag=direct" (the source being a 10G disk, residing entirely in the host buffer cache), the additional locking does not cause any penalty with only one dd process, but 2 simultaneous I/O operations improve their times by 3%: number of simultaneous dd 1 2 ---------------------------------------- current 5.9958s 10.2640s patched 5.9531s 9.8663s (Times are best of 10). Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-07-20[SCSI] virtio-scsi: split locking per vqPaolo Bonzini
Keep a separate lock for each virtqueue. While not particularly important now, it prepares the code for when we will add support for multiple request queues. It is also more tidy as soon as we introduce a separate lock for the sglist. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-07-20[SCSI] virtio-scsi: unlock during kickPaolo Bonzini
Separate virtqueue_kick_prepare from virtqueue_notify, so that the expensive vmexit is done without holding the lock. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-05-10[SCSI] virtio_scsi: fix TMF use-after-freePaolo Bonzini
Fix a use-after-free in the TMF path, where cmd may have been already freed by virtscsi_complete_free when wait_for_completion restarts executing virtscsi_tmf. Technically a race, but in practice the command will always be freed long before the completion waiter is awoken. The fix is to make callers specifying a completion responsible for freeing the command in all cases. Signed-off-by: Hu Tao <hutao@cn.fujitsu.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-02-19[SCSI] virtio-scsi: SCSI driver for QEMU based virtual machinesPaolo Bonzini
The virtio-scsi HBA is the basis of an alternative storage stack for QEMU-based virtual machines (including KVM). Compared to virtio-blk it is more scalable, because it supports many LUNs on a single PCI slot), more powerful (it more easily supports passthrough of host devices to the guest) and more easily extensible (new SCSI features implemented by QEMU should not require updating the driver in the guest). Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>