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| author | Stefan Hajnoczi | 2020-08-18 16:33:46 +0200 |
|---|---|---|
| committer | Michael S. Tsirkin | 2020-08-27 14:29:13 +0200 |
| commit | 6a558822849fab604a1fcb71e7c4e528cafa21d9 (patch) | |
| tree | baeec7fcfa10f0b0ff3a3290c614453adc0f5e02 /include/hw/virtio | |
| parent | virtio-scsi: introduce a constant for fixed virtqueues (diff) | |
| download | qemu-6a558822849fab604a1fcb71e7c4e528cafa21d9.tar.gz qemu-6a558822849fab604a1fcb71e7c4e528cafa21d9.tar.xz qemu-6a558822849fab604a1fcb71e7c4e528cafa21d9.zip | |
virtio-scsi-pci: default num_queues to -smp N
Automatically size the number of virtio-scsi-pci, vhost-scsi-pci, and
vhost-user-scsi-pci request virtqueues to match the number of vCPUs.
Other transports continue to default to 1 request virtqueue.
A 1:1 virtqueue:vCPU mapping ensures that completion interrupts are
handled on the same vCPU that submitted the request. No IPI is
necessary to complete an I/O request and performance is improved. The
maximum number of MSI-X vectors and virtqueues limit are respected.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20200818143348.310613-6-stefanha@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'include/hw/virtio')
| -rw-r--r-- | include/hw/virtio/virtio-scsi.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/hw/virtio/virtio-scsi.h b/include/hw/virtio/virtio-scsi.h index 9f293bcb80..c0b8e4dd7e 100644 --- a/include/hw/virtio/virtio-scsi.h +++ b/include/hw/virtio/virtio-scsi.h @@ -39,6 +39,8 @@ /* Number of virtqueues that are always present */ #define VIRTIO_SCSI_VQ_NUM_FIXED 2 +#define VIRTIO_SCSI_AUTO_NUM_QUEUES UINT32_MAX + typedef struct virtio_scsi_cmd_req VirtIOSCSICmdReq; typedef struct virtio_scsi_cmd_resp VirtIOSCSICmdResp; typedef struct virtio_scsi_ctrl_tmf_req VirtIOSCSICtrlTMFReq; |