diff options
| author | Stefan Hajnoczi <stefanha@redhat.com> | 2020-08-18 15:33:46 +0100 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2020-08-27 08:29:13 -0400 |
| commit | 6a558822849fab604a1fcb71e7c4e528cafa21d9 (patch) | |
| tree | baeec7fcfa10f0b0ff3a3290c614453adc0f5e02 /hw/scsi/virtio-scsi.c | |
| parent | 4e5163bd844429711b4d60d51030ab83048d80cd (diff) | |
| download | qemu-6a558822849fab604a1fcb71e7c4e528cafa21d9.zip qemu-6a558822849fab604a1fcb71e7c4e528cafa21d9.tar.gz qemu-6a558822849fab604a1fcb71e7c4e528cafa21d9.tar.bz2 | |
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 'hw/scsi/virtio-scsi.c')
| -rw-r--r-- | hw/scsi/virtio-scsi.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c index eecdd05..3a71ea7 100644 --- a/hw/scsi/virtio-scsi.c +++ b/hw/scsi/virtio-scsi.c @@ -891,6 +891,9 @@ void virtio_scsi_common_realize(DeviceState *dev, virtio_init(vdev, "virtio-scsi", VIRTIO_ID_SCSI, sizeof(VirtIOSCSIConfig)); + if (s->conf.num_queues == VIRTIO_SCSI_AUTO_NUM_QUEUES) { + s->conf.num_queues = 1; + } if (s->conf.num_queues == 0 || s->conf.num_queues > VIRTIO_QUEUE_MAX - VIRTIO_SCSI_VQ_NUM_FIXED) { error_setg(errp, "Invalid number of queues (= %" PRIu32 "), " @@ -964,7 +967,8 @@ static void virtio_scsi_device_unrealize(DeviceState *dev) } static Property virtio_scsi_properties[] = { - DEFINE_PROP_UINT32("num_queues", VirtIOSCSI, parent_obj.conf.num_queues, 1), + DEFINE_PROP_UINT32("num_queues", VirtIOSCSI, parent_obj.conf.num_queues, + VIRTIO_SCSI_AUTO_NUM_QUEUES), DEFINE_PROP_UINT32("virtqueue_size", VirtIOSCSI, parent_obj.conf.virtqueue_size, 256), DEFINE_PROP_BOOL("seg_max_adjust", VirtIOSCSI, |