diff options
| author | Stefan Hajnoczi <stefanha@redhat.com> | 2020-08-18 15:33:47 +0100 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2020-08-27 08:29:13 -0400 |
| commit | 9445e1e15e66c19e42bea942ba810db28052cd05 (patch) | |
| tree | 04f90ede63d0f327c660fefbbc45f04c610ec429 /hw/core | |
| parent | 6a558822849fab604a1fcb71e7c4e528cafa21d9 (diff) | |
| download | qemu-9445e1e15e66c19e42bea942ba810db28052cd05.zip qemu-9445e1e15e66c19e42bea942ba810db28052cd05.tar.gz qemu-9445e1e15e66c19e42bea942ba810db28052cd05.tar.bz2 | |
virtio-blk-pci: default num_queues to -smp N
Automatically size the number of virtio-blk-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.
Performance improves from 78k to 104k IOPS on a 32 vCPU guest with 101
virtio-blk-pci devices (ioengine=libaio, iodepth=1, bs=4k, rw=randread
with NVMe storage).
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Message-Id: <20200818143348.310613-7-stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'hw/core')
| -rw-r--r-- | hw/core/machine.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/hw/core/machine.c b/hw/core/machine.c index 9ee2aa0..7f65fa8 100644 --- a/hw/core/machine.c +++ b/hw/core/machine.c @@ -31,6 +31,7 @@ GlobalProperty hw_compat_5_1[] = { { "vhost-scsi", "num_queues", "1"}, { "vhost-user-scsi", "num_queues", "1"}, + { "virtio-blk-device", "num-queues", "1"}, { "virtio-scsi-device", "num_queues", "1"}, }; const size_t hw_compat_5_1_len = G_N_ELEMENTS(hw_compat_5_1); |