From a4eef0711b2cf7a7476c3e2c202a414b68a1baa0 Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Tue, 18 Aug 2020 15:33:48 +0100 Subject: vhost-user-blk-pci: default num_queues to -smp N Automatically size the number of request virtqueues to match the number of vCPUs. This 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 Reviewed-by: Cornelia Huck Reviewed-by: Raphael Norwitz Message-Id: <20200818143348.310613-8-stefanha@redhat.com> Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/block/vhost-user-blk.c | 6 +++++- hw/core/machine.c | 1 + hw/virtio/vhost-user-blk-pci.c | 4 ++++ include/hw/virtio/vhost-user-blk.h | 2 ++ 4 files changed, 12 insertions(+), 1 deletion(-) diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c index a00b854736..39aec42dae 100644 --- a/hw/block/vhost-user-blk.c +++ b/hw/block/vhost-user-blk.c @@ -420,6 +420,9 @@ static void vhost_user_blk_device_realize(DeviceState *dev, Error **errp) return; } + if (s->num_queues == VHOST_USER_BLK_AUTO_NUM_QUEUES) { + s->num_queues = 1; + } if (!s->num_queues || s->num_queues > VIRTIO_QUEUE_MAX) { error_setg(errp, "vhost-user-blk: invalid number of IO queues"); return; @@ -531,7 +534,8 @@ static const VMStateDescription vmstate_vhost_user_blk = { static Property vhost_user_blk_properties[] = { DEFINE_PROP_CHR("chardev", VHostUserBlk, chardev), - DEFINE_PROP_UINT16("num-queues", VHostUserBlk, num_queues, 1), + DEFINE_PROP_UINT16("num-queues", VHostUserBlk, num_queues, + VHOST_USER_BLK_AUTO_NUM_QUEUES), DEFINE_PROP_UINT32("queue-size", VHostUserBlk, queue_size, 128), DEFINE_PROP_BIT("config-wce", VHostUserBlk, config_wce, 0, true), DEFINE_PROP_END_OF_LIST(), diff --git a/hw/core/machine.c b/hw/core/machine.c index 7f65fa8743..ea26d61237 100644 --- a/hw/core/machine.c +++ b/hw/core/machine.c @@ -30,6 +30,7 @@ GlobalProperty hw_compat_5_1[] = { { "vhost-scsi", "num_queues", "1"}, + { "vhost-user-blk", "num-queues", "1"}, { "vhost-user-scsi", "num_queues", "1"}, { "virtio-blk-device", "num-queues", "1"}, { "virtio-scsi-device", "num_queues", "1"}, diff --git a/hw/virtio/vhost-user-blk-pci.c b/hw/virtio/vhost-user-blk-pci.c index 4f5d5cbf44..a62a71e067 100644 --- a/hw/virtio/vhost-user-blk-pci.c +++ b/hw/virtio/vhost-user-blk-pci.c @@ -54,6 +54,10 @@ static void vhost_user_blk_pci_realize(VirtIOPCIProxy *vpci_dev, Error **errp) VHostUserBlkPCI *dev = VHOST_USER_BLK_PCI(vpci_dev); DeviceState *vdev = DEVICE(&dev->vdev); + if (dev->vdev.num_queues == VHOST_USER_BLK_AUTO_NUM_QUEUES) { + dev->vdev.num_queues = virtio_pci_optimal_num_queues(0); + } + if (vpci_dev->nvectors == DEV_NVECTORS_UNSPECIFIED) { vpci_dev->nvectors = dev->vdev.num_queues + 1; } diff --git a/include/hw/virtio/vhost-user-blk.h b/include/hw/virtio/vhost-user-blk.h index 34ad6f0c0e..292d17147c 100644 --- a/include/hw/virtio/vhost-user-blk.h +++ b/include/hw/virtio/vhost-user-blk.h @@ -25,6 +25,8 @@ #define VHOST_USER_BLK(obj) \ OBJECT_CHECK(VHostUserBlk, (obj), TYPE_VHOST_USER_BLK) +#define VHOST_USER_BLK_AUTO_NUM_QUEUES UINT16_MAX + typedef struct VHostUserBlk { VirtIODevice parent_obj; CharBackend chardev; -- cgit v1.2.3