From 2e8e18c2e46307a355e547129b5a7a7000a0cf0d Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Tue, 11 Mar 2025 21:26:14 +0800 Subject: virtio-scsi: add iothread-vq-mapping parameter Allow virtio-scsi virtqueues to be assigned to different IOThreads. This makes it possible to take advantage of host multi-queue block layer scalability by assigning virtqueues that have affinity with vCPUs to different IOThreads that have affinity with host CPUs. The same feature was introduced for virtio-blk in the past: https://developers.redhat.com/articles/2024/09/05/scaling-virtio-blk-disk-io-iothread-virtqueue-mapping Here are fio randread 4k iodepth=64 results from a 4 vCPU guest with an Intel P4800X SSD: iothreads IOPS ------------------------------ 1 189576 2 312698 4 346744 Signed-off-by: Stefan Hajnoczi Message-ID: <20250311132616.1049687-12-stefanha@redhat.com> Tested-by: Peter Krempa [kwolf: Updated 051 output, virtio-scsi can now use any iothread] Reviewed-by: Kevin Wolf Signed-off-by: Kevin Wolf --- include/hw/virtio/virtio-scsi.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/hw/virtio/virtio-scsi.h b/include/hw/virtio/virtio-scsi.h index 7b7e3ce..086201e 100644 --- a/include/hw/virtio/virtio-scsi.h +++ b/include/hw/virtio/virtio-scsi.h @@ -22,6 +22,7 @@ #include "hw/virtio/virtio.h" #include "hw/scsi/scsi.h" #include "chardev/char-fe.h" +#include "qapi/qapi-types-virtio.h" #include "system/iothread.h" #define TYPE_VIRTIO_SCSI_COMMON "virtio-scsi-common" @@ -60,6 +61,7 @@ struct VirtIOSCSIConf { CharBackend chardev; uint32_t boot_tpgt; IOThread *iothread; + IOThreadVirtQueueMappingList *iothread_vq_mapping_list; }; struct VirtIOSCSI; @@ -97,7 +99,7 @@ struct VirtIOSCSI { QTAILQ_HEAD(, VirtIOSCSIReq) tmf_bh_list; /* Fields for dataplane below */ - AioContext *ctx; /* one iothread per virtio-scsi-pci for now */ + AioContext **vq_aio_context; /* per-virtqueue AioContext pointer */ bool dataplane_started; bool dataplane_starting; @@ -115,6 +117,7 @@ void virtio_scsi_common_realize(DeviceState *dev, void virtio_scsi_common_unrealize(DeviceState *dev); void virtio_scsi_dataplane_setup(VirtIOSCSI *s, Error **errp); +void virtio_scsi_dataplane_cleanup(VirtIOSCSI *s); int virtio_scsi_dataplane_start(VirtIODevice *s); void virtio_scsi_dataplane_stop(VirtIODevice *s); -- cgit v1.1