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>
107 lines
3.2 KiB
C
107 lines
3.2 KiB
C
/*
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* Virtio blk PCI Bindings
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*
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* Copyright IBM, Corp. 2007
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* Copyright (c) 2009 CodeSourcery
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*
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* Authors:
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* Anthony Liguori <aliguori@us.ibm.com>
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* Paul Brook <paul@codesourcery.com>
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*
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* This work is licensed under the terms of the GNU GPL, version 2. See
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* the COPYING file in the top-level directory.
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*
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* Contributions after 2012-01-13 are licensed under the terms of the
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* GNU GPL, version 2 or (at your option) any later version.
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*/
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#include "qemu/osdep.h"
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#include "hw/qdev-properties.h"
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#include "hw/virtio/virtio-blk.h"
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#include "virtio-pci.h"
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#include "qapi/error.h"
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#include "qemu/module.h"
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typedef struct VirtIOBlkPCI VirtIOBlkPCI;
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/*
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* virtio-blk-pci: This extends VirtioPCIProxy.
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*/
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#define TYPE_VIRTIO_BLK_PCI "virtio-blk-pci-base"
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#define VIRTIO_BLK_PCI(obj) \
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OBJECT_CHECK(VirtIOBlkPCI, (obj), TYPE_VIRTIO_BLK_PCI)
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struct VirtIOBlkPCI {
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VirtIOPCIProxy parent_obj;
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VirtIOBlock vdev;
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};
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static Property virtio_blk_pci_properties[] = {
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DEFINE_PROP_UINT32("class", VirtIOPCIProxy, class_code, 0),
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DEFINE_PROP_BIT("ioeventfd", VirtIOPCIProxy, flags,
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VIRTIO_PCI_FLAG_USE_IOEVENTFD_BIT, true),
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DEFINE_PROP_UINT32("vectors", VirtIOPCIProxy, nvectors,
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DEV_NVECTORS_UNSPECIFIED),
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DEFINE_PROP_END_OF_LIST(),
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};
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static void virtio_blk_pci_realize(VirtIOPCIProxy *vpci_dev, Error **errp)
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{
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VirtIOBlkPCI *dev = VIRTIO_BLK_PCI(vpci_dev);
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DeviceState *vdev = DEVICE(&dev->vdev);
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VirtIOBlkConf *conf = &dev->vdev.conf;
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if (conf->num_queues == VIRTIO_BLK_AUTO_NUM_QUEUES) {
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conf->num_queues = virtio_pci_optimal_num_queues(0);
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}
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if (vpci_dev->nvectors == DEV_NVECTORS_UNSPECIFIED) {
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vpci_dev->nvectors = conf->num_queues + 1;
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}
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qdev_realize(vdev, BUS(&vpci_dev->bus), errp);
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}
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static void virtio_blk_pci_class_init(ObjectClass *klass, void *data)
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{
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DeviceClass *dc = DEVICE_CLASS(klass);
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VirtioPCIClass *k = VIRTIO_PCI_CLASS(klass);
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PCIDeviceClass *pcidev_k = PCI_DEVICE_CLASS(klass);
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set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
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device_class_set_props(dc, virtio_blk_pci_properties);
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k->realize = virtio_blk_pci_realize;
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pcidev_k->vendor_id = PCI_VENDOR_ID_REDHAT_QUMRANET;
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pcidev_k->device_id = PCI_DEVICE_ID_VIRTIO_BLOCK;
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pcidev_k->revision = VIRTIO_PCI_ABI_VERSION;
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pcidev_k->class_id = PCI_CLASS_STORAGE_SCSI;
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}
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static void virtio_blk_pci_instance_init(Object *obj)
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{
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VirtIOBlkPCI *dev = VIRTIO_BLK_PCI(obj);
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virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
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TYPE_VIRTIO_BLK);
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object_property_add_alias(obj, "bootindex", OBJECT(&dev->vdev),
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"bootindex");
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}
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static const VirtioPCIDeviceTypeInfo virtio_blk_pci_info = {
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.base_name = TYPE_VIRTIO_BLK_PCI,
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.generic_name = "virtio-blk-pci",
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.transitional_name = "virtio-blk-pci-transitional",
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.non_transitional_name = "virtio-blk-pci-non-transitional",
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.instance_size = sizeof(VirtIOBlkPCI),
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.instance_init = virtio_blk_pci_instance_init,
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.class_init = virtio_blk_pci_class_init,
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};
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static void virtio_blk_pci_register(void)
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{
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virtio_pci_types_register(&virtio_blk_pci_info);
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}
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type_init(virtio_blk_pci_register)
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