qemu-e2k/hw/virtio/vhost-scsi-pci.c
Stefan Hajnoczi 6a55882284 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>
2020-08-27 08:29:13 -04:00

104 lines
3.1 KiB
C

/*
* Vhost scsi PCI bindings
*
* Copyright IBM, Corp. 2011
*
* Authors:
* Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
*
* Changes for QEMU mainline + tcm_vhost kernel upstream:
* Nicholas Bellinger <nab@risingtidesystems.com>
*
* This work is licensed under the terms of the GNU LGPL, version 2 or later.
* See the COPYING.LIB file in the top-level directory.
*
*/
#include "qemu/osdep.h"
#include "standard-headers/linux/virtio_pci.h"
#include "hw/qdev-properties.h"
#include "hw/virtio/vhost-scsi.h"
#include "qapi/error.h"
#include "qemu/module.h"
#include "virtio-pci.h"
typedef struct VHostSCSIPCI VHostSCSIPCI;
/*
* vhost-scsi-pci: This extends VirtioPCIProxy.
*/
#define TYPE_VHOST_SCSI_PCI "vhost-scsi-pci-base"
#define VHOST_SCSI_PCI(obj) \
OBJECT_CHECK(VHostSCSIPCI, (obj), TYPE_VHOST_SCSI_PCI)
struct VHostSCSIPCI {
VirtIOPCIProxy parent_obj;
VHostSCSI vdev;
};
static Property vhost_scsi_pci_properties[] = {
DEFINE_PROP_UINT32("vectors", VirtIOPCIProxy, nvectors,
DEV_NVECTORS_UNSPECIFIED),
DEFINE_PROP_END_OF_LIST(),
};
static void vhost_scsi_pci_realize(VirtIOPCIProxy *vpci_dev, Error **errp)
{
VHostSCSIPCI *dev = VHOST_SCSI_PCI(vpci_dev);
DeviceState *vdev = DEVICE(&dev->vdev);
VirtIOSCSIConf *conf = &dev->vdev.parent_obj.parent_obj.conf;
if (conf->num_queues == VIRTIO_SCSI_AUTO_NUM_QUEUES) {
conf->num_queues =
virtio_pci_optimal_num_queues(VIRTIO_SCSI_VQ_NUM_FIXED);
}
if (vpci_dev->nvectors == DEV_NVECTORS_UNSPECIFIED) {
vpci_dev->nvectors = conf->num_queues + VIRTIO_SCSI_VQ_NUM_FIXED + 1;
}
qdev_realize(vdev, BUS(&vpci_dev->bus), errp);
}
static void vhost_scsi_pci_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
VirtioPCIClass *k = VIRTIO_PCI_CLASS(klass);
PCIDeviceClass *pcidev_k = PCI_DEVICE_CLASS(klass);
k->realize = vhost_scsi_pci_realize;
set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
device_class_set_props(dc, vhost_scsi_pci_properties);
pcidev_k->vendor_id = PCI_VENDOR_ID_REDHAT_QUMRANET;
pcidev_k->device_id = PCI_DEVICE_ID_VIRTIO_SCSI;
pcidev_k->revision = 0x00;
pcidev_k->class_id = PCI_CLASS_STORAGE_SCSI;
}
static void vhost_scsi_pci_instance_init(Object *obj)
{
VHostSCSIPCI *dev = VHOST_SCSI_PCI(obj);
virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
TYPE_VHOST_SCSI);
object_property_add_alias(obj, "bootindex", OBJECT(&dev->vdev),
"bootindex");
}
static const VirtioPCIDeviceTypeInfo vhost_scsi_pci_info = {
.base_name = TYPE_VHOST_SCSI_PCI,
.generic_name = "vhost-scsi-pci",
.transitional_name = "vhost-scsi-pci-transitional",
.non_transitional_name = "vhost-scsi-pci-non-transitional",
.instance_size = sizeof(VHostSCSIPCI),
.instance_init = vhost_scsi_pci_instance_init,
.class_init = vhost_scsi_pci_class_init,
};
static void vhost_scsi_pci_register(void)
{
virtio_pci_types_register(&vhost_scsi_pci_info);
}
type_init(vhost_scsi_pci_register)