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-rw-r--r--hw/acpi/pcihp.c23
-rw-r--r--hw/acpi/piix4.c5
-rw-r--r--hw/arm/virt-acpi-build.c2
-rw-r--r--hw/block/vhost-user-blk.c6
-rw-r--r--hw/block/virtio-blk.c6
-rw-r--r--hw/core/machine.c8
-rw-r--r--hw/i386/acpi-build.c4
-rw-r--r--hw/scsi/vhost-scsi.c3
-rw-r--r--hw/scsi/vhost-user-scsi.c5
-rw-r--r--hw/scsi/virtio-scsi.c13
-rw-r--r--hw/smbios/smbios.c36
-rw-r--r--hw/virtio/vhost-scsi-pci.c9
-rw-r--r--hw/virtio/vhost-user-blk-pci.c4
-rw-r--r--hw/virtio/vhost-user-scsi-pci.c9
-rw-r--r--hw/virtio/virtio-blk-pci.c7
-rw-r--r--hw/virtio/virtio-pci.c32
-rw-r--r--hw/virtio/virtio-pci.h9
-rw-r--r--hw/virtio/virtio-scsi-pci.c9
18 files changed, 164 insertions, 26 deletions
diff --git a/hw/acpi/pcihp.c b/hw/acpi/pcihp.c
index 9e31ab2da4..39b1f74442 100644
--- a/hw/acpi/pcihp.c
+++ b/hw/acpi/pcihp.c
@@ -104,6 +104,24 @@ static void acpi_set_pci_info(void)
}
}
+static void acpi_pcihp_disable_root_bus(void)
+{
+ static bool root_hp_disabled;
+ PCIBus *bus;
+
+ if (root_hp_disabled) {
+ return;
+ }
+
+ bus = find_i440fx();
+ if (bus) {
+ /* setting the hotplug handler to NULL makes the bus non-hotpluggable */
+ qbus_set_hotplug_handler(BUS(bus), NULL);
+ }
+ root_hp_disabled = true;
+ return;
+}
+
static void acpi_pcihp_test_hotplug_bus(PCIBus *bus, void *opaque)
{
AcpiPciHpFind *find = opaque;
@@ -209,8 +227,11 @@ static void acpi_pcihp_update(AcpiPciHpState *s)
}
}
-void acpi_pcihp_reset(AcpiPciHpState *s)
+void acpi_pcihp_reset(AcpiPciHpState *s, bool acpihp_root_off)
{
+ if (acpihp_root_off) {
+ acpi_pcihp_disable_root_bus();
+ }
acpi_set_pci_info();
acpi_pcihp_update(s);
}
diff --git a/hw/acpi/piix4.c b/hw/acpi/piix4.c
index 26bac4f16c..e6163bb6ce 100644
--- a/hw/acpi/piix4.c
+++ b/hw/acpi/piix4.c
@@ -78,6 +78,7 @@ typedef struct PIIX4PMState {
AcpiPciHpState acpi_pci_hotplug;
bool use_acpi_hotplug_bridge;
+ bool use_acpi_root_pci_hotplug;
uint8_t disable_s3;
uint8_t disable_s4;
@@ -324,7 +325,7 @@ static void piix4_pm_reset(DeviceState *dev)
pci_conf[0x5B] = 0x02;
}
pm_io_space_update(s);
- acpi_pcihp_reset(&s->acpi_pci_hotplug);
+ acpi_pcihp_reset(&s->acpi_pci_hotplug, !s->use_acpi_root_pci_hotplug);
}
static void piix4_pm_powerdown_req(Notifier *n, void *opaque)
@@ -635,6 +636,8 @@ static Property piix4_pm_properties[] = {
DEFINE_PROP_UINT8(ACPI_PM_PROP_S4_VAL, PIIX4PMState, s4_val, 2),
DEFINE_PROP_BOOL("acpi-pci-hotplug-with-bridge-support", PIIX4PMState,
use_acpi_hotplug_bridge, true),
+ DEFINE_PROP_BOOL("acpi-root-pci-hotplug", PIIX4PMState,
+ use_acpi_root_pci_hotplug, true),
DEFINE_PROP_BOOL("memory-hotplug-support", PIIX4PMState,
acpi_memory_hotplug.is_enabled, true),
DEFINE_PROP_END_OF_LIST(),
diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
index 91f0df7b13..0a482ff6f7 100644
--- a/hw/arm/virt-acpi-build.c
+++ b/hw/arm/virt-acpi-build.c
@@ -170,7 +170,7 @@ static void acpi_dsdt_add_pci(Aml *scope, const MemMapEntry *memmap,
aml_append(dev, aml_name_decl("_CID", aml_string("PNP0A03")));
aml_append(dev, aml_name_decl("_SEG", aml_int(0)));
aml_append(dev, aml_name_decl("_BBN", aml_int(0)));
- aml_append(dev, aml_name_decl("_UID", aml_string("PCI0")));
+ aml_append(dev, aml_name_decl("_UID", aml_int(0)));
aml_append(dev, aml_name_decl("_STR", aml_unicode("PCIe 0 Device")));
aml_append(dev, aml_name_decl("_CCA", aml_int(1)));
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/block/virtio-blk.c b/hw/block/virtio-blk.c
index 413783693c..2204ba149e 100644
--- a/hw/block/virtio-blk.c
+++ b/hw/block/virtio-blk.c
@@ -1147,6 +1147,9 @@ static void virtio_blk_device_realize(DeviceState *dev, Error **errp)
error_setg(errp, "Device needs media, but drive is empty");
return;
}
+ if (conf->num_queues == VIRTIO_BLK_AUTO_NUM_QUEUES) {
+ conf->num_queues = 1;
+ }
if (!conf->num_queues) {
error_setg(errp, "num-queues property must be larger than 0");
return;
@@ -1281,7 +1284,8 @@ static Property virtio_blk_properties[] = {
#endif
DEFINE_PROP_BIT("request-merging", VirtIOBlock, conf.request_merging, 0,
true),
- DEFINE_PROP_UINT16("num-queues", VirtIOBlock, conf.num_queues, 1),
+ DEFINE_PROP_UINT16("num-queues", VirtIOBlock, conf.num_queues,
+ VIRTIO_BLK_AUTO_NUM_QUEUES),
DEFINE_PROP_UINT16("queue-size", VirtIOBlock, conf.queue_size, 256),
DEFINE_PROP_BOOL("seg-max-adjust", VirtIOBlock, conf.seg_max_adjust, true),
DEFINE_PROP_LINK("iothread", VirtIOBlock, conf.iothread, TYPE_IOTHREAD,
diff --git a/hw/core/machine.c b/hw/core/machine.c
index cf5f2dfaeb..ea26d61237 100644
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -28,7 +28,13 @@
#include "hw/mem/nvdimm.h"
#include "migration/vmstate.h"
-GlobalProperty hw_compat_5_1[] = {};
+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"},
+};
const size_t hw_compat_5_1_len = G_N_ELEMENTS(hw_compat_5_1);
GlobalProperty hw_compat_5_0[] = {
diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index b7bcbbbb2a..7a5a8b3521 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -1497,7 +1497,7 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
dev = aml_device("PCI0");
aml_append(dev, aml_name_decl("_HID", aml_eisaid("PNP0A03")));
aml_append(dev, aml_name_decl("_ADR", aml_int(0)));
- aml_append(dev, aml_name_decl("_UID", aml_int(1)));
+ aml_append(dev, aml_name_decl("_UID", aml_int(0)));
aml_append(sb_scope, dev);
aml_append(dsdt, sb_scope);
@@ -1512,7 +1512,7 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
aml_append(dev, aml_name_decl("_HID", aml_eisaid("PNP0A08")));
aml_append(dev, aml_name_decl("_CID", aml_eisaid("PNP0A03")));
aml_append(dev, aml_name_decl("_ADR", aml_int(0)));
- aml_append(dev, aml_name_decl("_UID", aml_int(1)));
+ aml_append(dev, aml_name_decl("_UID", aml_int(0)));
aml_append(dev, build_q35_osc_method());
aml_append(sb_scope, dev);
aml_append(dsdt, sb_scope);
diff --git a/hw/scsi/vhost-scsi.c b/hw/scsi/vhost-scsi.c
index 13b05af29b..a83ffeefc8 100644
--- a/hw/scsi/vhost-scsi.c
+++ b/hw/scsi/vhost-scsi.c
@@ -270,7 +270,8 @@ static Property vhost_scsi_properties[] = {
DEFINE_PROP_STRING("vhostfd", VirtIOSCSICommon, conf.vhostfd),
DEFINE_PROP_STRING("wwpn", VirtIOSCSICommon, conf.wwpn),
DEFINE_PROP_UINT32("boot_tpgt", VirtIOSCSICommon, conf.boot_tpgt, 0),
- DEFINE_PROP_UINT32("num_queues", VirtIOSCSICommon, conf.num_queues, 1),
+ DEFINE_PROP_UINT32("num_queues", VirtIOSCSICommon, conf.num_queues,
+ VIRTIO_SCSI_AUTO_NUM_QUEUES),
DEFINE_PROP_UINT32("virtqueue_size", VirtIOSCSICommon, conf.virtqueue_size,
128),
DEFINE_PROP_BOOL("seg_max_adjust", VirtIOSCSICommon, conf.seg_max_adjust,
diff --git a/hw/scsi/vhost-user-scsi.c b/hw/scsi/vhost-user-scsi.c
index f2e524438a..7c0631656c 100644
--- a/hw/scsi/vhost-user-scsi.c
+++ b/hw/scsi/vhost-user-scsi.c
@@ -114,7 +114,7 @@ static void vhost_user_scsi_realize(DeviceState *dev, Error **errp)
goto free_virtio;
}
- vsc->dev.nvqs = 2 + vs->conf.num_queues;
+ vsc->dev.nvqs = VIRTIO_SCSI_VQ_NUM_FIXED + vs->conf.num_queues;
vsc->dev.vqs = g_new0(struct vhost_virtqueue, vsc->dev.nvqs);
vsc->dev.vq_index = 0;
vsc->dev.backend_features = 0;
@@ -162,7 +162,8 @@ static void vhost_user_scsi_unrealize(DeviceState *dev)
static Property vhost_user_scsi_properties[] = {
DEFINE_PROP_CHR("chardev", VirtIOSCSICommon, conf.chardev),
DEFINE_PROP_UINT32("boot_tpgt", VirtIOSCSICommon, conf.boot_tpgt, 0),
- DEFINE_PROP_UINT32("num_queues", VirtIOSCSICommon, conf.num_queues, 1),
+ DEFINE_PROP_UINT32("num_queues", VirtIOSCSICommon, conf.num_queues,
+ VIRTIO_SCSI_AUTO_NUM_QUEUES),
DEFINE_PROP_UINT32("virtqueue_size", VirtIOSCSICommon, conf.virtqueue_size,
128),
DEFINE_PROP_UINT32("max_sectors", VirtIOSCSICommon, conf.max_sectors,
diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c
index b49775269e..3a71ea7097 100644
--- a/hw/scsi/virtio-scsi.c
+++ b/hw/scsi/virtio-scsi.c
@@ -191,7 +191,7 @@ static void virtio_scsi_save_request(QEMUFile *f, SCSIRequest *sreq)
VirtIOSCSIReq *req = sreq->hba_private;
VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(req->dev);
VirtIODevice *vdev = VIRTIO_DEVICE(req->dev);
- uint32_t n = virtio_get_queue_index(req->vq) - 2;
+ uint32_t n = virtio_get_queue_index(req->vq) - VIRTIO_SCSI_VQ_NUM_FIXED;
assert(n < vs->conf.num_queues);
qemu_put_be32s(f, &n);
@@ -891,11 +891,15 @@ void virtio_scsi_common_realize(DeviceState *dev,
virtio_init(vdev, "virtio-scsi", VIRTIO_ID_SCSI,
sizeof(VirtIOSCSIConfig));
+ if (s->conf.num_queues == VIRTIO_SCSI_AUTO_NUM_QUEUES) {
+ s->conf.num_queues = 1;
+ }
if (s->conf.num_queues == 0 ||
- s->conf.num_queues > VIRTIO_QUEUE_MAX - 2) {
+ s->conf.num_queues > VIRTIO_QUEUE_MAX - VIRTIO_SCSI_VQ_NUM_FIXED) {
error_setg(errp, "Invalid number of queues (= %" PRIu32 "), "
"must be a positive integer less than %d.",
- s->conf.num_queues, VIRTIO_QUEUE_MAX - 2);
+ s->conf.num_queues,
+ VIRTIO_QUEUE_MAX - VIRTIO_SCSI_VQ_NUM_FIXED);
virtio_cleanup(vdev);
return;
}
@@ -963,7 +967,8 @@ static void virtio_scsi_device_unrealize(DeviceState *dev)
}
static Property virtio_scsi_properties[] = {
- DEFINE_PROP_UINT32("num_queues", VirtIOSCSI, parent_obj.conf.num_queues, 1),
+ DEFINE_PROP_UINT32("num_queues", VirtIOSCSI, parent_obj.conf.num_queues,
+ VIRTIO_SCSI_AUTO_NUM_QUEUES),
DEFINE_PROP_UINT32("virtqueue_size", VirtIOSCSI,
parent_obj.conf.virtqueue_size, 256),
DEFINE_PROP_BOOL("seg_max_adjust", VirtIOSCSI,
diff --git a/hw/smbios/smbios.c b/hw/smbios/smbios.c
index f560826904..7cc950b41c 100644
--- a/hw/smbios/smbios.c
+++ b/hw/smbios/smbios.c
@@ -92,9 +92,21 @@ static struct {
const char *manufacturer, *version, *serial, *asset, *sku;
} type3;
+/*
+ * SVVP requires max_speed and current_speed to be set and not being
+ * 0 which counts as unknown (SMBIOS 3.1.0/Table 21). Set the
+ * default value to 2000MHz as we did before.
+ */
+#define DEFAULT_CPU_SPEED 2000
+
static struct {
const char *sock_pfx, *manufacturer, *version, *serial, *asset, *part;
-} type4;
+ uint64_t max_speed;
+ uint64_t current_speed;
+} type4 = {
+ .max_speed = DEFAULT_CPU_SPEED,
+ .current_speed = DEFAULT_CPU_SPEED
+};
static struct {
size_t nvalues;
@@ -273,6 +285,14 @@ static const QemuOptDesc qemu_smbios_type4_opts[] = {
.type = QEMU_OPT_STRING,
.help = "version number",
},{
+ .name = "max-speed",
+ .type = QEMU_OPT_NUMBER,
+ .help = "max speed in MHz",
+ },{
+ .name = "current-speed",
+ .type = QEMU_OPT_NUMBER,
+ .help = "speed at system boot in MHz",
+ },{
.name = "serial",
.type = QEMU_OPT_STRING,
.help = "serial number",
@@ -586,9 +606,8 @@ static void smbios_build_type_4_table(MachineState *ms, unsigned instance)
SMBIOS_TABLE_SET_STR(4, processor_version_str, type4.version);
t->voltage = 0;
t->external_clock = cpu_to_le16(0); /* Unknown */
- /* SVVP requires max_speed and current_speed to not be unknown. */
- t->max_speed = cpu_to_le16(2000); /* 2000 MHz */
- t->current_speed = cpu_to_le16(2000); /* 2000 MHz */
+ t->max_speed = cpu_to_le16(type4.max_speed);
+ t->current_speed = cpu_to_le16(type4.current_speed);
t->status = 0x41; /* Socket populated, CPU enabled */
t->processor_upgrade = 0x01; /* Other */
t->l1_cache_handle = cpu_to_le16(0xFFFF); /* N/A */
@@ -1116,6 +1135,15 @@ void smbios_entry_add(QemuOpts *opts, Error **errp)
save_opt(&type4.serial, opts, "serial");
save_opt(&type4.asset, opts, "asset");
save_opt(&type4.part, opts, "part");
+ type4.max_speed = qemu_opt_get_number(opts, "max-speed",
+ DEFAULT_CPU_SPEED);
+ type4.current_speed = qemu_opt_get_number(opts, "current-speed",
+ DEFAULT_CPU_SPEED);
+ if (type4.max_speed > UINT16_MAX ||
+ type4.current_speed > UINT16_MAX) {
+ error_setg(errp, "SMBIOS CPU speed is too large (> %d)",
+ UINT16_MAX);
+ }
return;
case 11:
if (!qemu_opts_validate(opts, qemu_smbios_type11_opts, errp)) {
diff --git a/hw/virtio/vhost-scsi-pci.c b/hw/virtio/vhost-scsi-pci.c
index 095af23f3f..a6bb0dc60d 100644
--- a/hw/virtio/vhost-scsi-pci.c
+++ b/hw/virtio/vhost-scsi-pci.c
@@ -47,10 +47,15 @@ static void vhost_scsi_pci_realize(VirtIOPCIProxy *vpci_dev, Error **errp)
{
VHostSCSIPCI *dev = VHOST_SCSI_PCI(vpci_dev);
DeviceState *vdev = DEVICE(&dev->vdev);
- VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(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 = vs->conf.num_queues + 3;
+ vpci_dev->nvectors = conf->num_queues + VIRTIO_SCSI_VQ_NUM_FIXED + 1;
}
qdev_realize(vdev, BUS(&vpci_dev->bus), errp);
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/hw/virtio/vhost-user-scsi-pci.c b/hw/virtio/vhost-user-scsi-pci.c
index 4705cd54e8..25e97ca54e 100644
--- a/hw/virtio/vhost-user-scsi-pci.c
+++ b/hw/virtio/vhost-user-scsi-pci.c
@@ -53,10 +53,15 @@ static void vhost_user_scsi_pci_realize(VirtIOPCIProxy *vpci_dev, Error **errp)
{
VHostUserSCSIPCI *dev = VHOST_USER_SCSI_PCI(vpci_dev);
DeviceState *vdev = DEVICE(&dev->vdev);
- VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(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 = vs->conf.num_queues + 3;
+ vpci_dev->nvectors = conf->num_queues + VIRTIO_SCSI_VQ_NUM_FIXED + 1;
}
qdev_realize(vdev, BUS(&vpci_dev->bus), errp);
diff --git a/hw/virtio/virtio-blk-pci.c b/hw/virtio/virtio-blk-pci.c
index 849cc7dfd8..37c6e0aeb4 100644
--- a/hw/virtio/virtio-blk-pci.c
+++ b/hw/virtio/virtio-blk-pci.c
@@ -50,9 +50,14 @@ static void virtio_blk_pci_realize(VirtIOPCIProxy *vpci_dev, Error **errp)
{
VirtIOBlkPCI *dev = VIRTIO_BLK_PCI(vpci_dev);
DeviceState *vdev = DEVICE(&dev->vdev);
+ VirtIOBlkConf *conf = &dev->vdev.conf;
+
+ if (conf->num_queues == VIRTIO_BLK_AUTO_NUM_QUEUES) {
+ conf->num_queues = virtio_pci_optimal_num_queues(0);
+ }
if (vpci_dev->nvectors == DEV_NVECTORS_UNSPECIFIED) {
- vpci_dev->nvectors = dev->vdev.conf.num_queues + 1;
+ vpci_dev->nvectors = conf->num_queues + 1;
}
qdev_realize(vdev, BUS(&vpci_dev->bus), errp);
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index ccdf54e81c..fc69570dcc 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -19,6 +19,7 @@
#include "exec/memop.h"
#include "standard-headers/linux/virtio_pci.h"
+#include "hw/boards.h"
#include "hw/virtio/virtio.h"
#include "migration/qemu-file-types.h"
#include "hw/pci/pci.h"
@@ -2058,6 +2059,37 @@ void virtio_pci_types_register(const VirtioPCIDeviceTypeInfo *t)
g_free(base_name);
}
+unsigned virtio_pci_optimal_num_queues(unsigned fixed_queues)
+{
+ /*
+ * 1:1 vq to vCPU mapping is ideal because the same vCPU that submitted
+ * virtqueue buffers can handle their completion. When a different vCPU
+ * handles completion it may need to IPI the vCPU that submitted the
+ * request and this adds overhead.
+ *
+ * Virtqueues consume guest RAM and MSI-X vectors. This is wasteful in
+ * guests with very many vCPUs and a device that is only used by a few
+ * vCPUs. Unfortunately optimizing that case requires manual pinning inside
+ * the guest, so those users might as well manually set the number of
+ * queues. There is no upper limit that can be applied automatically and
+ * doing so arbitrarily would result in a sudden performance drop once the
+ * threshold number of vCPUs is exceeded.
+ */
+ unsigned num_queues = current_machine->smp.cpus;
+
+ /*
+ * The maximum number of MSI-X vectors is PCI_MSIX_FLAGS_QSIZE + 1, but the
+ * config change interrupt and the fixed virtqueues must be taken into
+ * account too.
+ */
+ num_queues = MIN(num_queues, PCI_MSIX_FLAGS_QSIZE - fixed_queues);
+
+ /*
+ * There is a limit to how many virtqueues a device can have.
+ */
+ return MIN(num_queues, VIRTIO_QUEUE_MAX - fixed_queues);
+}
+
/* virtio-pci-bus */
static void virtio_pci_bus_new(VirtioBusState *bus, size_t bus_size,
diff --git a/hw/virtio/virtio-pci.h b/hw/virtio/virtio-pci.h
index e2eaaa9182..91096f0291 100644
--- a/hw/virtio/virtio-pci.h
+++ b/hw/virtio/virtio-pci.h
@@ -243,4 +243,13 @@ typedef struct VirtioPCIDeviceTypeInfo {
/* Register virtio-pci type(s). @t must be static. */
void virtio_pci_types_register(const VirtioPCIDeviceTypeInfo *t);
+/**
+ * virtio_pci_optimal_num_queues:
+ * @fixed_queues: number of queues that are always present
+ *
+ * Returns: The optimal number of queues for a multi-queue device, excluding
+ * @fixed_queues.
+ */
+unsigned virtio_pci_optimal_num_queues(unsigned fixed_queues);
+
#endif
diff --git a/hw/virtio/virtio-scsi-pci.c b/hw/virtio/virtio-scsi-pci.c
index c23a134202..fa4b3bfb50 100644
--- a/hw/virtio/virtio-scsi-pci.c
+++ b/hw/virtio/virtio-scsi-pci.c
@@ -46,12 +46,17 @@ static void virtio_scsi_pci_realize(VirtIOPCIProxy *vpci_dev, Error **errp)
{
VirtIOSCSIPCI *dev = VIRTIO_SCSI_PCI(vpci_dev);
DeviceState *vdev = DEVICE(&dev->vdev);
- VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
DeviceState *proxy = DEVICE(vpci_dev);
+ VirtIOSCSIConf *conf = &dev->vdev.parent_obj.conf;
char *bus_name;
+ 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 = vs->conf.num_queues + 3;
+ vpci_dev->nvectors = conf->num_queues + VIRTIO_SCSI_VQ_NUM_FIXED + 1;
}
/*
generated by cgit v1.2.3 (git 2.26.2) at 2025-02-20 12:42:59 +0000