[PATCH RFC 21/21] qemu: Implement support for configuring iothread to virtqueue mapping for disks
Peter Krempa
pkrempa at redhat.com
Thu Mar 2 14:38:03 UTC 2023
Add validation and formatting of the commandline.
Note that this is based on Stefan's RFC series which only adds the qemu
interface:
https://lists.gnu.org/archive/html/qemu-devel/2023-01/msg04090.html
---
src/qemu/qemu_command.c | 45 +++++++
src/qemu/qemu_validate.c | 117 ++++++++++++++++--
.../iothreads-disk.x86_64-latest.args | 4 +-
3 files changed, 153 insertions(+), 13 deletions(-)
diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index cc476addce..d9bb984101 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -1746,6 +1746,45 @@ qemuBuildDriveStr(virDomainDiskDef *disk)
}
+static virJSONValue *
+qemuBuildDiskDeviceIothreadMappingProps(GSList *iothreads)
+{
+ g_autoptr(virJSONValue) ret = virJSONValueNewArray();
+ GSList *n;
+
+ for (n = iothreads; n; n = n->next) {
+ virDomainDiskIothreadDef *ioth = n->data;
+ g_autoptr(virJSONValue) props = NULL;
+ g_autoptr(virJSONValue) queues = NULL;
+ g_autofree char *alias = g_strdup_printf("iothread%u", ioth->id);
+ size_t i;
+
+ if (ioth->nqueues > 0) {
+ queues = virJSONValueNewArray();
+
+ for (i = 0; i < ioth->nqueues; i++) {
+ g_autoptr(virJSONValue) vq = virJSONValueNewNumberUint(ioth->queues[i]);
+
+ if (virJSONValueArrayAppend(queues, &vq))
+ return NULL;
+ }
+ }
+
+ if (virJSONValueObjectAdd(&props,
+ "s:iothread", alias,
+ "A:vqs", &queues,
+ NULL) < 0)
+ return NULL;
+
+
+ if (virJSONValueArrayAppend(ret, &props))
+ return NULL;
+ }
+
+ return g_steal_pointer(&ret);
+}
+
+
virJSONValue *
qemuBuildDiskDeviceProps(const virDomainDef *def,
virDomainDiskDef *disk,
@@ -1804,11 +1843,16 @@ qemuBuildDiskDeviceProps(const virDomainDef *def,
case VIR_DOMAIN_DISK_BUS_VIRTIO: {
virTristateSwitch scsi = VIR_TRISTATE_SWITCH_ABSENT;
+ g_autoptr(virJSONValue) iothreadMapping = NULL;
g_autofree char *iothread = NULL;
if (disk->iothread > 0)
iothread = g_strdup_printf("iothread%u", disk->iothread);
+ if (disk->iothreads &&
+ !(iothreadMapping = qemuBuildDiskDeviceIothreadMappingProps(disk->iothreads)))
+ return NULL;
+
if (virStorageSourceGetActualType(disk->src) != VIR_STORAGE_TYPE_VHOST_USER &&
virQEMUCapsGet(qemuCaps, QEMU_CAPS_VIRTIO_BLK_SCSI)) {
/* if sg_io is true but the scsi option isn't supported,
@@ -1832,6 +1876,7 @@ qemuBuildDiskDeviceProps(const virDomainDef *def,
"T:scsi", scsi,
"p:num-queues", disk->queues,
"p:queue-size", disk->queue_size,
+ "A:iothread-vq-mapping", &iothreadMapping,
NULL) < 0)
return NULL;
}
diff --git a/src/qemu/qemu_validate.c b/src/qemu/qemu_validate.c
index c877aa73d4..79096a2fcf 100644
--- a/src/qemu/qemu_validate.c
+++ b/src/qemu/qemu_validate.c
@@ -2822,12 +2822,24 @@ qemuValidateDomainDeviceDefDiskSerial(const char *value)
}
-static bool
+static int
qemuValidateDomainDeviceDefDiskIOThreads(const virDomainDef *def,
- const virDomainDiskDef *disk)
+ const virDomainDiskDef *disk,
+ virQEMUCaps *qemuCaps)
{
+ if (disk->iothread == 0 && !disk->iothreads)
+ return 0;
+
switch ((virDomainDiskBus)disk->bus) {
case VIR_DOMAIN_DISK_BUS_VIRTIO:
+ if (disk->iothreads) {
+ if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_VIRTIO_BLK_IOTHREAD_MAPPING)) {
+ virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+ _("IOThread mapping for disk '%s' is not available with this QEMU binary"),
+ disk->dst);
+ return -1;
+ }
+ }
break;
case VIR_DOMAIN_DISK_BUS_IDE:
@@ -2843,18 +2855,101 @@ qemuValidateDomainDeviceDefDiskIOThreads(const virDomainDef *def,
virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
_("IOThreads not available for bus %s target %s"),
virDomainDiskBusTypeToString(disk->bus), disk->dst);
- return false;
+ return -1;
}
- /* Can we find the disk iothread in the iothreadid list? */
- if (!virDomainIOThreadIDFind(def, disk->iothread)) {
- virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
- _("Disk iothread '%u' not defined in iothreadid"),
- disk->iothread);
- return false;
+ if (disk->iothreads) {
+ virDomainDiskIothreadDef *first_ioth = disk->iothreads->data;
+ g_autoptr(virBitmap) queueMap = NULL;
+ g_autoptr(GHashTable) iothreads = virHashNew(NULL);
+ ssize_t unused;
+ GSList *n;
+
+ if (first_ioth->queues) {
+ if (disk->queues == 0) {
+ virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+ _("disk 'queue' count must be configured for explicit iothread to queue mapping"));
+ return -1;
+ }
+
+ queueMap = virBitmapNew(disk->queues);
+ }
+
+ /* we are validating that:
+ * - there are no duplicate iothreads
+ * - there are only valid iothreads
+ * - if queue mapping is provided
+ * - queue is in range
+ * - it must be provided for all assigned iothreads
+ * - it must be provided for all queues
+ * - queue must be assigned only once
+ */
+ for (n = disk->iothreads; n; n = n->next) {
+ virDomainDiskIothreadDef *ioth = n->data;
+ g_autofree char *alias = g_strdup_printf("iothread%u", ioth->id);
+ size_t i;
+
+ if (g_hash_table_contains(iothreads, alias)) {
+ virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+ _("Duplicate mapping for iothread '%u'"), ioth->id);
+ return -1;
+ }
+
+ g_hash_table_insert(iothreads, g_steal_pointer(&alias), NULL);
+
+ if (!virDomainIOThreadIDFind(def, ioth->id)) {
+ virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+ _("Disk iothread '%u' not defined in iothreadid"),
+ ioth->id);
+ return -1;
+ }
+
+ if (!!queueMap != !!ioth->queues) {
+ virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+ _("iothread to queue mapping must be provided for all iothreads or for none"));
+ return -1;
+ }
+
+ for (i = 0; i < ioth->nqueues; i++) {
+ bool hasMapping;
+
+ if (virBitmapGetBit(queueMap, ioth->queues[i], &hasMapping) < 0) {
+ virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+ _("disk iothread queue '%u' mapping out of range"),
+ ioth->queues[i]);
+ return -1;
+ }
+
+ if (hasMapping) {
+ virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+ _("disk iothread queue '%u' is already assigned"),
+ ioth->queues[i]);
+ return -1;
+ }
+
+ ignore_value(virBitmapSetBit(queueMap, ioth->queues[i]));
+
+ }
+ }
+
+ if (queueMap) {
+ if ((unused = virBitmapNextClearBit(queueMap, -1)) >= 0) {
+ virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+ _("missing iothread mapping for queue '%zd'"),
+ unused);
+ return -1;
+ }
+ }
+ } else {
+ if (!virDomainIOThreadIDFind(def, disk->iothread)) {
+ virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+ _("Disk iothread '%u' not defined in iothreadid"),
+ disk->iothread);
+ return -1;
+ }
}
- return true;
+ return 0;
}
@@ -3147,7 +3242,7 @@ qemuValidateDomainDeviceDefDiskFrontend(const virDomainDiskDef *disk,
qemuValidateDomainDeviceDefDiskSerial(disk->serial) < 0)
return -1;
- if (disk->iothread && !qemuValidateDomainDeviceDefDiskIOThreads(def, disk))
+ if (qemuValidateDomainDeviceDefDiskIOThreads(def, disk, qemuCaps))
return -1;
return 0;
diff --git a/tests/qemuxml2argvdata/iothreads-disk.x86_64-latest.args b/tests/qemuxml2argvdata/iothreads-disk.x86_64-latest.args
index d1953327a7..05729acde5 100644
--- a/tests/qemuxml2argvdata/iothreads-disk.x86_64-latest.args
+++ b/tests/qemuxml2argvdata/iothreads-disk.x86_64-latest.args
@@ -37,10 +37,10 @@ XDG_CONFIG_HOME=/tmp/lib/domain--1-QEMUGuest1/.config \
-device '{"driver":"virtio-blk-pci","iothread":"iothread1","bus":"pci.0","addr":"0x4","drive":"libvirt-3-format","id":"virtio-disk1","bootindex":1}' \
-blockdev '{"driver":"file","filename":"/var/lib/libvirt/images/iothrtest2.img","node-name":"libvirt-2-storage","auto-read-only":true,"discard":"unmap"}' \
-blockdev '{"node-name":"libvirt-2-format","read-only":false,"driver":"raw","file":"libvirt-2-storage"}' \
--device '{"driver":"virtio-blk-pci","num-queues":4,"bus":"pci.0","addr":"0x2","drive":"libvirt-2-format","id":"virtio-disk2"}' \
+-device '{"driver":"virtio-blk-pci","num-queues":4,"iothread-vq-mapping":[{"iothread":"iothread2","vqs":[1,3]},{"iothread":"iothread3","vqs":[0,2]}],"bus":"pci.0","addr":"0x2","drive":"libvirt-2-format","id":"virtio-disk2"}' \
-blockdev '{"driver":"file","filename":"/var/lib/libvirt/images/iothrtest3.img","node-name":"libvirt-1-storage","auto-read-only":true,"discard":"unmap"}' \
-blockdev '{"node-name":"libvirt-1-format","read-only":false,"driver":"raw","file":"libvirt-1-storage"}' \
--device '{"driver":"virtio-blk-pci","bus":"pci.0","addr":"0x3","drive":"libvirt-1-format","id":"virtio-disk3"}' \
+-device '{"driver":"virtio-blk-pci","iothread-vq-mapping":[{"iothread":"iothread4"},{"iothread":"iothread1"}],"bus":"pci.0","addr":"0x3","drive":"libvirt-1-format","id":"virtio-disk3"}' \
-audiodev '{"id":"audio1","driver":"none"}' \
-sandbox on,obsolete=deny,elevateprivileges=deny,spawn=deny,resourcecontrol=deny \
-msg timestamp=on
--
2.39.2
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