Open /dev/vhost-scsi, and record the resulting file descriptor, so that
the guest has access to the host device outside of the libvirt daemon.
Pass this information, along with data parsed from the XML file, to build
a device string for the qemu command line. That device string will be
for either a vhost-scsi-ccw device in the case of an s390 machine, or
vhost-scsi-pci for any others.
Signed-off-by: Eric Farman <farman@xxxxxxxxxxxxxxxxxx>
---
src/libvirt_private.syms | 1 +
src/qemu/qemu_command.c | 80 ++++++++++++++++++++++++++++++++++++++++++++++++
src/qemu/qemu_command.h | 6 ++++
src/util/virscsi.c | 26 ++++++++++++++++
src/util/virscsi.h | 1 +
5 files changed, 114 insertions(+)
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index d62c74c..22fe14d 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -2265,6 +2265,7 @@ virSCSIDeviceListNew;
virSCSIDeviceListSteal;
virSCSIDeviceNew;
virSCSIDeviceSetUsedBy;
+virSCSIOpenVhost;
# util/virseclabel.h
diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 982c33c..479dde2 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -4711,6 +4711,52 @@ qemuBuildSCSIiSCSIHostdevDrvStr(virDomainHostdevDefPtr dev)
}
char *
+qemuBuildHostHostdevDevStr(const virDomainDef *def,
+ virDomainHostdevDefPtr dev,
+ virQEMUCapsPtr qemuCaps,
+ char *vhostfdName,
+ size_t vhostfdSize)
+{
+ virBuffer buf = VIR_BUFFER_INITIALIZER;
+ virDomainHostdevSubsysHostPtr hostsrc = &dev->source.subsys.u.host;
+
+ if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_DEVICE_VHOST_SCSI)) {
+ virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+ _("This QEMU doesn't support vhost-scsi devices"));
+ goto cleanup;
+ }
+
+ if (ARCH_IS_S390(def->os.arch))
+ virBufferAddLit(&buf, "vhost-scsi-ccw");
+ else
+ virBufferAddLit(&buf, "vhost-scsi-pci");
+
+ virBufferAsprintf(&buf, ",wwpn=%s", hostsrc->wwpn);
+
+ if (vhostfdSize == 1) {
+ virBufferAsprintf(&buf, ",vhostfd=%s", vhostfdName);
+ } else {
+ virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+ _("QEMU supports a single vhost-scsi file descriptor"));
+ goto cleanup;
+ }
+
+ virBufferAsprintf(&buf, ",id=%s", dev->info->alias);
+
+ if (qemuBuildDeviceAddressStr(&buf, def, dev->info, qemuCaps) < 0)
+ goto cleanup;
+
+ if (virBufferCheckError(&buf) < 0)
+ goto cleanup;
+
+ return virBufferContentAndReset(&buf);
+
+ cleanup:
+ virBufferFreeAndReset(&buf);
+ return NULL;
+}
+
+char *
qemuBuildSCSIHostdevDrvStr(virDomainHostdevDefPtr dev)
{
virBuffer buf = VIR_BUFFER_INITIALIZER;
@@ -5156,6 +5202,40 @@ qemuBuildHostdevCommandLine(virCommandPtr cmd,
return -1;
}
}
+
+ /* SCSI_host */
+ if (hostdev->mode == VIR_DOMAIN_HOSTDEV_MODE_SUBSYS &&
+ subsys->type == VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_HOST) {
+ if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_DEVICE_SCSI_GENERIC)) {
+ if (hostdev->source.subsys.u.host.protocol == VIR_DOMAIN_HOSTDEV_HOST_PROTOCOL_TYPE_VHOST) {
+ char *vhostfdName = NULL;
+ int vhostfd = -1;
+ size_t vhostfdSize = 1;
+
+ if (virSCSIOpenVhost(&vhostfd, &vhostfdSize) < 0)
+ return -1;
+
+ if (virAsprintf(&vhostfdName, "%d", vhostfd) < 0) {
+ VIR_FORCE_CLOSE(vhostfd);
+ return -1;
+ }
+
+ virCommandPassFD(cmd, vhostfd, VIR_COMMAND_PASS_FD_CLOSE_PARENT);
+
+ virCommandAddArg(cmd, "-device");
+ if (!(devstr = qemuBuildHostHostdevDevStr(def, hostdev, qemuCaps, vhostfdName, vhostfdSize)))
+ return -1;
+ virCommandAddArg(cmd, devstr);
+
+ VIR_FREE(vhostfdName);
+ VIR_FREE(devstr);
+ }
+ } else {
+ virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+ _("SCSI passthrough is not supported by this version of qemu"));
+ return -1;
+ }
+ }
}
return 0;
diff --git a/src/qemu/qemu_command.h b/src/qemu/qemu_command.h
index 9b9ccb6..78179de 100644
--- a/src/qemu/qemu_command.h
+++ b/src/qemu/qemu_command.h
@@ -158,6 +158,12 @@ char *qemuBuildSCSIHostdevDrvStr(virDomainHostdevDefPtr dev);
char *qemuBuildSCSIHostdevDevStr(const virDomainDef *def,
virDomainHostdevDefPtr dev,
virQEMUCapsPtr qemuCaps);
+char *
+qemuBuildHostHostdevDevStr(const virDomainDef *def,
+ virDomainHostdevDefPtr dev,
+ virQEMUCapsPtr qemuCaps,
+ char *vhostfdName,
+ size_t vhostfdSize);
char *qemuBuildRedirdevDevStr(const virDomainDef *def,
virDomainRedirdevDefPtr dev,
diff --git a/src/util/virscsi.c b/src/util/virscsi.c
index 4843367..290b692 100644
--- a/src/util/virscsi.c
+++ b/src/util/virscsi.c
@@ -105,6 +105,32 @@ virSCSIDeviceGetAdapterId(const char *adapter,
return -1;
}
+int
+virSCSIOpenVhost(int *vhostfd,
+ size_t *vhostfdSize)
+{
+ size_t i;
+
+ for (i = 0; i < *vhostfdSize; i++) {
+ vhostfd[i] = open("/dev/vhost-scsi", O_RDWR);
+
+ if (vhostfd[i] < 0) {
+ virReportSystemError(errno, "%s",
+ _("vhost-scsi was requested for an interface, "
+ "but is unavailable"));
+ goto error;
+ }
+ }
+
+ return 0;
+
+ error:
+ while (i--)
+ VIR_FORCE_CLOSE(vhostfd[i]);
+
+ return -1;
+}
+
char *
virSCSIDeviceGetSgName(const char *sysfs_prefix,
const char *adapter,
diff --git a/src/util/virscsi.h b/src/util/virscsi.h
index df40d7f..cb37da8 100644
--- a/src/util/virscsi.h
+++ b/src/util/virscsi.h
@@ -33,6 +33,7 @@ typedef virSCSIDevice *virSCSIDevicePtr;
typedef struct _virSCSIDeviceList virSCSIDeviceList;
typedef virSCSIDeviceList *virSCSIDeviceListPtr;
+int virSCSIOpenVhost(int *vhostfd, size_t *vhostfdSize);
char *virSCSIDeviceGetSgName(const char *sysfs_prefix,
const char *adapter,
unsigned int bus,
--
1.9.1
--
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