[libvirt] [PATCH 05/10] qemu: Introduce activeScsiHostdevs list for scsi host devices

Osier Yang jyang at redhat.com
Fri Apr 26 20:15:29 UTC 2013


From: Han Cheng <hanc.fnst at cn.fujitsu.com>

Although virtio-scsi supports SCSI PR, the device on host may do not
support it. To avoid losing data, we only allow one scsi hostdev to
be passthroughed to one live guest, Just like what we do for PCI
and USB devices.

Signed-off-by: Han Cheng <hanc.fnst at cn.fujitsu.com>

---
v2.5 - v3:
  * Small changes, mainly on errors & coding style
---
 src/qemu/qemu_conf.h    |   2 +
 src/qemu/qemu_driver.c  |   3 +
 src/qemu/qemu_hostdev.c | 213 ++++++++++++++++++++++++++++++++++++++++++++++++
 src/qemu/qemu_hostdev.h |  10 +++
 src/qemu/qemu_process.c |   3 +
 5 files changed, 231 insertions(+)

diff --git a/src/qemu/qemu_conf.h b/src/qemu/qemu_conf.h
index 77d3d2f..30a2a22 100644
--- a/src/qemu/qemu_conf.h
+++ b/src/qemu/qemu_conf.h
@@ -36,6 +36,7 @@
 # include "security/security_manager.h"
 # include "virpci.h"
 # include "virusb.h"
+# include "virscsi.h"
 # include "cpu_conf.h"
 # include "driver.h"
 # include "virportallocator.h"
@@ -203,6 +204,7 @@ struct _virQEMUDriver {
     virPCIDeviceListPtr activePciHostdevs;
     virPCIDeviceListPtr inactivePciHostdevs;
     virUSBDeviceListPtr activeUsbHostdevs;
+    virSCSIDeviceListPtr activeScsiHostdevs;
 
     /* Immutable pointer. Unsafe APIs. XXX */
     virHashTablePtr sharedDisks;
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 13d6d60..24eca08 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -675,6 +675,9 @@ qemuStateInitialize(bool privileged,
     if ((qemu_driver->inactivePciHostdevs = virPCIDeviceListNew()) == NULL)
         goto error;
 
+    if (!(qemu_driver->activeScsiHostdevs = virSCSIDeviceListNew()))
+        goto error;
+
     if (!(qemu_driver->sharedDisks = virHashCreate(30, qemuSharedDiskEntryFree)))
         goto error;
 
diff --git a/src/qemu/qemu_hostdev.c b/src/qemu/qemu_hostdev.c
index 0db9ddd..445db67 100644
--- a/src/qemu/qemu_hostdev.c
+++ b/src/qemu/qemu_hostdev.c
@@ -29,6 +29,7 @@
 #include "viralloc.h"
 #include "virpci.h"
 #include "virusb.h"
+#include "virscsi.h"
 #include "virnetdev.h"
 
 #define VIR_FROM_THIS VIR_FROM_QEMU
@@ -214,6 +215,47 @@ cleanup:
     return ret;
 }
 
+int
+qemuUpdateActiveScsiHostdevs(virQEMUDriverPtr driver,
+                             virDomainDefPtr def)
+{
+    virDomainHostdevDefPtr hostdev = NULL;
+    int i;
+    int ret = -1;
+
+    if (!def->nhostdevs)
+        return 0;
+
+    virObjectLock(driver->activeScsiHostdevs);
+    for (i = 0; i < def->nhostdevs; i++) {
+        virSCSIDevicePtr scsi = NULL;
+        hostdev = def->hostdevs[i];
+
+        if (hostdev->mode != VIR_DOMAIN_HOSTDEV_MODE_SUBSYS ||
+            hostdev->source.subsys.type != VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_SCSI)
+            continue;
+
+        if (!(scsi = virSCSIDeviceNew(hostdev->source.subsys.u.scsi.adapter,
+                                      hostdev->source.subsys.u.scsi.bus,
+                                      hostdev->source.subsys.u.scsi.target,
+                                      hostdev->source.subsys.u.scsi.unit,
+                                      hostdev->readonly)))
+            goto cleanup;
+
+        virSCSIDeviceSetUsedBy(scsi, def->name);
+
+        if (virSCSIDeviceListAdd(driver->activeScsiHostdevs, scsi) < 0) {
+            virSCSIDeviceFree(scsi);
+            goto cleanup;
+        }
+    }
+    ret = 0;
+
+cleanup:
+    virObjectUnlock(driver->activeScsiHostdevs);
+    return ret;
+}
+
 static int
 qemuDomainHostdevPciSysfsPath(virDomainHostdevDefPtr hostdev, char **sysfs_path)
 {
@@ -811,6 +853,107 @@ cleanup:
     return ret;
 }
 
+int
+qemuPrepareHostdevSCSIDevices(virQEMUDriverPtr driver,
+                              const char *name,
+                              virDomainHostdevDefPtr *hostdevs,
+                              int nhostdevs)
+{
+    int i, j, count;
+    virSCSIDeviceListPtr list;
+    virSCSIDevicePtr tmp;
+
+    /* To prevent situation where SCSI device is assigned to two domains
+     * we need to keep a list of currently assigned SCSI devices.
+     * This is done in several loops which cannot be joined into one big
+     * loop. See qemuPrepareHostdevPCIDevices()
+     */
+    if (!(list = virSCSIDeviceListNew()))
+        goto cleanup;
+
+    /* Loop 1: build temporary list */
+    for (i = 0 ; i < nhostdevs ; i++) {
+        virDomainHostdevDefPtr hostdev = hostdevs[i];
+        virSCSIDevicePtr scsi;
+
+        if (hostdev->mode != VIR_DOMAIN_HOSTDEV_MODE_SUBSYS ||
+            hostdev->source.subsys.type != VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_SCSI)
+            continue;
+
+        if (hostdev->managed) {
+            virReportError(VIR_ERR_XML_ERROR, "%s",
+                           _("SCSI host device doesn't support managed mode"));
+            goto cleanup;
+        }
+
+        if (!(scsi = virSCSIDeviceNew(hostdev->source.subsys.u.scsi.adapter,
+                                      hostdev->source.subsys.u.scsi.bus,
+                                      hostdev->source.subsys.u.scsi.target,
+                                      hostdev->source.subsys.u.scsi.unit,
+                                      hostdev->readonly)))
+            goto cleanup;
+
+        if (scsi && virSCSIDeviceListAdd(list, scsi) < 0) {
+            virSCSIDeviceFree(scsi);
+            goto cleanup;
+        }
+    }
+
+    /* Loop 2: Mark devices in temporary list as used by @name
+     * and add them to driver list. However, if something goes
+     * wrong, perform rollback.
+     */
+    virObjectLock(driver->activeScsiHostdevs);
+    count = virSCSIDeviceListCount(list);
+
+    for (i = 0; i < count; i++) {
+        virSCSIDevicePtr scsi = virSCSIDeviceListGet(list, i);
+        if ((tmp = virSCSIDeviceListFind(driver->activeScsiHostdevs, scsi))) {
+            const char *other_name = virSCSIDeviceGetUsedBy(tmp);
+
+            if (other_name)
+                virReportError(VIR_ERR_OPERATION_INVALID,
+                               _("SCSI device %s is in use by domain %s"),
+                               virSCSIDeviceGetName(tmp), other_name);
+            else
+                virReportError(VIR_ERR_OPERATION_INVALID,
+                               _("SCSI device %s is already in use"),
+                               virSCSIDeviceGetName(tmp));
+            goto error;
+        }
+
+        virSCSIDeviceSetUsedBy(scsi, name);
+        VIR_DEBUG("Adding %s to activeScsiHostdevs", virSCSIDeviceGetName(scsi));
+
+        if (virSCSIDeviceListAdd(driver->activeScsiHostdevs, scsi) < 0)
+            goto error;
+    }
+
+    virObjectUnlock(driver->activeScsiHostdevs);
+
+    /* Loop 3: Temporary list was successfully merged with
+     * driver list, so steal all items to avoid freeing them
+     * when freeing temporary list.
+     */
+    while (virSCSIDeviceListCount(list) > 0) {
+        tmp = virSCSIDeviceListGet(list, 0);
+        virSCSIDeviceListSteal(list, tmp);
+    }
+
+    virObjectUnref(list);
+    return 0;
+
+error:
+    for (j = 0; j < i; j++) {
+        tmp = virSCSIDeviceListGet(list, i);
+        virSCSIDeviceListSteal(driver->activeScsiHostdevs, tmp);
+    }
+    virObjectUnlock(driver->activeScsiHostdevs);
+cleanup:
+    virObjectUnref(list);
+    return -1;
+}
+
 int qemuPrepareHostDevices(virQEMUDriverPtr driver,
                            virDomainDefPtr def,
                            bool coldBoot)
@@ -825,6 +968,10 @@ int qemuPrepareHostDevices(virQEMUDriverPtr driver,
     if (qemuPrepareHostUSBDevices(driver, def, coldBoot) < 0)
         return -1;
 
+    if (qemuPrepareHostdevSCSIDevices(driver, def->name,
+                                      def->hostdevs, def->nhostdevs) < 0)
+        return -1;
+
     return 0;
 }
 
@@ -1009,6 +1156,69 @@ qemuDomainReAttachHostUsbDevices(virQEMUDriverPtr driver,
     virObjectUnlock(driver->activeUsbHostdevs);
 }
 
+void
+qemuDomainReAttachHostScsiDevices(virQEMUDriverPtr driver,
+                                  const char *name,
+                                  virDomainHostdevDefPtr *hostdevs,
+                                  int nhostdevs)
+{
+    int i;
+
+    virObjectLock(driver->activeScsiHostdevs);
+    for (i = 0; i < nhostdevs; i++) {
+        virDomainHostdevDefPtr hostdev = hostdevs[i];
+        virSCSIDevicePtr scsi, tmp;
+        const char *used_by = NULL;
+
+        if (hostdev->mode != VIR_DOMAIN_HOSTDEV_MODE_SUBSYS ||
+            hostdev->source.subsys.type != VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_SCSI)
+            continue;
+
+        if (!(scsi = virSCSIDeviceNew(hostdev->source.subsys.u.scsi.adapter,
+                                      hostdev->source.subsys.u.scsi.bus,
+                                      hostdev->source.subsys.u.scsi.target,
+                                      hostdev->source.subsys.u.scsi.unit,
+                                      hostdev->readonly))) {
+            VIR_WARN("Unable to reattach SCSI device %s:%d:%d:%d on domain %s",
+                     hostdev->source.subsys.u.scsi.adapter,
+                     hostdev->source.subsys.u.scsi.bus,
+                     hostdev->source.subsys.u.scsi.target,
+                     hostdev->source.subsys.u.scsi.unit,
+                     name);
+            continue;
+        }
+
+        /* Only delete the devices which are marked as being used by @name,
+         * because qemuProcessStart could fail on the half way. */
+
+        tmp = virSCSIDeviceListFind(driver->activeScsiHostdevs, scsi);
+        virSCSIDeviceFree(scsi);
+
+        if (!tmp) {
+            VIR_WARN("Unable to find device %s:%d:%d:%d "
+                     "in list of active SCSI devices",
+                     hostdev->source.subsys.u.scsi.adapter,
+                     hostdev->source.subsys.u.scsi.bus,
+                     hostdev->source.subsys.u.scsi.target,
+                     hostdev->source.subsys.u.scsi.unit);
+            continue;
+        }
+
+        used_by = virSCSIDeviceGetUsedBy(tmp);
+        if (STREQ_NULLABLE(used_by, name)) {
+            VIR_DEBUG("Removing %s:%d:%d:%d dom=%s from activeScsiHostdevs",
+                      hostdev->source.subsys.u.scsi.adapter,
+                      hostdev->source.subsys.u.scsi.bus,
+                      hostdev->source.subsys.u.scsi.target,
+                      hostdev->source.subsys.u.scsi.unit,
+                      name);
+
+            virSCSIDeviceListDel(driver->activeScsiHostdevs, tmp);
+        }
+    }
+    virObjectUnlock(driver->activeScsiHostdevs);
+}
+
 void qemuDomainReAttachHostDevices(virQEMUDriverPtr driver,
                                    virDomainDefPtr def)
 {
@@ -1020,4 +1230,7 @@ void qemuDomainReAttachHostDevices(virQEMUDriverPtr driver,
 
     qemuDomainReAttachHostUsbDevices(driver, def->name, def->hostdevs,
                                      def->nhostdevs);
+
+    qemuDomainReAttachHostScsiDevices(driver, def->name, def->hostdevs,
+                                      def->nhostdevs);
 }
diff --git a/src/qemu/qemu_hostdev.h b/src/qemu/qemu_hostdev.h
index a1b8b9e..327d4d5 100644
--- a/src/qemu/qemu_hostdev.h
+++ b/src/qemu/qemu_hostdev.h
@@ -31,6 +31,8 @@ int qemuUpdateActivePciHostdevs(virQEMUDriverPtr driver,
                                 virDomainDefPtr def);
 int qemuUpdateActiveUsbHostdevs(virQEMUDriverPtr driver,
                                 virDomainDefPtr def);
+int qemuUpdateActiveScsiHostdevs(virQEMUDriverPtr driver,
+                                 virDomainDefPtr def);
 int qemuPrepareHostdevPCIDevices(virQEMUDriverPtr driver,
                                  const char *name,
                                  const unsigned char *uuid,
@@ -42,9 +44,17 @@ int qemuFindHostdevUSBDevice(virDomainHostdevDefPtr hostdev,
 int qemuPrepareHostdevUSBDevices(virQEMUDriverPtr driver,
                                  const char *name,
                                  virUSBDeviceListPtr list);
+int qemuPrepareHostdevSCSIDevices(virQEMUDriverPtr driver,
+                                  const char *name,
+                                  virDomainHostdevDefPtr *hostdevs,
+                                  int nhostdevs);
 int qemuPrepareHostDevices(virQEMUDriverPtr driver,
                            virDomainDefPtr def,
                            bool coldBoot);
+void qemuDomainReAttachHostScsiDevices(virQEMUDriverPtr driver,
+                                       const char *name,
+                                       virDomainHostdevDefPtr *hostdevs,
+                                       int nhostdevs);
 void qemuReattachPciDevice(virPCIDevicePtr dev, virQEMUDriverPtr driver);
 void qemuDomainReAttachHostdevDevices(virQEMUDriverPtr driver,
                                       const char *name,
diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index 925939d..f87ffbe 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -3008,6 +3008,9 @@ qemuProcessReconnect(void *opaque)
     if (qemuUpdateActiveUsbHostdevs(driver, obj->def) < 0)
         goto error;
 
+    if (qemuUpdateActiveScsiHostdevs(driver, obj->def) < 0)
+        goto error;
+
     if (qemuInitCgroup(driver, obj, false) < 0)
         goto error;
 
-- 
1.8.1.4




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