[libvirt] [PATCH] qemu: forbid user aliases for implicit pci-root controllers
Ján Tomko
jtomko at redhat.com
Tue Nov 28 13:51:35 UTC 2017
For implicit controllers, we do not format user aliases on the command
line so we provide a translation between the user alias and the qemu
alias.
However for pci-root controllers, the logic determining whether to use
'pci' or 'pci.0' depends on:
* domain architecture
* machine type
* QEMU version (for PPC)
Since we do not store the QEMU version in status XML and as of
commit 5b783379 we no longer have the QEMU_CAPS_PCI_MULTIBUS
capability formatted there either, we can only rely on the alias
of the controller formatted there.
Forbid user aliases for the implicit pci-root controllers so that
we retain this information.
This allows us to drop the call to virQEMUCapsHasPCIMultiBus,
and fixing hotplug after daemon restart, since virQEMUCapsHasPCIMultiBus
relies on qemuCaps->arch which is not filled out by reading
the status XML either.
Partially reverts commit 937f3195 which added the user alias ->
qemu alias mapping for implicit PCI controllers.
https://bugzilla.redhat.com/show_bug.cgi?id=1518148
---
While we cannot reliably map user aliases to qemu aliases in
every corner case, I am not sure where to draw the line.
For x86_64, HasPCIMultiBus could be fixed by using def->os.arch instead
of qemuCaps->arch. So only PPC is unfixable, but this looked like the option
with the least amount of exceptions.
src/conf/domain_conf.c | 3 +--
src/conf/domain_conf.h | 2 ++
src/qemu/qemu_command.c | 16 +++++--------
src/qemu/qemu_domain.c | 26 +++++++++++++++++++++-
.../qemuxml2argvdata/qemuxml2argv-user-aliases.xml | 4 +---
5 files changed, 35 insertions(+), 16 deletions(-)
diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 66536653b..d3cd598c8 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -6623,7 +6623,6 @@ virDomainDeviceAddressParseXML(xmlNodePtr address,
}
-#define USER_ALIAS_PREFIX "ua-"
#define USER_ALIAS_CHARS \
"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_-"
@@ -6680,7 +6679,7 @@ virDomainDeviceInfoParseXML(virDomainXMLOptionPtr xmlopt ATTRIBUTE_UNUSED,
if (!(flags & VIR_DOMAIN_DEF_PARSE_INACTIVE) ||
(xmlopt->config.features & VIR_DOMAIN_DEF_FEATURE_USER_ALIAS &&
- STRPREFIX(aliasStr, USER_ALIAS_PREFIX) &&
+ STRPREFIX(aliasStr, VIR_DOMAIN_USER_ALIAS_PREFIX) &&
strspn(aliasStr, USER_ALIAS_CHARS) == strlen(aliasStr)))
VIR_STEAL_PTR(info->alias, aliasStr);
}
diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
index dabbff1c2..de34fb163 100644
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@@ -57,6 +57,8 @@
# include "virtypedparam.h"
# include "virsavecookie.h"
+# define VIR_DOMAIN_USER_ALIAS_PREFIX "ua-"
+
/* forward declarations of all device types, required by
* virDomainDeviceDef
*/
diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 0eb591253..89e8b5350 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -321,16 +321,12 @@ qemuBuildDeviceAddressStr(virBufferPtr buf,
contIsPHB = virDomainControllerIsPSeriesPHB(cont);
contTargetIndex = cont->opts.pciopts.targetIndex;
- /* When domain has builtin pci-root controller we don't put it
- * onto cmd line. Therefore we can't set its alias. In that
- * case, use the default one. */
- if (!qemuDomainIsPSeries(domainDef) &&
- cont->model == VIR_DOMAIN_CONTROLLER_MODEL_PCI_ROOT) {
- if (virQEMUCapsHasPCIMultiBus(qemuCaps, domainDef))
- contAlias = "pci.0";
- else
- contAlias = "pci";
- } else if (cont->model == VIR_DOMAIN_CONTROLLER_MODEL_PCIE_ROOT) {
+ /* The builtin pcie-root controller is not put on the command line.
+ * We cannot set a user alias, but we can reliably predict the one
+ * qemu will use.
+ * For builtin pci-root controllers we cannot do that once a domain
+ * is started, but user aliases are forbidden for those. */
+ if (cont->model == VIR_DOMAIN_CONTROLLER_MODEL_PCIE_ROOT) {
contAlias = "pcie.0";
} else {
contAlias = cont->info.alias;
diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index 9dab6b24b..ec33f3bad 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -3718,6 +3718,27 @@ qemuDomainDeviceDefValidateDisk(const virDomainDiskDef *disk)
static int
+qemuDomainDeviceDefValidateController(const virDomainControllerDef *controller,
+ const virDomainDef *def)
+{
+ /* Forbid user aliases for implicit controllers where
+ * the qemu's device alias depends on the version and therefore
+ * we cannot figure it out for an already running domain. */
+ if (controller->model == VIR_DOMAIN_CONTROLLER_MODEL_PCI_ROOT &&
+ !qemuDomainIsPSeries(def) &&
+ controller->info.alias &&
+ STRPREFIX(controller->info.alias, VIR_DOMAIN_USER_ALIAS_PREFIX)) {
+ virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+ _("user aliases are not available for "
+ "implicit pci-root controller"));
+ return -1;
+ }
+
+ return 0;
+}
+
+
+static int
qemuDomainDeviceDefValidate(const virDomainDeviceDef *dev,
const virDomainDef *def,
void *opaque ATTRIBUTE_UNUSED)
@@ -3761,11 +3782,14 @@ qemuDomainDeviceDefValidate(const virDomainDeviceDef *dev,
ret = qemuDomainDeviceDefValidateDisk(dev->data.disk);
break;
+ case VIR_DOMAIN_DEVICE_CONTROLLER:
+ ret = qemuDomainDeviceDefValidateController(dev->data.controller, def);
+ break;
+
case VIR_DOMAIN_DEVICE_LEASE:
case VIR_DOMAIN_DEVICE_FS:
case VIR_DOMAIN_DEVICE_INPUT:
case VIR_DOMAIN_DEVICE_SOUND:
- case VIR_DOMAIN_DEVICE_CONTROLLER:
case VIR_DOMAIN_DEVICE_GRAPHICS:
case VIR_DOMAIN_DEVICE_HUB:
case VIR_DOMAIN_DEVICE_MEMBALLOON:
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-user-aliases.xml b/tests/qemuxml2argvdata/qemuxml2argv-user-aliases.xml
index c760098fe..d1cb8fea6 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-user-aliases.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-user-aliases.xml
@@ -74,9 +74,7 @@
<alias name='ua-SomeWeirdController'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x2'/>
</controller>
- <controller type='pci' index='0' model='pci-root'>
- <alias name='ua-MyPCIRootController'/>
- </controller>
+ <controller type='pci' index='0' model='pci-root'/>
<controller type='ide' index='0'>
<alias name='ua-DoesAnybodyStillUseIDE'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/>
--
2.13.6
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