qemu: Taint cpu host-passthrough only after migration

From a discussion last year[1], Dan recommended libvirt drop the tain
flag for cpu host-passthrough, unless the VM has been migrated.

This repurposes the existing host-cpu taint flag to do just that.

[1]: https://www.redhat.com/archives/virt-tools-list/2019-February/msg00041.html

https://bugzilla.redhat.com/show_bug.cgi?id=1673098

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Cole Robinson <crobinso@redhat.com>

diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
index 9a44315519be6bc58fb1516f69a100e570457c6a..450686dfb5b1099d1c0277aa9ce810250189969d 100644 (file)
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@@ -2736,7 +2736,7 @@ typedef enum {
     VIR_DOMAIN_TAINT_SHELL_SCRIPTS,    /* Network configuration using opaque shell scripts */
     VIR_DOMAIN_TAINT_DISK_PROBING,     /* Relying on potentially unsafe disk format probing */
     VIR_DOMAIN_TAINT_EXTERNAL_LAUNCH,  /* Externally launched guest domain */
-    VIR_DOMAIN_TAINT_HOST_CPU,         /* Host CPU passthrough in use */
+    VIR_DOMAIN_TAINT_HOST_CPU,         /* Host CPU passthrough in use after migration */
     VIR_DOMAIN_TAINT_HOOK,             /* Domain (possibly) changed via hook script */
     VIR_DOMAIN_TAINT_CDROM_PASSTHROUGH,/* CDROM passthrough */
     VIR_DOMAIN_TAINT_CUSTOM_DTB,       /* Custom device tree blob was specified */

diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index 0331fd55e021eece62b42a905f025b7690903322..ed4bdbd7fb03755e54822212c53bc897528f67ce 100644 (file)
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -6115,7 +6115,8 @@ void qemuDomainObjTaint(virQEMUDriverPtr driver,
 
 void qemuDomainObjCheckTaint(virQEMUDriverPtr driver,
                              virDomainObjPtr obj,
-                             qemuDomainLogContextPtr logCtxt)
+                             qemuDomainLogContextPtr logCtxt,
+                             bool incomingMigration)
 {
     size_t i;
     g_autoptr(virQEMUDriverConfig) cfg = virQEMUDriverGetConfig(driver);
@@ -6144,7 +6145,9 @@ void qemuDomainObjCheckTaint(virQEMUDriverPtr driver,
                            VIR_DOMAIN_TAINT_CUSTOM_HYPERVISOR_FEATURE, logCtxt);
     }
 
-    if (obj->def->cpu && obj->def->cpu->mode == VIR_CPU_MODE_HOST_PASSTHROUGH)
+    if (obj->def->cpu &&
+        obj->def->cpu->mode == VIR_CPU_MODE_HOST_PASSTHROUGH &&
+        incomingMigration)
         qemuDomainObjTaint(driver, obj, VIR_DOMAIN_TAINT_HOST_CPU, logCtxt);
 
     for (i = 0; i < obj->def->ndisks; i++)

diff --git a/src/qemu/qemu_domain.h b/src/qemu/qemu_domain.h
index ec776ced72b6b71b6df188892bcd7aa42eccb5ee..9bf32e16c9af3a90f8faacf49de0e956022f27d5 100644 (file)
--- a/src/qemu/qemu_domain.h
+++ b/src/qemu/qemu_domain.h
@@ -567,7 +567,8 @@ void qemuDomainObjTaint(virQEMUDriverPtr driver,
 
 void qemuDomainObjCheckTaint(virQEMUDriverPtr driver,
                              virDomainObjPtr obj,
-                             qemuDomainLogContextPtr logCtxt);
+                             qemuDomainLogContextPtr logCtxt,
+                             bool incomingMigration);
 void qemuDomainObjCheckDiskTaint(virQEMUDriverPtr driver,
                                  virDomainObjPtr obj,
                                  virDomainDiskDefPtr disk,

diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index 8d28d676921871d2c4cec09ebf4d311a6bf8c380..e8892fa65b2c4a244b08bf340845c25e94e0e7bf 100644 (file)
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -6852,7 +6852,7 @@ qemuProcessLaunch(virConnectPtr conn,
 
     qemuLogOperation(vm, "starting up", cmd, logCtxt);
 
-    qemuDomainObjCheckTaint(driver, vm, logCtxt);
+    qemuDomainObjCheckTaint(driver, vm, logCtxt, incoming != NULL);
 
     qemuDomainLogContextMarkPosition(logCtxt);