From 819c3b24c77321202d820bbe08963f313035cb3c Mon Sep 17 00:00:00 2001

Message-Id: <819c3b24c77321202d820bbe08963f313035cb3c@dist-git>

From: Andrea Bolognani <abologna@redhat.com>

Date: Mon, 28 Aug 2017 16:59:14 +0200

Subject: [PATCH] qemu: Handle host devices not being available better

We can't retrieve the isolation group of a device that's not present

in the system. However, it's very common for VFs to be created late

in the boot, so they might not be present yet when libvirtd starts,

which would cause the guests using them to disappear.

Moreover, for other architectures and even ppc64 before isolation

groups were introduced, it's considered perfectly fine to configure a

guest to use a device that's not yet (or no longer) available to the

host, with the obvious caveat that such a guest won't be able to

start before the device is available.

In order to be consistent, when a device's isolation group can't be

determined fall back to not isolating it rather than erroring out or,

worse, making the guest disappear.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1484254

Signed-off-by: Andrea Bolognani <abologna@redhat.com>

(cherry picked from commit 1f43393283ff04d1a3905abb3669cdd5665610b4)

Signed-off-by: Andrea Bolognani <abologna@redhat.com>

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>

---

 src/qemu/qemu_domain_address.c | 29 +++++++++++------------------

 1 file changed, 11 insertions(+), 18 deletions(-)

diff --git a/src/qemu/qemu_domain_address.c b/src/qemu/qemu_domain_address.c

index 3d5e7cc442..4fa17c76b5 100644

--- a/src/qemu/qemu_domain_address.c

+++ b/src/qemu/qemu_domain_address.c

@@ -977,8 +977,6 @@ int

 qemuDomainFillDeviceIsolationGroup(virDomainDefPtr def,

                                    virDomainDeviceDefPtr dev)

 {

-    int ret = -1;

-

     /* Only host devices need their isolation group to be different from

      * the default. Interfaces of type hostdev are just host devices in

      * disguise, but we don't need to handle them separately because for

@@ -1007,12 +1005,11 @@ qemuDomainFillDeviceIsolationGroup(virDomainDefPtr def,

         tmp = virPCIDeviceAddressGetIOMMUGroupNum(hostAddr);

         if (tmp < 0) {

-            virReportError(VIR_ERR_INTERNAL_ERROR,

-                           _("Can't look up isolation group for host device "

-                             "%04x:%02x:%02x.%x"),

-                           hostAddr->domain, hostAddr->bus,

-                           hostAddr->slot, hostAddr->function);

-            goto cleanup;

+            VIR_WARN("Can't look up isolation group for host device "

+                     "%04x:%02x:%02x.%x, device won't be isolated",

+                     hostAddr->domain, hostAddr->bus,

+                     hostAddr->slot, hostAddr->function);

+            goto skip;

         }

         /* The isolation group for a host device is its IOMMU group,

@@ -1052,12 +1049,11 @@ qemuDomainFillDeviceIsolationGroup(virDomainDefPtr def,

         tmp = qemuDomainFindUnusedIsolationGroup(def);

         if (tmp == 0) {

-            virReportError(VIR_ERR_INTERNAL_ERROR,

-                           _("Can't obtain usable isolation group for "

-                             "interface configured to use hostdev-backed "

-                             "network '%s'"),

-                             iface->data.network.name);

-            goto cleanup;

+            VIR_WARN("Can't obtain usable isolation group for interface "

+                     "configured to use hostdev-backed network '%s', "

+                     "device won't be isolated",

+                     iface->data.network.name);

+            goto skip;

         }

         info->isolationGroup = tmp;

@@ -1068,10 +1064,7 @@ qemuDomainFillDeviceIsolationGroup(virDomainDefPtr def,

     }

  skip:

-    ret = 0;

-

- cleanup:

-    return ret;

+    return 0;

 }

-- 

2.14.1