Blame SOURCES/libvirt-domain-don-t-try-to-interpret-driver-as-virtio-config-for-hostdev-interfaces.patch

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From c18594a43b583f497baaf07b4d540bf7cab8634f Mon Sep 17 00:00:00 2001
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Message-Id: <c18594a43b583f497baaf07b4d540bf7cab8634f.1389183248.git.jdenemar@redhat.com>
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From: Laine Stump <laine@laine.org>
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Date: Thu, 2 Jan 2014 03:12:52 -0700
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Subject: [PATCH] domain: don't try to interpret <driver> as virtio config for
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 hostdev interfaces
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This resolves:
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  https://bugzilla.redhat.com/show_bug.cgi?id=1046337
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The <driver> name attribute of an interface is interpreted in two
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different ways depending on the <interface> type - if the interface is
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type='hostdev', then the driver name describes which backend to use
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for the hostdev device assignment (vfio or kvm), but if the interface
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is any emulated type *and* the model type is "virtio", then the driver
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name can be "vhost" or "qemu", telling which backend qemu should use
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to communicate with the emulated device.
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The problem comes when someone has defined a an interface like this
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(which is accepted by the parser as long as no <driver name='xxx'/> is
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specified):
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    <interface type='hostdev'>
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       ...
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       <model type='virtio'/>
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       ...
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    </interface>
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As libvirt storing this definition in the domain's status, the driver
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name is automatically filled in with the backend that was
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automatically decided by libvirt, so it stores this in the status:
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    <interface type='hostdev'>
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       ...
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       <driver name='vfio'/>
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       ...
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       <model type='virtio'/>
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       ...
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    </interface>
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This isn't noticed until the next time libvirtd is restarted - as it
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is reading the status of all domains, it encounters the above
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interface definition, logs an error:
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  internal error: Unknown interface <driver name='vfio'> has been specified
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and fails to reload the domain status, so the domain is marked as
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inactive.
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The solution is to stop the parser from interpreting <driver>
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attributes as if the device was an emulated virtio device, when it is
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actually a hostdev.
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(Although the bug has existed since vfio support was added, it has
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just recently become more apparent because libvirt previously didn't
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automatically set the driver name for hostdev interfaces in the domain
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status to vfio/kvm as it does since commit f094aa, first appearing in
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v1.1.4.)
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(cherry picked from commit 3337a98a5ee41ee1d5de796abcb378eacb9bded0)
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Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
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---
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 src/conf/domain_conf.c | 3 ++-
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 1 file changed, 2 insertions(+), 1 deletion(-)
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diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
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index 656fa93..d4161a5 100644
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--- a/src/conf/domain_conf.c
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+++ b/src/conf/domain_conf.c
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@@ -6607,7 +6607,8 @@ virDomainNetDefParseXML(virDomainXMLOptionPtr xmlopt,
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         model = NULL;
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     }
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-    if (def->model && STREQ(def->model, "virtio")) {
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+    if (def->type != VIR_DOMAIN_NET_TYPE_HOSTDEV &&
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+        STREQ_NULLABLE(def->model, "virtio")) {
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         if (backend != NULL) {
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             int name;
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             if ((name = virDomainNetBackendTypeFromString(backend)) < 0 ||
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-- 
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1.8.5.2
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