On Fri, Jan 22, 2010 at 11:40:39AM -0500, Chris Lalancette wrote:
> When libvirtd shuts down, it places a <state/> tag in the XML
> state file it writes out for guests with PCI passthrough
> devices. For devices that are attached at bootup time, the
> state tag is empty. However, at libvirtd startup time, it
> ignores anything with a <state/> tag in the XML, effectively
> hiding the guest.
This description doesn't make any sense to me.
At libvirtd startup
- Running guest state is loaded from /var/lib/libvirt/qemu/$NAME.xml
using flags=VIR_DOMAIN_XML_INTERNAL_STATUS
- Persistent configs are loaded from /etc/libvirt/qemu/$NAME.xml
using flags=0
The <state/> tags are only ever written into the configs that are
in /var/lib/libvirt/qemu/, so flags=VIR_DOMAIN_XML_INTERNAL_STATUS
means the <state/> element is read at startup.
Regardless, simply ignoring the <state/> tag won't cause the guest
to be hidden.
> I can think of at least 3 ways to fix this:
>
> 1) Don't throw an error on "unknown" tags in
> virDomainHostdevSubsysPciDefParseXML().
> 2) Have virDomainLoadAllConfigs() pass the
> VIR_DOMAIN_XML_INTERNAL_STATUS flag when parsing the domain
> XML.
> 3) Remove the check for VIR_DOMAIN_XML_INTERNAL_STATUS
> when parsing the XML.
>
> I chose approach 3). My reasoning for this is that the
> <state> tag is a legitimate part of the XML, so we should
> always offer to parse it. This fixes the problem with
> reconnecting to domains that have PCI passthrough devices.
I don't think there's a clear enough description of the original
problem to come up with a fix here.
>
> Signed-off-by: Chris Lalancette <clalance@xxxxxxxxxx>
> ---
> src/conf/domain_conf.c | 5 ++---
> 1 files changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
> index 74c2337..595c46c 100644
> --- a/src/conf/domain_conf.c
> +++ b/src/conf/domain_conf.c
> @@ -2876,7 +2876,7 @@ static int
> virDomainHostdevSubsysPciDefParseXML(virConnectPtr conn,
> const xmlNodePtr node,
> virDomainHostdevDefPtr def,
> - int flags) {
> + int flags ATTRIBUTE_UNUSED) {
>
> int ret = -1;
> xmlNodePtr cur;
> @@ -2890,8 +2890,7 @@ virDomainHostdevSubsysPciDefParseXML(virConnectPtr conn,
>
> if (virDomainDevicePCIAddressParseXML(conn, cur, addr) < 0)
> goto out;
> - } else if ((flags & VIR_DOMAIN_XML_INTERNAL_STATUS) &&
> - xmlStrEqual(cur->name, BAD_CAST "state")) {
> + } else if (xmlStrEqual(cur->name, BAD_CAST "state")) {
> /* Legacy back-compat. Don't add any more attributes here */
> char *devaddr = virXMLPropString(cur, "devaddr");
> if (devaddr &&
NACK to this change. This lets end users inject bogus state into libvirtd.
Daniel
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