qemu: caps: Use unique key for domCaps caching

When searching qemuCaps->domCapsCache for existing domCaps data,
we check for a matching pair of arch+virttype+machine+emulator. However
for the hash table key we only use the machine string. So if the
cache already contains:

  x86_64 + kvm + pc + /usr/bin/qemu-kvm

But a new VM is defined with

  x86_64 + qemu + pc + /usr/bin/qemu-kvm

We correctly fail to find matching cached domCaps, but then attempt
to use a colliding key with virHashAddEntry

Fix this by building a hash key from the 4 values, not just machine

Reviewed-by: Jonathon Jongsma <jjongsma@redhat.com>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: Cole Robinson <crobinso@redhat.com>
This commit is contained in:
Cole Robinson 2019-10-15 11:47:10 -04:00
parent b83884d1a0
commit fbf7c23c2d

View File

@ -1396,6 +1396,8 @@ virQEMUDriverGetDomainCapabilities(virQEMUDriverPtr driver,
domCaps = virHashSearch(domCapsCache,
virQEMUDriverSearchDomcaps, &data, NULL);
if (!domCaps) {
g_autofree char *key = NULL;
/* hash miss, build new domcaps */
if (!(domCaps = virDomainCapsNew(data.path, data.machine,
data.arch, data.virttype)))
@ -1406,7 +1408,14 @@ virQEMUDriverGetDomainCapabilities(virQEMUDriverPtr driver,
cfg->firmwares, cfg->nfirmwares) < 0)
return NULL;
if (virHashAddEntry(domCapsCache, machine, domCaps) < 0)
if (virAsprintf(&key, "%d:%d:%s:%s",
data.arch,
data.virttype,
NULLSTR(data.machine),
NULLSTR(data.path)) < 0)
return NULL;
if (virHashAddEntry(domCapsCache, key, domCaps) < 0)
return NULL;
}