Re: [PATCH] qemu: caps: Use unique key for domCaps caching

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 





On 10/15/19 1:01 PM, Cole Robinson wrote:
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

Signed-off-by: Cole Robinson <crobinso@xxxxxxxxxx>
---
qemu_domain.c validation should be affected, but it is covered up
by another bug, fixed here:
https://www.redhat.com/archives/libvir-list/2019-October/msg00708.html

  src/qemu/qemu_conf.c | 11 ++++++++++-
  1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/src/qemu/qemu_conf.c b/src/qemu/qemu_conf.c
index 08cd784054..64ac8cbdd3 100644
--- a/src/qemu/qemu_conf.c
+++ b/src/qemu/qemu_conf.c
@@ -1396,6 +1396,8 @@ virQEMUDriverGetDomainCapabilities(virQEMUDriverPtr driver,
      domCaps = virHashSearch(domCapsCache,
                              virQEMUDriverSearchDomcaps, &data, NULL);
      if (!domCaps) {
+        VIR_AUTOFREE(char *) key = NULL;
+

"g_autofree char *key = NULL;" instead of VIR_AUTOFREE for extra karma
points. Everything else LGTM.



Reviewed-by: Daniel Henrique Barboza <danielhb413@xxxxxxxxx>




          /* 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;
      }

--
libvir-list mailing list
libvir-list@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/libvir-list



[Index of Archives]     [Virt Tools]     [Libvirt Users]     [Lib OS Info]     [Fedora Users]     [Fedora Desktop]     [Fedora SELinux]     [Big List of Linux Books]     [Yosemite News]     [KDE Users]     [Fedora Tools]

  Powered by Linux