[libvirt] [PATCH 7/8] qemu: Discard caps cache when KVM availability changes
Since CPU capabilities depend on accelerator used when probing QEMU the
cache becomes invalid when KVM becomes available or if it is not
available anymore.
Signed-off-by: Jiri Denemark <jdenemar(a)redhat.com>
---
src/qemu/qemu_capabilities.c | 37 ++++++++++++++++++++++++++++++++-----
src/qemu/qemu_capabilities.h | 4 +++-
2 files changed, 35 insertions(+), 6 deletions(-)
diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c
index d1c31ad..9fe4363 100644
--- a/src/qemu/qemu_capabilities.c
+++ b/src/qemu/qemu_capabilities.c
@@ -3469,7 +3469,9 @@ virQEMUCapsReset(virQEMUCapsPtr qemuCaps)
static int
virQEMUCapsInitCached(virCapsPtr caps,
virQEMUCapsPtr qemuCaps,
- const char *cacheDir)
+ const char *cacheDir,
+ uid_t runUid,
+ gid_t runGid)
{
char *capsdir = NULL;
char *capsfile = NULL;
@@ -3519,7 +3521,7 @@ virQEMUCapsInitCached(virCapsPtr caps,
goto discard;
}
- if (!virQEMUCapsIsValid(qemuCaps, qemuctime))
+ if (!virQEMUCapsIsValid(qemuCaps, qemuctime, runUid, runGid))
goto discard;
/* Discard cache if QEMU binary or libvirtd changed */
@@ -4067,7 +4069,8 @@ virQEMUCapsNewForBinaryInternal(virCapsPtr caps,
if (!cacheDir)
rv = 0;
- else if ((rv = virQEMUCapsInitCached(caps, qemuCaps, cacheDir)) < 0)
+ else if ((rv = virQEMUCapsInitCached(caps, qemuCaps, cacheDir,
+ runUid, runGid)) < 0)
goto error;
if (rv == 0) {
@@ -4115,8 +4118,12 @@ virQEMUCapsNewForBinary(virCapsPtr caps,
bool
virQEMUCapsIsValid(virQEMUCapsPtr qemuCaps,
- time_t ctime)
+ time_t ctime,
+ uid_t runUid,
+ gid_t runGid)
{
+ bool kvmUsable;
+
if (!qemuCaps->binary)
return true;
@@ -4142,6 +4149,26 @@ virQEMUCapsIsValid(virQEMUCapsPtr qemuCaps,
return false;
}
+ kvmUsable = virFileAccessibleAs("/dev/kvm", R_OK | W_OK,
+ runUid, runGid) == 0;
+
+ if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_KVM) &&
+ virQEMUCapsGet(qemuCaps, QEMU_CAPS_ENABLE_KVM) &&
+ kvmUsable) {
+ VIR_DEBUG("Dropping cached capabilities for '%s': KVM was not
"
+ "enabled when probing, but it should be usable now",
+ qemuCaps->binary);
+ return false;
+ }
+
+ if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_KVM) &&
+ !kvmUsable) {
+ VIR_DEBUG("Dropping cached capabilities for '%s': KVM was enabled
"
+ "when probing, but it is not available now",
+ qemuCaps->binary);
+ return false;
+ }
+
return true;
}
@@ -4235,7 +4262,7 @@ virQEMUCapsCacheLookup(virCapsPtr caps,
virMutexLock(&cache->lock);
ret = virHashLookup(cache->binaries, binary);
if (ret &&
- !virQEMUCapsIsValid(ret, 0)) {
+ !virQEMUCapsIsValid(ret, 0, cache->runUid, cache->runGid)) {
VIR_DEBUG("Cached capabilities %p no longer valid for %s",
ret, binary);
virHashRemoveEntry(cache->binaries, binary);
diff --git a/src/qemu/qemu_capabilities.h b/src/qemu/qemu_capabilities.h
index 6c45a67..5310416 100644
--- a/src/qemu/qemu_capabilities.h
+++ b/src/qemu/qemu_capabilities.h
@@ -450,7 +450,9 @@ int virQEMUCapsGetMachineTypesCaps(virQEMUCapsPtr qemuCaps,
virCapsGuestMachinePtr **machines);
bool virQEMUCapsIsValid(virQEMUCapsPtr qemuCaps,
- time_t ctime);
+ time_t ctime,
+ uid_t runUid,
+ gid_t runGid);
void virQEMUCapsFilterByMachineType(virQEMUCapsPtr qemuCaps,
const char *machineType);
--
2.10.2