qemu: switch QEMU capabilities to use virFileCache

The switch contains considerable amount of changes:

  virQEMUCapsRememberCached() is removed because this is now handled
  by virFileCacheSave().

  virQEMUCapsInitCached() is removed because this is now handled by
  virFileCacheLoad().

  virQEMUCapsNewForBinary() is split into two functions,
  virQEMUCapsNewData() which creates new data if there is nothing
  cached and virQEMUCapsLoadFile() which loads the cached data.
  This is now handled by virFileCacheNewData().

  virQEMUCapsCacheValidate() is removed because this is now handled by
  virFileCacheValidate().

  virQEMUCapsCacheFree() is removed because it's no longer required.

  Add virCapsPtr into virQEMUCapsCachePriv because for each call of
  virFileCacheLookup*() we need to use current virCapsPtr.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Jiri Denemark <jdenemar@redhat.com>

src/qemu/qemu_capabilities.c

@@ -29,6 +29,7 @@
 #include "virlog.h"
 #include "virerror.h"
 #include "virfile.h"
+#include "virfilecache.h"
 #include "virpidfile.h"
 #include "virprocess.h"
 #include "cpu/cpu.h"
@@ -957,7 +958,7 @@ virQEMUCapsFindBinaryForArch(virArch hostarch,
 
 static int
 virQEMUCapsInitGuest(virCapsPtr caps,
-                     virQEMUCapsCachePtr cache,
+                     virFileCachePtr cache,
                      virArch hostarch,
                      virArch guestarch)
 {
@@ -1174,7 +1175,8 @@ virQEMUCapsProbeHostCPUForEmulator(virArch hostArch,
 }
 
 
-virCapsPtr virQEMUCapsInit(virQEMUCapsCachePtr cache)
+virCapsPtr
+virQEMUCapsInit(virFileCachePtr cache)
 {
     virCapsPtr caps;
     size_t i;
@@ -2172,7 +2174,7 @@ virQEMUCapsExtractDeviceStr(const char *qemu,
 
 
 int virQEMUCapsGetDefaultVersion(virCapsPtr caps,
-                                 virQEMUCapsCachePtr capsCache,
+                                 virFileCachePtr capsCache,
                                  unsigned int *version)
 {
     virQEMUCapsPtr qemucaps;
@@ -3775,8 +3777,10 @@ virQEMUCapsLoadCPUModels(virQEMUCapsPtr qemuCaps,
 
 
 static void
-virQEMUCapsCachePrivFree(virQEMUCapsCachePrivPtr priv)
+virQEMUCapsCachePrivFree(void *privData)
 {
+    virQEMUCapsCachePrivPtr priv = privData;
+
     VIR_FREE(priv->libDir);
     VIR_FREE(priv);
 }
@@ -4205,8 +4209,11 @@ virQEMUCapsFormatCache(virQEMUCapsPtr qemuCaps)
 
 
 static int
-virQEMUCapsSaveCache(virQEMUCapsPtr qemuCaps, const char *filename)
+virQEMUCapsSaveFile(void *data,
+                    const char *filename,
+                    void *privData ATTRIBUTE_UNUSED)
 {
+    virQEMUCapsPtr qemuCaps = data;
     char *xml = NULL;
     int ret = -1;
 
@@ -4230,48 +4237,13 @@ virQEMUCapsSaveCache(virQEMUCapsPtr qemuCaps, const char *filename)
     return ret;
 }
 
-static int
-virQEMUCapsRememberCached(virQEMUCapsPtr qemuCaps, const char *cacheDir)
-{
-    char *capsdir = NULL;
-    char *capsfile = NULL;
-    int ret = -1;
-    char *binaryhash = NULL;
-
-    if (virAsprintf(&capsdir, "%s/capabilities", cacheDir) < 0)
-        goto cleanup;
-
-    if (virCryptoHashString(VIR_CRYPTO_HASH_SHA256,
-                            qemuCaps->binary,
-                            &binaryhash) < 0)
-        goto cleanup;
-
-    if (virAsprintf(&capsfile, "%s/%s.xml", capsdir, binaryhash) < 0)
-        goto cleanup;
-
-    if (virFileMakePath(capsdir) < 0) {
-        virReportSystemError(errno,
-                             _("Unable to create directory '%s'"),
-                             capsdir);
-        goto cleanup;
-    }
-
-    if (virQEMUCapsSaveCache(qemuCaps, capsfile) < 0)
-        goto cleanup;
-
-    ret = 0;
- cleanup:
-    VIR_FREE(binaryhash);
-    VIR_FREE(capsfile);
-    VIR_FREE(capsdir);
-    return ret;
-}
-
 
 static bool
-virQEMUCapsIsValid(virQEMUCapsPtr qemuCaps,
+virQEMUCapsIsValid(void *data,
-                   virQEMUCapsCachePrivPtr priv)
+                   void *privData)
 {
+    virQEMUCapsPtr qemuCaps = data;
+    virQEMUCapsCachePrivPtr priv = privData;
     bool kvmUsable;
     struct stat sb;
 
@@ -4330,86 +4302,6 @@ virQEMUCapsIsValid(virQEMUCapsPtr qemuCaps,
 }
 
 
-static int
-virQEMUCapsInitCached(virQEMUCapsPtr *qemuCaps,
-                      const char *binary,
-                      const char *cacheDir,
-                      virQEMUCapsCachePrivPtr priv)
-{
-    char *capsdir = NULL;
-    char *capsfile = NULL;
-    int ret = -1;
-    char *binaryhash = NULL;
-    struct stat sb;
-    virQEMUCapsPtr qemuCapsNew = NULL;
-
-    if (virAsprintf(&capsdir, "%s/capabilities", cacheDir) < 0)
-        goto cleanup;
-
-    if (virCryptoHashString(VIR_CRYPTO_HASH_SHA256, binary, &binaryhash) < 0)
-        goto cleanup;
-
-    if (virAsprintf(&capsfile, "%s/%s.xml", capsdir, binaryhash) < 0)
-        goto cleanup;
-
-    if (virFileMakePath(capsdir) < 0) {
-        virReportSystemError(errno,
-                             _("Unable to create directory '%s'"),
-                             capsdir);
-        goto cleanup;
-    }
-
-    if (stat(capsfile, &sb) < 0) {
-        if (errno == ENOENT) {
-            VIR_DEBUG("No cached capabilities '%s' for '%s'",
-                      capsfile, binary);
-            ret = 0;
-            goto cleanup;
-        }
-        virReportSystemError(errno,
-                             _("Unable to access cache '%s' for '%s'"),
-                             capsfile, binary);
-        goto cleanup;
-    }
-
-    if (!(qemuCapsNew = virQEMUCapsNew()))
-        goto cleanup;
-
-    if (VIR_STRDUP(qemuCapsNew->binary, binary) < 0)
-        goto discard;
-
-    if (virQEMUCapsLoadCache(priv->hostArch, qemuCapsNew, capsfile) < 0) {
-        VIR_WARN("Failed to load cached caps from '%s' for '%s': %s",
-                 capsfile, qemuCapsNew->binary, virGetLastErrorMessage());
-        virResetLastError();
-        goto discard;
-    }
-
-    if (!virQEMUCapsIsValid(qemuCapsNew, priv))
-        goto discard;
-
-    VIR_DEBUG("Loaded '%s' for '%s' ctime %lld usedQMP=%d",
-              capsfile, qemuCapsNew->binary,
-              (long long)qemuCapsNew->ctime, qemuCapsNew->usedQMP);
-
-    ret = 1;
-    *qemuCaps = qemuCapsNew;
- cleanup:
-    VIR_FREE(binaryhash);
-    VIR_FREE(capsfile);
-    VIR_FREE(capsdir);
-    return ret;
-
- discard:
-    VIR_DEBUG("Dropping cached capabilities '%s' for '%s'",
-              capsfile, qemuCapsNew->binary);
-    ignore_value(unlink(capsfile));
-    virObjectUnref(qemuCapsNew);
-    ret = 0;
-    goto cleanup;
-}
-
-
 #define QEMU_SYSTEM_PREFIX "qemu-system-"
 
 static int
@@ -5287,36 +5179,45 @@ virQEMUCapsNewForBinaryInternal(virArch hostArch,
     goto cleanup;
 }
 
-static virQEMUCapsPtr
+static void *
-virQEMUCapsNewForBinary(const char *binary,
+virQEMUCapsNewData(const char *binary,
-                        const char *cacheDir,
+                   void *privData)
-                        virQEMUCapsCachePrivPtr priv)
 {
-    int rv;
+    virQEMUCapsCachePrivPtr priv = privData;
-    virQEMUCapsPtr qemuCaps = NULL;
 
-    if ((rv = virQEMUCapsInitCached(&qemuCaps, binary, cacheDir, priv)) < 0)
+    return virQEMUCapsNewForBinaryInternal(priv->hostArch,
-        goto error;
-
-    if (rv == 0) {
-        if (!(qemuCaps = virQEMUCapsNewForBinaryInternal(priv->hostArch,
                                            binary,
                                            priv->libDir,
                                            priv->runUid,
                                            priv->runGid,
-                                                         false))) {
+                                           false);
-            goto error;
+}
-        }
 
-        if (virQEMUCapsRememberCached(qemuCaps, cacheDir) < 0)
-            goto error;
-    }
 
+static void *
+virQEMUCapsLoadFile(const char *filename,
+                    const char *binary,
+                    void *privData)
+{
+    virQEMUCapsPtr qemuCaps = virQEMUCapsNew();
+    virQEMUCapsCachePrivPtr priv = privData;
+
+    if (!qemuCaps)
+        return NULL;
+
+    if (VIR_STRDUP(qemuCaps->binary, binary) < 0)
+        goto error;
+
+    if (virQEMUCapsLoadCache(priv->hostArch, qemuCaps, filename) < 0)
+        goto error;
+
+ cleanup:
     return qemuCaps;
 
  error:
     virObjectUnref(qemuCaps);
-    return NULL;
+    qemuCaps = NULL;
+    goto cleanup;
 }
 
 
@@ -5358,90 +5259,61 @@ virQEMUCapsFilterByMachineType(virQEMUCapsPtr qemuCaps,
 }
 
 
-virQEMUCapsCachePtr
+virFileCacheHandlers qemuCapsCacheHandlers = {
+    .isValid = virQEMUCapsIsValid,
+    .newData = virQEMUCapsNewData,
+    .loadFile = virQEMUCapsLoadFile,
+    .saveFile = virQEMUCapsSaveFile,
+    .privFree = virQEMUCapsCachePrivFree,
+};
+
+
+virFileCachePtr
 virQEMUCapsCacheNew(const char *libDir,
                     const char *cacheDir,
                     uid_t runUid,
                     gid_t runGid)
 {
-    virQEMUCapsCachePtr cache;
+    char *capsCacheDir = NULL;
+    virFileCachePtr cache = NULL;
+    virQEMUCapsCachePrivPtr priv = NULL;
 
-    if (VIR_ALLOC(cache) < 0)
+    if (virAsprintf(&capsCacheDir, "%s/capabilities", cacheDir) < 0)
-        return NULL;
-
-    if (virMutexInit(&cache->lock) < 0) {
-        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
-                       _("Unable to initialize mutex"));
-        VIR_FREE(cache);
-        return NULL;
-    }
-
-    if (!(cache->binaries = virHashCreate(10, virObjectFreeHashData)))
-        goto error;
-    if (VIR_STRDUP(cache->cacheDir, cacheDir) < 0)
         goto error;
 
-    if (VIR_ALLOC(cache->priv) < 0)
+    if (!(cache = virFileCacheNew(capsCacheDir, "xml", &qemuCapsCacheHandlers)))
         goto error;
 
-    if (VIR_STRDUP(cache->priv->libDir, libDir) < 0)
+    if (VIR_ALLOC(priv) < 0)
+        goto error;
+    virFileCacheSetPriv(cache, priv);
+
+    if (VIR_STRDUP(priv->libDir, libDir) < 0)
         goto error;
 
-    cache->priv->hostArch = virArchFromHost();
+    priv->hostArch = virArchFromHost();
 
-    cache->priv->runUid = runUid;
+    priv->runUid = runUid;
-    cache->priv->runGid = runGid;
+    priv->runGid = runGid;
 
+ cleanup:
+    VIR_FREE(capsCacheDir);
     return cache;
 
  error:
-    virQEMUCapsCacheFree(cache);
+    virObjectUnref(cache);
-    return NULL;
+    cache = NULL;
-}
+    goto cleanup;
-
-
-static void ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_NONNULL(3)
-virQEMUCapsCacheValidate(virQEMUCapsCachePtr cache,
-                         const char *binary,
-                         virQEMUCapsPtr *qemuCaps)
-{
-    if (*qemuCaps &&
-        !virQEMUCapsIsValid(*qemuCaps, cache->priv)) {
-        VIR_DEBUG("Cached capabilities %p no longer valid for %s",
-                  *qemuCaps, binary);
-        virHashRemoveEntry(cache->binaries, binary);
-        *qemuCaps = NULL;
-    }
-
-    if (!*qemuCaps) {
-        VIR_DEBUG("Creating capabilities for %s", binary);
-        *qemuCaps = virQEMUCapsNewForBinary(binary,
-                                            cache->cacheDir,
-                                            cache->priv);
-        if (*qemuCaps) {
-            VIR_DEBUG("Caching capabilities %p for %s", *qemuCaps, binary);
-            if (virHashAddEntry(cache->binaries, binary, *qemuCaps) < 0) {
-                virObjectUnref(*qemuCaps);
-                *qemuCaps = NULL;
-            }
-        }
-    }
 }
 
 
 virQEMUCapsPtr
-virQEMUCapsCacheLookup(virQEMUCapsCachePtr cache,
+virQEMUCapsCacheLookup(virFileCachePtr cache,
                        const char *binary)
 {
     virQEMUCapsPtr ret = NULL;
 
-    virMutexLock(&cache->lock);
+    ret = virFileCacheLookup(cache, binary);
-
-    ret = virHashLookup(cache->binaries, binary);
-    virQEMUCapsCacheValidate(cache, binary, &ret);
-    virObjectRef(ret);
-
-    virMutexUnlock(&cache->lock);
 
     VIR_DEBUG("Returning caps %p for %s", ret, binary);
     return ret;
@@ -5449,7 +5321,7 @@ virQEMUCapsCacheLookup(virQEMUCapsCachePtr cache,
 
 
 virQEMUCapsPtr
-virQEMUCapsCacheLookupCopy(virQEMUCapsCachePtr cache,
+virQEMUCapsCacheLookupCopy(virFileCachePtr cache,
                            const char *binary,
                            const char *machineType)
 {
@@ -5483,64 +5355,36 @@ virQEMUCapsCompareArch(const void *payload,
 
 
 virQEMUCapsPtr
-virQEMUCapsCacheLookupByArch(virQEMUCapsCachePtr cache,
+virQEMUCapsCacheLookupByArch(virFileCachePtr cache,
                              virArch arch)
 {
     virQEMUCapsPtr ret = NULL;
     virArch target;
     struct virQEMUCapsSearchData data = { .arch = arch };
 
-    virMutexLock(&cache->lock);
+    ret = virFileCacheLookupByFunc(cache, virQEMUCapsCompareArch, &data);
-    ret = virHashSearch(cache->binaries, virQEMUCapsCompareArch, &data, NULL);
     if (!ret) {
         /* If the first attempt at finding capabilities has failed, try
          * again using the QEMU target as lookup key instead */
         target = virQEMUCapsFindTarget(virArchFromHost(), data.arch);
         if (target != data.arch) {
             data.arch = target;
-            ret = virHashSearch(cache->binaries, virQEMUCapsCompareArch,
+            ret = virFileCacheLookupByFunc(cache, virQEMUCapsCompareArch, &data);
-                                &data, NULL);
         }
     }
 
-    if (ret) {
+    if (!ret) {
-        char *binary;
-
-        if (VIR_STRDUP(binary, ret->binary) < 0) {
-            ret = NULL;
-        } else {
-            virQEMUCapsCacheValidate(cache, binary, &ret);
-            VIR_FREE(binary);
-        }
-    } else {
         virReportError(VIR_ERR_INVALID_ARG,
                        _("unable to find any emulator to serve '%s' "
                          "architecture"), virArchToString(arch));
     }
 
-    virObjectRef(ret);
-    virMutexUnlock(&cache->lock);
-
     VIR_DEBUG("Returning caps %p for arch %s", ret, virArchToString(arch));
 
     return ret;
 }
 
 
-void
-virQEMUCapsCacheFree(virQEMUCapsCachePtr cache)
-{
-    if (!cache)
-        return;
-
-    virQEMUCapsCachePrivFree(cache->priv);
-    VIR_FREE(cache->cacheDir);
-    virHashFree(cache->binaries);
-    virMutexDestroy(&cache->lock);
-    VIR_FREE(cache);
-}
-
-
 bool
 virQEMUCapsSupportsVmport(virQEMUCapsPtr qemuCaps,
                           const virDomainDef *def)

src/qemu/qemu_capabilities.h

@@ -30,6 +30,7 @@
 # include "qemu_monitor.h"
 # include "domain_capabilities.h"
 # include "virfirmware.h"
+# include "virfilecache.h"
 
 /*
  * Internal flags to keep track of qemu command line capabilities
@@ -427,9 +428,6 @@ typedef enum {
 typedef struct _virQEMUCaps virQEMUCaps;
 typedef virQEMUCaps *virQEMUCapsPtr;
 
-typedef struct _virQEMUCapsCache virQEMUCapsCache;
-typedef virQEMUCapsCache *virQEMUCapsCachePtr;
-
 virQEMUCapsPtr virQEMUCapsNew(void);
 
 void virQEMUCapsSet(virQEMUCapsPtr qemuCaps,
@@ -501,22 +499,21 @@ int virQEMUCapsGetMachineTypesCaps(virQEMUCapsPtr qemuCaps,
 void virQEMUCapsFilterByMachineType(virQEMUCapsPtr qemuCaps,
                                     const char *machineType);
 
-virQEMUCapsCachePtr virQEMUCapsCacheNew(const char *libDir,
+virFileCachePtr virQEMUCapsCacheNew(const char *libDir,
                                         const char *cacheDir,
                                         uid_t uid, gid_t gid);
-virQEMUCapsPtr virQEMUCapsCacheLookup(virQEMUCapsCachePtr cache,
+virQEMUCapsPtr virQEMUCapsCacheLookup(virFileCachePtr cache,
                                       const char *binary);
-virQEMUCapsPtr virQEMUCapsCacheLookupCopy(virQEMUCapsCachePtr cache,
+virQEMUCapsPtr virQEMUCapsCacheLookupCopy(virFileCachePtr cache,
                                           const char *binary,
                                           const char *machineType);
-virQEMUCapsPtr virQEMUCapsCacheLookupByArch(virQEMUCapsCachePtr cache,
+virQEMUCapsPtr virQEMUCapsCacheLookupByArch(virFileCachePtr cache,
                                             virArch arch);
-void virQEMUCapsCacheFree(virQEMUCapsCachePtr cache);
 
-virCapsPtr virQEMUCapsInit(virQEMUCapsCachePtr cache);
+virCapsPtr virQEMUCapsInit(virFileCachePtr cache);
 
 int virQEMUCapsGetDefaultVersion(virCapsPtr caps,
-                                 virQEMUCapsCachePtr capsCache,
+                                 virFileCachePtr capsCache,
                                  unsigned int *version);
 
 VIR_ENUM_DECL(virQEMUCaps);

src/qemu/qemu_capspriv.h

@@ -39,12 +39,6 @@ struct _virQEMUCapsCachePriv {
 typedef struct _virQEMUCapsCachePriv virQEMUCapsCachePriv;
 typedef virQEMUCapsCachePriv *virQEMUCapsCachePrivPtr;
 
-struct _virQEMUCapsCache {
-    virMutex lock;
-    virHashTablePtr binaries;
-    char *cacheDir;
-    virQEMUCapsCachePrivPtr priv;
-};
 
 virQEMUCapsPtr virQEMUCapsNewCopy(virQEMUCapsPtr qemuCaps);
 

src/qemu/qemu_conf.h

@@ -48,6 +48,7 @@
 # include "virclosecallbacks.h"
 # include "virhostdev.h"
 # include "virfile.h"
+# include "virfilecache.h"
 # include "virfirmware.h"
 
 # ifdef CPU_SETSIZE /* Linux */
@@ -245,7 +246,7 @@ struct _virQEMUDriver {
     virDomainXMLOptionPtr xmlopt;
 
     /* Immutable pointer, self-locking APIs */
-    virQEMUCapsCachePtr qemuCapsCache;
+    virFileCachePtr qemuCapsCache;
 
     /* Immutable pointer, self-locking APIs */
     virObjectEventStatePtr domainEventState;

src/qemu/qemu_driver.c

@@ -1079,7 +1079,7 @@ qemuStateCleanup(void)
     virObjectUnref(qemu_driver->hostdevMgr);
     virHashFree(qemu_driver->sharedDevices);
     virObjectUnref(qemu_driver->caps);
-    virQEMUCapsCacheFree(qemu_driver->qemuCapsCache);
+    virObjectUnref(qemu_driver->qemuCapsCache);
 
     virObjectUnref(qemu_driver->domains);
     virObjectUnref(qemu_driver->remotePorts);

tests/testutilsqemu.c

@@ -12,6 +12,7 @@
 # define __QEMU_CAPSPRIV_H_ALLOW__
 # include "qemu/qemu_capspriv.h"
 # include "virstring.h"
+# include "virfilecache.h"
 
 # define VIR_FROM_THIS VIR_FROM_QEMU
 
@@ -511,14 +512,14 @@ void qemuTestDriverFree(virQEMUDriver *driver)
         virFileDeleteTree(driver->config->stateDir);
         virFileDeleteTree(driver->config->configDir);
     }
-    virQEMUCapsCacheFree(driver->qemuCapsCache);
+    virObjectUnref(driver->qemuCapsCache);
     virObjectUnref(driver->xmlopt);
     virObjectUnref(driver->caps);
     virObjectUnref(driver->config);
     virObjectUnref(driver->securityManager);
 }
 
-int qemuTestCapsCacheInsert(virQEMUCapsCachePtr cache,
+int qemuTestCapsCacheInsert(virFileCachePtr cache,
                             virQEMUCapsPtr caps)
 {
     size_t i;
@@ -533,9 +534,7 @@ int qemuTestCapsCacheInsert(virQEMUCapsCachePtr cache,
 
     for (i = 0; i < ARRAY_CARDINALITY(QEMUBinList); i++) {
         virObjectRef(tmpCaps);
-        if (virHashUpdateEntry(cache->binaries,
+        if (virFileCacheInsertData(cache, QEMUBinList[i], tmpCaps) < 0) {
-                               QEMUBinList[i],
-                               tmpCaps) < 0) {
             virObjectUnref(tmpCaps);
             return -1;
         }

tests/testutilsqemu.h

@@ -1,6 +1,7 @@
 #ifdef WITH_QEMU
 
 # include "capabilities.h"
+# include "virfilecache.h"
 # include "domain_conf.h"
 # include "qemu/qemu_capabilities.h"
 # include "qemu/qemu_conf.h"
@@ -30,7 +31,7 @@ void qemuTestSetHostCPU(virCapsPtr caps,
 
 int qemuTestDriverInit(virQEMUDriver *driver);
 void qemuTestDriverFree(virQEMUDriver *driver);
-int qemuTestCapsCacheInsert(virQEMUCapsCachePtr cache,
+int qemuTestCapsCacheInsert(virFileCachePtr cache,
                             virQEMUCapsPtr caps);
 
 int testQemuCapsSetGIC(virQEMUCapsPtr qemuCaps,