[libvirt] [PATCH 07/22] qemu_capabilities: Introduce virQEMUCapsCacheLookupDefault

Jiri Denemark jdenemar at redhat.com
Wed May 16 08:39:26 UTC 2018


virConnectGetDomainCapabilities needs to lookup QEMU capabilities
matching a specified binary, architecture, virt type, and machine type
while using default values when any of the parameters are not provided
by the user. Let's extract the lookup code into
virQEMUCapsCacheLookupDefault to make it reusable.

Signed-off-by: Jiri Denemark <jdenemar at redhat.com>
---
 src/qemu/qemu_capabilities.c | 118 +++++++++++++++++++++++++++++++++++
 src/qemu/qemu_capabilities.h |   8 +++
 src/qemu/qemu_driver.c       |  86 ++++---------------------
 3 files changed, 137 insertions(+), 75 deletions(-)

diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c
index a5cb24fec6..77a4b4154e 100644
--- a/src/qemu/qemu_capabilities.c
+++ b/src/qemu/qemu_capabilities.c
@@ -4546,6 +4546,124 @@ virQEMUCapsCacheLookupByArch(virFileCachePtr cache,
 }
 
 
+/**
+ * virQEMUCapsCacheLookupDefault:
+ * @cache: QEMU capabilities cache
+ * @binary: optional path to QEMU binary
+ * @archStr: optional guest architecture
+ * @virttypeStr: optional virt type
+ * @machine: optional machine type
+ * @retArch: if non-NULL, guest architecture will be returned here
+ * @retVirttype: if non-NULL, domain virt type will be returned here
+ * @retMachine: if non-NULL, canonical machine type will be returned here
+ *
+ * Looks up the QEMU binary specified by @binary and @archStr, checks it can
+ * provide the required @virttypeStr and @machine and returns its capabilities.
+ * Sensible defaults are used for any argument which is NULL (the function can
+ * even be called with all NULL arguments).
+ *
+ * Returns QEMU capabilities matching the requirements, NULL on error.
+ */
+virQEMUCapsPtr
+virQEMUCapsCacheLookupDefault(virFileCachePtr cache,
+                              const char *binary,
+                              const char *archStr,
+                              const char *virttypeStr,
+                              const char *machine,
+                              virArch *retArch,
+                              virDomainVirtType *retVirttype,
+                              const char **retMachine)
+{
+    int virttype = VIR_DOMAIN_VIRT_NONE;
+    int arch = virArchFromHost();
+    virDomainVirtType capsType;
+    virQEMUCapsPtr qemuCaps = NULL;
+    virQEMUCapsPtr ret = NULL;
+
+    if (virttypeStr &&
+        (virttype = virDomainVirtTypeFromString(virttypeStr)) < 0) {
+        virReportError(VIR_ERR_INVALID_ARG,
+                       _("unknown virttype: %s"), virttypeStr);
+        goto cleanup;
+    }
+
+    if (archStr &&
+        (arch = virArchFromString(archStr)) == VIR_ARCH_NONE) {
+        virReportError(VIR_ERR_INVALID_ARG,
+                       _("unknown architecture: %s"), archStr);
+        goto cleanup;
+    }
+
+    if (binary) {
+        virArch arch_from_caps;
+
+        if (!(qemuCaps = virQEMUCapsCacheLookup(cache, binary)))
+            goto cleanup;
+
+        arch_from_caps = virQEMUCapsGetArch(qemuCaps);
+
+        if (arch_from_caps != arch &&
+            !((ARCH_IS_X86(arch) && ARCH_IS_X86(arch_from_caps)) ||
+              (ARCH_IS_PPC(arch) && ARCH_IS_PPC(arch_from_caps)) ||
+              (ARCH_IS_ARM(arch) && ARCH_IS_ARM(arch_from_caps)) ||
+              (ARCH_IS_S390(arch) && ARCH_IS_S390(arch_from_caps)))) {
+            virReportError(VIR_ERR_INVALID_ARG,
+                           _("architecture from emulator '%s' doesn't "
+                             "match given architecture '%s'"),
+                           virArchToString(arch_from_caps),
+                           virArchToString(arch));
+            goto cleanup;
+        }
+    } else {
+        if (!(qemuCaps = virQEMUCapsCacheLookupByArch(cache, arch)))
+            goto cleanup;
+
+        binary = virQEMUCapsGetBinary(qemuCaps);
+    }
+
+    if (machine) {
+        /* Turn @machine into canonical name */
+        machine = virQEMUCapsGetCanonicalMachine(qemuCaps, machine);
+
+        if (!virQEMUCapsIsMachineSupported(qemuCaps, machine)) {
+            virReportError(VIR_ERR_INVALID_ARG,
+                           _("the machine '%s' is not supported by emulator '%s'"),
+                           machine, binary);
+            goto cleanup;
+        }
+    } else {
+        machine = virQEMUCapsGetDefaultMachine(qemuCaps);
+    }
+
+    if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_KVM))
+        capsType = VIR_DOMAIN_VIRT_KVM;
+    else
+        capsType = VIR_DOMAIN_VIRT_QEMU;
+
+    if (virttype == VIR_DOMAIN_VIRT_NONE)
+        virttype = capsType;
+
+    if (virttype == VIR_DOMAIN_VIRT_KVM && capsType == VIR_DOMAIN_VIRT_QEMU) {
+        virReportError(VIR_ERR_INVALID_ARG,
+                       _("KVM is not supported by '%s' on this host"),
+                       binary);
+        goto cleanup;
+    }
+
+    if (retArch)
+        *retArch = arch;
+    if (retVirttype)
+        *retVirttype = virttype;
+    if (retMachine)
+        *retMachine = machine;
+
+    VIR_STEAL_PTR(ret, qemuCaps);
+
+ cleanup:
+    virObjectUnref(qemuCaps);
+    return ret;
+}
+
 bool
 virQEMUCapsSupportsVmport(virQEMUCapsPtr qemuCaps,
                           const virDomainDef *def)
diff --git a/src/qemu/qemu_capabilities.h b/src/qemu/qemu_capabilities.h
index d23c34c24d..6f095bfbfe 100644
--- a/src/qemu/qemu_capabilities.h
+++ b/src/qemu/qemu_capabilities.h
@@ -559,6 +559,14 @@ virQEMUCapsPtr virQEMUCapsCacheLookupCopy(virFileCachePtr cache,
                                           const char *machineType);
 virQEMUCapsPtr virQEMUCapsCacheLookupByArch(virFileCachePtr cache,
                                             virArch arch);
+virQEMUCapsPtr virQEMUCapsCacheLookupDefault(virFileCachePtr cache,
+                                             const char *binary,
+                                             const char *archStr,
+                                             const char *virttypeStr,
+                                             const char *machine,
+                                             virArch *retArch,
+                                             virDomainVirtType *retVirttype,
+                                             const char **retMachine);
 
 virCapsPtr virQEMUCapsInit(virFileCachePtr cache);
 
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 9037818e2a..6c086b9ef8 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -19249,10 +19249,9 @@ qemuConnectGetDomainCapabilities(virConnectPtr conn,
     char *ret = NULL;
     virQEMUDriverPtr driver = conn->privateData;
     virQEMUCapsPtr qemuCaps = NULL;
-    int virttype = VIR_DOMAIN_VIRT_NONE;
-    virDomainVirtType capsType;
+    virArch arch;
+    virDomainVirtType virttype;
     virDomainCapsPtr domCaps = NULL;
-    int arch = virArchFromHost(); /* virArch */
     virQEMUDriverConfigPtr cfg = NULL;
     virCapsPtr caps = NULL;
 
@@ -19266,80 +19265,17 @@ qemuConnectGetDomainCapabilities(virConnectPtr conn,
     if (!(caps = virQEMUDriverGetCapabilities(driver, false)))
         goto cleanup;
 
-    if (virttype_str &&
-        (virttype = virDomainVirtTypeFromString(virttype_str)) < 0) {
-        virReportError(VIR_ERR_INVALID_ARG,
-                       _("unknown virttype: %s"),
-                       virttype_str);
+    qemuCaps = virQEMUCapsCacheLookupDefault(driver->qemuCapsCache,
+                                             emulatorbin,
+                                             arch_str,
+                                             virttype_str,
+                                             machine,
+                                             &arch, &virttype, &machine);
+    if (!qemuCaps)
         goto cleanup;
-    }
 
-    if (arch_str && (arch = virArchFromString(arch_str)) == VIR_ARCH_NONE) {
-        virReportError(VIR_ERR_INVALID_ARG,
-                       _("unknown architecture: %s"),
-                       arch_str);
-        goto cleanup;
-    }
-
-    if (emulatorbin) {
-        virArch arch_from_caps;
-
-        if (!(qemuCaps = virQEMUCapsCacheLookup(driver->qemuCapsCache,
-                                                emulatorbin)))
-            goto cleanup;
-
-        arch_from_caps = virQEMUCapsGetArch(qemuCaps);
-
-        if (arch_from_caps != arch &&
-            !((ARCH_IS_X86(arch) && ARCH_IS_X86(arch_from_caps)) ||
-              (ARCH_IS_PPC(arch) && ARCH_IS_PPC(arch_from_caps)) ||
-              (ARCH_IS_ARM(arch) && ARCH_IS_ARM(arch_from_caps)) ||
-              (ARCH_IS_S390(arch) && ARCH_IS_S390(arch_from_caps)))) {
-            virReportError(VIR_ERR_INVALID_ARG,
-                           _("architecture from emulator '%s' doesn't "
-                             "match given architecture '%s'"),
-                           virArchToString(arch_from_caps),
-                           virArchToString(arch));
-            goto cleanup;
-        }
-    } else {
-        if (!(qemuCaps = virQEMUCapsCacheLookupByArch(driver->qemuCapsCache,
-                                                      arch)))
-            goto cleanup;
-
-        emulatorbin = virQEMUCapsGetBinary(qemuCaps);
-    }
-
-    if (machine) {
-        /* Turn @machine into canonical name */
-        machine = virQEMUCapsGetCanonicalMachine(qemuCaps, machine);
-
-        if (!virQEMUCapsIsMachineSupported(qemuCaps, machine)) {
-            virReportError(VIR_ERR_INVALID_ARG,
-                           _("the machine '%s' is not supported by emulator '%s'"),
-                           machine, emulatorbin);
-            goto cleanup;
-        }
-    } else {
-        machine = virQEMUCapsGetDefaultMachine(qemuCaps);
-    }
-
-    if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_KVM))
-        capsType = VIR_DOMAIN_VIRT_KVM;
-    else
-        capsType = VIR_DOMAIN_VIRT_QEMU;
-
-    if (virttype == VIR_DOMAIN_VIRT_NONE)
-        virttype = capsType;
-
-    if (virttype == VIR_DOMAIN_VIRT_KVM && capsType == VIR_DOMAIN_VIRT_QEMU) {
-        virReportError(VIR_ERR_INVALID_ARG,
-                       _("KVM is not supported by '%s' on this host"),
-                       emulatorbin);
-        goto cleanup;
-    }
-
-    if (!(domCaps = virDomainCapsNew(emulatorbin, machine, arch, virttype)))
+    if (!(domCaps = virDomainCapsNew(virQEMUCapsGetBinary(qemuCaps), machine,
+                                     arch, virttype)))
         goto cleanup;
 
     if (virQEMUCapsFillDomainCaps(caps, domCaps, qemuCaps,
-- 
2.17.0




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