[libvirt] [PATCH 1/4] qemu: get arch name from <cpu> element

[Paolo Bonzini]

The qemu32 CPU model is chosen based on the <os arch=...> name when
creating the QEMU command line.  Reflect the kvm32/kvm64/qemu32/qemu64
CPU models in the <os> element when doing the opposite transformation.
To do this, we need to not look at def->os.arch until after the
command-line has been parsed.

At the same time, avoid creating an empty <cpu> element when the QEMU
command-line specifies the default CPU model for the guest arch.

Signed-off-by: Paolo Bonzini <pbonzini at redhat.com>
---
 src/qemu/qemu_command.c |   70 +++++++++++++++++++++++++++++++----------------
 1 files changed, 46 insertions(+), 24 deletions(-)

diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index aaccf62..7c4460e 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -6779,12 +6779,10 @@ static int
 qemuParseCommandLineCPU(virDomainDefPtr dom,
                         const char *val)
 {
-    virCPUDefPtr cpu;
+    virCPUDefPtr cpu = NULL;
     const char *p = val;
     const char *next;
-
-    if (!(cpu = qemuInitGuestCPU(dom)))
-        goto error;
+    char *model = NULL;
 
     do {
         if (*p == '\0' || *p == ',')
@@ -6793,13 +6791,13 @@ qemuParseCommandLineCPU(virDomainDefPtr dom,
         if ((next = strchr(p, ',')))
             next++;
 
-        if (!cpu->model) {
+        if (!model) {
             if (next)
-                cpu->model = strndup(p, next - p - 1);
+                model = strndup(p, next - p - 1);
             else
-                cpu->model = strdup(p);
+                model = strdup(p);
 
-            if (!cpu->model)
+            if (!model)
                 goto no_memory;
         }
         else if (*p == '+' || *p == '-') {
@@ -6824,6 +6822,9 @@ qemuParseCommandLineCPU(virDomainDefPtr dom,
             if (!feature)
                 goto no_memory;
 
+            if (!cpu && !(cpu = qemuInitGuestCPU(dom)))
+                goto error;
+
             ret = virCPUDefAddFeature(cpu, feature, policy);
             VIR_FREE(feature);
             if (ret < 0)
@@ -6831,6 +6832,21 @@ qemuParseCommandLineCPU(virDomainDefPtr dom,
         }
     } while ((p = next));
 
+    if (model) {
+        if (STREQ(model, "qemu32") || STREQ(model, "kvm32")) {
+            dom->os.arch = strdup("i686");
+            VIR_FREE(model);
+        } else if (STREQ(model, "qemu64") || STREQ(model, "kvm64")) {
+            dom->os.arch = strdup("x86_64");
+            VIR_FREE(model);
+        } else {
+            if (!cpu && !(cpu = qemuInitGuestCPU(dom)))
+                goto error;
+
+            cpu->model = model;
+        }
+    }
+
     return 0;
 
 syntax:
@@ -6942,6 +6958,7 @@ virDomainDefPtr qemuParseCommandLine(virCapsPtr caps,
     const char **nics = NULL;
     int video = VIR_DOMAIN_VIDEO_TYPE_CIRRUS;
     int nvirtiodisk = 0;
+    int disabled_features = 0;
     qemuDomainCmdlineDefPtr cmd = NULL;
     virDomainDiskDefPtr disk = NULL;
     const char *ceph_args = qemuFindEnv(progenv, "CEPH_ARGS");
@@ -7000,21 +7017,6 @@ virDomainDefPtr qemuParseCommandLine(virCapsPtr caps,
     if (!def->os.type)
         goto no_memory;
 
-    if (STRPREFIX(def->emulator, "qemu"))
-        path = def->emulator;
-    else
-        path = strstr(def->emulator, "qemu");
-    if (path &&
-        STRPREFIX(path, "qemu-system-"))
-        def->os.arch = strdup(path + strlen("qemu-system-"));
-    else
-        def->os.arch = strdup("i686");
-    if (!def->os.arch)
-        goto no_memory;
-
-    if (STREQ(def->os.arch, "i686")||STREQ(def->os.arch, "x86_64"))
-        def->features = (1 << VIR_DOMAIN_FEATURE_ACPI)
-        /*| (1 << VIR_DOMAIN_FEATURE_APIC)*/;
 #define WANT_VALUE()                                                   \
     const char *val = progargv[++i];                                   \
     if (!val) {                                                        \
@@ -7246,7 +7248,7 @@ virDomainDefPtr qemuParseCommandLine(virCapsPtr caps,
             def->disks[def->ndisks++] = disk;
             disk = NULL;
         } else if (STREQ(arg, "-no-acpi")) {
-            def->features &= ~(1 << VIR_DOMAIN_FEATURE_ACPI);
+            disabled_features |= (1 << VIR_DOMAIN_FEATURE_ACPI);
         } else if (STREQ(arg, "-no-reboot")) {
             def->onReboot = VIR_DOMAIN_LIFECYCLE_DESTROY;
         } else if (STREQ(arg, "-no-kvm")) {
@@ -7542,6 +7544,26 @@ virDomainDefPtr qemuParseCommandLine(virCapsPtr caps,
         }
     }
 
+    if (!def->os.arch) {
+        if (STRPREFIX(def->emulator, "qemu"))
+            path = def->emulator;
+        else
+            path = strstr(def->emulator, "qemu");
+        if (path &&
+            STRPREFIX(path, "qemu-system-"))
+            def->os.arch = strdup(path + strlen("qemu-system-"));
+        else
+            def->os.arch = strdup("i686");
+        if (!def->os.arch)
+            goto no_memory;
+    }
+
+    if (STREQ(def->os.arch, "i686")||STREQ(def->os.arch, "x86_64"))
+        def->features = (1 << VIR_DOMAIN_FEATURE_ACPI)
+        /*| (1 << VIR_DOMAIN_FEATURE_APIC)*/;
+
+    def->features &= ~disabled_features;
+
 #undef WANT_VALUE
     if (def->ndisks > 0 && ceph_args) {
         char *hosts, *port, *saveptr = NULL, *token;
-- 
1.7.7.1