[libvirt] [PATCH v3 2/7] cpu: add function to get the models for an arch

[Giuseppe Scrivano]

Eric Blake <eblake at redhat.com> writes:

> NACK, needs a v4; this is where we need to fix things to do the right
> subdriver mapping. Quoting IRC:
>
> and I know which one to change
> [15:30]	jdenemar	eblake: cpu-models should work for both x86 and x86_64 imho
> [15:31]	eblake	yep - where the map file lists x86, we need the
> cpu-models to support it for both i686 and x86_64
> [15:32]	jdenemar	yeah, the x86 in cpu_map.xml is actually a cpu driver
> name and the driver has a list of archs it supports
> [15:34]	eblake	jdenemar: giuseppe_s used cpuMapLoad(arch, ...) - which
> is only doing a literal string match
> [15:34]	eblake	so where do we reverse map the driver names in the map
> file into actual arch names?
> [15:35]	eblake	or, where SHOULD we be doing that mapping?
> [15:38]	jdenemar	every cpu api in cpu.c calls cpuGetSubDriver to get the
> driver from a real arch
> [15:41]	jdenemar	so there should be a high level cpu api that takes a
> real arch and gives model names, that should look up the appropriate sub
> driver, call its api and it should load its section of cpu_map.xml and
> return the list

Jiri, would something like this suffice or am I missing some other
details?

Thanks,
Giuseppe


+int
+cpuGetModels(const char *archName, char ***models)
+{
+    struct cpuGetModelsData data;
+    virArch arch;
+    struct cpuArchDriver *driver;
+    data.data = NULL;
+    data.len = 1;
+
+    arch = virArchFromString(archName);
+    if (arch == VIR_ARCH_NONE) {
+        virReportError(VIR_ERR_INVALID_ARG,
+                       _("cannot find architecture %s"),
+                       archName);
+        goto error;
+    }
+
+    driver = cpuGetSubDriver(arch);
+    if (driver == NULL) {
+        virReportError(VIR_ERR_INVALID_ARG,
+                       _("cannot find a driver for the architecture %s"),
+                       archName);
+        goto error;
+    }
+
+    if (models && VIR_ALLOC_N(data.data, data.len) < 0)
+        goto error;
+
+    if (cpuGetArchModels(driver->name, &data) < 0)
+        goto error;
+
+    if (models)
+        *models = data.data;
+
+    return data.len - 1;
+
+error:
+    virStringFreeList(data.data);
+    return -1;
+}