Re: [libvirt] [Qemu-devel] [PATCH 6/7] target-i386: add implementation of query-cpudefs
Eduardo Habkost <ehabkost(a)redhat.com> writes:
On Fri, Jul 27, 2012 at 08:37:18AM -0500, Anthony Liguori wrote:
> Signed-off-by: Anthony Liguori <aliguori(a)us.ibm.com>
> ---
> target-i386/cpu.c | 22 ++++++++++++++++++++++
> 1 files changed, 22 insertions(+), 0 deletions(-)
>
> diff --git a/target-i386/cpu.c b/target-i386/cpu.c
> index 6b9659f..b398439 100644
> --- a/target-i386/cpu.c
> +++ b/target-i386/cpu.c
> @@ -28,6 +28,7 @@
> #include "qemu-config.h"
>
> #include "qapi/qapi-visit-core.h"
> +#include "qmp-commands.h"
>
> #include "hyperv.h"
>
> @@ -1123,6 +1124,27 @@ void x86_cpu_list(FILE *f, fprintf_function cpu_fprintf, const
char *optarg)
> }
> }
>
> +CpuDefInfoList *qmp_query_cpudefs(Error **errp)
> +{
> + CpuDefInfoList *cpu_list = NULL;
> + x86_def_t *def;
> +
> + for (def = x86_defs; def; def = def->next) {
> + CpuDefInfoList *entry;
> + CpuDefInfo *info;
> +
> + info = g_malloc0(sizeof(*info));
> + info->name = g_strdup(def->name);
> +
> + entry = g_malloc0(sizeof(*entry));
> + entry->value = info;
> + entry->next = cpu_list;
> + cpu_list = entry;
> + }
> +
> + return cpu_list;
> +}
How would the interface look like once we:
- let libvirt know which features are available on each CPU model
(libvirt needs that information[1]); and
I'm not sure I understand why libvirt needs this information. Can you elaborate?
- add machine-type-specific cpudef compatibility changes?
I think we've discussed this in IRC. I don't think we need to worry
about this.
Would the command report different results depending on -machine?
No.
Would the command return the latest cpudef without any machine-type
hacks, and libvirt would have to query for the cpudef compatibility data
for each machine-type and combine both pieces of information itself?
I'm not sure what you mean by compatibility data.
Regards,
Anthony Liguori
[1] Note that it doesn't have to be low-level leaf-by-leaf
register-by-register CPUID bits (I prefer a more high-level
interface, myself), but it has to at least say "feature FOO is
enabled/disabled" for a set of features libvirt cares about.
--
Eduardo