On Wed, 2 Sep 2015 11:19:11 -0300
Eduardo Habkost <ehabk...@redhat.com> wrote:
> The host cache information may not make sense for the guest if the VM
> CPU topology doesn't match the host CPU topology. To make sure we won't
> expose broken cache information to the guest, disable cache info
> passthrough by default, and add a new "host-cache-info" property that
> can be used to enable the old behavior for users that really need it.
>
> Cc: Benoît Canet <ben...@irqsave.net>
> Signed-off-by: Eduardo Habkost <ehabk...@redhat.com>
Reviewed-by: Igor Mammedov <imamm...@redhat.com>
> ---
> Changes v1 -> v2:
> * Rebased on top of:
> Subject: [PATCH 0/3] pc-*-2.5 machine-types
> * Added host-cache-info=on to PC_COMPAT_2_4 to keep compatibility
> on migration
> Reported-by: Igor Mammedov <imamm...@redhat.com>
> ---
> include/hw/i386/pc.h | 7 ++++++-
> target-i386/cpu.c | 4 +---
> 2 files changed, 7 insertions(+), 4 deletions(-)
>
> diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
> index 21c1cff..d41b901 100644
> --- a/include/hw/i386/pc.h
> +++ b/include/hw/i386/pc.h
> @@ -285,7 +285,12 @@ int e820_get_num_entries(void);
> bool e820_get_entry(int, uint32_t, uint64_t *, uint64_t *);
>
> #define PC_COMPAT_2_4 \
> - HW_COMPAT_2_4
> + HW_COMPAT_2_4 \
> + {\
> + .driver = "host" "-" TYPE_X86_CPU,\
> + .property = "host-cache-info",\
> + .value = "on",\
> + },
>
> #define PC_COMPAT_2_3 \
> PC_COMPAT_2_4 \
> diff --git a/target-i386/cpu.c b/target-i386/cpu.c
> index 32fee00..152ced2 100644
> --- a/target-i386/cpu.c
> +++ b/target-i386/cpu.c
> @@ -689,7 +689,6 @@ struct X86CPUDefinition {
> int stepping;
> FeatureWordArray features;
> char model_id[48];
> - bool cache_info_passthrough;
> };
>
> static X86CPUDefinition builtin_x86_defs[] = {
> @@ -1416,6 +1415,7 @@ static X86CPUDefinition host_cpudef;
>
> static Property host_x86_cpu_properties[] = {
> DEFINE_PROP_BOOL("migratable", X86CPU, migratable, true),
> + DEFINE_PROP_BOOL("host-cache-info", X86CPU, cache_info_passthrough,
> false),
> DEFINE_PROP_END_OF_LIST()
> };
>
> @@ -1442,7 +1442,6 @@ static void host_x86_cpu_class_init(ObjectClass *oc,
> void *data)
> cpu_x86_fill_model_id(host_cpudef.model_id);
>
> xcc->cpu_def = &host_cpudef;
> - host_cpudef.cache_info_passthrough = true;
>
> /* level, xlevel, xlevel2, and the feature words are initialized on
> * instance_init, because they require KVM to be initialized.
> @@ -2076,7 +2075,6 @@ static void x86_cpu_load_def(X86CPU *cpu,
> X86CPUDefinition *def, Error **errp)
> object_property_set_int(OBJECT(cpu), def->stepping, "stepping", errp);
> object_property_set_int(OBJECT(cpu), def->xlevel, "xlevel", errp);
> object_property_set_int(OBJECT(cpu), def->xlevel2, "xlevel2", errp);
> - cpu->cache_info_passthrough = def->cache_info_passthrough;
> object_property_set_str(OBJECT(cpu), def->model_id, "model-id", errp);
> for (w = 0; w < FEATURE_WORDS; w++) {
> env->features[w] = def->features[w];
