Re: [Qemu-devel] [PATCH v7 4/4] arm: implement query-gic-capabilities

[Sergey Fedorov <serge.fdrv@gmail.com>]

On 24/03/16 05:55, Peter Xu wrote:
> For emulated GIC capabilities, currently only gicv2 is supported. We
> need to add gicv3 in when emulated gicv3 ready. For KVM accelerated ARM
> VM, we detect the capability bits by creating a scratch VM.
>
> Signed-off-by: Peter Xu <peterx@redhat.com>

Acked-by: Sergey Fedorov <serge.fdrv@gmail.com>

Kind regards,
Sergey


> ---
>  target-arm/monitor.c | 58 +++++++++++++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 57 insertions(+), 1 deletion(-)
>
> diff --git a/target-arm/monitor.c b/target-arm/monitor.c
> index 4c9bef3..1ee59a2 100644
> --- a/target-arm/monitor.c
> +++ b/target-arm/monitor.c
> @@ -21,8 +21,64 @@
>   */
>  #include "qemu/osdep.h"
>  #include "qmp-commands.h"
> +#include "hw/boards.h"
> +#include "kvm_arm.h"
> +
> +static GICCapability *gic_cap_new(int version)
> +{
> +    GICCapability *cap = g_new0(GICCapability, 1);
> +    cap->version = version;
> +    /* by default, support none */
> +    cap->emulated = false;
> +    cap->kernel = false;
> +    return cap;
> +}
> +
> +static GICCapabilityList *gic_cap_list_add(GICCapabilityList *head,
> +                                           GICCapability *cap)
> +{
> +    GICCapabilityList *item = g_new0(GICCapabilityList, 1);
> +    item->value = cap;
> +    item->next = head;
> +    return item;
> +}
> +
> +static inline void gic_cap_kvm_probe(GICCapability *v2, GICCapability *v3)
> +{
> +#ifdef CONFIG_KVM
> +    int fdarray[3];
> +
> +    if (!kvm_arm_create_scratch_host_vcpu(NULL, fdarray, NULL)) {
> +        return;
> +    }
> +
> +    /* Test KVM GICv2 */
> +    if (kvm_device_supported(fdarray[1], KVM_DEV_TYPE_ARM_VGIC_V2)) {
> +        v2->kernel = true;
> +    }
> +
> +    /* Test KVM GICv3 */
> +    if (kvm_device_supported(fdarray[1], KVM_DEV_TYPE_ARM_VGIC_V3)) {
> +        v3->kernel = true;
> +    }
> +
> +    kvm_arm_destroy_scratch_host_vcpu(fdarray);
> +#endif
> +}
>  
>  GICCapabilityList *qmp_query_gic_capabilities(Error **errp)
>  {
> -    return NULL;
> +    GICCapabilityList *head = NULL;
> +    GICCapability *v2 = gic_cap_new(2), *v3 = gic_cap_new(3);
> +
> +    v2->emulated = true;
> +    /* TODO: we'd change to true after we get emulated GICv3. */
> +    v3->emulated = false;
> +
> +    gic_cap_kvm_probe(v2, v3);
> +
> +    head = gic_cap_list_add(head, v2);
> +    head = gic_cap_list_add(head, v3);
> +
> +    return head;
>  }