viridian: add a new '_HVMPV_ex_processor_masks' bit into HVM_PARAM_VIRIDIAN...

... and advertise ExProcessorMasks support if it is set.

Support is advertised by setting bit 11 in CPUID:40000004:EAX.

Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Acked-by: Wei Liu <wl@xen.org>

xen/arch/x86/hvm/viridian/viridian.c

@@ -84,6 +84,7 @@ typedef union _HV_CRASH_CTL_REG_CONTENTS
 #define CPUID4A_MSR_BASED_APIC         (1 << 3)
 #define CPUID4A_RELAX_TIMER_INT        (1 << 5)
 #define CPUID4A_SYNTHETIC_CLUSTER_IPI  (1 << 10)
+#define CPUID4A_EX_PROCESSOR_MASKS     (1 << 11)
 
 /* Viridian CPUID leaf 6: Implementation HW features detected and in use */
 #define CPUID6A_APIC_OVERLAY    (1 << 0)
@@ -197,6 +198,8 @@ void cpuid_viridian_leaves(const struct vcpu *v, uint32_t leaf,
             res->a |= CPUID4A_MSR_BASED_APIC;
         if ( viridian_feature_mask(d) & HVMPV_hcall_ipi )
             res->a |= CPUID4A_SYNTHETIC_CLUSTER_IPI;
+        if ( viridian_feature_mask(d) & HVMPV_ex_processor_masks )
+            res->a |= CPUID4A_EX_PROCESSOR_MASKS;
 
         /*
          * This value is the recommended number of attempts to try to

xen/include/public/hvm/params.h

@@ -164,6 +164,10 @@
 #define _HVMPV_hcall_ipi 9
 #define HVMPV_hcall_ipi (1 << _HVMPV_hcall_ipi)
 
+/* Enable ExProcessorMasks */
+#define _HVMPV_ex_processor_masks 10
+#define HVMPV_ex_processor_masks (1 << _HVMPV_ex_processor_masks)
+
 #define HVMPV_feature_mask \
         (HVMPV_base_freq | \
          HVMPV_no_freq | \
@@ -174,7 +178,8 @@
          HVMPV_crash_ctl | \
          HVMPV_synic | \
          HVMPV_stimer | \
-         HVMPV_hcall_ipi)
+         HVMPV_hcall_ipi | \
+         HVMPV_ex_processor_masks)
 
 #endif