[Xen-devel] [PATCH 07/10] x86/cpuid: Handle leaf 0xa in guest_cpuid()

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

Leaf 0xa is reserved by AMD, and only exposed to Intel guests when vPMU is
enabled.  Leave the logic as-was, ready to be cleaned up when further
toolstack infrastructure is in place.

Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
CC: Jan Beulich <JBeulich@xxxxxxxx>
---
 xen/arch/x86/cpuid.c | 43 ++++++++++++++++---------------------------
 1 file changed, 16 insertions(+), 27 deletions(-)

diff --git a/xen/arch/x86/cpuid.c b/xen/arch/x86/cpuid.c
index 2a5e011..c8dadab 100644
--- a/xen/arch/x86/cpuid.c
+++ b/xen/arch/x86/cpuid.c
@@ -208,7 +208,7 @@ static void recalculate_misc(struct cpuid_policy *p)
 
         zero_leaves(p->basic.raw, 0x2, 0x3);
         memset(p->cache.raw, 0, sizeof(p->cache.raw));
-        p->basic.raw[0x9] = EMPTY_LEAF;
+        zero_leaves(p->basic.raw, 0x9, 0xa);
 
         p->extd.vendor_ebx = p->basic.vendor_ebx;
         p->extd.vendor_ecx = p->basic.vendor_ecx;
@@ -634,22 +634,11 @@ static void pv_cpuid(uint32_t leaf, uint32_t subleaf, 
struct cpuid_leaf *res)
 
     switch ( leaf )
     {
-    case 0x0000000a: /* Architectural Performance Monitor Features (Intel) */
-        if ( boot_cpu_data.x86_vendor != X86_VENDOR_INTEL ||
-             !vpmu_enabled(curr) )
-            goto unsupported;
-
-        /* Report at most version 3 since that's all we currently emulate. */
-        if ( (res->a & 0xff) > 3 )
-            res->a = (res->a & ~0xff) | 3;
-        break;
-
     case 0x0000000b: /* Extended Topology Enumeration */
-    unsupported:
         *res = EMPTY_LEAF;
         break;
 
-    case 0x0 ... 0x9:
+    case 0x0 ... 0xa:
     case 0xc ... XSTATE_CPUID:
     case 0x80000000 ... 0xffffffff:
         ASSERT_UNREACHABLE();
@@ -671,19 +660,7 @@ static void hvm_cpuid(uint32_t leaf, uint32_t subleaf, 
struct cpuid_leaf *res)
         res->d = v->vcpu_id * 2;
         break;
 
-    case 0x0000000a: /* Architectural Performance Monitor Features (Intel) */
-        if ( boot_cpu_data.x86_vendor != X86_VENDOR_INTEL || !vpmu_enabled(v) )
-        {
-            *res = EMPTY_LEAF;
-            break;
-        }
-
-        /* Report at most version 3 since that's all we currently emulate */
-        if ( (res->a & 0xff) > 3 )
-            res->a = (res->a & ~0xff) | 3;
-        break;
-
-    case 0x0 ... 0x9:
+    case 0x0 ... 0xa:
     case 0xc ... XSTATE_CPUID:
     case 0x80000000 ... 0xffffffff:
         ASSERT_UNREACHABLE();
@@ -744,7 +721,7 @@ void guest_cpuid(const struct vcpu *v, uint32_t leaf,
 
         case 0x0 ... 0x3:
         case 0x5 ... 0x6:
-        case 0x8 ... 0x9:
+        case 0x8 ... 0xa:
         case 0xc:
             *res = p->basic.raw[leaf];
             break;
@@ -970,6 +947,18 @@ void guest_cpuid(const struct vcpu *v, uint32_t leaf,
         }
         break;
 
+    case 0xa:
+        /* TODO: Rework vPMU control in terms of toolstack choices. */
+        if ( boot_cpu_data.x86_vendor != X86_VENDOR_INTEL || !vpmu_enabled(v) )
+            *res = EMPTY_LEAF;
+        else
+        {
+            /* Report at most v3 since that's all we currently emulate. */
+            if ( (res->a & 0xff) > 3 )
+                res->a = (res->a & ~0xff) | 3;
+        }
+        break;
+
     case XSTATE_CPUID:
         switch ( subleaf )
         {
-- 
2.1.4


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