[PATCH v2 3/4] x86/hvm: Add HVM-specific hypervisor CPUID leaf

[Boris Ostrovsky <boris.ostrovsky@oracle.com>]

CPUID leaf 0x40000004 is for HVM-specific features.

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
---
 xen/arch/x86/hvm/hvm.c        |   16 ++++++++++++++++
 xen/arch/x86/traps.c          |    8 ++++++--
 xen/include/asm-x86/hvm/hvm.h |    7 +++++++
 3 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index ae24211..fcbdcfc 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -2980,6 +2980,22 @@ unsigned long copy_from_user_hvm(void *to, const void *from, unsigned len)
     return rc ? len : 0; /* fake a copy_from_user() return code */
 }
 
+void hvm_hypervisor_cpuid_leaf(uint32_t idx, uint32_t sub_idx,
+                               uint32_t *eax, uint32_t *ebx,
+                               uint32_t *ecx, uint32_t *edx)
+{
+    if ( idx != 4 )
+        return;
+
+    *eax = *ebx = *ecx = *edx = 0;
+    if ( !hvm_funcs.hypervisor_cpuid_leaf )
+            return;
+
+    hvm_funcs.hypervisor_cpuid_leaf(idx, sub_idx, eax, ebx, ecx, edx);
+
+    return;
+}
+
 void hvm_cpuid(unsigned int input, unsigned int *eax, unsigned int *ebx,
                                    unsigned int *ecx, unsigned int *edx)
 {
diff --git a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c
index 75a0ceb..88956b8 100644
--- a/xen/arch/x86/traps.c
+++ b/xen/arch/x86/traps.c
@@ -680,7 +680,7 @@ int cpuid_hypervisor_leaves( uint32_t idx, uint32_t sub_idx,
 
     idx -= base;
 
-    if ( idx > 3 ) 
+    if ( idx > 4 ) 
         return 0;
 
     if ( domain_cpuid_exists(d, base + idx, sub_idx, eax, ebx, ecx, edx) )
@@ -689,7 +689,7 @@ int cpuid_hypervisor_leaves( uint32_t idx, uint32_t sub_idx,
     switch ( idx )
     {
     case 0:
-        *eax = base + 3; /* Largest leaf */
+        *eax = base + 4; /* Largest leaf */
         *ebx = XEN_CPUID_SIGNATURE_EBX;
         *ecx = XEN_CPUID_SIGNATURE_ECX;
         *edx = XEN_CPUID_SIGNATURE_EDX;
@@ -718,6 +718,10 @@ int cpuid_hypervisor_leaves( uint32_t idx, uint32_t sub_idx,
         cpuid_time_leaf( sub_idx, eax, ebx, ecx, edx );
         break;
 
+    case 4:
+        hvm_hypervisor_cpuid_leaf(idx, sub_idx, eax, ebx, ecx, edx);
+        break;
+
     default:
         BUG();
     }
diff --git a/xen/include/asm-x86/hvm/hvm.h b/xen/include/asm-x86/hvm/hvm.h
index dcc3483..e6b1399 100644
--- a/xen/include/asm-x86/hvm/hvm.h
+++ b/xen/include/asm-x86/hvm/hvm.h
@@ -200,6 +200,10 @@ struct hvm_function_table {
                                 paddr_t *L1_gpa, unsigned int *page_order,
                                 uint8_t *p2m_acc, bool_t access_r,
                                 bool_t access_w, bool_t access_x);
+
+    void (*hypervisor_cpuid_leaf)(uint32_t idx, uint32_t sub_idx,
+                                  uint32_t *eax, uint32_t *ebx,
+                                  uint32_t *ecx, uint32_t *edx);
 };
 
 extern struct hvm_function_table hvm_funcs;
@@ -336,6 +340,9 @@ static inline unsigned long hvm_get_shadow_gs_base(struct vcpu *v)
 #define is_viridian_domain(_d)                                             \
  (is_hvm_domain(_d) && ((_d)->arch.hvm_domain.params[HVM_PARAM_VIRIDIAN]))
 
+void hvm_hypervisor_cpuid_leaf(uint32_t idx, uint32_t sub_idx,
+                               uint32_t *eax, uint32_t *ebx,
+                               uint32_t *ecx, uint32_t *edx);
 void hvm_cpuid(unsigned int input, unsigned int *eax, unsigned int *ebx,
                                    unsigned int *ecx, unsigned int *edx);
 void hvm_migrate_timers(struct vcpu *v);
-- 
1.7.10.4