[PATCH v9 2/3] 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>
Reviewed-off-by: Jan Beulich <jbeulich@suse.com>
---
 xen/arch/x86/hvm/hvm.c              |    9 +++++++++
 xen/arch/x86/traps.c                |    4 ++++
 xen/include/asm-x86/hvm/hvm.h       |    7 +++++++
 xen/include/public/arch-x86/cpuid.h |    7 ++++++-
 4 files changed, 26 insertions(+), 1 deletions(-)

diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index ae7a645..16b968c 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -2983,6 +2983,15 @@ 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 sub_idx,
+                               uint32_t *eax, uint32_t *ebx,
+                               uint32_t *ecx, uint32_t *edx)
+{
+    *eax = *ebx = *ecx = *edx = 0;
+    if ( hvm_funcs.hypervisor_cpuid_leaf )
+        hvm_funcs.hypervisor_cpuid_leaf(sub_idx, eax, ebx, ecx, edx);
+}
+
 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 48d722d..dfced11 100644
--- a/xen/arch/x86/traps.c
+++ b/xen/arch/x86/traps.c
@@ -726,6 +726,10 @@ 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(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..a030ea4 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 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 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);
diff --git a/xen/include/public/arch-x86/cpuid.h b/xen/include/public/arch-x86/cpuid.h
index 19fc9dd..fff972a 100644
--- a/xen/include/public/arch-x86/cpuid.h
+++ b/xen/include/public/arch-x86/cpuid.h
@@ -65,6 +65,11 @@
 #define _XEN_CPUID_FEAT1_MMU_PT_UPDATE_PRESERVE_AD 0
 #define XEN_CPUID_FEAT1_MMU_PT_UPDATE_PRESERVE_AD  (1u<<0)
 
-#define XEN_CPUID_MAX_NUM_LEAVES 3
+/*
+ * Leaf 5 (0x40000004)
+ * HVM-specific features
+ */
+
+#define XEN_CPUID_MAX_NUM_LEAVES 4
 
 #endif /* __XEN_PUBLIC_ARCH_X86_CPUID_H__ */
-- 
1.7.1