vmx: merge MSR management routines

vmx_add_host_load_msr() and vmx_add_guest_msr() share fair amount of code. Merge
them to simplify code maintenance.

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Acked-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Dietmar Hahn <dietmar.hahn@ts.fujitsu.com>
Tested-by: Dietmar Hahn <dietmar.hahn@ts.fujitsu.com>

xen/arch/x86/hvm/vmx/vmcs.c

@@ -1201,64 +1201,62 @@ int vmx_write_guest_msr(u32 msr, u64 val)
     return -ESRCH;
 }
 
-int vmx_add_guest_msr(u32 msr)
+int vmx_add_msr(u32 msr, int type)
 {
     struct vcpu *curr = current;
-    unsigned int i, msr_count = curr->arch.hvm_vmx.msr_count;
-    struct vmx_msr_entry *msr_area = curr->arch.hvm_vmx.msr_area;
+    unsigned int idx, *msr_count;
+    struct vmx_msr_entry **msr_area, *msr_area_elem;
 
-    if ( msr_area == NULL )
+    if ( type == VMX_GUEST_MSR )
     {
-        if ( (msr_area = alloc_xenheap_page()) == NULL )
-            return -ENOMEM;
-        curr->arch.hvm_vmx.msr_area = msr_area;
-        __vmwrite(VM_EXIT_MSR_STORE_ADDR, virt_to_maddr(msr_area));
-        __vmwrite(VM_ENTRY_MSR_LOAD_ADDR, virt_to_maddr(msr_area));
+        msr_count = &curr->arch.hvm_vmx.msr_count;
+        msr_area = &curr->arch.hvm_vmx.msr_area;
+    }
+    else
+    {
+        ASSERT(type == VMX_HOST_MSR);
+        msr_count = &curr->arch.hvm_vmx.host_msr_count;
+        msr_area = &curr->arch.hvm_vmx.host_msr_area;
     }
 
-    for ( i = 0; i < msr_count; i++ )
-        if ( msr_area[i].index == msr )
-            return 0;
-
-    if ( msr_count == (PAGE_SIZE / sizeof(struct vmx_msr_entry)) )
-        return -ENOSPC;
-
-    msr_area[msr_count].index = msr;
-    msr_area[msr_count].mbz   = 0;
-    msr_area[msr_count].data  = 0;
-    curr->arch.hvm_vmx.msr_count = ++msr_count;
-    __vmwrite(VM_EXIT_MSR_STORE_COUNT, msr_count);
-    __vmwrite(VM_ENTRY_MSR_LOAD_COUNT, msr_count);
-
-    return 0;
-}
-
-int vmx_add_host_load_msr(u32 msr)
-{
-    struct vcpu *curr = current;
-    unsigned int i, msr_count = curr->arch.hvm_vmx.host_msr_count;
-    struct vmx_msr_entry *msr_area = curr->arch.hvm_vmx.host_msr_area;
-
-    if ( msr_area == NULL )
+    if ( *msr_area == NULL )
     {
-        if ( (msr_area = alloc_xenheap_page()) == NULL )
+        if ( (*msr_area = alloc_xenheap_page()) == NULL )
             return -ENOMEM;
-        curr->arch.hvm_vmx.host_msr_area = msr_area;
-        __vmwrite(VM_EXIT_MSR_LOAD_ADDR, virt_to_maddr(msr_area));
+
+        if ( type == VMX_GUEST_MSR )
+        {
+            __vmwrite(VM_EXIT_MSR_STORE_ADDR, virt_to_maddr(*msr_area));
+            __vmwrite(VM_ENTRY_MSR_LOAD_ADDR, virt_to_maddr(*msr_area));
+        }
+        else
+            __vmwrite(VM_EXIT_MSR_LOAD_ADDR, virt_to_maddr(*msr_area));
     }
 
-    for ( i = 0; i < msr_count; i++ )
-        if ( msr_area[i].index == msr )
+    for ( idx = 0; idx < *msr_count; idx++ )
+        if ( (*msr_area)[idx].index == msr )
             return 0;
 
-    if ( msr_count == (PAGE_SIZE / sizeof(struct vmx_msr_entry)) )
+    if ( *msr_count == (PAGE_SIZE / sizeof(struct vmx_msr_entry)) )
         return -ENOSPC;
 
-    msr_area[msr_count].index = msr;
-    msr_area[msr_count].mbz   = 0;
-    rdmsrl(msr, msr_area[msr_count].data);
-    curr->arch.hvm_vmx.host_msr_count = ++msr_count;
-    __vmwrite(VM_EXIT_MSR_LOAD_COUNT, msr_count);
+    msr_area_elem = *msr_area + *msr_count;
+    msr_area_elem->index = msr;
+    msr_area_elem->mbz = 0;
+
+    ++*msr_count;
+
+    if ( type == VMX_GUEST_MSR )
+    {
+        msr_area_elem->data = 0;
+        __vmwrite(VM_EXIT_MSR_STORE_COUNT, *msr_count);
+        __vmwrite(VM_ENTRY_MSR_LOAD_COUNT, *msr_count);
+    }
+    else
+    {
+        rdmsrl(msr, msr_area_elem->data);
+        __vmwrite(VM_EXIT_MSR_LOAD_COUNT, *msr_count);
+    }
 
     return 0;
 }

xen/include/asm-x86/hvm/vmx/vmcs.h

@@ -456,12 +456,15 @@ extern const unsigned int vmx_introspection_force_enabled_msrs_size;
 
 #define MSR_TYPE_R 1
 #define MSR_TYPE_W 2
+
+#define VMX_GUEST_MSR 0
+#define VMX_HOST_MSR  1
+
 void vmx_disable_intercept_for_msr(struct vcpu *v, u32 msr, int type);
 void vmx_enable_intercept_for_msr(struct vcpu *v, u32 msr, int type);
 int vmx_read_guest_msr(u32 msr, u64 *val);
 int vmx_write_guest_msr(u32 msr, u64 val);
-int vmx_add_guest_msr(u32 msr);
-int vmx_add_host_load_msr(u32 msr);
+int vmx_add_msr(u32 msr, int type);
 void vmx_vmcs_switch(struct vmcs_struct *from, struct vmcs_struct *to);
 void vmx_set_eoi_exit_bitmap(struct vcpu *v, u8 vector);
 void vmx_clear_eoi_exit_bitmap(struct vcpu *v, u8 vector);
@@ -471,6 +474,15 @@ void virtual_vmcs_exit(void *vvmcs);
 u64 virtual_vmcs_vmread(void *vvmcs, u32 vmcs_encoding);
 void virtual_vmcs_vmwrite(void *vvmcs, u32 vmcs_encoding, u64 val);
 
+static inline int vmx_add_guest_msr(u32 msr)
+{
+    return vmx_add_msr(msr, VMX_GUEST_MSR);
+}
+static inline int vmx_add_host_load_msr(u32 msr)
+{
+    return vmx_add_msr(msr, VMX_HOST_MSR);
+}
+
 DECLARE_PER_CPU(bool_t, vmxon);
 
 #endif /* ASM_X86_HVM_VMX_VMCS_H__ */