KVM: x86: Move lookup of indexed CPUID leafs to helper

Determining which CPUID leafs have significant ECX/index values is
also needed by guest kernel code when doing SEV-SNP-validated CPUID
lookups. Move this to common code to keep future updates in sync.

Signed-off-by: Michael Roth <michael.roth@amd.com>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Venu Busireddy <venu.busireddy@oracle.com>
Link: https://lore.kernel.org/r/20220307213356.2797205-31-brijesh.singh@amd.com

diff --git a/arch/x86/include/asm/cpuid.h b/arch/x86/include/asm/cpuid.h
new file mode 100644 (file)
index 0000000..70b2db1
--- /dev/null
+++ b/arch/x86/include/asm/cpuid.h
@@ -0,0 +1,34 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * CPUID-related helpers/definitions
+ *
+ * Derived from arch/x86/kvm/cpuid.c
+ */
+
+#ifndef _ASM_X86_CPUID_H
+#define _ASM_X86_CPUID_H
+
+static __always_inline bool cpuid_function_is_indexed(u32 function)
+{
+       switch (function) {
+       case 4:
+       case 7:
+       case 0xb:
+       case 0xd:
+       case 0xf:
+       case 0x10:
+       case 0x12:
+       case 0x14:
+       case 0x17:
+       case 0x18:
+       case 0x1d:
+       case 0x1e:
+       case 0x1f:
+       case 0x8000001d:
+               return true;
+       }
+
+       return false;
+}
+
+#endif /* _ASM_X86_CPUID_H */

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index b24ca7f..4b62d80 100644 (file)
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -19,6 +19,7 @@
 #include <asm/user.h>
 #include <asm/fpu/xstate.h>
 #include <asm/sgx.h>
+#include <asm/cpuid.h>
 #include "cpuid.h"
 #include "lapic.h"
 #include "mmu.h"
@@ -744,24 +745,8 @@ static struct kvm_cpuid_entry2 *do_host_cpuid(struct kvm_cpuid_array *array,
        cpuid_count(entry->function, entry->index,
                    &entry->eax, &entry->ebx, &entry->ecx, &entry->edx);
 
-       switch (function) {
-       case 4:
-       case 7:
-       case 0xb:
-       case 0xd:
-       case 0xf:
-       case 0x10:
-       case 0x12:
-       case 0x14:
-       case 0x17:
-       case 0x18:
-       case 0x1d:
-       case 0x1e:
-       case 0x1f:
-       case 0x8000001d:
+       if (cpuid_function_is_indexed(function))
                entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
-               break;
-       }
 
        return entry;
 }