[v10,30/45] KVM: x86: Move lookup of indexed CPUID leafs to helper

Commit Message

Brijesh Singh Feb. 9, 2022, 6:10 p.m. UTC

From: Michael Roth <[e-mail]>

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.

Reviewed-by: Venu Busireddy <[e-mail]>
Signed-off-by: Michael Roth <[e-mail]>
Signed-off-by: Brijesh Singh <[e-mail]>
---
 arch/x86/include/asm/cpuid.h | 34 ++++++++++++++++++++++++++++++++++
 arch/x86/kvm/cpuid.c         | 19 ++-----------------
 2 files changed, 36 insertions(+), 17 deletions(-)
 create mode 100644 arch/x86/include/asm/cpuid.h

Patch

diff --git a/arch/x86/include/asm/cpuid.h b/arch/x86/include/asm/cpuid.h
new file mode 100644
index 000000000000..70b2db18165e
--- /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 868fc9526e5a..18a20434759b 100644
--- 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"
@@ -719,24 +720,8 @@  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;
 }