[PATCH v7 28/45] KVM: x86: move lookup of indexed CPUID leafs to helper

Brijesh Singh
2021-11-10T22:09:24Z

From: Michael Roth <michael.roth@amd.com>

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>
---
arch/x86/include/asm/cpuid.h | 26 ++++++++++++++++++++++++++
arch/x86/kvm/cpuid.c | 17 ++---------------
2 files changed, 28 insertions(+), 15 deletions(-)
create mode 100644 arch/x86/include/asm/cpuid.h

diff --git a/arch/x86/include/asm/cpuid.h b/arch/x86/include/asm/cpuid.h
new file mode 100644
index 000000000000..61426eb1f665
--- /dev/null
+++ b/arch/x86/include/asm/cpuid.h
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#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 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 751aa85a3001..312b0382e541 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"
@@ -582,22 +583,8 @@ 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 0x1f:
- case 0x8000001d:
+ if (cpuid_function_is_indexed(function))
entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
- break;
- }

return entry;
}
--
2.25.1