Re: [PATCH 07/11] treewide: Replace the use of mem_encrypt_active() with prot_guest_has()

From: Kuppuswamy, Sathyanarayanan
Date: Tue Aug 10 2021 - 14:45:15 EST




On 7/27/21 3:26 PM, Tom Lendacky wrote:
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index de01903c3735..cafed6456d45 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -19,7 +19,7 @@
#include <linux/start_kernel.h>
#include <linux/io.h>
#include <linux/memblock.h>
-#include <linux/mem_encrypt.h>
+#include <linux/protected_guest.h>
#include <linux/pgtable.h>
#include <asm/processor.h>
@@ -285,7 +285,7 @@ unsigned long __head __startup_64(unsigned long physaddr,
* there is no need to zero it after changing the memory encryption
* attribute.
*/
- if (mem_encrypt_active()) {
+ if (prot_guest_has(PATTR_MEM_ENCRYPT)) {
vaddr = (unsigned long)__start_bss_decrypted;
vaddr_end = (unsigned long)__end_bss_decrypted;


Since this change is specific to AMD, can you replace PATTR_MEM_ENCRYPT with
prot_guest_has(PATTR_SME) || prot_guest_has(PATTR_SEV). It is not used in
TDX.

--
Sathyanarayanan Kuppuswamy
Linux Kernel Developer