On 9/20/21 2:23 PM, Kirill A. Shutemov wrote:
On Wed, Sep 08, 2021 at 05:58:36PM -0500, Tom Lendacky wrote:
diff --git a/arch/x86/mm/mem_encrypt_identity.c b/arch/x86/mm/mem_encrypt_identity.c index 470b20208430..eff4d19f9cb4 100644 --- a/arch/x86/mm/mem_encrypt_identity.c +++ b/arch/x86/mm/mem_encrypt_identity.c @@ -30,6 +30,7 @@ #include <linux/kernel.h> #include <linux/mm.h> #include <linux/mem_encrypt.h> +#include <linux/cc_platform.h>
#include <asm/setup.h> #include <asm/sections.h> @@ -287,7 +288,7 @@ void __init sme_encrypt_kernel(struct boot_params *bp) unsigned long pgtable_area_len; unsigned long decrypted_base;
- if (!sme_active())
if (!cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT)) return;
/*
This change break boot for me (in KVM on Intel host). It only reproduces with allyesconfig. More reasonable config works fine, but I didn't try to find exact cause in config.
Looks like instrumentation during early boot. I worked with Boris offline to exclude arch/x86/kernel/cc_platform.c from some of the instrumentation and that allowed an allyesconfig to boot.
Thanks, Tom
Convertion to cc_platform_has() in __startup_64() in 8/8 has the same effect.
I believe it caused by sme_me_mask access from __startup_64() without fixup_pointer() magic. I think __startup_64() requires special treatement and we should avoid cc_platform_has() there (or have a special version of the helper). Note that only AMD requires these cc_platform_has() to return true.