From 72dafb567760320f2de7447cd6e979bf9d4e5d17 Mon Sep 17 00:00:00 2001 From: Kevin Loughlin Date: Fri, 22 Nov 2024 20:23:22 +0000 Subject: [PATCH 1/2] x86/sev: Add missing RIP_REL_REF() invocations during sme_enable() The following commit: 1c811d403afd ("x86/sev: Fix position dependent variable references in startup code") introduced RIP_REL_REF() to force RIP-relative accesses to global variables, as needed to prevent crashes during early SEV/SME startup code. For completeness, RIP_REL_REF() should be used with additional variables during sme_enable(): https://lore.kernel.org/all/CAMj1kXHnA0fJu6zh634=fbJswp59kSRAbhW+ubDGj1+NYwZJ-Q@mail.gmail.com/ Access these vars with RIP_REL_REF() to prevent problem reoccurence. Fixes: 1c811d403afd ("x86/sev: Fix position dependent variable references in startup code") Signed-off-by: Kevin Loughlin Signed-off-by: Ingo Molnar Reviewed-by: Ard Biesheuvel Reviewed-by: Tom Lendacky Cc: Dave Hansen Link: https://lore.kernel.org/r/20241122202322.977678-1-kevinloughlin@google.com --- arch/x86/mm/mem_encrypt_identity.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/mm/mem_encrypt_identity.c b/arch/x86/mm/mem_encrypt_identity.c index e6c7686f443a0..9fce5b87b8c50 100644 --- a/arch/x86/mm/mem_encrypt_identity.c +++ b/arch/x86/mm/mem_encrypt_identity.c @@ -565,7 +565,7 @@ void __head sme_enable(struct boot_params *bp) } RIP_REL_REF(sme_me_mask) = me_mask; - physical_mask &= ~me_mask; - cc_vendor = CC_VENDOR_AMD; + RIP_REL_REF(physical_mask) &= ~me_mask; + RIP_REL_REF(cc_vendor) = CC_VENDOR_AMD; cc_set_mask(me_mask); } From f0373cc0907ca7918266a507d6b3b5d75ee839ba Mon Sep 17 00:00:00 2001 From: Peng Hao Date: Fri, 14 Mar 2025 20:19:53 +0800 Subject: [PATCH 2/2] x86/sev: Simplify the code by removing unnecessary 'else' statement No need for an 'else' statement after a 'return'. [ mingo: Clarified the changelog ] Signed-off-by: Peng Hao Signed-off-by: Ingo Molnar Cc: linux-kernel@vger.kernel.org --- arch/x86/coco/sev/core.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/arch/x86/coco/sev/core.c b/arch/x86/coco/sev/core.c index 82492efc5d949..4e8b8002d48b1 100644 --- a/arch/x86/coco/sev/core.c +++ b/arch/x86/coco/sev/core.c @@ -1482,8 +1482,7 @@ static enum es_result vc_handle_msr(struct ghcb *ghcb, struct es_em_ctxt *ctxt) case MSR_AMD64_GUEST_TSC_FREQ: if (sev_status & MSR_AMD64_SNP_SECURE_TSC) return __vc_handle_secure_tsc_msrs(regs, write); - else - break; + break; default: break; }