From: Hans-Jörg Höxer Subject: SEV-ES guest: lfence near returns in vctrap handler To: Date: Wed, 25 Jun 2025 14:57:29 +0200 Hi, I think we should add lfence to the near returns in the locore0 vctrap handler code. While there, I tweaked a comment, as prompted by mlarkin. Take care, Hans-Joerg ---- commit 25a9ae17c445ba4e4b7383fbb4bccdb61738192c Author: Hans-Joerg Hoexer Date: Wed Jun 25 12:41:42 2025 +0200 SEV-ES guest: lfence near returns in vctrap handler While there, tweak comment. diff --git a/sys/arch/amd64/amd64/locore0.S b/sys/arch/amd64/amd64/locore0.S index ab8d1d1c978..3f79af0d3cc 100644 --- a/sys/arch/amd64/amd64/locore0.S +++ b/sys/arch/amd64/amd64/locore0.S @@ -208,7 +208,8 @@ bi_size_ok: * 2) locore_vc_trap64: Triggered when we are running in * 32-bit compatibility mode. * - * The latter one is used by vmd(8). + * The latter one is used by vmd(8) when direct kernel + * launch is configured. */ movl $RELOC(early_idt), %ecx movl $T_VC, %edx @@ -814,6 +815,7 @@ vc_cpuid64: rep vmmcall rdmsr ret + lfence .globl locore_vc_trap64 locore_vc_trap64: @@ -870,6 +872,7 @@ vc_cpuid32: rep vmmcall rdmsr ret + lfence .globl locore_vc_trap32 locore_vc_trap32: