From 0ff7f9c5aa02cd2469a8fc03f1ed262f18933721 Mon Sep 17 00:00:00 2001 From: Andrew Cooper Date: Thu, 20 May 2021 01:21:39 +0100 Subject: [PATCH] x86/spec-ctrl: Mitigate TAA after S3 resume The user chosen setting for MSR_TSX_CTRL needs restoring after S3. All APs get the correct setting via start_secondary(), but the BSP was missed out. This is XSA-377 / CVE-2021-28690. Fixes: 8c4330818f6 ("x86/spec-ctrl: Mitigate the TSX Asynchronous Abort sidechannel") Signed-off-by: Andrew Cooper Reviewed-by: Jan Beulich (cherry picked from commit 8cf276cb2e0b99b96333865873f56b0b31555ff1) --- xen/arch/x86/acpi/power.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/xen/arch/x86/acpi/power.c b/xen/arch/x86/acpi/power.c index 7f162a4df9..604cb7e222 100644 --- a/xen/arch/x86/acpi/power.c +++ b/xen/arch/x86/acpi/power.c @@ -286,6 +286,8 @@ static int enter_state(u32 state) microcode_update_one(); + tsx_init(); /* Needs microcode. May change HLE/RTM feature bits. */ + if ( !recheck_cpu_features(0) ) panic("Missing previously available feature(s)\n"); -- 2.30.2