From 6e9de3f3fa020b351960f4f528f175aa802eb536 Mon Sep 17 00:00:00 2001 From: Eduardo Habkost Date: Wed, 26 Sep 2018 18:50:59 +0200 Subject: [PATCH] target-i386: cpu: Add downstream-only STIBP CPUID flag RH-Author: Eduardo Habkost Message-id: <20180926185059.20691-1-ehabkost@redhat.com> Patchwork-id: 82301 O-Subject: [RHEL-7.6 qemu-kvm-rhev PATCH] target-i386: cpu: Add downstream-only STIBP CPUID flag Bugzilla: 1638077 RH-Acked-by: Dr. David Alan Gilbert RH-Acked-by: Kashyap Chamarthy RH-Acked-by: Igor Mammedov From: Paolo Bonzini We accidentally dropped the downstream-only STIBP CPUID flag during the 2.12.0 rebase. STIBP is a CPUID flag that was considered for the Spectre (CVE-2017-5715) mitigations, but in the end it was not necessary: spec-ctrl/IBRS was deemed enough. The kernel KVM STIBP CPUID code was never merged upstream, but it's present on RHEL-7. This means we may have existing VMs created on RHEL-7.5 hosts with the STIBP flag enabled, and we need to support live-migration of those VMs to RHEL-7.6. Signed-off-by: Eduardo Habkost Signed-off-by: Miroslav Rezanina --- target/i386/cpu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 6b5acdf..91f5a97 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -1007,7 +1007,7 @@ static FeatureWordInfo feature_word_info[FEATURE_WORDS] = { NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, - NULL, NULL, "spec-ctrl", NULL, + NULL, NULL, "spec-ctrl", "stibp", NULL, NULL, NULL, "ssbd", }, .cpuid_eax = 7, -- 1.8.3.1