i386: define the AMD 'virt-ssbd' CPUID feature bit (CVE-2018-3639)

AMD Zen expose the Intel equivalant to Speculative Store Bypass Disable
via the 0x80000008_EBX[25] CPUID feature bit.

This needs to be exposed to guest OS to allow them to protect
against CVE-2018-3639.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20180521215424.13520-3-berrange@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
(cherry picked from commit 403503b162ffc33fb64cfefdf7b880acf41772cd)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>

diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 2f5263e22f01f201a654c7c081e3e320622e30f8..2e305ab6890d8c36d6472e981ab1a0d1f65de6e6 100644 (file)
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -541,7 +541,7 @@ static FeatureWordInfo feature_word_info[FEATURE_WORDS] = {
             "ibpb", NULL, NULL, NULL,
             NULL, NULL, NULL, NULL,
             NULL, NULL, NULL, NULL,
-            NULL, NULL, NULL, NULL,
+            NULL, "virt-ssbd", NULL, NULL,
             NULL, NULL, NULL, NULL,
         },
         .cpuid_eax = 0x80000008,