Commit 542ad0eb authored by Peter Maydell's avatar Peter Maydell
Browse files

Merge remote-tracking branch 'remotes/ehabkost/tags/x86-next-pull-request' into staging 



x86 MDS feature flags

md-clear and mds-no feature flags, for detection and mitigation
of MDS vulnerabilities (CVE-2018-12126, CVE-2018-12127,
CVE-2018-12130, CVE-2019-11091).

# gpg: Signature made Tue 21 May 2019 19:42:43 BST
# gpg:                using RSA key 2807936F984DC5A6
# gpg: Good signature from "Eduardo Habkost <ehabkost@redhat.com>" [full]
# Primary key fingerprint: 5A32 2FD5 ABC4 D3DB ACCF  D1AA 2807 936F 984D C5A6

* remotes/ehabkost/tags/x86-next-pull-request:
  target/i386: add MDS-NO feature
  docs: recommend use of md-clear feature on all Intel CPUs
  target/i386: define md-clear bit

Signed-off-by: default avatarPeter Maydell <peter.maydell@linaro.org>
parents a4f667b6 20140a82

docs/qemu-cpu-models.texi

+12 −0
Original line number Diff line number Diff line
@@ -200,6 +200,18 @@ Not included by default in any Intel CPU model. 
Should be explicitly turned on for all Intel CPU models.



Note that not all CPU hardware will support this feature.



@item @code{md-clear}



Required to confirm the MDS (CVE-2018-12126, CVE-2018-12127, CVE-2018-12130,

CVE-2019-11091) fixes.



Not included by default in any Intel CPU model.



Must be explicitly turned on for all Intel CPU models.



Requires the host CPU microcode to support this feature before it

can be used for guest CPUs.

@end table

target/i386/cpu.c

+2 −2
Original line number Diff line number Diff line
@@ -1077,7 +1077,7 @@ static FeatureWordInfo feature_word_info[FEATURE_WORDS] = { 
        .feat_names = {

            NULL, NULL, "avx512-4vnniw", "avx512-4fmaps",

            NULL, NULL, NULL, NULL,

            NULL, NULL, NULL, NULL,

            NULL, NULL, "md-clear", NULL,

            NULL, NULL, NULL, NULL,

            NULL, NULL, NULL, NULL,

            NULL, NULL, NULL, NULL,
@@ -1184,7 +1184,7 @@ static FeatureWordInfo feature_word_info[FEATURE_WORDS] = { 
        .type = MSR_FEATURE_WORD,

        .feat_names = {

            "rdctl-no", "ibrs-all", "rsba", "skip-l1dfl-vmentry",

            "ssb-no", NULL, NULL, NULL,

            "ssb-no", "mds-no", NULL, NULL,

            NULL, NULL, NULL, NULL,

            NULL, NULL, NULL, NULL,

            NULL, NULL, NULL, NULL,