[v2] target/i386: Export GDS_NO bit to guests

[PATCH v2] target/i386: Export GDS_NO bit to guests

Posted by Pawan Gupta 9 months, 1 week ago

Gather Data Sampling (GDS) is a side-channel attack using Gather
instructions. Some Intel processors will set ARCH_CAP_GDS_NO bit in
MSR IA32_ARCH_CAPABILITIES to report that they are not vulnerable to
GDS.

Make this bit available to guests.

Closes: https://lore.kernel.org/qemu-devel/CAMGffEmG6TNq0n3+4OJAgXc8J0OevY60KHZekXCBs3LoK9vehA@mail.gmail.com/
Reported-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Tested-by: Jack Wang <jinpu.wang@ionos.com>
Tested-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
---
v2: Added commit tags

v1: https://lore.kernel.org/qemu-devel/c373f3f92b542b738f296d44bb6a916a1cded7bd.1691774049.git.pawan.kumar.gupta@linux.intel.com/

 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 97ad229d8ba3..48709b77689f 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -1155,7 +1155,7 @@ FeatureWordInfo feature_word_info[FEATURE_WORDS] = {
             NULL, "sbdr-ssdp-no", "fbsdp-no", "psdp-no",
             NULL, "fb-clear", NULL, NULL,
             NULL, NULL, NULL, NULL,
-            "pbrsb-no", NULL, NULL, NULL,
+            "pbrsb-no", NULL, "gds-no", NULL,
             NULL, NULL, NULL, NULL,
         },
         .msr = {
-- 
2.34.1

Re: [PATCH v2] target/i386: Export GDS_NO bit to guests

Posted by Xiaoyao Li 9 months, 1 week ago

On 8/15/2023 12:54 PM, Pawan Gupta wrote:
> Gather Data Sampling (GDS) is a side-channel attack using Gather
> instructions. Some Intel processors will set ARCH_CAP_GDS_NO bit in
> MSR IA32_ARCH_CAPABILITIES to report that they are not vulnerable to
> GDS.
> 
> Make this bit available to guests.
> 
> Closes: https://lore.kernel.org/qemu-devel/CAMGffEmG6TNq0n3+4OJAgXc8J0OevY60KHZekXCBs3LoK9vehA@mail.gmail.com/
> Reported-by: Jack Wang <jinpu.wang@ionos.com>
> Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
> Tested-by: Jack Wang <jinpu.wang@ionos.com>
> Tested-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>

Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>

> ---
> v2: Added commit tags
> 
> v1: https://lore.kernel.org/qemu-devel/c373f3f92b542b738f296d44bb6a916a1cded7bd.1691774049.git.pawan.kumar.gupta@linux.intel.com/
> 
>   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 97ad229d8ba3..48709b77689f 100644
> --- a/target/i386/cpu.c
> +++ b/target/i386/cpu.c
> @@ -1155,7 +1155,7 @@ FeatureWordInfo feature_word_info[FEATURE_WORDS] = {
>               NULL, "sbdr-ssdp-no", "fbsdp-no", "psdp-no",
>               NULL, "fb-clear", NULL, NULL,
>               NULL, NULL, NULL, NULL,
> -            "pbrsb-no", NULL, NULL, NULL,
> +            "pbrsb-no", NULL, "gds-no", NULL,
>               NULL, NULL, NULL, NULL,
>           },
>           .msr = {

Re: [PATCH v2] target/i386: Export GDS_NO bit to guests

Posted by Jinpu Wang 8 months, 1 week ago

Hi Paolo,

Ping!

Thx!

On Tue, Aug 15, 2023 at 7:44 AM Xiaoyao Li <xiaoyao.li@intel.com> wrote:
>
> On 8/15/2023 12:54 PM, Pawan Gupta wrote:
> > Gather Data Sampling (GDS) is a side-channel attack using Gather
> > instructions. Some Intel processors will set ARCH_CAP_GDS_NO bit in
> > MSR IA32_ARCH_CAPABILITIES to report that they are not vulnerable to
> > GDS.
> >
> > Make this bit available to guests.
> >
> > Closes: https://lore.kernel.org/qemu-devel/CAMGffEmG6TNq0n3+4OJAgXc8J0OevY60KHZekXCBs3LoK9vehA@mail.gmail.com/
> > Reported-by: Jack Wang <jinpu.wang@ionos.com>
> > Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
> > Tested-by: Jack Wang <jinpu.wang@ionos.com>
> > Tested-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
>
> Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
>
> > ---
> > v2: Added commit tags
> >
> > v1: https://lore.kernel.org/qemu-devel/c373f3f92b542b738f296d44bb6a916a1cded7bd.1691774049.git.pawan.kumar.gupta@linux.intel.com/
> >
> >   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 97ad229d8ba3..48709b77689f 100644
> > --- a/target/i386/cpu.c
> > +++ b/target/i386/cpu.c
> > @@ -1155,7 +1155,7 @@ FeatureWordInfo feature_word_info[FEATURE_WORDS] = {
> >               NULL, "sbdr-ssdp-no", "fbsdp-no", "psdp-no",
> >               NULL, "fb-clear", NULL, NULL,
> >               NULL, NULL, NULL, NULL,
> > -            "pbrsb-no", NULL, NULL, NULL,
> > +            "pbrsb-no", NULL, "gds-no", NULL,
> >               NULL, NULL, NULL, NULL,
> >           },
> >           .msr = {
>