elf: Fix tst-cpu-features-cpuinfo for KVM guests on some AMD systems [BZ #28704]
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Patch applied to master at the time it was sent
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dj/TryBot-32bit |
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Build for i686
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Commit Message
On KVM guests running on some AMD systems, the IBRS feature is reported
as a synthetic feature using the Intel feature, while the cpuinfo entry
keeps the same. Handle that by first checking the presence of the Intel
feature on AMD systems.
Fixes bug 28704.
---
sysdeps/x86/tst-cpu-features-cpuinfo.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
(H.J. Lu: resending because I wrongly send it to you instead of sending
it to the list and Cc:ing you. Sorry)
Comments
On Wed, Dec 15, 2021 at 10:41 PM Aurelien Jarno <aurelien@aurel32.net> wrote:
>
> On KVM guests running on some AMD systems, the IBRS feature is reported
> as a synthetic feature using the Intel feature, while the cpuinfo entry
> keeps the same. Handle that by first checking the presence of the Intel
> feature on AMD systems.
>
> Fixes bug 28704.
> ---
> sysdeps/x86/tst-cpu-features-cpuinfo.c | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
> (H.J. Lu: resending because I wrongly send it to you instead of sending
> it to the list and Cc:ing you. Sorry)
>
> diff --git a/sysdeps/x86/tst-cpu-features-cpuinfo.c b/sysdeps/x86/tst-cpu-features-cpuinfo.c
> index 2d4927f5e5..830aaca2ec 100644
> --- a/sysdeps/x86/tst-cpu-features-cpuinfo.c
> +++ b/sysdeps/x86/tst-cpu-features-cpuinfo.c
> @@ -169,7 +169,14 @@ do_test (int argc, char **argv)
> else if (cpu_features->basic.kind == arch_kind_amd)
> {
> fails += CHECK_PROC (ibpb, AMD_IBPB);
> - fails += CHECK_PROC (ibrs, AMD_IBRS);
> +
> + /* The IBRS feature on AMD processors is reported using the Intel feature
> + * on KVM guests (synthetic bit). In both cases the cpuinfo entry is the
> + * same. */
> + if (HAS_CPU_FEATURE (IBRS_IBPB))
> + fails += CHECK_PROC (ibrs, IBRS_IBPB);
> + else
> + fails += CHECK_PROC (ibrs, AMD_IBRS);
> fails += CHECK_PROC (stibp, AMD_STIBP);
> }
> fails += CHECK_PROC (ibt, IBT);
> --
> 2.33.0
>
LGTM.
Thanks.
@@ -169,7 +169,14 @@ do_test (int argc, char **argv)
else if (cpu_features->basic.kind == arch_kind_amd)
{
fails += CHECK_PROC (ibpb, AMD_IBPB);
- fails += CHECK_PROC (ibrs, AMD_IBRS);
+
+ /* The IBRS feature on AMD processors is reported using the Intel feature
+ * on KVM guests (synthetic bit). In both cases the cpuinfo entry is the
+ * same. */
+ if (HAS_CPU_FEATURE (IBRS_IBPB))
+ fails += CHECK_PROC (ibrs, IBRS_IBPB);
+ else
+ fails += CHECK_PROC (ibrs, AMD_IBRS);
fails += CHECK_PROC (stibp, AMD_STIBP);
}
fails += CHECK_PROC (ibt, IBT);