public-mirrors/linux
1
0
Fork 0
mirror of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2025-09-18 22:14:16 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

x86/rfds: Exclude P-only parts from the RFDS affected list

Browse source 
The affected CPU table (cpu_vuln_blacklist) marks Alderlake and Raptorlake
P-only parts affected by RFDS. This is not true because only E-cores are
affected by RFDS. With the current family/model matching it is not possible
to differentiate the unaffected parts, as the affected and unaffected
hybrid variants have the same model number.

Add a cpu-type match as well for such parts so as to exclude P-only parts
being marked as affected.

Note, family/model and cpu-type enumeration could be inaccurate in
virtualized environments. In a guest affected status is decided by RFDS_NO
and RFDS_CLEAR bits exposed by VMMs.

Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/r/20250311-add-cpu-type-v8-5-e8514dcaaff2@linux.intel.com
This commit is contained in:
Pawan Gupta 2025-03-11 08:03:08 -07:00 • committed by Ingo Molnar
parent adf2de5e8d
commit 722fa0dba7
2 changed files with 5 additions and 10 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

8
Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst
View file

@ -29,14 +29,6 @@ Below is the list of affected Intel processors [#f1]_:
RAPTORLAKE_S 06_BFH
=================== ============
As an exception to this table, Intel Xeon E family parts ALDERLAKE(06_97H) and
RAPTORLAKE(06_B7H) codenamed Catlow are not affected. They are reported as
vulnerable in Linux because they share the same family/model with an affected
part. Unlike their affected counterparts, they do not enumerate RFDS_CLEAR or
CPUID.HYBRID. This information could be used to distinguish between the
affected and unaffected parts, but it is deemed not worth adding complexity as
the reporting is fixed automatically when these parts enumerate RFDS_NO.
Mitigation
==========
Intel released a microcode update that enables software to clear sensitive

7
arch/x86/kernel/cpu/common.c
View file

@ -1203,6 +1203,9 @@ static const __initconst struct x86_cpu_id cpu_vuln_whitelist[] = {
#define VULNBL_INTEL_STEPS(vfm, max_stepping, issues) \
X86_MATCH_VFM_STEPS(vfm, X86_STEP_MIN, max_stepping, issues)
#define VULNBL_INTEL_TYPE(vfm, cpu_type, issues) \
X86_MATCH_VFM_CPU_TYPE(vfm, INTEL_CPU_TYPE_##cpu_type, issues)
#define VULNBL_AMD(family, blacklist) \
VULNBL(AMD, family, X86_MODEL_ANY, blacklist)
@ -1251,9 +1254,9 @@ static const struct x86_cpu_id cpu_vuln_blacklist[] __initconst = {
VULNBL_INTEL_STEPS(INTEL_TIGERLAKE, X86_STEP_MAX, GDS),
VULNBL_INTEL_STEPS(INTEL_LAKEFIELD, X86_STEP_MAX, MMIO | MMIO_SBDS | RETBLEED),
VULNBL_INTEL_STEPS(INTEL_ROCKETLAKE, X86_STEP_MAX, MMIO | RETBLEED | GDS),
VULNBL_INTEL_STEPS(INTEL_ALDERLAKE, X86_STEP_MAX, RFDS),
VULNBL_INTEL_TYPE(INTEL_ALDERLAKE, ATOM, RFDS),
VULNBL_INTEL_STEPS(INTEL_ALDERLAKE_L, X86_STEP_MAX, RFDS),
VULNBL_INTEL_STEPS(INTEL_RAPTORLAKE, X86_STEP_MAX, RFDS),
VULNBL_INTEL_TYPE(INTEL_RAPTORLAKE, ATOM, RFDS),
VULNBL_INTEL_STEPS(INTEL_RAPTORLAKE_P, X86_STEP_MAX, RFDS),
VULNBL_INTEL_STEPS(INTEL_RAPTORLAKE_S, X86_STEP_MAX, RFDS),
VULNBL_INTEL_STEPS(INTEL_ATOM_GRACEMONT, X86_STEP_MAX, RFDS),