diff options
author | David Woodhouse <dwmw@amazon.co.uk> | 2018-05-20 20:52:05 +0100 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-05-22 16:58:00 +0200 |
commit | f854434b37bbf8953900226acd6139081f60d3da (patch) | |
tree | 460b976563ac70e55b5db0071d4fbbe1b46b87ee /arch/x86/include | |
parent | 99b13116965f16b2e608e7796cd59198eee5bf06 (diff) |
x86/bugs/AMD: Add support to disable RDS on Fam[15,16,17]h if requested
commit 764f3c21588a059cd783c6ba0734d4db2d72822d upstream
AMD does not need the Speculative Store Bypass mitigation to be enabled.
The parameters for this are already available and can be done via MSR
C001_1020. Each family uses a different bit in that MSR for this.
[ tglx: Expose the bit mask via a variable and move the actual MSR fiddling
into the bugs code as that's the right thing to do and also required
to prepare for dynamic enable/disable ]
Suggested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86/include')
-rw-r--r-- | arch/x86/include/asm/cpufeatures.h | 1 | ||||
-rw-r--r-- | arch/x86/include/asm/nospec-branch.h | 4 |
2 files changed, 5 insertions, 0 deletions
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h index 013f3defc6fa..87970694cac1 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -205,6 +205,7 @@ #define X86_FEATURE_USE_IBPB ( 7*32+21) /* "" Indirect Branch Prediction Barrier enabled */ #define X86_FEATURE_USE_IBRS_FW ( 7*32+22) /* "" Use IBRS during runtime firmware calls */ #define X86_FEATURE_SPEC_STORE_BYPASS_DISABLE ( 7*32+23) /* "" Disable Speculative Store Bypass. */ +#define X86_FEATURE_AMD_RDS (7*32+24) /* "" AMD RDS implementation */ /* Virtualization flags: Linux defined, word 8 */ #define X86_FEATURE_TPR_SHADOW ( 8*32+ 0) /* Intel TPR Shadow */ diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h index 7b9eacfc03f3..3a1541cf32de 100644 --- a/arch/x86/include/asm/nospec-branch.h +++ b/arch/x86/include/asm/nospec-branch.h @@ -244,6 +244,10 @@ enum ssb_mitigation { SPEC_STORE_BYPASS_DISABLE, }; +/* AMD specific Speculative Store Bypass MSR data */ +extern u64 x86_amd_ls_cfg_base; +extern u64 x86_amd_ls_cfg_rds_mask; + extern char __indirect_thunk_start[]; extern char __indirect_thunk_end[]; |