3.16.59-rc1 review patch. If anyone has any objections, please let me know.
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From: Thomas Gleixner tglx@linutronix.de
commit 52817587e706686fcdb27f14c1b000c92f266c96 upstream.
The SSBD enumeration is similarly to the other bits magically shared between Intel and AMD though the mechanisms are different.
Make X86_FEATURE_SSBD synthetic and set it depending on the vendor specific features or family dependent setup.
Change the Intel bit to X86_FEATURE_SPEC_CTRL_SSBD to denote that SSBD is controlled via MSR_SPEC_CTRL and fix up the usage sites.
Signed-off-by: Thomas Gleixner tglx@linutronix.de Reviewed-by: Borislav Petkov bp@suse.de Reviewed-by: Konrad Rzeszutek Wilk konrad.wilk@oracle.com Signed-off-by: David Woodhouse dwmw@amazon.co.uk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org [bwh: Backported to 3.16: - Use the next available bit number in CPU feature word 7 - Adjust filename, context] Signed-off-by: Ben Hutchings ben@decadent.org.uk --- arch/x86/include/asm/cpufeature.h | 5 +++-- arch/x86/kernel/cpu/amd.c | 7 +------ arch/x86/kernel/cpu/bugs.c | 10 +++++----- arch/x86/kernel/cpu/common.c | 3 +++ arch/x86/kernel/cpu/intel.c | 1 + arch/x86/kernel/process.c | 2 +- 6 files changed, 14 insertions(+), 14 deletions(-)
--- a/arch/x86/include/asm/cpufeature.h +++ b/arch/x86/include/asm/cpufeature.h @@ -192,11 +192,12 @@ #define X86_FEATURE_USE_IBPB (7*32+12) /* "" Indirect Branch Prediction Barrier enabled */ #define X86_FEATURE_USE_IBRS_FW (7*32+13) /* "" Use IBRS during runtime firmware calls */ #define X86_FEATURE_SPEC_STORE_BYPASS_DISABLE (7*32+14) /* "" Disable Speculative Store Bypass. */ -#define X86_FEATURE_AMD_SSBD (7*32+15) /* "" AMD SSBD implementation */ +#define X86_FEATURE_LS_CFG_SSBD (7*32+15) /* "" AMD SSBD implementation */ #define X86_FEATURE_IBRS (7*32+16) /* Indirect Branch Restricted Speculation */ #define X86_FEATURE_IBPB (7*32+17) /* Indirect Branch Prediction Barrier */ #define X86_FEATURE_STIBP (7*32+18) /* Single Thread Indirect Branch Predictors */ #define X86_FEATURE_MSR_SPEC_CTRL (7*32+19) /* "" MSR SPEC_CTRL is implemented */ +#define X86_FEATURE_SSBD (7*32+20) /* Speculative Store Bypass Disable */
#define X86_FEATURE_RETPOLINE (7*32+29) /* "" Generic Retpoline mitigation for Spectre variant 2 */ #define X86_FEATURE_RETPOLINE_AMD (7*32+30) /* "" AMD Retpoline mitigation for Spectre variant 2 */ @@ -247,7 +248,7 @@ #define X86_FEATURE_SPEC_CTRL (10*32+26) /* "" Speculation Control (IBRS + IBPB) */ #define X86_FEATURE_INTEL_STIBP (10*32+27) /* "" Single Thread Indirect Branch Predictors */ #define X86_FEATURE_ARCH_CAPABILITIES (10*32+29) /* IA32_ARCH_CAPABILITIES MSR (Intel) */ -#define X86_FEATURE_SSBD (10*32+31) /* Speculative Store Bypass Disable */ +#define X86_FEATURE_SPEC_CTRL_SSBD (10*32+31) /* "" Speculative Store Bypass Disable */
/* AMD-defined CPU features, CPUID level 0x80000008 (EBX), word 11 */ #define X86_FEATURE_AMD_IBPB (11*32+12) /* Indirect Branch Prediction Barrier */ --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -486,8 +486,8 @@ static void bsp_init_amd(struct cpuinfo_ * avoid RMW. If that faults, do not enable SSBD. */ if (!rdmsrl_safe(MSR_AMD64_LS_CFG, &x86_amd_ls_cfg_base)) { + setup_force_cpu_cap(X86_FEATURE_LS_CFG_SSBD); setup_force_cpu_cap(X86_FEATURE_SSBD); - setup_force_cpu_cap(X86_FEATURE_AMD_SSBD); x86_amd_ls_cfg_ssbd_mask = 1ULL << bit; } } @@ -801,11 +801,6 @@ static void init_amd(struct cpuinfo_x86 set_cpu_bug(c, X86_BUG_AMD_APIC_C1E);
rdmsr_safe(MSR_AMD64_PATCH_LEVEL, &c->microcode, &dummy); - - if (boot_cpu_has(X86_FEATURE_AMD_SSBD)) { - set_cpu_cap(c, X86_FEATURE_SSBD); - set_cpu_cap(c, X86_FEATURE_AMD_SSBD); - } }
#ifdef CONFIG_X86_32 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -220,8 +220,8 @@ void x86_spec_ctrl_set_guest(u64 guest_s if (!static_cpu_has(X86_FEATURE_MSR_SPEC_CTRL)) return;
- /* Intel controls SSB in MSR_SPEC_CTRL */ - if (static_cpu_has(X86_FEATURE_SPEC_CTRL)) + /* SSBD controlled in MSR_SPEC_CTRL */ + if (static_cpu_has(X86_FEATURE_SPEC_CTRL_SSBD)) host |= ssbd_tif_to_spec_ctrl(current_thread_info()->flags);
if (host != guest_spec_ctrl) @@ -237,8 +237,8 @@ void x86_spec_ctrl_restore_host(u64 gues if (!static_cpu_has(X86_FEATURE_MSR_SPEC_CTRL)) return;
- /* Intel controls SSB in MSR_SPEC_CTRL */ - if (static_cpu_has(X86_FEATURE_SPEC_CTRL)) + /* SSBD controlled in MSR_SPEC_CTRL */ + if (static_cpu_has(X86_FEATURE_SPEC_CTRL_SSBD)) host |= ssbd_tif_to_spec_ctrl(current_thread_info()->flags);
if (host != guest_spec_ctrl) @@ -250,7 +250,7 @@ static void x86_amd_ssb_disable(void) { u64 msrval = x86_amd_ls_cfg_base | x86_amd_ls_cfg_ssbd_mask;
- if (boot_cpu_has(X86_FEATURE_AMD_SSBD)) + if (boot_cpu_has(X86_FEATURE_LS_CFG_SSBD)) wrmsrl(MSR_AMD64_LS_CFG, msrval); }
--- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -700,6 +700,9 @@ static void init_speculation_control(str if (cpu_has(c, X86_FEATURE_INTEL_STIBP)) set_cpu_cap(c, X86_FEATURE_STIBP);
+ if (cpu_has(c, X86_FEATURE_SPEC_CTRL_SSBD)) + set_cpu_cap(c, X86_FEATURE_SSBD); + if (cpu_has(c, X86_FEATURE_AMD_IBRS)) { set_cpu_cap(c, X86_FEATURE_IBRS); set_cpu_cap(c, X86_FEATURE_MSR_SPEC_CTRL); --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -122,6 +122,7 @@ static void early_init_intel(struct cpui setup_clear_cpu_cap(X86_FEATURE_MSR_SPEC_CTRL); setup_clear_cpu_cap(X86_FEATURE_INTEL_STIBP); setup_clear_cpu_cap(X86_FEATURE_SSBD); + setup_clear_cpu_cap(X86_FEATURE_SPEC_CTRL_SSBD); }
/* --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -221,7 +221,7 @@ static __always_inline void __speculativ { u64 msr;
- if (static_cpu_has(X86_FEATURE_AMD_SSBD)) { + if (static_cpu_has(X86_FEATURE_LS_CFG_SSBD)) { msr = x86_amd_ls_cfg_base | ssbd_tif_to_amd_ls_cfg(tifn); wrmsrl(MSR_AMD64_LS_CFG, msr); } else {