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- Add Emerald Rapids to the list of Intel models supporting PPIN

Browse Source 
- Finally use a CPUID bit for split lock detection instead of
   enumerating every model
 
 - Make sure automatic IBRS is set on AMD, even though the AP bringup
   code does that now by replicating the MSR which contains the switch
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Merge tag 'x86_cpu_for_v6.4_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 cpu model updates from Borislav Petkov:

 - Add Emerald Rapids to the list of Intel models supporting PPIN

 - Finally use a CPUID bit for split lock detection instead of
   enumerating every model

 - Make sure automatic IBRS is set on AMD, even though the AP bringup
   code does that now by replicating the MSR which contains the switch

* tag 'x86_cpu_for_v6.4_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/cpu: Add Xeon Emerald Rapids to list of CPUs that support PPIN
  x86/split_lock: Enumerate architectural split lock disable bit
  x86/CPU/AMD: Make sure EFER[AIBRSE] is set
This commit is contained in:
Linus Torvalds 2023-04-25 10:20:52 -07:00
commit e3420f98f8
5 changed files with 43 additions and 46 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
arch/x86/kernel/cpu/amd.c
View File

@ -1009,6 +1009,17 @@ static void init_amd(struct cpuinfo_x86 *c)
msr_set_bit(MSR_K7_HWCR, MSR_K7_HWCR_IRPERF_EN_BIT);
check_null_seg_clears_base(c);
/*
* Make sure EFER[AIBRSE - Automatic IBRS Enable] is set. The APs are brought up
* using the trampoline code and as part of it, MSR_EFER gets prepared there in
* order to be replicated onto them. Regardless, set it here again, if not set,
* to protect against any future refactoring/code reorganization which might
* miss setting this important bit.
*/
if (spectre_v2_in_eibrs_mode(spectre_v2_enabled) &&
cpu_has(c, X86_FEATURE_AUTOIBRS))
WARN_ON_ONCE(msr_set_bit(MSR_EFER, _EFER_AUTOIBRS));
}
#ifdef CONFIG_X86_32

10
arch/x86/kernel/cpu/bugs.c
View File

@ -784,8 +784,7 @@ static int __init nospectre_v1_cmdline(char *str)
}
early_param("nospectre_v1", nospectre_v1_cmdline);
static enum spectre_v2_mitigation spectre_v2_enabled __ro_after_init =
SPECTRE_V2_NONE;
enum spectre_v2_mitigation spectre_v2_enabled __ro_after_init = SPECTRE_V2_NONE;
#undef pr_fmt
#define pr_fmt(fmt) "RETBleed: " fmt
@ -1133,13 +1132,6 @@ spectre_v2_parse_user_cmdline(void)
return SPECTRE_V2_USER_CMD_AUTO;
}
static inline bool spectre_v2_in_eibrs_mode(enum spectre_v2_mitigation mode)
{
return mode == SPECTRE_V2_EIBRS ||
mode == SPECTRE_V2_EIBRS_RETPOLINE ||
mode == SPECTRE_V2_EIBRS_LFENCE;
}
static inline bool spectre_v2_in_ibrs_mode(enum spectre_v2_mitigation mode)
{
return spectre_v2_in_eibrs_mode(mode) || mode == SPECTRE_V2_IBRS;

1
arch/x86/kernel/cpu/common.c
View File

@ -121,6 +121,7 @@ static const struct x86_cpu_id ppin_cpuids[] = {
X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_X, &ppin_info[X86_VENDOR_INTEL]),
X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_D, &ppin_info[X86_VENDOR_INTEL]),
X86_MATCH_INTEL_FAM6_MODEL(SAPPHIRERAPIDS_X, &ppin_info[X86_VENDOR_INTEL]),
X86_MATCH_INTEL_FAM6_MODEL(EMERALDRAPIDS_X, &ppin_info[X86_VENDOR_INTEL]),
X86_MATCH_INTEL_FAM6_MODEL(XEON_PHI_KNL, &ppin_info[X86_VENDOR_INTEL]),
X86_MATCH_INTEL_FAM6_MODEL(XEON_PHI_KNM, &ppin_info[X86_VENDOR_INTEL]),

8
arch/x86/kernel/cpu/cpu.h
View File

@ -83,4 +83,12 @@ unsigned int aperfmperf_get_khz(int cpu);
extern void x86_spec_ctrl_setup_ap(void);
extern void update_srbds_msr(void);
extern enum spectre_v2_mitigation spectre_v2_enabled;
static inline bool spectre_v2_in_eibrs_mode(enum spectre_v2_mitigation mode)
{
return mode == SPECTRE_V2_EIBRS ||
mode == SPECTRE_V2_EIBRS_RETPOLINE ||
mode == SPECTRE_V2_EIBRS_LFENCE;
}
#endif /* ARCH_X86_CPU_H */

59
arch/x86/kernel/cpu/intel.c
View File

@ -1451,31 +1451,13 @@ void handle_bus_lock(struct pt_regs *regs)
}
/*
* Bits in the IA32_CORE_CAPABILITIES are not architectural, so they should
* only be trusted if it is confirmed that a CPU model implements a
* specific feature at a particular bit position.
*
* The possible driver data field values:
*
* - 0: CPU models that are known to have the per-core split-lock detection
* feature even though they do not enumerate IA32_CORE_CAPABILITIES.
*
* - 1: CPU models which may enumerate IA32_CORE_CAPABILITIES and if so use
* bit 5 to enumerate the per-core split-lock detection feature.
* CPU models that are known to have the per-core split-lock detection
* feature even though they do not enumerate IA32_CORE_CAPABILITIES.
*/
static const struct x86_cpu_id split_lock_cpu_ids[] __initconst = {
X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_X, 0),
X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_L, 0),
X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_D, 0),
X86_MATCH_INTEL_FAM6_MODEL(ATOM_TREMONT, 1),
X86_MATCH_INTEL_FAM6_MODEL(ATOM_TREMONT_D, 1),
X86_MATCH_INTEL_FAM6_MODEL(ATOM_TREMONT_L, 1),
X86_MATCH_INTEL_FAM6_MODEL(TIGERLAKE_L, 1),
X86_MATCH_INTEL_FAM6_MODEL(TIGERLAKE, 1),
X86_MATCH_INTEL_FAM6_MODEL(SAPPHIRERAPIDS_X, 1),
X86_MATCH_INTEL_FAM6_MODEL(ALDERLAKE, 1),
X86_MATCH_INTEL_FAM6_MODEL(ALDERLAKE_L, 1),
X86_MATCH_INTEL_FAM6_MODEL(RAPTORLAKE, 1),
X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_X, 0),
X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_L, 0),
X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_D, 0),
{}
};
@ -1487,24 +1469,27 @@ static void __init split_lock_setup(struct cpuinfo_x86 *c)
if (boot_cpu_has(X86_FEATURE_HYPERVISOR))
return;
/* Check for CPUs that have support but do not enumerate it: */
m = x86_match_cpu(split_lock_cpu_ids);
if (!m)
if (m)
goto supported;
if (!cpu_has(c, X86_FEATURE_CORE_CAPABILITIES))
return;
switch (m->driver_data) {
case 0:
break;
case 1:
if (!cpu_has(c, X86_FEATURE_CORE_CAPABILITIES))
return;
rdmsrl(MSR_IA32_CORE_CAPS, ia32_core_caps);
if (!(ia32_core_caps & MSR_IA32_CORE_CAPS_SPLIT_LOCK_DETECT))
return;
break;
default:
return;
}
/*
* Not all bits in MSR_IA32_CORE_CAPS are architectural, but
* MSR_IA32_CORE_CAPS_SPLIT_LOCK_DETECT is. All CPUs that set
* it have split lock detection.
*/
rdmsrl(MSR_IA32_CORE_CAPS, ia32_core_caps);
if (ia32_core_caps & MSR_IA32_CORE_CAPS_SPLIT_LOCK_DETECT)
goto supported;
/* CPU is not in the model list and does not have the MSR bit: */
return;
supported:
cpu_model_supports_sld = true;
__split_lock_setup();
}