Messages in this thread Patch in this message | | | From | Ricardo Neri <> | Subject | [PATCH v3 23/24] x86/hreset: Configure history reset | Date | Mon, 6 Feb 2023 21:11:04 -0800 |
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Configure the MSR that controls the behavior of HRESET on each logical processor.
Cc: Ben Segall <bsegall@google.com> Cc: Daniel Bristot de Oliveira <bristot@redhat.com> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Ionela Voinescu <ionela.voinescu@arm.com> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Len Brown <len.brown@intel.com> Cc: Lukasz Luba <lukasz.luba@arm.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Tim C. Chen <tim.c.chen@intel.com> Cc: Valentin Schneider <vschneid@redhat.com> Cc: x86@kernel.org Cc: linux-pm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com> --- Changes since v2: * None
Changes since v1: * Marked hardware_history_features as __ro_after_init instead of __read_mostly. (PeterZ) --- arch/x86/kernel/cpu/common.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 831a1a07d357..f3f936f7de5f 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -412,6 +412,26 @@ static __always_inline void setup_umip(struct cpuinfo_x86 *c) cr4_clear_bits(X86_CR4_UMIP); } +static u32 hardware_history_features __ro_after_init; + +static __always_inline void setup_hreset(struct cpuinfo_x86 *c) +{ + if (!cpu_feature_enabled(X86_FEATURE_HRESET)) + return; + + /* + * Use on all CPUs the hardware history features that the boot + * CPU supports. + */ + if (c == &boot_cpu_data) + hardware_history_features = cpuid_ebx(0x20); + + if (!hardware_history_features) + return; + + wrmsrl(MSR_IA32_HW_HRESET_ENABLE, hardware_history_features); +} + /* These bits should not change their value after CPU init is finished. */ static const unsigned long cr4_pinned_mask = X86_CR4_SMEP | X86_CR4_SMAP | X86_CR4_UMIP | @@ -1848,10 +1868,11 @@ static void identify_cpu(struct cpuinfo_x86 *c) /* Disable the PN if appropriate */ squash_the_stupid_serial_number(c); - /* Set up SMEP/SMAP/UMIP */ + /* Set up SMEP/SMAP/UMIP/HRESET */ setup_smep(c); setup_smap(c); setup_umip(c); + setup_hreset(c); /* Enable FSGSBASE instructions if available. */ if (cpu_has(c, X86_FEATURE_FSGSBASE)) { -- 2.25.1
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