diff options
| -rw-r--r-- | arch/x86/include/asm/processor.h | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/common.c | 36 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/microcode/core.c | 6 |
3 files changed, 30 insertions, 13 deletions
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index f256a4ddd25d..a77dee6a2bf2 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -698,6 +698,7 @@ bool xen_set_default_idle(void); void __noreturn stop_this_cpu(void *dummy); void microcode_check(struct cpuinfo_x86 *prev_info); +void store_cpu_caps(struct cpuinfo_x86 *info); enum l1tf_mitigations { L1TF_MITIGATION_OFF, diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 0f5a173d0871..5ff73baa5583 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -2298,6 +2298,25 @@ void cpu_init_secondary(void) #ifdef CONFIG_MICROCODE_LATE_LOADING /** + * store_cpu_caps() - Store a snapshot of CPU capabilities + * @curr_info: Pointer where to store it + * + * Returns: None + */ +void store_cpu_caps(struct cpuinfo_x86 *curr_info) +{ + /* Reload CPUID max function as it might've changed. */ + curr_info->cpuid_level = cpuid_eax(0); + + /* Copy all capability leafs and pick up the synthetic ones. */ + memcpy(&curr_info->x86_capability, &boot_cpu_data.x86_capability, + sizeof(curr_info->x86_capability)); + + /* Get the hardware CPUID leafs */ + get_cpu_cap(curr_info); +} + +/** * microcode_check() - Check if any CPU capabilities changed after an update. * @prev_info: CPU capabilities stored before an update. * @@ -2309,22 +2328,13 @@ void cpu_init_secondary(void) */ void microcode_check(struct cpuinfo_x86 *prev_info) { - perf_check_microcode(); - - /* Reload CPUID max function as it might've changed. */ - prev_info->cpuid_level = cpuid_eax(0); + struct cpuinfo_x86 curr_info; - /* - * Copy all capability leafs to pick up the synthetic ones so that - * memcmp() below doesn't fail on that. The ones coming from CPUID will - * get overwritten in get_cpu_cap(). - */ - memcpy(&prev_info->x86_capability, &boot_cpu_data.x86_capability, - sizeof(prev_info->x86_capability)); + perf_check_microcode(); - get_cpu_cap(prev_info); + store_cpu_caps(&curr_info); - if (!memcmp(&prev_info->x86_capability, &boot_cpu_data.x86_capability, + if (!memcmp(&prev_info->x86_capability, &curr_info.x86_capability, sizeof(prev_info->x86_capability))) return; diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c index dc5dfba7e78e..8ec38c107dc3 100644 --- a/arch/x86/kernel/cpu/microcode/core.c +++ b/arch/x86/kernel/cpu/microcode/core.c @@ -446,6 +446,12 @@ static int microcode_reload_late(void) atomic_set(&late_cpus_in, 0); atomic_set(&late_cpus_out, 0); + /* + * Take a snapshot before the microcode update in order to compare and + * check whether any bits changed after an update. + */ + store_cpu_caps(&prev_info); + ret = stop_machine_cpuslocked(__reload_late, NULL, cpu_online_mask); if (ret == 0) microcode_check(&prev_info); |