6.6-stable review patch. If anyone has any objections, please let me know.
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From: Thomas Gleixner tglx@linutronix.de
commit b48b26f992a3828b4ae274669f99ce68451d4904 upstream
Microcode is applied on the APs during early bringup. There is no point in trying to apply the microcode again during the hotplug operations and neither at the point where the microcode device is initialized.
Collect CPU info and microcode revision in setup_online_cpu() for now. This will move to the CPU hotplug callback later.
[ bp: Leave the starting notifier for the following scenario:
- boot, late load, suspend to disk, resume
without the starting notifier, only the last core manages to update the microcode upon resume:
# rdmsr -a 0x8b 10000bf 10000bf 10000bf 10000bf 10000bf 10000dc <----
This is on an AMD F10h machine.
For the future, one should check whether potential unification of the CPU init path could cover the resume path too so that this can be simplified even more.
tglx: This is caused by the odd handling of APs which try to find the microcode blob in builtin or initrd instead of caching the microcode blob during early init before the APs are brought up. Will be cleaned up in a later step. ]
Signed-off-by: Borislav Petkov (AMD) bp@alien8.de Signed-off-by: Thomas Gleixner tglx@linutronix.de Link: https://lore.kernel.org/r/20231017211723.018821624@linutronix.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/kernel/cpu/microcode/core.c | 23 ++++++----------------- 1 file changed, 6 insertions(+), 17 deletions(-)
--- a/arch/x86/kernel/cpu/microcode/core.c +++ b/arch/x86/kernel/cpu/microcode/core.c @@ -493,17 +493,6 @@ static void microcode_fini_cpu(int cpu) microcode_ops->microcode_fini_cpu(cpu); }
-static enum ucode_state microcode_init_cpu(int cpu) -{ - struct ucode_cpu_info *uci = ucode_cpu_info + cpu; - - memset(uci, 0, sizeof(*uci)); - - microcode_ops->collect_cpu_info(cpu, &uci->cpu_sig); - - return microcode_ops->apply_microcode(cpu); -} - /** * microcode_bsp_resume - Update boot CPU microcode during resume. */ @@ -558,14 +547,14 @@ static int mc_cpu_down_prep(unsigned int static void setup_online_cpu(struct work_struct *work) { int cpu = smp_processor_id(); - enum ucode_state err; + struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
- err = microcode_init_cpu(cpu); - if (err == UCODE_ERROR) { - pr_err("Error applying microcode on CPU%d\n", cpu); - return; - } + memset(uci, 0, sizeof(*uci));
+ microcode_ops->collect_cpu_info(cpu, &uci->cpu_sig); + cpu_data(cpu).microcode = uci->cpu_sig.rev; + if (!cpu) + boot_cpu_data.microcode = uci->cpu_sig.rev; mc_cpu_online(cpu); }