Messages in this thread Patch in this message | | | From | Ashok Raj <> | Subject | [v2 13/13] x86/microcode/intel: Add ability to update microcode even if rev is unchanged | Date | Thu, 3 Nov 2022 17:59:01 +0000 |
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This comes in handy for testing without the need for a new microcode file. Default is OFF. It can be switched dynamically at run time via debugfs file /sys/kernel/debug/microcode/load_same.
NOT_FOR_INCLUSION: Leave it to the discretion of Boris if its suitable for inclusion. It will at least serve to validate some parts of the series without the need for a new microcode, since it goes through all the renedezvous parts except not updating the microcode itself.
Reviewed-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Ashok Raj <ashok.raj@intel.com> --- arch/x86/include/asm/microcode.h | 2 ++ arch/x86/kernel/cpu/microcode/amd.c | 2 +- arch/x86/kernel/cpu/microcode/core.c | 23 ++++++++++++++++++----- arch/x86/kernel/cpu/microcode/intel.c | 4 ++-- 4 files changed, 23 insertions(+), 8 deletions(-)
diff --git a/arch/x86/include/asm/microcode.h b/arch/x86/include/asm/microcode.h index 6286b4056792..a356a6a5207e 100644 --- a/arch/x86/include/asm/microcode.h +++ b/arch/x86/include/asm/microcode.h @@ -47,6 +47,8 @@ struct ucode_patch { extern struct list_head microcode_cache; +extern bool ucode_load_same; + struct cpu_signature { unsigned int sig; unsigned int pf; diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c index b103d5e5f447..802212e194b3 100644 --- a/arch/x86/kernel/cpu/microcode/amd.c +++ b/arch/x86/kernel/cpu/microcode/amd.c @@ -694,7 +694,7 @@ static enum ucode_state apply_microcode_amd(int cpu) rdmsr(MSR_AMD64_PATCH_LEVEL, rev, dummy); /* need to apply patch? */ - if (rev >= mc_amd->hdr.patch_id) { + if (rev >= mc_amd->hdr.patch_id && !ucode_load_same) { ret = UCODE_OK; goto out; } diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c index a7d0cbbb2505..2d0cd8ca3ea2 100644 --- a/arch/x86/kernel/cpu/microcode/core.c +++ b/arch/x86/kernel/cpu/microcode/core.c @@ -23,6 +23,7 @@ #include <linux/miscdevice.h> #include <linux/capability.h> #include <linux/firmware.h> +#include <linux/debugfs.h> #include <linux/kernel.h> #include <linux/delay.h> #include <linux/mutex.h> @@ -48,6 +49,7 @@ static struct microcode_ops *microcode_ops; static bool dis_ucode_ldr = true; +bool ucode_load_same; bool initrd_gone; @@ -490,11 +492,12 @@ static int __reload_late(void *info) goto wait_for_siblings; } - if (err >= UCODE_NFOUND) { - if (err == UCODE_ERROR) + if (ret || err >= UCODE_NFOUND) { + if (err == UCODE_ERROR || + (err == UCODE_NFOUND && !ucode_load_same)) { pr_warn("Error reloading microcode on CPU %d\n", cpu); - - ret = -1; + ret = -1; + } } wait_for_siblings: @@ -632,9 +635,13 @@ static ssize_t reload_store(struct device *dev, } tmp_ret = microcode_ops->request_microcode_fw(bsp, µcode_pdev->dev); - if (tmp_ret != UCODE_NEW) + if (tmp_ret == UCODE_ERROR || + (tmp_ret != UCODE_NEW && !ucode_load_same)) goto put; + if (tmp_ret != UCODE_NEW) + pr_info("Force loading ucode\n"); + mutex_lock(µcode_mutex); ret = microcode_reload_late(); mutex_unlock(µcode_mutex); @@ -781,6 +788,7 @@ static const struct attribute_group cpu_root_microcode_group = { static int __init microcode_init(void) { struct cpuinfo_x86 *c = &boot_cpu_data; + static struct dentry *dentry_ucode; int error; if (dis_ucode_ldr) @@ -815,7 +823,12 @@ static int __init microcode_init(void) cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "x86/microcode:online", mc_cpu_online, mc_cpu_down_prep); + dentry_ucode = debugfs_create_dir("microcode", NULL); + debugfs_create_bool("load_same", 0644, dentry_ucode, &ucode_load_same); + pr_info("Microcode Update Driver: v%s.", DRIVER_VERSION); + pr_info("ucode_load_same is %s\n", + ucode_load_same ? "enabled" : "disabled"); return 0; diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c index 7086670da606..08ba6e009d54 100644 --- a/arch/x86/kernel/cpu/microcode/intel.c +++ b/arch/x86/kernel/cpu/microcode/intel.c @@ -763,7 +763,7 @@ static enum ucode_state apply_microcode_intel(int cpu) * already. */ rev = intel_get_microcode_revision(); - if (rev >= mc->hdr.rev) { + if (rev >= mc->hdr.rev && !ucode_load_same) { ret = UCODE_OK; goto out; } @@ -782,7 +782,7 @@ static enum ucode_state apply_microcode_intel(int cpu) return UCODE_ERROR; } - if (bsp && rev != prev_rev) { + if (bsp && (rev != prev_rev || ucode_load_same)) { pr_info("update 0x%x -> 0x%x, date = %04x-%02x-%02x\n", prev_rev, rev, mc->hdr.date & 0xffff, -- 2.34.1
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