Messages in this thread Patch in this message | | | Date | Wed, 19 Oct 2022 08:51:14 -0700 | From | Ashok Raj <> | Subject | Re: [PATCH 13/13] x86/microcode/intel: Add ability to update microcode even if rev is unchanged |
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Hi Boris,
There is a minor bug in this force reload option I added for testing.
See below:
On Fri, Oct 14, 2022 at 01:09:13PM -0700, Ashok Raj wrote:
[snip]
> diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c > index eb2caa74de01..632c7a1fcffb 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> > @@ -46,6 +47,7 @@ > > static struct microcode_ops *microcode_ops; > static bool dis_ucode_ldr = true; > +bool ucode_load_same; > > bool initrd_gone; > > @@ -542,11 +544,12 @@ 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: > @@ -636,9 +639,12 @@ static ssize_t reload_store(struct device *dev, > } > > tmp_ret = microcode_ops->request_microcode_fw(bsp, µcode_pdev->dev, true); > - if (tmp_ret != UCODE_NEW) > + if (tmp_ret != UCODE_NEW && !ucode_load_same) > goto put; > > + if (tmp_ret != UCODE_NEW) > + pr_info("Force loading ucode\n"); > +
The above needs additional check for UCODE_ERROR. If you are testing with old microcode with minrev=0, noticed this went and tried to perform an update without the UCODE_ERROR check.
I've queued for the next update.
- 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); > @@ -841,6 +847,7 @@ 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) > @@ -884,7 +891,12 @@ 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 c61aa661ac2f..c9f1e6f5e53b 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; > } > @@ -779,7 +779,7 @@ 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("updated to revision 0x%x, date = %04x-%02x-%02x\n", > rev, > mc->hdr.date & 0xffff, > -- > 2.34.1 >
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