[PATCH] x86/MCE: Get microcode revision from cpu_info instead of boot_cpu_data

[PATCH] x86/MCE: Get microcode revision from cpu_info instead of boot_cpu_data

[Filippo Sironi]

Commit fa94d0c6e0f3 ("x86/MCE: Save microcode revision in machine check
records") extended MCE entries to report the microcode revision taken
from boot_cpu_data. Unfortunately, boot_cpu_data isn't updated on late
microcode loading, thus making MCE entries slightly incorrect.
Use cpu_info instead, which is updated on late microcode loading.

Fixes: fa94d0c6e0f3 ("x86/MCE: Save microcode revision in machine check records")
Signed-off-by: Filippo Sironi <sironi@amazon.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: linux-edac@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
---
 arch/x86/kernel/cpu/mcheck/mce.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index 42cf2880d0ed..4be323f9b390 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -134,7 +134,7 @@ void mce_setup(struct mce *m)
 	if (this_cpu_has(X86_FEATURE_INTEL_PPIN))
 		rdmsrl(MSR_PPIN, m->ppin);
 
-	m->microcode = boot_cpu_data.microcode;
+	m->microcode = cpu_data(m->extcpu).microcode;
 }
 
 DEFINE_PER_CPU(struct mce, injectm);
-- 
2.7.4

Re: [PATCH] x86/MCE: Get microcode revision from cpu_info instead of boot_cpu_data

[Borislav Petkov]

On Fri, Jun 01, 2018 at 01:30:26PM +0200, Filippo Sironi wrote:
> Commit fa94d0c6e0f3 ("x86/MCE: Save microcode revision in machine check
> records") extended MCE entries to report the microcode revision taken
> from boot_cpu_data. Unfortunately, boot_cpu_data isn't updated on late
> microcode loading,

Actually, I'd prefer if we fixed *that* instead by adding:

	/* Update boot_cpu_data's revision too, if we're on the BSP: */
	if (c->cpu_index == boot_cpu_data.cpu_index)
		boot_cpu_data.microcode = <new rev>;

to the end of ->apply_microcode() functions so that boot_cpu_data has
the correct revision too, in case something else queries it.

Thx.

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.
--

Re: [PATCH] x86/MCE: Get microcode revision from cpu_info instead of boot_cpu_data

[Sironi, Filippo]

> On 1. Jun 2018, at 14:19, Borislav Petkov <bp@alien8.de> wrote:
> 
> On Fri, Jun 01, 2018 at 01:30:26PM +0200, Filippo Sironi wrote:
>> Commit fa94d0c6e0f3 ("x86/MCE: Save microcode revision in machine check
>> records") extended MCE entries to report the microcode revision taken
>> from boot_cpu_data. Unfortunately, boot_cpu_data isn't updated on late
>> microcode loading,
> 
> Actually, I'd prefer if we fixed *that* instead by adding:
> 
> 	/* Update boot_cpu_data's revision too, if we're on the BSP: */
> 	if (c->cpu_index == boot_cpu_data.cpu_index)
> 		boot_cpu_data.microcode = <new rev>;
> 
> to the end of ->apply_microcode() functions so that boot_cpu_data has
> the correct revision too, in case something else queries it.
> 
> Thx.
> 
> -- 
> Regards/Gruss,
>    Boris.
> 
> ECO tip #101: Trim your mails when you reply.
> --

I've that patch in my tree already, I can post it.
I'm still curious on why you'd prefer to use boot_cpu_data for all
CPUs instead of using cpu_data(m->extcpu) though.

Regards,
Filippo


Amazon Development Center Germany GmbH
Berlin - Dresden - Aachen
main office: Krausenstr. 38, 10117 Berlin
Geschaeftsfuehrer: Dr. Ralf Herbrich, Christian Schlaeger
Ust-ID: DE289237879
Eingetragen am Amtsgericht Charlottenburg HRB 149173 B

Re: [PATCH] x86/MCE: Get microcode revision from cpu_info instead of boot_cpu_data

[Borislav Petkov]

On Fri, Jun 01, 2018 at 12:32:02PM +0000, Sironi, Filippo wrote:
> I've that patch in my tree already, I can post it.
> I'm still curious on why you'd prefer to use boot_cpu_data for all
> CPUs instead of using cpu_data(m->extcpu) though.

Well, for starters, boot_cpu_data having stale revision is a bug in
itself already. So fixing that is already the Right Thing(tm) to do.

Then, one fine day when the whole cpu_data mess is cleaned up,
boot_cpu_data will morph into the global descriptor representing CPU
features and keeping it uptodate now will facilitate the replacement
without introducing bugs.

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.
--

[PATCH] arch/x86: Fix boot_cpu_data.microcode version output

[Prarit Bhargava]

On systems where a runtime microcode update has occurred the microcode
version output in a MCE log record is wrong because
boot_cpu_data.microcode is not updated during runtime.

Update boot_cpu_data.microcode when the BSP's microcode is updated.

Fixes: fa94d0c6e0f3 ("x86/MCE: Save microcode revision in machine check records")
Suggested-by: Borislav Petkov <bp@alien8.com>
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Cc: stable@vger.kernel.org
Cc: sironi@amazon.de
Cc: tony.luck@intel.com
---
 arch/x86/kernel/cpu/microcode/amd.c   | 4 ++++
 arch/x86/kernel/cpu/microcode/intel.c | 4 ++++
 2 files changed, 8 insertions(+)

diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c
index 0624957aa068..7f5b32535ac7 100644
--- a/arch/x86/kernel/cpu/microcode/amd.c
+++ b/arch/x86/kernel/cpu/microcode/amd.c
@@ -537,6 +537,10 @@ static enum ucode_state apply_microcode_amd(int cpu)
 	uci->cpu_sig.rev = mc_amd->hdr.patch_id;
 	c->microcode = mc_amd->hdr.patch_id;
 
+	/* Update boot_cpu_data's revision too, if we're on the BSP: */
+	if (c->cpu_index == boot_cpu_data.cpu_index)
+		boot_cpu_data.microcode = rev;
+
 	return UCODE_UPDATED;
 }
 
diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
index 97ccf4c3b45b..256d336cbc04 100644
--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -851,6 +851,10 @@ static enum ucode_state apply_microcode_intel(int cpu)
 	uci->cpu_sig.rev = rev;
 	c->microcode = rev;
 
+	/* Update boot_cpu_data's revision too, if we're on the BSP: */
+	if (c->cpu_index == boot_cpu_data.cpu_index)
+		boot_cpu_data.microcode = rev;
+
 	return UCODE_UPDATED;
 }
 
-- 
2.17.0

Re: [PATCH] arch/x86: Fix boot_cpu_data.microcode version output

[Prarit Bhargava]

On 07/30/2018 01:49 PM, Prarit Bhargava wrote:
> On systems where a runtime microcode update has occurred the microcode
> version output in a MCE log record is wrong because
> boot_cpu_data.microcode is not updated during runtime.
> 
> Update boot_cpu_data.microcode when the BSP's microcode is updated.
> 
> Fixes: fa94d0c6e0f3 ("x86/MCE: Save microcode revision in machine check records")
> Suggested-by: Borislav Petkov <bp@alien8.com>
> Signed-off-by: Prarit Bhargava <prarit@redhat.com>
> Cc: stable@vger.kernel.org
> Cc: sironi@amazon.de
> Cc: tony.luck@intel.com
> ---
>  arch/x86/kernel/cpu/microcode/amd.c   | 4 ++++
>  arch/x86/kernel/cpu/microcode/intel.c | 4 ++++
>  2 files changed, 8 insertions(+)
> 
> diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c
> index 0624957aa068..7f5b32535ac7 100644
> --- a/arch/x86/kernel/cpu/microcode/amd.c
> +++ b/arch/x86/kernel/cpu/microcode/amd.c
> @@ -537,6 +537,10 @@ static enum ucode_state apply_microcode_amd(int cpu)
>  	uci->cpu_sig.rev = mc_amd->hdr.patch_id;
>  	c->microcode = mc_amd->hdr.patch_id;
>  
> +	/* Update boot_cpu_data's revision too, if we're on the BSP: */
> +	if (c->cpu_index == boot_cpu_data.cpu_index)
> +		boot_cpu_data.microcode = rev;
> +

Borislav, hold off on this.  I want to double check something with AMD.

I think this has to be

	boot_cpu_data.microcode = mc_amd->hdr.patch_id;

I'm going to grab some old/new microcode and test.  I do know that the Intel
update below works.

P.

>  	return UCODE_UPDATED;
>  }
>  
> diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
> index 97ccf4c3b45b..256d336cbc04 100644
> --- a/arch/x86/kernel/cpu/microcode/intel.c
> +++ b/arch/x86/kernel/cpu/microcode/intel.c
> @@ -851,6 +851,10 @@ static enum ucode_state apply_microcode_intel(int cpu)
>  	uci->cpu_sig.rev = rev;
>  	c->microcode = rev;
>  
> +	/* Update boot_cpu_data's revision too, if we're on the BSP: */
> +	if (c->cpu_index == boot_cpu_data.cpu_index)
> +		boot_cpu_data.microcode = rev;
> +
>  	return UCODE_UPDATED;
>  }
>  
> 

Re: [PATCH] arch/x86: Fix boot_cpu_data.microcode version output

[Borislav Petkov]

On Mon, Jul 30, 2018 at 01:53:50PM -0400, Prarit Bhargava wrote:
> I think this has to be
> 
> 	boot_cpu_data.microcode = mc_amd->hdr.patch_id;

Yes, it does.

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.
--

[PATCH v2] arch/x86: Fix boot_cpu_data.microcode version output

[Prarit Bhargava]

I tested this on AMD Ryzen & Intel Broadwell system and dumped the
boot_cpu_data before and after a microcode update.  On the Intel
system I also did a fatal MCE using mce-inject to confirm the output
from the mce handling code.

P.

---8<---

On systems where a runtime microcode update has occurred the microcode
version output in a MCE log record is wrong because
boot_cpu_data.microcode is not updated during runtime.

Update boot_cpu_data.microcode when the BSP's microcode is updated.

Fixes: fa94d0c6e0f3 ("x86/MCE: Save microcode revision in machine check records")
Suggested-by: Borislav Petkov <bp@alien8.com>
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Cc: stable@vger.kernel.org
Cc: sironi@amazon.de
Cc: tony.luck@intel.com
---
Changes in v2: Use mc_amd->hdr.patch_id on AMD

 arch/x86/kernel/cpu/microcode/amd.c   | 4 ++++
 arch/x86/kernel/cpu/microcode/intel.c | 4 ++++
 2 files changed, 8 insertions(+)

diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c
index 0624957aa068..63b072377ba4 100644
--- a/arch/x86/kernel/cpu/microcode/amd.c
+++ b/arch/x86/kernel/cpu/microcode/amd.c
@@ -537,6 +537,10 @@ static enum ucode_state apply_microcode_amd(int cpu)
 	uci->cpu_sig.rev = mc_amd->hdr.patch_id;
 	c->microcode = mc_amd->hdr.patch_id;
 
+	/* Update boot_cpu_data's revision too, if we're on the BSP: */
+	if (c->cpu_index == boot_cpu_data.cpu_index)
+		boot_cpu_data.microcode =  mc_amd->hdr.patch_id;
+
 	return UCODE_UPDATED;
 }
 
diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
index 97ccf4c3b45b..256d336cbc04 100644
--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -851,6 +851,10 @@ static enum ucode_state apply_microcode_intel(int cpu)
 	uci->cpu_sig.rev = rev;
 	c->microcode = rev;
 
+	/* Update boot_cpu_data's revision too, if we're on the BSP: */
+	if (c->cpu_index == boot_cpu_data.cpu_index)
+		boot_cpu_data.microcode = rev;
+
 	return UCODE_UPDATED;
 }
 
-- 
2.17.0

Re: [PATCH v2] arch/x86: Fix boot_cpu_data.microcode version output

[Sironi, Filippo]

> On 31. Jul 2018, at 13:27, Prarit Bhargava <prarit@redhat.com> wrote:
> 
> I tested this on AMD Ryzen & Intel Broadwell system and dumped the
> boot_cpu_data before and after a microcode update.  On the Intel
> system I also did a fatal MCE using mce-inject to confirm the output
> from the mce handling code.
> 
> P.
> 
> ---8<---
> 
> On systems where a runtime microcode update has occurred the microcode
> version output in a MCE log record is wrong because
> boot_cpu_data.microcode is not updated during runtime.
> 
> Update boot_cpu_data.microcode when the BSP's microcode is updated.
> 
> Fixes: fa94d0c6e0f3 ("x86/MCE: Save microcode revision in machine check records")
> Suggested-by: Borislav Petkov <bp@alien8.com>
> Signed-off-by: Prarit Bhargava <prarit@redhat.com>
> Cc: stable@vger.kernel.org
> Cc: sironi@amazon.de
> Cc: tony.luck@intel.com
> ---
> Changes in v2: Use mc_amd->hdr.patch_id on AMD
> 
> arch/x86/kernel/cpu/microcode/amd.c   | 4 ++++
> arch/x86/kernel/cpu/microcode/intel.c | 4 ++++
> 2 files changed, 8 insertions(+)
> 
> diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c
> index 0624957aa068..63b072377ba4 100644
> --- a/arch/x86/kernel/cpu/microcode/amd.c
> +++ b/arch/x86/kernel/cpu/microcode/amd.c
> @@ -537,6 +537,10 @@ static enum ucode_state apply_microcode_amd(int cpu)
> 	uci->cpu_sig.rev = mc_amd->hdr.patch_id;
> 	c->microcode = mc_amd->hdr.patch_id;
> 
> +	/* Update boot_cpu_data's revision too, if we're on the BSP: */
> +	if (c->cpu_index == boot_cpu_data.cpu_index)
> +		boot_cpu_data.microcode =  mc_amd->hdr.patch_id;
> +
> 	return UCODE_UPDATED;
> }
> 
> diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
> index 97ccf4c3b45b..256d336cbc04 100644
> --- a/arch/x86/kernel/cpu/microcode/intel.c
> +++ b/arch/x86/kernel/cpu/microcode/intel.c
> @@ -851,6 +851,10 @@ static enum ucode_state apply_microcode_intel(int cpu)
> 	uci->cpu_sig.rev = rev;
> 	c->microcode = rev;
> 
> +	/* Update boot_cpu_data's revision too, if we're on the BSP: */
> +	if (c->cpu_index == boot_cpu_data.cpu_index)
> +		boot_cpu_data.microcode = rev;
> +
> 	return UCODE_UPDATED;
> }

There may be a chance of skipping this code, I think.

If the microcode is loaded on the hyperthread sibling of the boot cpu
before being loaded on the boot cpu, the boot cpu will exit earlier
from apply_microcode_intel() - in if (rev >= mc->hdr.rev) { ... }.

(This seems to be possible in apply_microcode_amd() as well.)

In my tree with the aforementioned change - Intel only - I also had
the following patch:

diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
index 97ccf4c3b45b..4bc869e829eb 100644
--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -797,6 +797,7 @@ static enum ucode_state apply_microcode_intel(int cpu)
        struct microcode_intel *mc;
        static int prev_rev;
        u32 rev;
+       enum ucode_state ret;
 
        /* We should bind the task to the CPU */
        if (WARN_ON(raw_smp_processor_id() != cpu))
@@ -817,9 +818,8 @@ static enum ucode_state apply_microcode_intel(int cpu)
         */
        rev = intel_get_microcode_revision();
        if (rev >= mc->hdr.rev) {
-               uci->cpu_sig.rev = rev;
-               c->microcode = rev;
-               return UCODE_OK;
+               ret = UCODE_OK;
+               goto out;
        }
 
        /*
@@ -848,10 +848,12 @@ static enum ucode_state apply_microcode_intel(int cpu)
                prev_rev = rev;
        }
 
+       ret = UCODE_UPDATED;
+out:
        uci->cpu_sig.rev = rev;
        c->microcode = rev;
 
-       return UCODE_UPDATED;
+       return ret;
 }
 
 static enum ucode_state generic_load_microcode(int cpu, void *data, size_t size,

which prevents the issue.

> -- 
> 2.17.0
> 
> 

Amazon Development Center Germany GmbH
Berlin - Dresden - Aachen
main office: Krausenstr. 38, 10117 Berlin
Geschaeftsfuehrer: Dr. Ralf Herbrich, Christian Schlaeger
Ust-ID: DE289237879
Eingetragen am Amtsgericht Charlottenburg HRB 149173 B

Re: [PATCH v2] arch/x86: Fix boot_cpu_data.microcode version output

[Borislav Petkov]

On Tue, Jul 31, 2018 at 11:46:09AM +0000, Sironi, Filippo wrote:
> There may be a chance of skipping this code, I think.
> 
> If the microcode is loaded on the hyperthread sibling of the boot cpu
> before being loaded on the boot cpu, the boot cpu will exit earlier
> from apply_microcode_intel() - in if (rev >= mc->hdr.rev) { ... }.
> 
> (This seems to be possible in apply_microcode_amd() as well.)
> 
> In my tree with the aforementioned change - Intel only - I also had
> the following patch:

Yap, good catch.

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.
--

Re: [PATCH v2] arch/x86: Fix boot_cpu_data.microcode version output

[Sironi, Filippo]

> On 31. Jul 2018, at 15:00, Borislav Petkov <bp@alien8.de> wrote:
> 
> On Tue, Jul 31, 2018 at 11:46:09AM +0000, Sironi, Filippo wrote:
>> There may be a chance of skipping this code, I think.
>> 
>> If the microcode is loaded on the hyperthread sibling of the boot cpu
>> before being loaded on the boot cpu, the boot cpu will exit earlier
>> from apply_microcode_intel() - in if (rev >= mc->hdr.rev) { ... }.
>> 
>> (This seems to be possible in apply_microcode_amd() as well.)
>> 
>> In my tree with the aforementioned change - Intel only - I also had
>> the following patch:
> 
> Yap, good catch.
> 
> -- 
> Regards/Gruss,
>    Boris.
> 
> ECO tip #101: Trim your mails when you reply.
> --
> 

Boris, Prarit,

I've sent the patch the I had in my tree and extended it to cover
apply_microcode_amd(). I don't have an AMD host available for testing,
can one of you give that a spin?

Thanks,
Filippo


Amazon Development Center Germany GmbH
Berlin - Dresden - Aachen
main office: Krausenstr. 38, 10117 Berlin
Geschaeftsfuehrer: Dr. Ralf Herbrich, Christian Schlaeger
Ust-ID: DE289237879
Eingetragen am Amtsgericht Charlottenburg HRB 149173 B

Re: [PATCH v2] arch/x86: Fix boot_cpu_data.microcode version output

[Borislav Petkov]

(dropping stable@)

On Tue, Jul 31, 2018 at 07:27:39AM -0400, Prarit Bhargava wrote:
> I tested this on AMD Ryzen & Intel Broadwell system and dumped the
> boot_cpu_data before and after a microcode update.  On the Intel
> system I also did a fatal MCE using mce-inject to confirm the output
> from the mce handling code.

Ok, sending the two patches I've massaged into submission as a reply to
this message - please run them on your boxes. You can also inject MCEs
on the AMD box to verify - simply enable CONFIG_X86_MCE_INJECT, go to
debugfs and do, for example:

cd /sys/kernel/debug/mce-inject/
echo 10 > /sys/devices/system/machinecheck/machinecheck0/check_interval
echo 0x9c7d410092080813 > status; echo 0x000000006d3d483b > addr; echo 2 > cpu; echo 4 > bank; echo hw > flags
echo 0xbc00200000010015 > status; echo 0x00000000942e4d98 > addr; echo 6 > cpu; echo 2 > bank; echo hw > flags
echo 0xfe000010000b0c0f > status; echo 0xe1101add1e550012 > addr; echo 0xcafebeef > misc; echo 2 > cpu; echo hw > flags; echo 4 > bank

Thanks!

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.
--

[PATCH 1/2] x86/microcode: Make sure boot_cpu_data.microcode is up-to-date

[Borislav Petkov]

From: Prarit Bhargava <prarit@redhat.com>

The MCE code uses boot_cpu_data.microcode to prepare the MCE record.
However, on systems where late microcode update has occurred, the
microcode revision output in a MCE log record is wrong because
boot_cpu_data.microcode is not updated when the microcode gets updated.

However, the microcode revision saved in boot_cpu_data's microcode
member should be kept up-to-date, regardless, for consistency.

Make it so.

Fixes: fa94d0c6e0f3 ("x86/MCE: Save microcode revision in machine check records")
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: sironi@amazon.de
Cc: stable@vger.kernel.org
Cc: x86-ml <x86@kernel.org>
Link: http://lkml.kernel.org/r/20180731112739.32338-1-prarit@redhat.com
[ Make commit message more precise. ]
Signed-off-by: Borislav Petkov <bp@suse.de>
---
 arch/x86/kernel/cpu/microcode/amd.c   | 4 ++++
 arch/x86/kernel/cpu/microcode/intel.c | 4 ++++
 2 files changed, 8 insertions(+)

diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c
index 0624957aa068..63b072377ba4 100644
--- a/arch/x86/kernel/cpu/microcode/amd.c
+++ b/arch/x86/kernel/cpu/microcode/amd.c
@@ -537,6 +537,10 @@ static enum ucode_state apply_microcode_amd(int cpu)
 	uci->cpu_sig.rev = mc_amd->hdr.patch_id;
 	c->microcode = mc_amd->hdr.patch_id;
 
+	/* Update boot_cpu_data's revision too, if we're on the BSP: */
+	if (c->cpu_index == boot_cpu_data.cpu_index)
+		boot_cpu_data.microcode =  mc_amd->hdr.patch_id;
+
 	return UCODE_UPDATED;
 }
 
diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
index 97ccf4c3b45b..256d336cbc04 100644
--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -851,6 +851,10 @@ static enum ucode_state apply_microcode_intel(int cpu)
 	uci->cpu_sig.rev = rev;
 	c->microcode = rev;
 
+	/* Update boot_cpu_data's revision too, if we're on the BSP: */
+	if (c->cpu_index == boot_cpu_data.cpu_index)
+		boot_cpu_data.microcode = rev;
+
 	return UCODE_UPDATED;
 }
 
-- 
2.18.0.321.gffc6fa0e3962


-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.
--

[PATCH 2/2] x86/microcode: Update the new microcode revision unconditionally

[Borislav Petkov]

From: Filippo Sironi <sironi@amazon.de>

Handle the case where microcode gets loaded on the BSP's hyperthread
sibling first and the boot_cpu_data's microcode revision doesn't get
updated because of early exit due to the siblings sharing a microcode
engine.

For that, simply write the updated revision on all CPUs unconditionally.

Signed-off-by: Filippo Sironi <sironi@amazon.de>
Cc: prarit@redhat.com
Cc: stable@vger.kernel.org
Cc: x86-ml <x86@kernel.org>
Link: http://lkml.kernel.org/r/1533050970-14385-1-git-send-email-sironi@amazon.de
[ Massage everything a bit. ]
Signed-off-by: Borislav Petkov <bp@suse.de>
---
 arch/x86/kernel/cpu/microcode/amd.c   | 22 +++++++++++++---------
 arch/x86/kernel/cpu/microcode/intel.c | 13 ++++++++-----
 2 files changed, 21 insertions(+), 14 deletions(-)

diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c
index 63b072377ba4..07b5fc00b188 100644
--- a/arch/x86/kernel/cpu/microcode/amd.c
+++ b/arch/x86/kernel/cpu/microcode/amd.c
@@ -504,6 +504,7 @@ static enum ucode_state apply_microcode_amd(int cpu)
 	struct microcode_amd *mc_amd;
 	struct ucode_cpu_info *uci;
 	struct ucode_patch *p;
+	enum ucode_state ret;
 	u32 rev, dummy;
 
 	BUG_ON(raw_smp_processor_id() != cpu);
@@ -521,9 +522,8 @@ static enum ucode_state apply_microcode_amd(int cpu)
 
 	/* need to apply patch? */
 	if (rev >= mc_amd->hdr.patch_id) {
-		c->microcode = rev;
-		uci->cpu_sig.rev = rev;
-		return UCODE_OK;
+		ret = UCODE_OK;
+		goto out;
 	}
 
 	if (__apply_microcode_amd(mc_amd)) {
@@ -531,17 +531,21 @@ static enum ucode_state apply_microcode_amd(int cpu)
 			cpu, mc_amd->hdr.patch_id);
 		return UCODE_ERROR;
 	}
-	pr_info("CPU%d: new patch_level=0x%08x\n", cpu,
-		mc_amd->hdr.patch_id);
 
-	uci->cpu_sig.rev = mc_amd->hdr.patch_id;
-	c->microcode = mc_amd->hdr.patch_id;
+	rev = mc_amd->hdr.patch_id;
+	ret = UCODE_UPDATED;
+
+	pr_info("CPU%d: new patch_level=0x%08x\n", cpu, rev);
+
+out:
+	uci->cpu_sig.rev = rev;
+	c->microcode	 = rev;
 
 	/* Update boot_cpu_data's revision too, if we're on the BSP: */
 	if (c->cpu_index == boot_cpu_data.cpu_index)
-		boot_cpu_data.microcode =  mc_amd->hdr.patch_id;
+		boot_cpu_data.microcode = rev;
 
-	return UCODE_UPDATED;
+	return ret;
 }
 
 static int install_equiv_cpu_table(const u8 *buf)
diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
index 256d336cbc04..16936a24795c 100644
--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -795,6 +795,7 @@ static enum ucode_state apply_microcode_intel(int cpu)
 	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 	struct cpuinfo_x86 *c = &cpu_data(cpu);
 	struct microcode_intel *mc;
+	enum ucode_state ret;
 	static int prev_rev;
 	u32 rev;
 
@@ -817,9 +818,8 @@ static enum ucode_state apply_microcode_intel(int cpu)
 	 */
 	rev = intel_get_microcode_revision();
 	if (rev >= mc->hdr.rev) {
-		uci->cpu_sig.rev = rev;
-		c->microcode = rev;
-		return UCODE_OK;
+		ret = UCODE_OK;
+		goto out;
 	}
 
 	/*
@@ -848,14 +848,17 @@ static enum ucode_state apply_microcode_intel(int cpu)
 		prev_rev = rev;
 	}
 
+	ret = UCODE_UPDATED;
+
+out:
 	uci->cpu_sig.rev = rev;
-	c->microcode = rev;
+	c->microcode	 = rev;
 
 	/* Update boot_cpu_data's revision too, if we're on the BSP: */
 	if (c->cpu_index == boot_cpu_data.cpu_index)
 		boot_cpu_data.microcode = rev;
 
-	return UCODE_UPDATED;
+	return ret;
 }
 
 static enum ucode_state generic_load_microcode(int cpu, void *data, size_t size,
-- 
2.18.0.321.gffc6fa0e3962


-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.
--

Re: [PATCH v2] arch/x86: Fix boot_cpu_data.microcode version output

[Prarit Bhargava]

On 08/01/2018 11:43 AM, Borislav Petkov wrote:
> (dropping stable@)
> 
> On Tue, Jul 31, 2018 at 07:27:39AM -0400, Prarit Bhargava wrote:
>> I tested this on AMD Ryzen & Intel Broadwell system and dumped the
>> boot_cpu_data before and after a microcode update.  On the Intel
>> system I also did a fatal MCE using mce-inject to confirm the output
>> from the mce handling code.
> 
> Ok, sending the two patches I've massaged into submission as a reply to
> this message - please run them on your boxes. You can also inject MCEs
> on the AMD box to verify - simply enable CONFIG_X86_MCE_INJECT, go to
> debugfs and do, for example:
> 
> cd /sys/kernel/debug/mce-inject/
> echo 10 > /sys/devices/system/machinecheck/machinecheck0/check_interval
> echo 0x9c7d410092080813 > status; echo 0x000000006d3d483b > addr; echo 2 > cpu; echo 4 > bank; echo hw > flags
> echo 0xbc00200000010015 > status; echo 0x00000000942e4d98 > addr; echo 6 > cpu; echo 2 > bank; echo hw > flags
> echo 0xfe000010000b0c0f > status; echo 0xe1101add1e550012 > addr; echo 0xcafebeef > misc; echo 2 > cpu; echo hw > flags; echo 4 > bank
> 

Borislav, I'm not sure if you saw his comments but Oleksandr, cc'd, has an
objection to overwriting the stored microcode version in boot_cpu_data.  He has
found that information useful in debugging microcode issues.

P.

> Thanks!
> 

[tip:x86/urgent] x86/microcode: Make sure boot_cpu_data.microcode is up-to-date

[tip-bot for Prarit Bhargava]

Commit-ID:  370a132bb2227ff76278f98370e0e701d86ff752
Gitweb:     https://git.kernel.org/tip/370a132bb2227ff76278f98370e0e701d86ff752
Author:     Prarit Bhargava <prarit@redhat.com>
AuthorDate: Tue, 31 Jul 2018 07:27:39 -0400
Committer:  Thomas Gleixner <tglx@linutronix.de>
CommitDate: Sun, 2 Sep 2018 14:10:54 +0200

x86/microcode: Make sure boot_cpu_data.microcode is up-to-date

When preparing an MCE record for logging, boot_cpu_data.microcode is used
to read out the microcode revision on the box.

However, on systems where late microcode update has happened, the microcode
revision output in a MCE log record is wrong because
boot_cpu_data.microcode is not updated when the microcode gets updated.

But, the microcode revision saved in boot_cpu_data's microcode member
should be kept up-to-date, regardless, for consistency.

Make it so.

Fixes: fa94d0c6e0f3 ("x86/MCE: Save microcode revision in machine check records")
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: sironi@amazon.de
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20180731112739.32338-1-prarit@redhat.com
---
 arch/x86/kernel/cpu/microcode/amd.c   | 4 ++++
 arch/x86/kernel/cpu/microcode/intel.c | 4 ++++
 2 files changed, 8 insertions(+)

diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c
index 0624957aa068..602f17134103 100644
--- a/arch/x86/kernel/cpu/microcode/amd.c
+++ b/arch/x86/kernel/cpu/microcode/amd.c
@@ -537,6 +537,10 @@ static enum ucode_state apply_microcode_amd(int cpu)
 	uci->cpu_sig.rev = mc_amd->hdr.patch_id;
 	c->microcode = mc_amd->hdr.patch_id;
 
+	/* Update boot_cpu_data's revision too, if we're on the BSP: */
+	if (c->cpu_index == boot_cpu_data.cpu_index)
+		boot_cpu_data.microcode = mc_amd->hdr.patch_id;
+
 	return UCODE_UPDATED;
 }
 
diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
index 97ccf4c3b45b..256d336cbc04 100644
--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -851,6 +851,10 @@ static enum ucode_state apply_microcode_intel(int cpu)
 	uci->cpu_sig.rev = rev;
 	c->microcode = rev;
 
+	/* Update boot_cpu_data's revision too, if we're on the BSP: */
+	if (c->cpu_index == boot_cpu_data.cpu_index)
+		boot_cpu_data.microcode = rev;
+
 	return UCODE_UPDATED;
 }