diff mbox series

[01/13] x86/microcode/intel: Print old and new rev after early microcode update

Message ID 20221014200913.14644-2-ashok.raj@intel.com
State New
Headers
Series Make microcode loading more robust |

Commit Message

Ashok Raj Oct. 14, 2022, 8:09 p.m. UTC 
  Print the old and new versions of microcode after an early load is
complete. This is useful to know what version was loaded by BIOS before an
early microcode load.

Signed-off-by: Ashok Raj <ashok.raj@intel.com>
---
 arch/x86/kernel/cpu/microcode/intel.c | 25 +++++++++++++++----------
 1 file changed, 15 insertions(+), 10 deletions(-)

Comments

Borislav Petkov Oct. 19, 2022, 10:12 a.m. UTC | #1 
On Fri, Oct 14, 2022 at 01:09:01PM -0700, Ashok Raj wrote:
> @@ -435,10 +435,10 @@ static bool load_builtin_intel_microcode(struct cpio_data *cp)
>   * Print ucode update info.
>   */
>  static void
> -print_ucode_info(struct ucode_cpu_info *uci, unsigned int date)
> +print_ucode_info(u32 old_rev, struct ucode_cpu_info *uci, unsigned int date)
>  {
> -	pr_info_once("microcode updated early to revision 0x%x, date = %04x-%02x-%02x\n",
> -		     uci->cpu_sig.rev,
> +	pr_info_once("microcode updated early from 0x%x to revision 0x%x, date = %04x-%02x-%02x\n",

That already has the "microcode: " prefix from pr_fmt so make that

		     "early update: 0x%x -> 0x%x, date = %04x-%02x-%02x\n"

and fix the late update message too, pls, to look the same without the
"early" in there.

> @@ -479,13 +481,15 @@ static void print_ucode(struct ucode_cpu_info *uci)
>  
>  	delay_ucode_info_p = (int *)__pa_nodebug(&delay_ucode_info);
>  	current_mc_date_p = (int *)__pa_nodebug(&current_mc_date);
> +	old_rev_p = (u32 *)__pa_nodebug(&early_old_rev);

No, you should add a

	u32 prev_rev;

to struct ucode_cpu_info, save it there and access it where needed.

Then I can do the same prev -> next revision dumping on the AMD side.

Thx.
Ashok Raj Oct. 19, 2022, 1:30 p.m. UTC | #2 
On Wed, Oct 19, 2022 at 12:12:00PM +0200, Borislav Petkov wrote:
> On Fri, Oct 14, 2022 at 01:09:01PM -0700, Ashok Raj wrote:
> > @@ -435,10 +435,10 @@ static bool load_builtin_intel_microcode(struct cpio_data *cp)
> >   * Print ucode update info.
> >   */
> >  static void
> > -print_ucode_info(struct ucode_cpu_info *uci, unsigned int date)
> > +print_ucode_info(u32 old_rev, struct ucode_cpu_info *uci, unsigned int date)
> >  {
> > -	pr_info_once("microcode updated early to revision 0x%x, date = %04x-%02x-%02x\n",
> > -		     uci->cpu_sig.rev,
> > +	pr_info_once("microcode updated early from 0x%x to revision 0x%x, date = %04x-%02x-%02x\n",
> 
> That already has the "microcode: " prefix from pr_fmt so make that
> 
> 		     "early update: 0x%x -> 0x%x, date = %04x-%02x-%02x\n"
> 
> and fix the late update message too, pls, to look the same without the
> "early" in there.

Good point, Fixed this.

> 
> > @@ -479,13 +481,15 @@ static void print_ucode(struct ucode_cpu_info *uci)
> >  
> >  	delay_ucode_info_p = (int *)__pa_nodebug(&delay_ucode_info);
> >  	current_mc_date_p = (int *)__pa_nodebug(&current_mc_date);
> > +	old_rev_p = (u32 *)__pa_nodebug(&early_old_rev);
> 
> No, you should add a
> 
> 	u32 prev_rev;
> 
> to struct ucode_cpu_info, save it there and access it where needed.

This seems like some 32bit restriction that we can't use printk early? I
wasn't sure, so I just followed what was done prior.

Today it seems we are doing the print just for BSP, not for all CPUs. Just
like what we do after update. Do you want to save this for all CPUs in
ucode_cpu_info[] for the previous revision?

Also its weird that cpu/common.c calls show_ucode_info_early(), but only
defined in cpu/microcode/intel.c. There is none in the AMD side.

Do you think we could have a generic function in cpu/microcore/core.c, that
calls vendor specific calls like the other early functions?
> 
> Then I can do the same prev -> next revision dumping on the AMD side.
> 

Cheers,
Ashok
diff mbox series

Patch

diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
index 1fcbd671f1df..cf1e2c30b230 100644
--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -435,10 +435,10 @@  static bool load_builtin_intel_microcode(struct cpio_data *cp)
  * Print ucode update info.
  */
 static void
-print_ucode_info(struct ucode_cpu_info *uci, unsigned int date)
+print_ucode_info(u32 old_rev, struct ucode_cpu_info *uci, unsigned int date)
 {
-	pr_info_once("microcode updated early to revision 0x%x, date = %04x-%02x-%02x\n",
-		     uci->cpu_sig.rev,
+	pr_info_once("microcode updated early from 0x%x to revision 0x%x, date = %04x-%02x-%02x\n",
+		     old_rev, uci->cpu_sig.rev,
 		     date & 0xffff,
 		     date >> 24,
 		     (date >> 16) & 0xff);
@@ -448,6 +448,7 @@  print_ucode_info(struct ucode_cpu_info *uci, unsigned int date)
 
 static int delay_ucode_info;
 static int current_mc_date;
+static u32 early_old_rev;
 
 /*
  * Print early updated ucode info after printk works. This is delayed info dump.
@@ -458,7 +459,7 @@  void show_ucode_info_early(void)
 
 	if (delay_ucode_info) {
 		intel_cpu_collect_info(&uci);
-		print_ucode_info(&uci, current_mc_date);
+		print_ucode_info(early_old_rev, &uci, current_mc_date);
 		delay_ucode_info = 0;
 	}
 }
@@ -467,11 +468,12 @@  void show_ucode_info_early(void)
  * At this point, we can not call printk() yet. Delay printing microcode info in
  * show_ucode_info_early() until printk() works.
  */
-static void print_ucode(struct ucode_cpu_info *uci)
+static void print_ucode(u32 old_rev, struct ucode_cpu_info *uci)
 {
 	struct microcode_intel *mc;
 	int *delay_ucode_info_p;
 	int *current_mc_date_p;
+	u32 *old_rev_p;
 
 	mc = uci->mc;
 	if (!mc)
@@ -479,13 +481,15 @@  static void print_ucode(struct ucode_cpu_info *uci)
 
 	delay_ucode_info_p = (int *)__pa_nodebug(&delay_ucode_info);
 	current_mc_date_p = (int *)__pa_nodebug(&current_mc_date);
+	old_rev_p = (u32 *)__pa_nodebug(&early_old_rev);
 
 	*delay_ucode_info_p = 1;
 	*current_mc_date_p = mc->hdr.date;
+	*old_rev_p = old_rev;
 }
 #else
 
-static inline void print_ucode(struct ucode_cpu_info *uci)
+static inline void print_ucode(u32 old_rev, struct ucode_cpu_info *uci)
 {
 	struct microcode_intel *mc;
 
@@ -493,14 +497,14 @@  static inline void print_ucode(struct ucode_cpu_info *uci)
 	if (!mc)
 		return;
 
-	print_ucode_info(uci, mc->hdr.date);
+	print_ucode_info(old_rev, uci, mc->hdr.date);
 }
 #endif
 
 static int apply_microcode_early(struct ucode_cpu_info *uci, bool early)
 {
 	struct microcode_intel *mc;
-	u32 rev;
+	u32 old_rev, rev;
 
 	mc = uci->mc;
 	if (!mc)
@@ -517,6 +521,7 @@  static int apply_microcode_early(struct ucode_cpu_info *uci, bool early)
 		return UCODE_OK;
 	}
 
+	old_rev = rev;
 	/*
 	 * Writeback and invalidate caches before updating microcode to avoid
 	 * internal issues depending on what the microcode is updating.
@@ -533,9 +538,9 @@  static int apply_microcode_early(struct ucode_cpu_info *uci, bool early)
 	uci->cpu_sig.rev = rev;
 
 	if (early)
-		print_ucode(uci);
+		print_ucode(old_rev, uci);
 	else
-		print_ucode_info(uci, mc->hdr.date);
+		print_ucode_info(old_rev, uci, mc->hdr.date);
 
 	return 0;
 }