[Patch v5 0/5] Some fixes and cleanups for microcode

[Patch v5 0/5] Some fixes and cleanups for microcode

[Ashok Raj]

Hi Boris,

Here is a followup after v4[1] with all comments addressed.

Please review and apply.

Changes since v4[1]:

Boris:
	- Fix compile errors for 32bit.
	- Drop last patch that displays loading failure during early load.

Changes since v3[2]:

Tony, Ingo
	- Display clear message when microcode load fails.

Boris
	- Changed function names microcode_store_cpu_caps() ->
	  store_cpu_caps().
	- Fix commit logs 
	- Document new parameter to microcode_check()

Dave Hansen
	- Fix commit log
	- Change parameter names from generic to something that's
	  meaningful.

[1] https://lore.kernel.org/lkml/20230109153555.4986-1-ashok.raj@intel.com/
[2] https://lore.kernel.org/lkml/20230103180212.333496-1-ashok.raj@intel.com/

Ashok Raj (5):
  x86/microcode: Add a parameter to microcode_check() to store CPU
    capabilities
  x86/microcode/core: Take a snapshot before and after applying
    microcode
  x86/microcode: Display revisions only when update is successful
  x86/microcode/intel: Use a plain revision argument for
    print_ucode_rev()
  x86/microcode/intel: Print old and new rev during early boot

 arch/x86/include/asm/processor.h      |  3 +-
 arch/x86/kernel/cpu/common.c          | 48 +++++++++++++++++++--------
 arch/x86/kernel/cpu/microcode/core.c  | 20 ++++++++---
 arch/x86/kernel/cpu/microcode/intel.c | 41 +++++++++--------------
 4 files changed, 69 insertions(+), 43 deletions(-)


base-commit: 5dc4c995db9eb45f6373a956eb1f69460e69e6d4

Cc: LKML <linux-kernel@vger.kernel.org>
Cc: x86 <x86@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: Reinette Chatre <reinette.chatre@intel.com>
Cc: Thomas Gleixner (Intel) <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Stefan Talpalaru <stefantalpalaru@yahoo.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Peter Zilstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Andrew Cooper <Andrew.Cooper3@citrix.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
-- 
2.34.1

[Patch v5 1/5] x86/microcode: Add a parameter to microcode_check() to store CPU capabilities

[Ashok Raj]

Add a parameter to store CPU capabilities before performing a microcode
update so that the code later can compare CPU capabilities before and after
performing the update.

Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Cc: LKML <linux-kernel@vger.kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>
Cc: x86 <x86@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: Reinette Chatre <reinette.chatre@intel.com>
Cc: Thomas Gleixner (Intel) <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Stefan Talpalaru <stefantalpalaru@yahoo.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Peter Zilstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Andrew Cooper <Andrew.Cooper3@citrix.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
---
Changes since V3

Boris:
- Fix commit log to drop "next patch".
- Add documentation to new parameter to microcode_check()
---
 arch/x86/include/asm/processor.h     |  2 +-
 arch/x86/kernel/cpu/common.c         | 21 +++++++++++++--------
 arch/x86/kernel/cpu/microcode/core.c |  3 ++-
 3 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 4e35c66edeb7..f256a4ddd25d 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -697,7 +697,7 @@ bool xen_set_default_idle(void);
 #endif
 
 void __noreturn stop_this_cpu(void *dummy);
-void microcode_check(void);
+void microcode_check(struct cpuinfo_x86 *prev_info);
 
 enum l1tf_mitigations {
 	L1TF_MITIGATION_OFF,
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 9cfca3d7d0e2..0f5a173d0871 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -2297,30 +2297,35 @@ void cpu_init_secondary(void)
 #endif
 
 #ifdef CONFIG_MICROCODE_LATE_LOADING
-/*
+/**
+ * microcode_check() - Check if any CPU capabilities changed after an update.
+ * @prev_info:	CPU capabilities stored before an update.
+ *
  * The microcode loader calls this upon late microcode load to recheck features,
  * only when microcode has been updated. Caller holds microcode_mutex and CPU
  * hotplug lock.
+ *
+ * Return: None
  */
-void microcode_check(void)
+void microcode_check(struct cpuinfo_x86 *prev_info)
 {
-	struct cpuinfo_x86 info;
-
 	perf_check_microcode();
 
 	/* Reload CPUID max function as it might've changed. */
-	info.cpuid_level = cpuid_eax(0);
+	prev_info->cpuid_level = cpuid_eax(0);
 
 	/*
 	 * Copy all capability leafs to pick up the synthetic ones so that
 	 * memcmp() below doesn't fail on that. The ones coming from CPUID will
 	 * get overwritten in get_cpu_cap().
 	 */
-	memcpy(&info.x86_capability, &boot_cpu_data.x86_capability, sizeof(info.x86_capability));
+	memcpy(&prev_info->x86_capability, &boot_cpu_data.x86_capability,
+	       sizeof(prev_info->x86_capability));
 
-	get_cpu_cap(&info);
+	get_cpu_cap(prev_info);
 
-	if (!memcmp(&info.x86_capability, &boot_cpu_data.x86_capability, sizeof(info.x86_capability)))
+	if (!memcmp(&prev_info->x86_capability, &boot_cpu_data.x86_capability,
+		    sizeof(prev_info->x86_capability)))
 		return;
 
 	pr_warn("x86/CPU: CPU features have changed after loading microcode, but might not take effect.\n");
diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c
index c4cd7328177b..e39d83be794b 100644
--- a/arch/x86/kernel/cpu/microcode/core.c
+++ b/arch/x86/kernel/cpu/microcode/core.c
@@ -439,6 +439,7 @@ static int __reload_late(void *info)
 static int microcode_reload_late(void)
 {
 	int old = boot_cpu_data.microcode, ret;
+	struct cpuinfo_x86 prev_info;
 
 	pr_err("Attempting late microcode loading - it is dangerous and taints the kernel.\n");
 	pr_err("You should switch to early loading, if possible.\n");
@@ -448,7 +449,7 @@ static int microcode_reload_late(void)
 
 	ret = stop_machine_cpuslocked(__reload_late, NULL, cpu_online_mask);
 	if (ret == 0)
-		microcode_check();
+		microcode_check(&prev_info);
 
 	pr_info("Reload completed, microcode revision: 0x%x -> 0x%x\n",
 		old, boot_cpu_data.microcode);
-- 
2.34.1

[Patch v5 2/5] x86/microcode/core: Take a snapshot before and after applying microcode

[Ashok Raj]

The kernel caches features about each CPU's features at boot in an
x86_capability[] structure. The microcode update takes one snapshot and
compares it with the saved copy at boot.

However, the capabilities in the boot copy can be turned off as a result of
certain command line parameters or configuration restrictions. This can
cause a mismatch when comparing the values before and after the microcode
update.

microcode_check() is called after an update to report any previously
cached CPUID bits might have changed due to the update.

store_cpu_caps() basically stores the original CPU reported
values and not the OS modified values. This will avoid giving a false
warning even when no capabilities have changed.

Ignore the capabilities recorded at boot. Take a new snapshot before the
update and compare with a snapshot after the update to eliminate the false
warning.

Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Fixes: 1008c52c09dc ("x86/CPU: Add a microcode loader callback")
Cc: LKML <linux-kernel@vger.kernel.org>
Cc: x86 <x86@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: Reinette Chatre <reinette.chatre@intel.com>
Cc: Thomas Gleixner (Intel) <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Stefan Talpalaru <stefantalpalaru@yahoo.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Peter Zilstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Andrew Cooper <Andrew.Cooper3@citrix.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
---
Changes since V3:
- Boris
	- Change function from microcode_store_cpu_caps -> store_cpu_caps
	- Split comments in store_cpu_caps().

- Dave Hansen
	- Change parameters names to something meaninful.
	- Cleaned up some commit log.

Changes since V2:

- Boris
	- Keep microcode_check() inside cpu/common.c and not bleed
	  get_cpu_caps() outside of core code.

- Thomas
	- Commit log changes.
---
 arch/x86/include/asm/processor.h     |  1 +
 arch/x86/kernel/cpu/common.c         | 39 ++++++++++++++++++++--------
 arch/x86/kernel/cpu/microcode/core.c |  7 +++++
 3 files changed, 36 insertions(+), 11 deletions(-)

diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index f256a4ddd25d..a77dee6a2bf2 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -698,6 +698,7 @@ bool xen_set_default_idle(void);
 
 void __noreturn stop_this_cpu(void *dummy);
 void microcode_check(struct cpuinfo_x86 *prev_info);
+void store_cpu_caps(struct cpuinfo_x86 *info);
 
 enum l1tf_mitigations {
 	L1TF_MITIGATION_OFF,
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 0f5a173d0871..f5c6feed6c26 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -2297,6 +2297,29 @@ void cpu_init_secondary(void)
 #endif
 
 #ifdef CONFIG_MICROCODE_LATE_LOADING
+/**
+ * store_cpu_caps() - Store a snapshot of CPU capabilities
+ *
+ * Returns: None
+ */
+void store_cpu_caps(struct cpuinfo_x86 *curr_info)
+{
+	/* Reload CPUID max function as it might've changed. */
+	curr_info->cpuid_level = cpuid_eax(0);
+
+	/*
+	 * Copy all capability leafs to pick up the synthetic ones
+	 */
+	memcpy(&curr_info->x86_capability, &boot_cpu_data.x86_capability,
+	       sizeof(curr_info->x86_capability));
+
+	/*
+	 * Capabilities copied from BSP will get overwritten
+	 * with the snapshot below
+	 */
+	get_cpu_cap(curr_info);
+}
+
 /**
  * microcode_check() - Check if any CPU capabilities changed after an update.
  * @prev_info:	CPU capabilities stored before an update.
@@ -2309,22 +2332,16 @@ void cpu_init_secondary(void)
  */
 void microcode_check(struct cpuinfo_x86 *prev_info)
 {
-	perf_check_microcode();
+	struct cpuinfo_x86 curr_info;
 
-	/* Reload CPUID max function as it might've changed. */
-	prev_info->cpuid_level = cpuid_eax(0);
+	perf_check_microcode();
 
 	/*
-	 * Copy all capability leafs to pick up the synthetic ones so that
-	 * memcmp() below doesn't fail on that. The ones coming from CPUID will
-	 * get overwritten in get_cpu_cap().
+	 * Get a snapshot of CPU capabilities
 	 */
-	memcpy(&prev_info->x86_capability, &boot_cpu_data.x86_capability,
-	       sizeof(prev_info->x86_capability));
-
-	get_cpu_cap(prev_info);
+	store_cpu_caps(&curr_info);
 
-	if (!memcmp(&prev_info->x86_capability, &boot_cpu_data.x86_capability,
+	if (!memcmp(&prev_info->x86_capability, &curr_info.x86_capability,
 		    sizeof(prev_info->x86_capability)))
 		return;
 
diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c
index e39d83be794b..bb943a91a364 100644
--- a/arch/x86/kernel/cpu/microcode/core.c
+++ b/arch/x86/kernel/cpu/microcode/core.c
@@ -447,6 +447,13 @@ static int microcode_reload_late(void)
 	atomic_set(&late_cpus_in,  0);
 	atomic_set(&late_cpus_out, 0);
 
+	/*
+	 * Take a snapshot before the microcode update, so we can compare
+	 * them after the update is successful to check for any bits
+	 * changed.
+	 */
+	store_cpu_caps(&prev_info);
+
 	ret = stop_machine_cpuslocked(__reload_late, NULL, cpu_online_mask);
 	if (ret == 0)
 		microcode_check(&prev_info);
-- 
2.34.1

[Patch v5 3/5] x86/microcode: Display revisions only when update is successful

[Ashok Raj]

Right now, microcode loading failures and successes print the same
message "Reloading completed". This is misleading to users.

Display the updated revision number only if an update was successful.
Display "Reload completed" only if the update was successful, otherwise
report the update failed.

Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Fixes: 9bd681251b7c ("x86/microcode: Announce reload operation's completion")
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/lkml/874judpqqd.ffs@tglx/
Cc: LKML <linux-kernel@vger.kernel.org>
Cc: x86 <x86@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: Reinette Chatre <reinette.chatre@intel.com>
Cc: Thomas Gleixner (Intel) <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Stefan Talpalaru <stefantalpalaru@yahoo.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Peter Zilstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Andrew Cooper <Andrew.Cooper3@citrix.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
---
Changes since V3:

Tony, Ingo
	- Print clear message if the update was successful or not.
---
 arch/x86/kernel/cpu/microcode/core.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c
index bb943a91a364..d7cbc83df9b6 100644
--- a/arch/x86/kernel/cpu/microcode/core.c
+++ b/arch/x86/kernel/cpu/microcode/core.c
@@ -455,11 +455,15 @@ static int microcode_reload_late(void)
 	store_cpu_caps(&prev_info);
 
 	ret = stop_machine_cpuslocked(__reload_late, NULL, cpu_online_mask);
-	if (ret == 0)
-		microcode_check(&prev_info);
 
-	pr_info("Reload completed, microcode revision: 0x%x -> 0x%x\n",
-		old, boot_cpu_data.microcode);
+	if (ret == 0) {
+		pr_info("Reload completed, microcode revision: 0x%x -> 0x%x\n",
+			old, boot_cpu_data.microcode);
+		microcode_check(&prev_info);
+	} else {
+		pr_info("Reload failed, current microcode revision: 0x%x\n",
+			boot_cpu_data.microcode);
+	}
 
 	return ret;
 }
-- 
2.34.1

[Patch v5 4/5] x86/microcode/intel: Use a plain revision argument for print_ucode_rev()

[Ashok Raj]

print_ucode_rev() takes a struct ucode_cpu_info argument. The sole purpose
of it is to print the microcode revision.

The only available ucode_cpu_info always describes the currently loaded
microcode revision. After a microcode update is successful, this is the new
revision, or on failure it is the original revision.

Subsequent changes need to print both the original and new revision, but
the original version will be cached in a plain integer, which makes the
code inconsistent.

Replace the struct ucode_cpu_info argument with a plain integer which
contains the revision number and adjust the call sites accordingly.

No functional change.

Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: LKML <linux-kernel@vger.kernel.org>
Cc: x86 <x86@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: Reinette Chatre <reinette.chatre@intel.com>
Cc: Thomas Gleixner (Intel) <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Stefan Talpalaru <stefantalpalaru@yahoo.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Peter Zilstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Andrew Cooper <Andrew.Cooper3@citrix.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
---
Changes since v4:
Boris:
 - Removed unused variable mc, and fixed compile error in
   show_ucode_info_early()

Changes since V1:

Thomas:
 - Updated commit log as suggested
 - Remove the line break after static void before print_ucode_info
---
 arch/x86/kernel/cpu/microcode/intel.c | 32 ++++++++-------------------
 1 file changed, 9 insertions(+), 23 deletions(-)

diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
index 6bebc46ad8b1..146a60a9449a 100644
--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -310,13 +310,10 @@ 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)
+static void print_ucode_info(unsigned int new_rev, unsigned int date)
 {
 	pr_info_once("microcode updated early to revision 0x%x, date = %04x-%02x-%02x\n",
-		     uci->cpu_sig.rev,
-		     date & 0xffff,
-		     date >> 24,
+		     new_rev, date & 0xffff, date >> 24,
 		     (date >> 16) & 0xff);
 }
 
@@ -334,7 +331,7 @@ 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(uci.cpu_sig.rev, current_mc_date);
 		delay_ucode_info = 0;
 	}
 }
@@ -343,33 +340,22 @@ 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(int new_rev, int date)
 {
-	struct microcode_intel *mc;
 	int *delay_ucode_info_p;
 	int *current_mc_date_p;
 
-	mc = uci->mc;
-	if (!mc)
-		return;
-
 	delay_ucode_info_p = (int *)__pa_nodebug(&delay_ucode_info);
 	current_mc_date_p = (int *)__pa_nodebug(&current_mc_date);
 
 	*delay_ucode_info_p = 1;
-	*current_mc_date_p = mc->hdr.date;
+	*current_mc_date_p = date;
 }
 #else
 
-static inline void print_ucode(struct ucode_cpu_info *uci)
+static inline void print_ucode(int new_rev, int date)
 {
-	struct microcode_intel *mc;
-
-	mc = uci->mc;
-	if (!mc)
-		return;
-
-	print_ucode_info(uci, mc->hdr.date);
+	print_ucode_info(new_rev, date);
 }
 #endif
 
@@ -409,9 +395,9 @@ static int apply_microcode_early(struct ucode_cpu_info *uci, bool early)
 	uci->cpu_sig.rev = rev;
 
 	if (early)
-		print_ucode(uci);
+		print_ucode(uci->cpu_sig.rev, mc->hdr.date);
 	else
-		print_ucode_info(uci, mc->hdr.date);
+		print_ucode_info(uci->cpu_sig.rev, mc->hdr.date);
 
 	return 0;
 }
-- 
2.34.1

[Patch v5 5/5] x86/microcode/intel: Print old and new rev during early boot

[Ashok Raj]

Make early loading message to match late loading messages. Print
both old and new revisions.

This is helpful to know what the BIOS loaded revision is before an early
update.

New dmesg log is shown below.

microcode: early update: 0x2b000041 -> 0x2b000070 date = 2000-01-01

Cache the early BIOS revision before the microcode update and change the
print_ucode_info() so it prints both the old and new revision in the same
format as microcode_reload_late().

Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: LKML <linux-kernel@vger.kernel.org>
Cc: x86 <x86@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: Reinette Chatre <reinette.chatre@intel.com>
Cc: Thomas Gleixner (Intel) <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Stefan Talpalaru <stefantalpalaru@yahoo.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Peter Zilstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Andrew Cooper <Andrew.Cooper3@citrix.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
---
Updates since V1:

Thomas: Commit log updates as suggested.
---
 arch/x86/kernel/cpu/microcode/intel.c | 25 +++++++++++++++----------
 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
index 146a60a9449a..4471d418f28a 100644
--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -310,10 +310,10 @@ static bool load_builtin_intel_microcode(struct cpio_data *cp)
 /*
  * Print ucode update info.
  */
-static void print_ucode_info(unsigned int new_rev, unsigned int date)
+static void print_ucode_info(int old_rev, int new_rev, unsigned int date)
 {
-	pr_info_once("microcode updated early to revision 0x%x, date = %04x-%02x-%02x\n",
-		     new_rev, date & 0xffff, date >> 24,
+	pr_info_once("early update: 0x%x -> 0x%x, date = %04x-%02x-%02x\n",
+		     old_rev, new_rev, date & 0xffff, date >> 24,
 		     (date >> 16) & 0xff);
 }
 
@@ -321,6 +321,7 @@ static void print_ucode_info(unsigned int new_rev, unsigned int date)
 
 static int delay_ucode_info;
 static int current_mc_date;
+static int early_old_rev;
 
 /*
  * Print early updated ucode info after printk works. This is delayed info dump.
@@ -331,7 +332,7 @@ void show_ucode_info_early(void)
 
 	if (delay_ucode_info) {
 		intel_cpu_collect_info(&uci);
-		print_ucode_info(uci.cpu_sig.rev, current_mc_date);
+		print_ucode_info(early_old_rev, uci.cpu_sig.rev, current_mc_date);
 		delay_ucode_info = 0;
 	}
 }
@@ -340,29 +341,32 @@ 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(int new_rev, int date)
+static void print_ucode(int old_rev, int new_rev, int date)
 {
 	int *delay_ucode_info_p;
 	int *current_mc_date_p;
+	int *early_old_rev_p;
 
 	delay_ucode_info_p = (int *)__pa_nodebug(&delay_ucode_info);
 	current_mc_date_p = (int *)__pa_nodebug(&current_mc_date);
+	early_old_rev_p = (int *)__pa_nodebug(&early_old_rev);
 
 	*delay_ucode_info_p = 1;
 	*current_mc_date_p = date;
+	*early_old_rev_p = old_rev;
 }
 #else
 
-static inline void print_ucode(int new_rev, int date)
+static inline void print_ucode(int old_rev, int new_rev, int date)
 {
-	print_ucode_info(new_rev, date);
+	print_ucode_info(old_rev, new_rev, date);
 }
 #endif
 
 static int apply_microcode_early(struct ucode_cpu_info *uci, bool early)
 {
 	struct microcode_intel *mc;
-	u32 rev;
+	u32 rev, old_rev;
 
 	mc = uci->mc;
 	if (!mc)
@@ -388,6 +392,7 @@ static int apply_microcode_early(struct ucode_cpu_info *uci, bool early)
 	/* write microcode via MSR 0x79 */
 	native_wrmsrl(MSR_IA32_UCODE_WRITE, (unsigned long)mc->bits);
 
+	old_rev = rev;
 	rev = intel_get_microcode_revision();
 	if (rev != mc->hdr.rev)
 		return -1;
@@ -395,9 +400,9 @@ static int apply_microcode_early(struct ucode_cpu_info *uci, bool early)
 	uci->cpu_sig.rev = rev;
 
 	if (early)
-		print_ucode(uci->cpu_sig.rev, mc->hdr.date);
+		print_ucode(old_rev, uci->cpu_sig.rev, mc->hdr.date);
 	else
-		print_ucode_info(uci->cpu_sig.rev, mc->hdr.date);
+		print_ucode_info(old_rev, uci->cpu_sig.rev, mc->hdr.date);
 
 	return 0;
 }
-- 
2.34.1

[tip: x86/microcode] x86/microcode/intel: Print old and new revision during early boot

[tip-bot2 for Ashok Raj]

The following commit has been merged into the x86/microcode branch of tip:

Commit-ID:     a9a5cac225b0830d1879640e25231a37e537f0da
Gitweb:        https://git.kernel.org/tip/a9a5cac225b0830d1879640e25231a37e537f0da
Author:        Ashok Raj <ashok.raj@intel.com>
AuthorDate:    Sun, 15 Jan 2023 19:57:27 +01:00
Committer:     Borislav Petkov (AMD) <bp@alien8.de>
CommitterDate: Sat, 21 Jan 2023 14:55:21 +01:00

x86/microcode/intel: Print old and new revision during early boot

Make early loading message match late loading message and print both old
and new revisions.

This is helpful to know what the BIOS loaded revision is before an early
update.

Cache the early BIOS revision before the microcode update and have
print_ucode_info() print both the old and new revision in the same
format as microcode_reload_late().

  [ bp: Massage, remove useless comment. ]

Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230120161923.118882-6-ashok.raj@intel.com
---
 arch/x86/kernel/cpu/microcode/intel.c | 28 ++++++++++++++------------
 1 file changed, 16 insertions(+), 12 deletions(-)

diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
index 9dbd007..467cf37 100644
--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -305,12 +305,10 @@ static bool load_builtin_intel_microcode(struct cpio_data *cp)
 	return false;
 }
 
-/*
- * Print ucode update info.
- */
-static void print_ucode_info(unsigned int new_rev, unsigned int date)
+static void print_ucode_info(int old_rev, int new_rev, unsigned int date)
 {
-	pr_info_once("microcode updated early to revision 0x%x, date = %04x-%02x-%02x\n",
+	pr_info_once("updated early: 0x%x -> 0x%x, date = %04x-%02x-%02x\n",
+		     old_rev,
 		     new_rev,
 		     date & 0xffff,
 		     date >> 24,
@@ -321,6 +319,7 @@ static void print_ucode_info(unsigned int new_rev, unsigned int date)
 
 static int delay_ucode_info;
 static int current_mc_date;
+static int early_old_rev;
 
 /*
  * Print early updated ucode info after printk works. This is delayed info dump.
@@ -331,7 +330,7 @@ void show_ucode_info_early(void)
 
 	if (delay_ucode_info) {
 		intel_cpu_collect_info(&uci);
-		print_ucode_info(uci.cpu_sig.rev, current_mc_date);
+		print_ucode_info(early_old_rev, uci.cpu_sig.rev, current_mc_date);
 		delay_ucode_info = 0;
 	}
 }
@@ -340,29 +339,32 @@ 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(int new_rev, int date)
+static void print_ucode(int old_rev, int new_rev, int date)
 {
 	int *delay_ucode_info_p;
 	int *current_mc_date_p;
+	int *early_old_rev_p;
 
 	delay_ucode_info_p = (int *)__pa_nodebug(&delay_ucode_info);
 	current_mc_date_p = (int *)__pa_nodebug(&current_mc_date);
+	early_old_rev_p = (int *)__pa_nodebug(&early_old_rev);
 
 	*delay_ucode_info_p = 1;
 	*current_mc_date_p = date;
+	*early_old_rev_p = old_rev;
 }
 #else
 
-static inline void print_ucode(int new_rev, int date)
+static inline void print_ucode(int old_rev, int new_rev, int date)
 {
-	print_ucode_info(new_rev, date);
+	print_ucode_info(old_rev, new_rev, date);
 }
 #endif
 
 static int apply_microcode_early(struct ucode_cpu_info *uci, bool early)
 {
 	struct microcode_intel *mc;
-	u32 rev;
+	u32 rev, old_rev;
 
 	mc = uci->mc;
 	if (!mc)
@@ -379,6 +381,8 @@ 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.
@@ -395,9 +399,9 @@ static int apply_microcode_early(struct ucode_cpu_info *uci, bool early)
 	uci->cpu_sig.rev = rev;
 
 	if (early)
-		print_ucode(uci->cpu_sig.rev, mc->hdr.date);
+		print_ucode(old_rev, uci->cpu_sig.rev, mc->hdr.date);
 	else
-		print_ucode_info(uci->cpu_sig.rev, mc->hdr.date);
+		print_ucode_info(old_rev, uci->cpu_sig.rev, mc->hdr.date);
 
 	return 0;
 }

[tip: x86/microcode] x86/microcode/intel: Pass the microcode revision to print_ucode_info() directly

[tip-bot2 for Ashok Raj]

The following commit has been merged into the x86/microcode branch of tip:

Commit-ID:     174f1b909ab0984e5369a634971fb14a618ca797
Gitweb:        https://git.kernel.org/tip/174f1b909ab0984e5369a634971fb14a618ca797
Author:        Ashok Raj <ashok.raj@intel.com>
AuthorDate:    Mon, 09 Jan 2023 07:35:53 -08:00
Committer:     Borislav Petkov (AMD) <bp@alien8.de>
CommitterDate: Sat, 21 Jan 2023 14:55:20 +01:00

x86/microcode/intel: Pass the microcode revision to print_ucode_info() directly

print_ucode_info() takes a struct ucode_cpu_info pointer as parameter.
Its sole purpose is to print the microcode revision.

The only available ucode_cpu_info always describes the currently loaded
microcode revision. After a microcode update is successful, this is the
new revision, or on failure it is the original revision.

In preparation for future changes, replace the struct ucode_cpu_info
pointer parameter with a plain integer which contains the revision
number and adjust the call sites accordingly.

No functional change.

  [ bp:
    - Fix + cleanup commit message.
    - Revert arbitrary, unrelated change.
  ]

Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230120161923.118882-5-ashok.raj@intel.com
---
 arch/x86/kernel/cpu/microcode/intel.c | 30 +++++++-------------------
 1 file changed, 9 insertions(+), 21 deletions(-)

diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
index cac2bdb..9dbd007 100644
--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -308,11 +308,10 @@ 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)
+static void print_ucode_info(unsigned int new_rev, unsigned int date)
 {
 	pr_info_once("microcode updated early to revision 0x%x, date = %04x-%02x-%02x\n",
-		     uci->cpu_sig.rev,
+		     new_rev,
 		     date & 0xffff,
 		     date >> 24,
 		     (date >> 16) & 0xff);
@@ -332,7 +331,7 @@ 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(uci.cpu_sig.rev, current_mc_date);
 		delay_ucode_info = 0;
 	}
 }
@@ -341,33 +340,22 @@ 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(int new_rev, int date)
 {
-	struct microcode_intel *mc;
 	int *delay_ucode_info_p;
 	int *current_mc_date_p;
 
-	mc = uci->mc;
-	if (!mc)
-		return;
-
 	delay_ucode_info_p = (int *)__pa_nodebug(&delay_ucode_info);
 	current_mc_date_p = (int *)__pa_nodebug(&current_mc_date);
 
 	*delay_ucode_info_p = 1;
-	*current_mc_date_p = mc->hdr.date;
+	*current_mc_date_p = date;
 }
 #else
 
-static inline void print_ucode(struct ucode_cpu_info *uci)
+static inline void print_ucode(int new_rev, int date)
 {
-	struct microcode_intel *mc;
-
-	mc = uci->mc;
-	if (!mc)
-		return;
-
-	print_ucode_info(uci, mc->hdr.date);
+	print_ucode_info(new_rev, date);
 }
 #endif
 
@@ -407,9 +395,9 @@ static int apply_microcode_early(struct ucode_cpu_info *uci, bool early)
 	uci->cpu_sig.rev = rev;
 
 	if (early)
-		print_ucode(uci);
+		print_ucode(uci->cpu_sig.rev, mc->hdr.date);
 	else
-		print_ucode_info(uci, mc->hdr.date);
+		print_ucode_info(uci->cpu_sig.rev, mc->hdr.date);
 
 	return 0;
 }