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From:   Ashok Raj <ashok.raj@intel.com>
To:     Borislav Petkov <bp@alien8.de>
Cc:     X86-kernel <x86@kernel.org>,
        LKML Mailing List <linux-kernel@vger.kernel.org>,
        Ashok Raj <ashok.raj@intel.com>,
        Dave Hansen <dave.hansen@intel.com>,
        Tony Luck <tony.luck@intel.com>, alison.schofield@intel.com,
        reinette.chatre@intel.com
Subject: [Patch V1 7/7] x86/microcode/intel: Print when early microcode loading fails
Date:   Tue, 29 Nov 2022 13:08:32 -0800
Message-Id: <20221129210832.107850-8-ashok.raj@intel.com>
In-Reply-To: <20221129210832.107850-1-ashok.raj@intel.com>
References: <20221129210832.107850-1-ashok.raj@intel.com>
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Currently when early microcode loading fails there is no way for user to
know that the update failed.

Store the failed status and pass it to print_ucode_info() to let early
loading failures to captured in console log.

Signed-off-by: Ashok Raj <ashok.raj@intel.com>
---
 arch/x86/kernel/cpu/microcode/intel.c | 29 ++++++++++++++++-----------
 1 file changed, 17 insertions(+), 12 deletions(-)

diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
index 3dbcf457f45d..3b299f437e35 100644
--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -309,13 +309,14 @@ static bool load_builtin_intel_microcode(struct cpio_data *cp)
  * Print ucode update info.
  */
 static void
-print_ucode_info(int old_rev, int new_rev, unsigned int date)
+print_ucode_info(bool failed, int old_rev, int new_rev, unsigned int date)
 {
-	pr_info_once("early update: 0x%x -> 0x%x, date = %04x-%02x-%02x\n",
+	pr_info_once("early update: 0x%x -> 0x%x, date = %04x-%02x-%02x %s\n",
 		     old_rev, new_rev,
 		     date & 0xffff,
 		     date >> 24,
-		     (date >> 16) & 0xff);
+		     (date >> 16) & 0xff,
+		     failed ? "FAILED" : "");
 }
 
 #ifdef CONFIG_X86_32
@@ -323,6 +324,7 @@ print_ucode_info(int old_rev, int new_rev, unsigned int date)
 static int delay_ucode_info;
 static int current_mc_date;
 static int early_old_rev;
+static bool early_failed;
 
 /*
  * Print early updated ucode info after printk works. This is delayed info dump.
@@ -333,7 +335,7 @@ void show_ucode_info_early(void)
 
 	if (delay_ucode_info) {
 		intel_cpu_collect_info(&uci);
-		print_ucode_info(early_old_rev, uci.cpu_sig.rev, current_mc_date);
+		print_ucode_info(early_failed, early_old_rev, uci.cpu_sig.rev, current_mc_date);
 		delay_ucode_info = 0;
 	}
 }
@@ -342,26 +344,28 @@ 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 old_rev, int new_rev, int date)
+static void print_ucode(bool failed, int old_rev, int new_rev, int date)
 {
-	struct microcode_intel *mc;
 	int *delay_ucode_info_p;
 	int *current_mc_date_p;
 	int *early_old_rev_p;
+	bool *early_failed_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);
+	early_failed_p = (int *)__pa_nodebug(&early_failed);
 
 	*delay_ucode_info_p = 1;
 	*current_mc_date_p = date;
 	*early_old_rev_p = old_rev;
+	*early_failed_p = failed;
 }
 #else
 
-static inline void print_ucode(int old_rev, int new_rev, int date)
+static inline void print_ucode(bool failed, int old_rev, int new_rev, int date)
 {
-	print_ucode_info(old_rev, new_rev, date);
+	print_ucode_info(failed, old_rev, new_rev, date);
 }
 #endif
 
@@ -369,6 +373,7 @@ static int apply_microcode_early(struct ucode_cpu_info *uci, bool early)
 {
 	struct microcode_intel *mc;
 	u32 rev, old_rev;
+	int retval = 0;
 
 	mc = uci->mc;
 	if (!mc)
@@ -397,16 +402,16 @@ static int apply_microcode_early(struct ucode_cpu_info *uci, bool early)
 	old_rev = rev;
 	rev = intel_get_microcode_revision();
 	if (rev != mc->hdr.rev)
-		return -1;
+		retval = -1;
 
 	uci->cpu_sig.rev = rev;
 
 	if (early)
-		print_ucode(old_rev, uci->cpu_sig.rev, mc->hdr.date);
+		print_ucode(retval, old_rev, mc->hdr.rev, mc->hdr.date);
 	else
-		print_ucode_info(old_rev, uci->cpu_sig.rev, mc->hdr.date);
+		print_ucode_info(retval, old_rev, uci->cpu_sig.rev, mc->hdr.date);
 
-	return 0;
+	return retval;
 }
 
 int __init save_microcode_in_initrd_intel(void)
-- 
2.34.1