From 46a03a1ef9f5cfd6cf3f55a92b8b55ec30bfcd07 Mon Sep 17 00:00:00 2001
From: robert <robert@openbsd.org>
Date: Thu, 22 Sep 2022 04:36:37 +0000
Subject: [PATCH] Call amd64_errata() from cpu_fix_msrs() instead of
 identifycpu() so that on resume, the errata is re-applied. In addition make
 amd64_errata() print the information about the applied errata only once for
 the first CPU.

input from jsg@ and deraadt@, ok deraadt@
---
 sys/arch/amd64/amd64/amd64errata.c | 41 ++++++++++++++++++++----------
 sys/arch/amd64/amd64/cpu.c         | 25 ++++++++++--------
 sys/arch/amd64/amd64/identcpu.c    |  5 +---
 3 files changed, 42 insertions(+), 29 deletions(-)

diff --git a/sys/arch/amd64/amd64/amd64errata.c b/sys/arch/amd64/amd64/amd64errata.c
index 1f891511093..5483eb3c47f 100644
--- a/sys/arch/amd64/amd64/amd64errata.c
+++ b/sys/arch/amd64/amd64/amd64errata.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: amd64errata.c,v 1.10 2022/09/20 07:54:27 jsg Exp $	*/
+/*	$OpenBSD: amd64errata.c,v 1.11 2022/09/22 04:36:37 robert Exp $	*/
 /*	$NetBSD: errata.c,v 1.6 2007/02/05 21:05:45 ad Exp $	*/
 
 /*-
@@ -49,7 +49,6 @@
 #include <machine/cpufunc.h>
 #include <machine/specialreg.h>
 
-
 typedef struct errata {
 	u_short		e_num;
 	u_short		e_reported;
@@ -294,6 +293,7 @@ amd64_errata(struct cpu_info *ci)
 	int rc;
 	int found = 0;
 	int corrected = 0;
+	static int printed = 0;
 
 	CPUID(0x80000001, code, dummy, dummy, dummy);
 
@@ -362,17 +362,22 @@ amd64_errata(struct cpu_info *ci)
 		int first = 1;
 
 		/* Print out found and corrected */
-		printf("%s: AMD %s", ci->ci_dev->dv_xname,
-		    (corrected == 1) ? "erratum" : "errata");
+		if (!printed) {
+			printf("%s: AMD %s", ci->ci_dev->dv_xname,
+			    (corrected == 1) ? "erratum" : "errata");
+		}
 		for (e = errata; e < ex; e++) {
 			if (e->e_reported == 2) {
-				if (! first)
-					printf(",");
-				printf(" %d", e->e_num);
+				if (!printed) {
+					if (! first)
+						printf(",");
+					printf(" %d", e->e_num);
+				}
 				first = 0;
 			}
 		}
-		printf(" detected and fixed\n");
+		if (!printed)
+			printf(" detected and fixed\n");
 	}
 #endif
 
@@ -380,16 +385,24 @@ amd64_errata(struct cpu_info *ci)
 		int first = 1;
 
 		/* Print out found but not corrected */
-		printf("%s: AMD %s", ci->ci_dev->dv_xname,
-		    (found == 1) ? "erratum" : "errata");
+		if (!printed) {
+			printf("%s: AMD %s", ci->ci_dev->dv_xname,
+			    (found == 1) ? "erratum" : "errata");
+		}
 		for (e = errata; e < ex; e++) {
 			if (e->e_reported == 1) {
-				if (! first)
-					printf(",");
-				printf(" %d", e->e_num);
+				if (!printed) {
+					if (! first)
+						printf(",");
+					printf(" %d", e->e_num);
+				}
 				first = 0;
 			}
 		}
-		printf(" present, BIOS upgrade may be required\n");
+		if (!printed)
+			printf(" present, BIOS upgrade may be required\n");
 	}
+
+	/* Print only one time for the first CPU */
+	printed = 1;
 }
diff --git a/sys/arch/amd64/amd64/cpu.c b/sys/arch/amd64/amd64/cpu.c
index 68c83d902a6..22736b3fc3e 100644
--- a/sys/arch/amd64/amd64/cpu.c
+++ b/sys/arch/amd64/amd64/cpu.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.c,v 1.160 2022/09/20 14:28:27 robert Exp $	*/
+/*	$OpenBSD: cpu.c,v 1.161 2022/09/22 04:36:37 robert Exp $	*/
 /* $NetBSD: cpu.c,v 1.1 2003/04/26 18:39:26 fvdl Exp $ */
 
 /*-
@@ -1146,17 +1146,20 @@ cpu_fix_msrs(struct cpu_info *ci)
 		}
 	}
 
-	/*
-	 * "Mitigation G-2" per AMD's Whitepaper "Software Techniques
-	 * for Managing Speculation on AMD Processors"
-	 *
-	 * By setting MSR C001_1029[1]=1, LFENCE becomes a dispatch
-	 * serializing instruction.
-	 *
-	 * This MSR is available on all AMD families >= 10h, except 11h
-	 * where LFENCE is always serializing.
-	 */
 	if (!strcmp(cpu_vendor, "AuthenticAMD")) {
+		/* Apply AMD errata */
+		amd64_errata(ci);
+
+		/*
+		 * "Mitigation G-2" per AMD's Whitepaper "Software Techniques
+		 * for Managing Speculation on AMD Processors"
+		 *
+		 * By setting MSR C001_1029[1]=1, LFENCE becomes a dispatch
+		 * serializing instruction.
+		 *
+		 * This MSR is available on all AMD families >= 10h, except 11h
+		 * where LFENCE is always serializing.
+		 */
 		if (family >= 0x10 && family != 0x11) {
 			msr = rdmsr(MSR_DE_CFG);
 			if ((msr & DE_CFG_SERIALIZE_LFENCE) == 0) {
diff --git a/sys/arch/amd64/amd64/identcpu.c b/sys/arch/amd64/amd64/identcpu.c
index 09c7ce842fa..001a437045b 100644
--- a/sys/arch/amd64/amd64/identcpu.c
+++ b/sys/arch/amd64/amd64/identcpu.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: identcpu.c,v 1.128 2022/09/20 14:28:27 robert Exp $	*/
+/*	$OpenBSD: identcpu.c,v 1.129 2022/09/22 04:36:38 robert Exp $	*/
 /*	$NetBSD: identcpu.c,v 1.1 2003/04/26 18:39:28 fvdl Exp $	*/
 
 /*
@@ -753,9 +753,6 @@ identifycpu(struct cpu_info *ci)
 	}
 #endif
 
-	if (!strcmp(cpu_vendor, "AuthenticAMD"))
-		amd64_errata(ci);
-
 	if (CPU_IS_PRIMARY(ci) && !strcmp(cpu_vendor, "CentaurHauls")) {
 		ci->cpu_setup = via_nano_setup;
 #ifndef SMALL_KERNEL
-- 
2.20.1