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Message-Id: <20170425152705.13991-1-dvlasenk@redhat.com>
Date: Tue, 25 Apr 2017 17:27:04 +0200
From: Denys Vlasenko <dvlasenk@...hat.com>
To: Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>
Cc: Denys Vlasenko <dvlasenk@...hat.com>,
Andy Lutomirski <luto@...nel.org>,
Brian Gerst <brgerst@...il.com>,
Peter Zijlstra <peterz@...radead.org>,
"H. Peter Anvin" <hpa@...ux.intel.com>, x86@...nel.org,
linux-kernel@...r.kernel.org
Subject: [PATCH v2] x86, msr: Document AMD "tweak MSRs", use MSR_FnnH_NAME scheme for them
MSRs in 0xC001102x range (and a few close to this range)
allow to modify some internal actions of the pipeline.
(There is one non-debug MSR in this range, introduced in Fam15h:
MSR 0xC0011027 Address Mask For DR0 Breakpoints, aka DR0_ADDR_MASK).
Sometimes these MSRs are used to fix erratas.
Let's have a comment about that.
Lat's use the following naming scheme for all of them: MSR_FnnH_REGNAME
This introduces some redundant names, but documents CPU family where
we are reasonably sure a particular register exists, and avoids the need
to explain why the same register is either "Combined Unit Cfg"
or "Bus Unit Cfg" - obviously, because the name depends on the CPU family.
Renaming:
MSR_AMD64_DC_CFG -> MSR_F10H_DC_CFG
MSR_AMD64_BU_CFG2 -> MSR_F10H_BU_CFG2
MSR_AMD64_LS_CFG -> MSR_F16H_LS_CFG
MSR_AMD64_DE_CFG -> MSR_F12H_DE_CFG (and moving to msr-index.h)
Here is a little compilation from about a dozen documents.
C001_1000:
15h Errata 608 "P-state Limit Changes May Not Generate Interrupts"
- worked around by setting bit 16.
15h Errata 671 "Debug Breakpoint on Misaligned Store May Cause System Hang"
- worked around by setting bit 17 to 0.
- AMD is really reluctant to this workaround, must be painful
15h Errata 727 "Processor Core May Hang During CC6 Resume"
- worked around by setting bit 15.
- HW fixed in models 10h?
C001_1020:
K8 Errata 106
"Potential Deadlock with Tightly Coupled Semaphores in an MP System"
- worked around by setting bit 25.
10h,12h Errata 670
"Segment Load May Cause System Hang or Fault After State Change"
- worked around by setting bit 8.
- this bit has something to do with handling of LOCK prefix.
14h Errata 530
"Potential Violation of Read Ordering Rules Between Semaphore Operation
and Subsequent Load Operations"
- worked around by setting bit 36.
14h Errata 551
"Processor May Not Forward Data From Store to a Page Crossing
Read-Modify-Write Operation"
- worked around by setting bit 25.
14h Errata 560
"Processor May Incorrectly Forward Data with Non-cacheable Floating-Point
128-bit SSE Operation"
- worked around by setting bit 18.
16h Errata 793
"Specific Combination of Writes to Write Combined Memory Types and Locked
Instructions May Cause Core Hang"
- worked around by setting bit 15.
C001_1021:
K8 Errata 94
"Sequential Prefetch Feature May Cause Incorrect Processor Operation"
- worked around by setting bit 11.
14h Errata 688
"Processor May Cause Unpredictable Program Behavior Under Highly Specific
Branch Conditions"
- worked around by setting bits 14 and 3.
16h Errata 776
"Incorrect Processor Branch Prediction for Two Consecutive Linear Pages"
- worked around by setting bit 26.
- HW fixed in models 30h?
C001_1022:
K8 Errata 97 "128-Bit Streaming Stores May Cause Coherency Failure"
- worked around by setting bit 3.
K8 Errata 81
"Cache Coherency Problem with Hardware Prefetching and Streaming Stores"
- worked around by setting bit 10.
10h Errata 261
"Processor May Stall Entering Stop-Grant Due to Pending Data Cache Scrub"
- worked around by setting bit 24.
10h Errata 326 "Misaligned Load Operation May Cause Processor Core Hang"
- worked around by setting bits 43:42 to 00.
10h Errata 383
"CPU Core May Machine Check When System Software Changes Page Tables
Dynamically"
- worked around by setting bit 47.
15h Errata 674
"Processor May Cache Prefetched Data from Remapped Memory Region"
- worked around by setting bit 13.
C001_1023:
K8 Errata 69
"Multiprocessor Coherency Problem with Hardware Prefetch Mechanism"
- worked around by setting bit 45.
K8 Errata 113 "Enhanced Write-Combining Feature Causes System Hang"
- worked around by setting bit 48.
10h Errata 254 "Internal Resource Livelock Involving Cached TLB Reload"
- worked around by setting bit 21.
10h Errata 298
"L2 Eviction May Occur During Processor Operation To Set Accessed or Dirty Bit"
- worked around by setting bit 1.
10h Errata 309
"Processor Core May Execute Incorrect Instructions on Concurrent L2 and
Northbridge Response"
- worked around by setting bit 23.
C001_1029:
10h,12h Errata 721 "Processor May Incorrectly Update Stack Pointer"
- worked around by setting bit 0.
12h Errata 665 "Integer Divide Instruction May Cause Unpredictable Behavior"
- worked around by setting bit 31.
Bit 23 serializes CLFLUSH instruction.
C001_102A:
15h Errata 503 "APIC Task-Priority Register May Be Incorrect"
- worked around by setting bit 11.
K8_BKDG documents none of these registers, but Revision Guide mentions
them a lot.
10h_BKDG documents them as:
MSRC001_1021 Instruction Cache Configuration Register (IC_CFG)
MSRC001_1022 Data Cache Configuration (DC_CFG)
MSRC001_1023 Bus Unit Configuration Register (BU_CFG)
MSRC001_102A Bus Unit Configuration 2 (BU_CFG2)
11h_BKDG documents:
MSRC001_1022 Data Cache Configuration (DC_CFG)
MSRC001_1023 Bus Unit Configuration Register (BU_CFG)
12h_BKDG documents:
MSRC001_1020 Load-Store Configuration (LS_CFG)
MSRC001_1021 Instruction Cache Configuration (IC_CFG)
MSRC001_1022 Data Cache Configuration (DC_CFG)
MSRC001_1029 Decode Configuration (DE_CFG)
MSRC001_102A Combined Unit Configuration 2 (CU_CFG2) - name change since 10h
14h_Mod_00h-0Fh_BKDG documents only:
MSRC001_1020 Load-Store Configuration (LS_CFG)
MSRC001_1021 Instruction Cache Configuration (IC_CFG)
MSRC001_1022 Data Cache Configuration (DC_CFG)
15h_Mod_00h-0Fh_BKDG documents more:
MSRC001_1020 Load-Store Configuration (LS_CFG)
MSRC001_1021 Instruction Cache Configuration (IC_CFG)
MSRC001_1022 Data Cache Configuration (DC_CFG)
MSRC001_1023 Combined Unit Configuration (CU_CFG) - name change since 11h
MSRC001_1028 Floating Point Configuration (FP_CFG)
MSRC001_1029 Decode Configuration (DE_CFG)
MSRC001_102A Combined Unit Configuration 2 (CU_CFG2)
MSRC001_102B Combined Unit Configuration 3 (CU_CFG3)
MSRC001_102C Execution Unit Configuration (EX_CFG)
MSRC001_102D Load-Store Configuration 2 (LS_CFG2)
15h_Mod_10h-1Fh_BKDG: does not mention MSRC001_1029 and MSRC001_102C.
15h_Mod_30h-3Fh_BKDG: does not mention MSRC001_1029, MSRC001_102C
and MSRC001_102D, adds new one:
MSRC001_102F Prefetch Throttling Configuration (CU_PFTCFG)
15h_Mod_60h-6Fh_BKDG: also fails to mention MSRC001_1029, MSRC001_102C
and MSRC001_102D, but has new ones:
MSRC001_101C Load-Store Configuration 3 (LS_CFG3)
MSRC001_1090 Processor Feedback Constants 0
MSRC001_10A1 Contention Blocking Buffer Control (CU_CBBCFG)
MSRC001_1000 is only mentioned in 15h erratas, name unknown.
16h_Mod_00h-0Fh_BKDG: stuff disappeared or got renamed
(1023 and 102A are "Bus Unit Configuration" again):
MSRC001_1020 Load-Store Configuration (LS_CFG)
MSRC001_1021 Instruction Cache Configuration (IC_CFG)
MSRC001_1022 Data Cache Configuration (DC_CFG)
MSRC001_1023 Bus Unit Configuration (BU_CFG)
MSRC001_1028 Floating Point Configuration (FP_CFG) - all bits are "reserved"
MSRC001_102A Bus Unit Configuration 2 (BU_CFG2)
16h_Mod_30h-3Fh_BKDG: FP_CFG now has one documented field
CC: Ingo Molnar <mingo@...hat.com>
CC: Andy Lutomirski <luto@...nel.org>
CC: Borislav Petkov <bp@...en8.de>
CC: Brian Gerst <brgerst@...il.com>
CC: Peter Zijlstra <peterz@...radead.org>
CC: "H. Peter Anvin" <hpa@...ux.intel.com>
CC: x86@...nel.org
CC: linux-kernel@...r.kernel.org
Signed-off-by: Denys Vlasenko <dvlasenk@...hat.com>
---
arch/x86/include/asm/msr-index.h | 63 +++++++++++++++++++++++++++++++++++++---
arch/x86/kernel/cpu/amd.c | 10 +++----
arch/x86/kvm/svm.c | 4 +--
arch/x86/kvm/x86.c | 4 +--
4 files changed, 67 insertions(+), 14 deletions(-)
diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index d8b5f8a..8f89dd3 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -293,9 +293,6 @@
#define MSR_AMD64_PATCH_LOADER 0xc0010020
#define MSR_AMD64_OSVW_ID_LENGTH 0xc0010140
#define MSR_AMD64_OSVW_STATUS 0xc0010141
-#define MSR_AMD64_LS_CFG 0xc0011020
-#define MSR_AMD64_DC_CFG 0xc0011022
-#define MSR_AMD64_BU_CFG2 0xc001102a
#define MSR_AMD64_IBSFETCHCTL 0xc0011030
#define MSR_AMD64_IBSFETCHLINAD 0xc0011031
#define MSR_AMD64_IBSFETCHPHYSAD 0xc0011032
@@ -315,6 +312,65 @@
#define MSR_AMD64_IBSOPDATA4 0xc001103d
#define MSR_AMD64_IBS_REG_COUNT_MAX 8 /* includes MSR_AMD64_IBSBRTARGET */
+/*
+ * MSRs in 0xc001101c-0xc001102f range are sparsely documented in BKDGs,
+ * but sometimes they can be found in errata documents.
+ * Registers 1020-1023 exist since K8 (mentioned in errata docs).
+ * Fam10h also has registers 1029, 102a (maybe more, not in docs).
+ * Fam15h BKDGs document registers 1028, 102b-102f, 101c, 1090, 10a1.
+ * Registers 1023 and 102a are called "Combined Unit Cfg" or "Bus Unit Cfg",
+ * depending on the CPU family.
+ */
+#define MSR_K8_LS_CFG 0xc0011020
+#define MSR_K8_IC_CFG 0xc0011021
+#define MSR_K8_DC_CFG 0xc0011022
+#define MSR_K8_BU_CFG 0xc0011023
+
+#define MSR_F10H_LS_CFG 0xc0011020
+#define MSR_F10H_IC_CFG 0xc0011021
+#define MSR_F10H_DC_CFG 0xc0011022
+#define MSR_F10H_BU_CFG 0xc0011023
+#define MSR_F10H_DE_CFG 0xc0011029
+#define MSR_F10H_BU_CFG2 0xc001102a
+
+#define MSR_F12H_LS_CFG 0xc0011020
+#define MSR_F12H_IC_CFG 0xc0011021
+#define MSR_F12H_DC_CFG 0xc0011022
+#define MSR_F12H_CU_CFG 0xc0011023
+#define MSR_F12H_DE_CFG 0xc0011029
+#define MSR_F12H_CU_CFG2 0xc001102a
+
+#define MSR_F14H_LS_CFG 0xc0011020
+#define MSR_F14H_IC_CFG 0xc0011021
+#define MSR_F14H_DC_CFG 0xc0011022
+#define MSR_F14H_CU_CFG 0xc0011023
+#define MSR_F14H_FP_CFG 0xc0011028
+#define MSR_F14H_DE_CFG 0xc0011029
+#define MSR_F14H_CU_CFG2 0xc001102a
+
+#define MSR_F16H_LS_CFG 0xc0011020
+#define MSR_F16H_IC_CFG 0xc0011021
+#define MSR_F16H_DC_CFG 0xc0011022
+#define MSR_F16H_BU_CFG 0xc0011023
+#define MSR_F16H_FP_CFG 0xc0011028
+#define MSR_F16H_DE_CFG 0xc0011029
+#define MSR_F16H_BU_CFG2 0xc001102a
+
+#define MSR_F15H_LS_CFG3 0xc001101c
+#define MSR_F15H_LS_CFG 0xc0011020
+#define MSR_F15H_IC_CFG 0xc0011021
+#define MSR_F15H_DC_CFG 0xc0011022
+#define MSR_F15H_CU_CFG 0xc0011023
+#define MSR_F15H_FP_CFG 0xc0011028
+#define MSR_F15H_DE_CFG 0xc0011029
+#define MSR_F15H_CU_CFG2 0xc001102a
+#define MSR_F15H_CU_CFG3 0xc001102b
+#define MSR_F15H_EX_CFG 0xc001102c
+#define MSR_F15H_LS_CFG2 0xc001102d
+#define MSR_F15H_CU_PFTCFG 0xc001102f
+#define MSR_F15H_CU_PROCFB_SCALE_0 0xc0011090
+#define MSR_F15H_CU_CBBCFG 0xc00110a1
+
/* Fam 17h MSRs */
#define MSR_F17H_IRPERF 0xc00000e9
@@ -332,7 +388,6 @@
#define MSR_F15H_NB_PERF_CTL 0xc0010240
#define MSR_F15H_NB_PERF_CTR 0xc0010241
#define MSR_F15H_PTSC 0xc0010280
-#define MSR_F15H_IC_CFG 0xc0011021
/* Fam 10h MSRs */
#define MSR_FAM10H_MMIO_CONF_BASE 0xc0010058
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index c36140d..f5f5e6f 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -601,7 +601,7 @@ static void early_init_amd(struct cpuinfo_x86 *c)
/* F16h erratum 793, CVE-2013-6885 */
if (c->x86 == 0x16 && c->x86_model <= 0xf)
- msr_set_bit(MSR_AMD64_LS_CFG, 15);
+ msr_set_bit(MSR_F16H_LS_CFG, 15);
/*
* Check whether the machine is affected by erratum 400. This is
@@ -676,26 +676,24 @@ static void init_amd_gh(struct cpuinfo_x86 *c)
* On family 10h BIOS may not have properly enabled WC+ support, causing
* it to be converted to CD memtype. This may result in performance
* degradation for certain nested-paging guests. Prevent this conversion
- * by clearing bit 24 in MSR_AMD64_BU_CFG2.
+ * by clearing bit 24 in BU_CFG2.
*
* NOTE: we want to use the _safe accessors so as not to #GP kvm
* guests on older kvm hosts.
*/
- msr_clear_bit(MSR_AMD64_BU_CFG2, 24);
+ msr_clear_bit(MSR_F10H_BU_CFG2, 24);
if (cpu_has_amd_erratum(c, amd_erratum_383))
set_cpu_bug(c, X86_BUG_AMD_TLB_MMATCH);
}
-#define MSR_AMD64_DE_CFG 0xC0011029
-
static void init_amd_ln(struct cpuinfo_x86 *c)
{
/*
* Apply erratum 665 fix unconditionally so machines without a BIOS
* fix work.
*/
- msr_set_bit(MSR_AMD64_DE_CFG, 31);
+ msr_set_bit(MSR_F12H_DE_CFG, 31);
}
static void init_amd_bd(struct cpuinfo_x86 *c)
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 5fba706..40685ec 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -678,7 +678,7 @@ static void svm_init_erratum_383(void)
return;
/* Use _safe variants to not break nested virtualization */
- val = native_read_msr_safe(MSR_AMD64_DC_CFG, &err);
+ val = native_read_msr_safe(MSR_F10H_DC_CFG, &err);
if (err)
return;
@@ -687,7 +687,7 @@ static void svm_init_erratum_383(void)
low = lower_32_bits(val);
high = upper_32_bits(val);
- native_write_msr_safe(MSR_AMD64_DC_CFG, low, high);
+ native_write_msr_safe(MSR_F10H_DC_CFG, low, high);
erratum_383_found = true;
}
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index ccbd45e..93b1d74 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2154,7 +2154,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
case MSR_IA32_UCODE_WRITE:
case MSR_VM_HSAVE_PA:
case MSR_AMD64_PATCH_LOADER:
- case MSR_AMD64_BU_CFG2:
+ case MSR_F10H_BU_CFG2:
break;
case MSR_EFER:
@@ -2415,7 +2415,7 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
case MSR_K8_INT_PENDING_MSG:
case MSR_AMD64_NB_CFG:
case MSR_FAM10H_MMIO_CONF_BASE:
- case MSR_AMD64_BU_CFG2:
+ case MSR_F10H_BU_CFG2:
case MSR_IA32_PERF_CTL:
msr_info->data = 0;
break;
--
2.9.2
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