2020-03-11 19:18:02

by Kim Phillips

[permalink] [raw]
Subject: [PATCH] x86/cpu/amd: Extend calling init_amd_zn() to Family 19h processors

Family 19h CPUs are Zen based and still share most architectural
features with Family 17h CPUs, and therefore still need to call
init_amd_zn() e.g., to set the RECLAIM_DISTANCE override.

init_amd_zn() also sets X86_FEATURE_ZEN, which today is only used
in amd_set_core_ssb_state(), which isn't called on some late
model Family 17h CPUs, nor on any Family 19h CPUs:
X86_FEATURE_AMD_SSBD replaces X86_FEATURE_LS_CFG_SSBD on those
later model CPUs, where the SSBD mitigation is done via the
SPEC_CTRL MSR instead of the LS_CFG MSR.

Family 19h CPUs also don't have the erratum where the CPB feature
bit isn't set, but that code can stay unchanged and run safely
on Family 19h.

Signed-off-by: Kim Phillips <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Tom Lendacky <[email protected]>
Cc: Josh Poimboeuf <[email protected]>
Cc: Frank van der Linden <[email protected]>
Cc: Michael Petlan <[email protected]>
Cc: [email protected]
Cc: [email protected]
---
arch/x86/include/asm/cpufeatures.h | 2 +-
arch/x86/kernel/cpu/amd.c | 3 ++-
2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index f3327cb56edf..f980efcacfeb 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -217,7 +217,7 @@
#define X86_FEATURE_IBRS ( 7*32+25) /* Indirect Branch Restricted Speculation */
#define X86_FEATURE_IBPB ( 7*32+26) /* Indirect Branch Prediction Barrier */
#define X86_FEATURE_STIBP ( 7*32+27) /* Single Thread Indirect Branch Predictors */
-#define X86_FEATURE_ZEN ( 7*32+28) /* "" CPU is AMD family 0x17 (Zen) */
+#define X86_FEATURE_ZEN ( 7*32+28) /* "" CPU is AMD family 0x17 or above (Zen) */
#define X86_FEATURE_L1TF_PTEINV ( 7*32+29) /* "" L1TF workaround PTE inversion */
#define X86_FEATURE_IBRS_ENHANCED ( 7*32+30) /* Enhanced IBRS */
#define X86_FEATURE_MSR_IA32_FEAT_CTL ( 7*32+31) /* "" MSR IA32_FEAT_CTL configured */
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 1f875fbe1384..af952d7ed2fc 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -926,7 +926,8 @@ static void init_amd(struct cpuinfo_x86 *c)
case 0x12: init_amd_ln(c); break;
case 0x15: init_amd_bd(c); break;
case 0x16: init_amd_jg(c); break;
- case 0x17: init_amd_zn(c); break;
+ case 0x17: fallthrough;
+ case 0x19: init_amd_zn(c); break;
}

/*
--
2.25.1


Subject: [tip: x86/cpu] x86/cpu/amd: Call init_amd_zn() om Family 19h processors too

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

Commit-ID: 753039ef8b2f1078e5bff8cd42f80578bf6385b0
Gitweb: https://git.kernel.org/tip/753039ef8b2f1078e5bff8cd42f80578bf6385b0
Author: Kim Phillips <[email protected]>
AuthorDate: Wed, 11 Mar 2020 14:14:51 -05:00
Committer: Borislav Petkov <[email protected]>
CommitterDate: Thu, 12 Mar 2020 12:13:44 +01:00

x86/cpu/amd: Call init_amd_zn() om Family 19h processors too

Family 19h CPUs are Zen-based and still share most architectural
features with Family 17h CPUs, and therefore still need to call
init_amd_zn() e.g., to set the RECLAIM_DISTANCE override.

init_amd_zn() also sets X86_FEATURE_ZEN, which today is only used
in amd_set_core_ssb_state(), which isn't called on some late
model Family 17h CPUs, nor on any Family 19h CPUs:
X86_FEATURE_AMD_SSBD replaces X86_FEATURE_LS_CFG_SSBD on those
later model CPUs, where the SSBD mitigation is done via the
SPEC_CTRL MSR instead of the LS_CFG MSR.

Family 19h CPUs also don't have the erratum where the CPB feature
bit isn't set, but that code can stay unchanged and run safely
on Family 19h.

Signed-off-by: Kim Phillips <[email protected]>
Signed-off-by: Borislav Petkov <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]
---
arch/x86/include/asm/cpufeatures.h | 2 +-
arch/x86/kernel/cpu/amd.c | 3 ++-
2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index f3327cb..f980efc 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -217,7 +217,7 @@
#define X86_FEATURE_IBRS ( 7*32+25) /* Indirect Branch Restricted Speculation */
#define X86_FEATURE_IBPB ( 7*32+26) /* Indirect Branch Prediction Barrier */
#define X86_FEATURE_STIBP ( 7*32+27) /* Single Thread Indirect Branch Predictors */
-#define X86_FEATURE_ZEN ( 7*32+28) /* "" CPU is AMD family 0x17 (Zen) */
+#define X86_FEATURE_ZEN ( 7*32+28) /* "" CPU is AMD family 0x17 or above (Zen) */
#define X86_FEATURE_L1TF_PTEINV ( 7*32+29) /* "" L1TF workaround PTE inversion */
#define X86_FEATURE_IBRS_ENHANCED ( 7*32+30) /* Enhanced IBRS */
#define X86_FEATURE_MSR_IA32_FEAT_CTL ( 7*32+31) /* "" MSR IA32_FEAT_CTL configured */
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index ac83a0f..dc6894a 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -925,7 +925,8 @@ static void init_amd(struct cpuinfo_x86 *c)
case 0x12: init_amd_ln(c); break;
case 0x15: init_amd_bd(c); break;
case 0x16: init_amd_jg(c); break;
- case 0x17: init_amd_zn(c); break;
+ case 0x17: fallthrough;
+ case 0x19: init_amd_zn(c); break;
}

/*