[PATCH 01/13] x86/CPU/AMD: Add ZenX generations flags

From: Borislav Petkov
Date: Mon Nov 20 2023 - 05:42:17 EST


From: "Borislav Petkov (AMD)" <bp@xxxxxxxxx>

Add X86_FEATURE flags for each Zen generation. They should be used from
now on instead of checking f/m/s.

Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx>
---
arch/x86/include/asm/cpufeatures.h | 6 ++-
arch/x86/kernel/cpu/amd.c | 70 +++++++++++++++++++++++++++++-
2 files changed, 72 insertions(+), 4 deletions(-)

diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index 4af140cf5719..6f6cf49e9891 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -218,7 +218,7 @@
#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 based on Zen microarchitecture */
+#define X86_FEATURE_ZEN ( 7*32+28) /* "" CPU based on Zen microarchitecture */
#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 */
@@ -308,10 +308,12 @@
#define X86_FEATURE_SMBA (11*32+21) /* "" Slow Memory Bandwidth Allocation */
#define X86_FEATURE_BMEC (11*32+22) /* "" Bandwidth Monitoring Event Configuration */
#define X86_FEATURE_USER_SHSTK (11*32+23) /* Shadow stack support for user mode applications */
-
#define X86_FEATURE_SRSO (11*32+24) /* "" AMD BTB untrain RETs */
#define X86_FEATURE_SRSO_ALIAS (11*32+25) /* "" AMD BTB untrain RETs through aliasing */
#define X86_FEATURE_IBPB_ON_VMEXIT (11*32+26) /* "" Issue an IBPB only on VMEXIT */
+#define X86_FEATURE_ZEN2 (11*32+27) /* "" CPU based on Zen2 microarchitecture */
+#define X86_FEATURE_ZEN3 (11*32+28) /* "" CPU based on Zen3 microarchitecture */
+#define X86_FEATURE_ZEN4 (11*32+29) /* "" CPU based on Zen4 microarchitecture */

/* Intel-defined CPU features, CPUID level 0x00000007:1 (EAX), word 12 */
#define X86_FEATURE_AVX_VNNI (12*32+ 4) /* AVX VNNI instructions */
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index a7eab05e5f29..fa6ba63ca7e2 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -616,6 +616,49 @@ static void bsp_init_amd(struct cpuinfo_x86 *c)
}

resctrl_cpu_detect(c);
+
+ /* Figure out Zen generations: */
+ switch (c->x86) {
+ case 0x17: {
+ switch (c->x86_model) {
+ case 0x00 ... 0x2f:
+ case 0x50 ... 0x5f:
+ setup_force_cpu_cap(X86_FEATURE_ZEN);
+ break;
+ case 0x30 ... 0x4f:
+ case 0x60 ... 0x7f:
+ case 0x90 ... 0x91:
+ case 0xa0 ... 0xaf:
+ setup_force_cpu_cap(X86_FEATURE_ZEN2);
+ break;
+ default:
+ goto warn;
+ }
+ break;
+ }
+ case 0x19: {
+ switch (c->x86_model) {
+ case 0x00 ... 0x0f:
+ case 0x20 ... 0x5f:
+ setup_force_cpu_cap(X86_FEATURE_ZEN3);
+ break;
+ case 0x10 ... 0x1f:
+ case 0x60 ... 0xaf:
+ setup_force_cpu_cap(X86_FEATURE_ZEN4);
+ break;
+ default:
+ goto warn;
+ }
+ break;
+ }
+ default:
+ break;
+ }
+
+ return;
+
+warn:
+ WARN_ONCE(1, "Family 0x%x, model: 0x%x??\n", c->x86, c->x86_model);
}

static void early_detect_mem_encrypt(struct cpuinfo_x86 *c)
@@ -974,8 +1017,6 @@ void init_spectral_chicken(struct cpuinfo_x86 *c)

static void init_amd_zn(struct cpuinfo_x86 *c)
{
- set_cpu_cap(c, X86_FEATURE_ZEN);
-
#ifdef CONFIG_NUMA
node_reclaim_distance = 32;
#endif
@@ -997,6 +1038,22 @@ static void init_amd_zn(struct cpuinfo_x86 *c)
}
}

+static void init_amd_zen(struct cpuinfo_x86 *c)
+{
+}
+
+static void init_amd_zen2(struct cpuinfo_x86 *c)
+{
+}
+
+static void init_amd_zen3(struct cpuinfo_x86 *c)
+{
+}
+
+static void init_amd_zen4(struct cpuinfo_x86 *c)
+{
+}
+
static bool cpu_has_zenbleed_microcode(void)
{
u32 good_rev = 0;
@@ -1077,6 +1134,15 @@ static void init_amd(struct cpuinfo_x86 *c)
case 0x19: init_amd_zn(c); break;
}

+ if (boot_cpu_has(X86_FEATURE_ZEN))
+ init_amd_zen(c);
+ else if (boot_cpu_has(X86_FEATURE_ZEN2))
+ init_amd_zen2(c);
+ else if (boot_cpu_has(X86_FEATURE_ZEN3))
+ init_amd_zen3(c);
+ else if (boot_cpu_has(X86_FEATURE_ZEN4))
+ init_amd_zen4(c);
+
/*
* Enable workaround for FXSAVE leak on CPUs
* without a XSaveErPtr feature
--
2.42.0.rc0.25.ga82fb66fed25