From 4a28bfe3267b68e22c663ac26185aa16c9b879ef Mon Sep 17 00:00:00 2001
From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Date: Wed, 25 Apr 2018 22:04:16 -0400
Subject: x86/bugs: Concentrate bug detection into a separate function

Combine the various logic which goes through all those
x86_cpu_id matching structures in one function.

Suggested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
---
 arch/x86/kernel/cpu/common.c | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

(limited to 'arch/x86/kernel/cpu/common.c')

diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index ce243f7d2d4e..9ed0a18ff6f6 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -927,21 +927,27 @@ static const __initconst struct x86_cpu_id cpu_no_meltdown[] = {
 	{}
 };
 
-static bool __init cpu_vulnerable_to_meltdown(struct cpuinfo_x86 *c)
+static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
 {
 	u64 ia32_cap = 0;
 
+	if (x86_match_cpu(cpu_no_speculation))
+		return;
+
+	setup_force_cpu_bug(X86_BUG_SPECTRE_V1);
+	setup_force_cpu_bug(X86_BUG_SPECTRE_V2);
+
 	if (x86_match_cpu(cpu_no_meltdown))
-		return false;
+		return;
 
 	if (cpu_has(c, X86_FEATURE_ARCH_CAPABILITIES))
 		rdmsrl(MSR_IA32_ARCH_CAPABILITIES, ia32_cap);
 
 	/* Rogue Data Cache Load? No! */
 	if (ia32_cap & ARCH_CAP_RDCL_NO)
-		return false;
+		return;
 
-	return true;
+	setup_force_cpu_bug(X86_BUG_CPU_MELTDOWN);
 }
 
 /*
@@ -992,12 +998,7 @@ static void __init early_identify_cpu(struct cpuinfo_x86 *c)
 
 	setup_force_cpu_cap(X86_FEATURE_ALWAYS);
 
-	if (!x86_match_cpu(cpu_no_speculation)) {
-		if (cpu_vulnerable_to_meltdown(c))
-			setup_force_cpu_bug(X86_BUG_CPU_MELTDOWN);
-		setup_force_cpu_bug(X86_BUG_SPECTRE_V1);
-		setup_force_cpu_bug(X86_BUG_SPECTRE_V2);
-	}
+	cpu_set_bug_bits(c);
 
 	fpu__init_system(c);
 
-- 
cgit v1.2.3-70-g09d2


From c456442cd3a59eeb1d60293c26cbe2ff2c4e42cf Mon Sep 17 00:00:00 2001
From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Date: Wed, 25 Apr 2018 22:04:20 -0400
Subject: x86/bugs: Expose /sys/../spec_store_bypass

Add the sysfs file for the new vulerability. It does not do much except
show the words 'Vulnerable' for recent x86 cores.

Intel cores prior to family 6 are known not to be vulnerable, and so are
some Atoms and some Xeon Phi.

It assumes that older Cyrix, Centaur, etc. cores are immune.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
---
 Documentation/ABI/testing/sysfs-devices-system-cpu |  1 +
 arch/x86/include/asm/cpufeatures.h                 |  1 +
 arch/x86/kernel/cpu/bugs.c                         |  5 +++++
 arch/x86/kernel/cpu/common.c                       | 23 ++++++++++++++++++++++
 drivers/base/cpu.c                                 |  8 ++++++++
 include/linux/cpu.h                                |  2 ++
 6 files changed, 40 insertions(+)

(limited to 'arch/x86/kernel/cpu/common.c')

diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu
index 025b7cf3768d..bd4975e132d3 100644
--- a/Documentation/ABI/testing/sysfs-devices-system-cpu
+++ b/Documentation/ABI/testing/sysfs-devices-system-cpu
@@ -478,6 +478,7 @@ What:		/sys/devices/system/cpu/vulnerabilities
 		/sys/devices/system/cpu/vulnerabilities/meltdown
 		/sys/devices/system/cpu/vulnerabilities/spectre_v1
 		/sys/devices/system/cpu/vulnerabilities/spectre_v2
+		/sys/devices/system/cpu/vulnerabilities/spec_store_bypass
 Date:		January 2018
 Contact:	Linux kernel mailing list <linux-kernel@vger.kernel.org>
 Description:	Information about CPU vulnerabilities
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index 578793e97431..3493b58ef2cc 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -363,5 +363,6 @@
 #define X86_BUG_CPU_MELTDOWN		X86_BUG(14) /* CPU is affected by meltdown attack and needs kernel page table isolation */
 #define X86_BUG_SPECTRE_V1		X86_BUG(15) /* CPU is affected by Spectre variant 1 attack with conditional branches */
 #define X86_BUG_SPECTRE_V2		X86_BUG(16) /* CPU is affected by Spectre variant 2 attack with indirect branches */
+#define X86_BUG_SPEC_STORE_BYPASS	X86_BUG(17) /* CPU is affected by speculative store bypass attack */
 
 #endif /* _ASM_X86_CPUFEATURES_H */
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 38a8626c894c..59a9f3aa9f7a 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -404,4 +404,9 @@ ssize_t cpu_show_spectre_v2(struct device *dev, struct device_attribute *attr, c
 {
 	return cpu_show_common(dev, attr, buf, X86_BUG_SPECTRE_V2);
 }
+
+ssize_t cpu_show_spec_store_bypass(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	return cpu_show_common(dev, attr, buf, X86_BUG_SPEC_STORE_BYPASS);
+}
 #endif
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 9ed0a18ff6f6..6ff0cc441a59 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -927,10 +927,33 @@ static const __initconst struct x86_cpu_id cpu_no_meltdown[] = {
 	{}
 };
 
+static const __initconst struct x86_cpu_id cpu_no_spec_store_bypass[] = {
+	{ X86_VENDOR_INTEL,	6,	INTEL_FAM6_ATOM_PINEVIEW	},
+	{ X86_VENDOR_INTEL,	6,	INTEL_FAM6_ATOM_LINCROFT	},
+	{ X86_VENDOR_INTEL,	6,	INTEL_FAM6_ATOM_PENWELL		},
+	{ X86_VENDOR_INTEL,	6,	INTEL_FAM6_ATOM_CLOVERVIEW	},
+	{ X86_VENDOR_INTEL,	6,	INTEL_FAM6_ATOM_CEDARVIEW	},
+	{ X86_VENDOR_INTEL,	6,	INTEL_FAM6_ATOM_SILVERMONT1	},
+	{ X86_VENDOR_INTEL,	6,	INTEL_FAM6_ATOM_AIRMONT		},
+	{ X86_VENDOR_INTEL,	6,	INTEL_FAM6_ATOM_SILVERMONT2	},
+	{ X86_VENDOR_INTEL,	6,	INTEL_FAM6_ATOM_MERRIFIELD	},
+	{ X86_VENDOR_INTEL,	6,	INTEL_FAM6_CORE_YONAH		},
+	{ X86_VENDOR_INTEL,	6,	INTEL_FAM6_XEON_PHI_KNL		},
+	{ X86_VENDOR_INTEL,	6,	INTEL_FAM6_XEON_PHI_KNM		},
+	{ X86_VENDOR_CENTAUR,	5,					},
+	{ X86_VENDOR_INTEL,	5,					},
+	{ X86_VENDOR_NSC,	5,					},
+	{ X86_VENDOR_ANY,	4,					},
+	{}
+};
+
 static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
 {
 	u64 ia32_cap = 0;
 
+	if (!x86_match_cpu(cpu_no_spec_store_bypass))
+		setup_force_cpu_bug(X86_BUG_SPEC_STORE_BYPASS);
+
 	if (x86_match_cpu(cpu_no_speculation))
 		return;
 
diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index 2da998baa75c..30cc9c877ebb 100644
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c
@@ -534,14 +534,22 @@ ssize_t __weak cpu_show_spectre_v2(struct device *dev,
 	return sprintf(buf, "Not affected\n");
 }
 
+ssize_t __weak cpu_show_spec_store_bypass(struct device *dev,
+					  struct device_attribute *attr, char *buf)
+{
+	return sprintf(buf, "Not affected\n");
+}
+
 static DEVICE_ATTR(meltdown, 0444, cpu_show_meltdown, NULL);
 static DEVICE_ATTR(spectre_v1, 0444, cpu_show_spectre_v1, NULL);
 static DEVICE_ATTR(spectre_v2, 0444, cpu_show_spectre_v2, NULL);
+static DEVICE_ATTR(spec_store_bypass, 0444, cpu_show_spec_store_bypass, NULL);
 
 static struct attribute *cpu_root_vulnerabilities_attrs[] = {
 	&dev_attr_meltdown.attr,
 	&dev_attr_spectre_v1.attr,
 	&dev_attr_spectre_v2.attr,
+	&dev_attr_spec_store_bypass.attr,
 	NULL
 };
 
diff --git a/include/linux/cpu.h b/include/linux/cpu.h
index 7b01bc11c692..a97a63eef59f 100644
--- a/include/linux/cpu.h
+++ b/include/linux/cpu.h
@@ -53,6 +53,8 @@ extern ssize_t cpu_show_spectre_v1(struct device *dev,
 				   struct device_attribute *attr, char *buf);
 extern ssize_t cpu_show_spectre_v2(struct device *dev,
 				   struct device_attribute *attr, char *buf);
+extern ssize_t cpu_show_spec_store_bypass(struct device *dev,
+					  struct device_attribute *attr, char *buf);
 
 extern __printf(4, 5)
 struct device *cpu_device_create(struct device *parent, void *drvdata,
-- 
cgit v1.2.3-70-g09d2


From 772439717dbf703b39990be58d8d4e3e4ad0598a Mon Sep 17 00:00:00 2001
From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Date: Wed, 25 Apr 2018 22:04:22 -0400
Subject: x86/bugs/intel: Set proper CPU features and setup RDS

Intel CPUs expose methods to:

 - Detect whether RDS capability is available via CPUID.7.0.EDX[31],

 - The SPEC_CTRL MSR(0x48), bit 2 set to enable RDS.

 - MSR_IA32_ARCH_CAPABILITIES, Bit(4) no need to enable RRS.

With that in mind if spec_store_bypass_disable=[auto,on] is selected set at
boot-time the SPEC_CTRL MSR to enable RDS if the platform requires it.

Note that this does not fix the KVM case where the SPEC_CTRL is exposed to
guests which can muck with it, see patch titled :
 KVM/SVM/VMX/x86/spectre_v2: Support the combination of guest and host IBRS.

And for the firmware (IBRS to be set), see patch titled:
 x86/spectre_v2: Read SPEC_CTRL MSR during boot and re-use reserved bits

[ tglx: Distangled it from the intel implementation and kept the call order ]

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
---
 arch/x86/include/asm/msr-index.h |  6 ++++++
 arch/x86/kernel/cpu/bugs.c       | 30 ++++++++++++++++++++++++++++--
 arch/x86/kernel/cpu/common.c     | 10 ++++++----
 arch/x86/kernel/cpu/cpu.h        |  2 ++
 arch/x86/kernel/cpu/intel.c      |  1 +
 5 files changed, 43 insertions(+), 6 deletions(-)

(limited to 'arch/x86/kernel/cpu/common.c')

diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index 53d5b1b9255e..21e1a6df9907 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -42,6 +42,7 @@
 #define MSR_IA32_SPEC_CTRL		0x00000048 /* Speculation Control */
 #define SPEC_CTRL_IBRS			(1 << 0)   /* Indirect Branch Restricted Speculation */
 #define SPEC_CTRL_STIBP			(1 << 1)   /* Single Thread Indirect Branch Predictors */
+#define SPEC_CTRL_RDS			(1 << 2)   /* Reduced Data Speculation */
 
 #define MSR_IA32_PRED_CMD		0x00000049 /* Prediction Command */
 #define PRED_CMD_IBPB			(1 << 0)   /* Indirect Branch Prediction Barrier */
@@ -68,6 +69,11 @@
 #define MSR_IA32_ARCH_CAPABILITIES	0x0000010a
 #define ARCH_CAP_RDCL_NO		(1 << 0)   /* Not susceptible to Meltdown */
 #define ARCH_CAP_IBRS_ALL		(1 << 1)   /* Enhanced IBRS support */
+#define ARCH_CAP_RDS_NO			(1 << 4)   /*
+						    * Not susceptible to Speculative Store Bypass
+						    * attack, so no Reduced Data Speculation control
+						    * required.
+						    */
 
 #define MSR_IA32_BBL_CR_CTL		0x00000119
 #define MSR_IA32_BBL_CR_CTL3		0x0000011e
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 2d1f1cb604aa..17edf5bdc361 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -117,7 +117,7 @@ static enum spectre_v2_mitigation spectre_v2_enabled = SPECTRE_V2_NONE;
 
 void x86_spec_ctrl_set(u64 val)
 {
-	if (val & ~SPEC_CTRL_IBRS)
+	if (val & ~(SPEC_CTRL_IBRS | SPEC_CTRL_RDS))
 		WARN_ONCE(1, "SPEC_CTRL MSR value 0x%16llx is unknown.\n", val);
 	else
 		wrmsrl(MSR_IA32_SPEC_CTRL, x86_spec_ctrl_base | val);
@@ -444,8 +444,28 @@ static enum ssb_mitigation_cmd __init __ssb_select_mitigation(void)
 		break;
 	}
 
-	if (mode != SPEC_STORE_BYPASS_NONE)
+	/*
+	 * We have three CPU feature flags that are in play here:
+	 *  - X86_BUG_SPEC_STORE_BYPASS - CPU is susceptible.
+	 *  - X86_FEATURE_RDS - CPU is able to turn off speculative store bypass
+	 *  - X86_FEATURE_SPEC_STORE_BYPASS_DISABLE - engage the mitigation
+	 */
+	if (mode != SPEC_STORE_BYPASS_NONE) {
 		setup_force_cpu_cap(X86_FEATURE_SPEC_STORE_BYPASS_DISABLE);
+		/*
+		 * Intel uses the SPEC CTRL MSR Bit(2) for this, while AMD uses
+		 * a completely different MSR and bit dependent on family.
+		 */
+		switch (boot_cpu_data.x86_vendor) {
+		case X86_VENDOR_INTEL:
+			x86_spec_ctrl_base |= SPEC_CTRL_RDS;
+			x86_spec_ctrl_set(SPEC_CTRL_RDS);
+			break;
+		case X86_VENDOR_AMD:
+			break;
+		}
+	}
+
 	return mode;
 }
 
@@ -459,6 +479,12 @@ static void ssb_select_mitigation()
 
 #undef pr_fmt
 
+void x86_spec_ctrl_setup_ap(void)
+{
+	if (boot_cpu_has(X86_FEATURE_IBRS))
+		x86_spec_ctrl_set(x86_spec_ctrl_base & (SPEC_CTRL_IBRS | SPEC_CTRL_RDS));
+}
+
 #ifdef CONFIG_SYSFS
 
 ssize_t cpu_show_common(struct device *dev, struct device_attribute *attr,
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 6ff0cc441a59..d6dc71d616ea 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -951,7 +951,11 @@ static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
 {
 	u64 ia32_cap = 0;
 
-	if (!x86_match_cpu(cpu_no_spec_store_bypass))
+	if (cpu_has(c, X86_FEATURE_ARCH_CAPABILITIES))
+		rdmsrl(MSR_IA32_ARCH_CAPABILITIES, ia32_cap);
+
+	if (!x86_match_cpu(cpu_no_spec_store_bypass) &&
+	   !(ia32_cap & ARCH_CAP_RDS_NO))
 		setup_force_cpu_bug(X86_BUG_SPEC_STORE_BYPASS);
 
 	if (x86_match_cpu(cpu_no_speculation))
@@ -963,9 +967,6 @@ static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
 	if (x86_match_cpu(cpu_no_meltdown))
 		return;
 
-	if (cpu_has(c, X86_FEATURE_ARCH_CAPABILITIES))
-		rdmsrl(MSR_IA32_ARCH_CAPABILITIES, ia32_cap);
-
 	/* Rogue Data Cache Load? No! */
 	if (ia32_cap & ARCH_CAP_RDCL_NO)
 		return;
@@ -1383,6 +1384,7 @@ void identify_secondary_cpu(struct cpuinfo_x86 *c)
 #endif
 	mtrr_ap_init();
 	validate_apic_and_package_id(c);
+	x86_spec_ctrl_setup_ap();
 }
 
 static __init int setup_noclflush(char *arg)
diff --git a/arch/x86/kernel/cpu/cpu.h b/arch/x86/kernel/cpu/cpu.h
index e806b11a99af..37672d299e35 100644
--- a/arch/x86/kernel/cpu/cpu.h
+++ b/arch/x86/kernel/cpu/cpu.h
@@ -50,4 +50,6 @@ extern void cpu_detect_cache_sizes(struct cpuinfo_x86 *c);
 
 unsigned int aperfmperf_get_khz(int cpu);
 
+extern void x86_spec_ctrl_setup_ap(void);
+
 #endif /* ARCH_X86_CPU_H */
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 60d1897041da..ef3f9c01c274 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -189,6 +189,7 @@ static void early_init_intel(struct cpuinfo_x86 *c)
 		setup_clear_cpu_cap(X86_FEATURE_STIBP);
 		setup_clear_cpu_cap(X86_FEATURE_SPEC_CTRL);
 		setup_clear_cpu_cap(X86_FEATURE_INTEL_STIBP);
+		setup_clear_cpu_cap(X86_FEATURE_RDS);
 	}
 
 	/*
-- 
cgit v1.2.3-70-g09d2


From 764f3c21588a059cd783c6ba0734d4db2d72822d Mon Sep 17 00:00:00 2001
From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Date: Wed, 25 Apr 2018 22:04:24 -0400
Subject: x86/bugs/AMD: Add support to disable RDS on Fam[15,16,17]h if
 requested

AMD does not need the Speculative Store Bypass mitigation to be enabled.

The parameters for this are already available and can be done via MSR
C001_1020. Each family uses a different bit in that MSR for this.

[ tglx: Expose the bit mask via a variable and move the actual MSR fiddling
  	into the bugs code as that's the right thing to do and also required
	to prepare for dynamic enable/disable ]

Suggested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
---
 arch/x86/include/asm/cpufeatures.h   |  1 +
 arch/x86/include/asm/nospec-branch.h |  4 ++++
 arch/x86/kernel/cpu/amd.c            | 26 ++++++++++++++++++++++++++
 arch/x86/kernel/cpu/bugs.c           | 27 ++++++++++++++++++++++++++-
 arch/x86/kernel/cpu/common.c         |  4 ++++
 5 files changed, 61 insertions(+), 1 deletion(-)

(limited to 'arch/x86/kernel/cpu/common.c')

diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index 58689ed969bb..b2464c1787df 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -215,6 +215,7 @@
 #define X86_FEATURE_USE_IBPB		( 7*32+21) /* "" Indirect Branch Prediction Barrier enabled */
 #define X86_FEATURE_USE_IBRS_FW		( 7*32+22) /* "" Use IBRS during runtime firmware calls */
 #define X86_FEATURE_SPEC_STORE_BYPASS_DISABLE	( 7*32+23) /* "" Disable Speculative Store Bypass. */
+#define X86_FEATURE_AMD_RDS		(7*32+24)  /* "" AMD RDS implementation */
 
 /* Virtualization flags: Linux defined, word 8 */
 #define X86_FEATURE_TPR_SHADOW		( 8*32+ 0) /* Intel TPR Shadow */
diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h
index 7b9eacfc03f3..3a1541cf32de 100644
--- a/arch/x86/include/asm/nospec-branch.h
+++ b/arch/x86/include/asm/nospec-branch.h
@@ -244,6 +244,10 @@ enum ssb_mitigation {
 	SPEC_STORE_BYPASS_DISABLE,
 };
 
+/* AMD specific Speculative Store Bypass MSR data */
+extern u64 x86_amd_ls_cfg_base;
+extern u64 x86_amd_ls_cfg_rds_mask;
+
 extern char __indirect_thunk_start[];
 extern char __indirect_thunk_end[];
 
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 12bc0a1139da..3d553fa5075d 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -10,6 +10,7 @@
 #include <asm/processor.h>
 #include <asm/apic.h>
 #include <asm/cpu.h>
+#include <asm/nospec-branch.h>
 #include <asm/smp.h>
 #include <asm/pci-direct.h>
 #include <asm/delay.h>
@@ -554,6 +555,26 @@ static void bsp_init_amd(struct cpuinfo_x86 *c)
 		rdmsrl(MSR_FAM10H_NODE_ID, value);
 		nodes_per_socket = ((value >> 3) & 7) + 1;
 	}
+
+	if (c->x86 >= 0x15 && c->x86 <= 0x17) {
+		unsigned int bit;
+
+		switch (c->x86) {
+		case 0x15: bit = 54; break;
+		case 0x16: bit = 33; break;
+		case 0x17: bit = 10; break;
+		default: return;
+		}
+		/*
+		 * Try to cache the base value so further operations can
+		 * avoid RMW. If that faults, do not enable RDS.
+		 */
+		if (!rdmsrl_safe(MSR_AMD64_LS_CFG, &x86_amd_ls_cfg_base)) {
+			setup_force_cpu_cap(X86_FEATURE_RDS);
+			setup_force_cpu_cap(X86_FEATURE_AMD_RDS);
+			x86_amd_ls_cfg_rds_mask = 1ULL << bit;
+		}
+	}
 }
 
 static void early_detect_mem_encrypt(struct cpuinfo_x86 *c)
@@ -898,6 +919,11 @@ static void init_amd(struct cpuinfo_x86 *c)
 	/* AMD CPUs don't reset SS attributes on SYSRET, Xen does. */
 	if (!cpu_has(c, X86_FEATURE_XENPV))
 		set_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS);
+
+	if (boot_cpu_has(X86_FEATURE_AMD_RDS)) {
+		set_cpu_cap(c, X86_FEATURE_RDS);
+		set_cpu_cap(c, X86_FEATURE_AMD_RDS);
+	}
 }
 
 #ifdef CONFIG_X86_32
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index d809d398675a..86cdf635636d 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -41,6 +41,13 @@ static u64 __ro_after_init x86_spec_ctrl_base;
  */
 static u64 __ro_after_init x86_spec_ctrl_mask = ~SPEC_CTRL_IBRS;
 
+/*
+ * AMD specific MSR info for Speculative Store Bypass control.
+ * x86_amd_ls_cfg_rds_mask is initialized in identify_boot_cpu().
+ */
+u64 __ro_after_init x86_amd_ls_cfg_base;
+u64 __ro_after_init x86_amd_ls_cfg_rds_mask;
+
 void __init check_bugs(void)
 {
 	identify_boot_cpu();
@@ -52,7 +59,8 @@ void __init check_bugs(void)
 
 	/*
 	 * Read the SPEC_CTRL MSR to account for reserved bits which may
-	 * have unknown values.
+	 * have unknown values. AMD64_LS_CFG MSR is cached in the early AMD
+	 * init code as it is not enumerated and depends on the family.
 	 */
 	if (boot_cpu_has(X86_FEATURE_IBRS))
 		rdmsrl(MSR_IA32_SPEC_CTRL, x86_spec_ctrl_base);
@@ -154,6 +162,14 @@ void x86_spec_ctrl_restore_host(u64 guest_spec_ctrl)
 }
 EXPORT_SYMBOL_GPL(x86_spec_ctrl_restore_host);
 
+static void x86_amd_rds_enable(void)
+{
+	u64 msrval = x86_amd_ls_cfg_base | x86_amd_ls_cfg_rds_mask;
+
+	if (boot_cpu_has(X86_FEATURE_AMD_RDS))
+		wrmsrl(MSR_AMD64_LS_CFG, msrval);
+}
+
 #ifdef RETPOLINE
 static bool spectre_v2_bad_module;
 
@@ -443,6 +459,11 @@ static enum ssb_mitigation_cmd __init __ssb_select_mitigation(void)
 
 	switch (cmd) {
 	case SPEC_STORE_BYPASS_CMD_AUTO:
+		/*
+		 * AMD platforms by default don't need SSB mitigation.
+		 */
+		if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
+			break;
 	case SPEC_STORE_BYPASS_CMD_ON:
 		mode = SPEC_STORE_BYPASS_DISABLE;
 		break;
@@ -469,6 +490,7 @@ static enum ssb_mitigation_cmd __init __ssb_select_mitigation(void)
 			x86_spec_ctrl_set(SPEC_CTRL_RDS);
 			break;
 		case X86_VENDOR_AMD:
+			x86_amd_rds_enable();
 			break;
 		}
 	}
@@ -490,6 +512,9 @@ void x86_spec_ctrl_setup_ap(void)
 {
 	if (boot_cpu_has(X86_FEATURE_IBRS))
 		x86_spec_ctrl_set(x86_spec_ctrl_base & ~x86_spec_ctrl_mask);
+
+	if (ssb_mode == SPEC_STORE_BYPASS_DISABLE)
+		x86_amd_rds_enable();
 }
 
 #ifdef CONFIG_SYSFS
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index d6dc71d616ea..e0517bcee446 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -943,6 +943,10 @@ static const __initconst struct x86_cpu_id cpu_no_spec_store_bypass[] = {
 	{ X86_VENDOR_CENTAUR,	5,					},
 	{ X86_VENDOR_INTEL,	5,					},
 	{ X86_VENDOR_NSC,	5,					},
+	{ X86_VENDOR_AMD,	0x12,					},
+	{ X86_VENDOR_AMD,	0x11,					},
+	{ X86_VENDOR_AMD,	0x10,					},
+	{ X86_VENDOR_AMD,	0xf,					},
 	{ X86_VENDOR_ANY,	4,					},
 	{}
 };
-- 
cgit v1.2.3-70-g09d2


From 9f65fb29374ee37856dbad847b4e121aab72b510 Mon Sep 17 00:00:00 2001
From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Date: Wed, 9 May 2018 21:41:38 +0200
Subject: x86/bugs: Rename _RDS to _SSBD

Intel collateral will reference the SSB mitigation bit in IA32_SPEC_CTL[2]
as SSBD (Speculative Store Bypass Disable).

Hence changing it.

It is unclear yet what the MSR_IA32_ARCH_CAPABILITIES (0x10a) Bit(4) name
is going to be. Following the rename it would be SSBD_NO but that rolls out
to Speculative Store Bypass Disable No.

Also fixed the missing space in X86_FEATURE_AMD_SSBD.

[ tglx: Fixup x86_amd_rds_enable() and rds_tif_to_amd_ls_cfg() as well ]

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 arch/x86/include/asm/cpufeatures.h |  4 ++--
 arch/x86/include/asm/msr-index.h   | 10 +++++-----
 arch/x86/include/asm/spec-ctrl.h   | 12 ++++++------
 arch/x86/include/asm/thread_info.h |  6 +++---
 arch/x86/kernel/cpu/amd.c          | 14 +++++++-------
 arch/x86/kernel/cpu/bugs.c         | 36 ++++++++++++++++++------------------
 arch/x86/kernel/cpu/common.c       |  2 +-
 arch/x86/kernel/cpu/intel.c        |  2 +-
 arch/x86/kernel/process.c          |  8 ++++----
 arch/x86/kvm/cpuid.c               |  2 +-
 arch/x86/kvm/vmx.c                 |  6 +++---
 11 files changed, 51 insertions(+), 51 deletions(-)

(limited to 'arch/x86/kernel/cpu/common.c')

diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index b2464c1787df..4e1c747acbf8 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -215,7 +215,7 @@
 #define X86_FEATURE_USE_IBPB		( 7*32+21) /* "" Indirect Branch Prediction Barrier enabled */
 #define X86_FEATURE_USE_IBRS_FW		( 7*32+22) /* "" Use IBRS during runtime firmware calls */
 #define X86_FEATURE_SPEC_STORE_BYPASS_DISABLE	( 7*32+23) /* "" Disable Speculative Store Bypass. */
-#define X86_FEATURE_AMD_RDS		(7*32+24)  /* "" AMD RDS implementation */
+#define X86_FEATURE_AMD_SSBD		( 7*32+24)  /* "" AMD SSBD implementation */
 
 /* Virtualization flags: Linux defined, word 8 */
 #define X86_FEATURE_TPR_SHADOW		( 8*32+ 0) /* Intel TPR Shadow */
@@ -336,7 +336,7 @@
 #define X86_FEATURE_SPEC_CTRL		(18*32+26) /* "" Speculation Control (IBRS + IBPB) */
 #define X86_FEATURE_INTEL_STIBP		(18*32+27) /* "" Single Thread Indirect Branch Predictors */
 #define X86_FEATURE_ARCH_CAPABILITIES	(18*32+29) /* IA32_ARCH_CAPABILITIES MSR (Intel) */
-#define X86_FEATURE_RDS			(18*32+31) /* Reduced Data Speculation */
+#define X86_FEATURE_SSBD		(18*32+31) /* Speculative Store Bypass Disable */
 
 /*
  * BUG word(s)
diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index 810f50bb338d..0da3ca260b06 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -42,8 +42,8 @@
 #define MSR_IA32_SPEC_CTRL		0x00000048 /* Speculation Control */
 #define SPEC_CTRL_IBRS			(1 << 0)   /* Indirect Branch Restricted Speculation */
 #define SPEC_CTRL_STIBP			(1 << 1)   /* Single Thread Indirect Branch Predictors */
-#define SPEC_CTRL_RDS_SHIFT		2	   /* Reduced Data Speculation bit */
-#define SPEC_CTRL_RDS			(1 << SPEC_CTRL_RDS_SHIFT)   /* Reduced Data Speculation */
+#define SPEC_CTRL_SSBD_SHIFT		2	   /* Speculative Store Bypass Disable bit */
+#define SPEC_CTRL_SSBD			(1 << SPEC_CTRL_SSBD_SHIFT)   /* Speculative Store Bypass Disable */
 
 #define MSR_IA32_PRED_CMD		0x00000049 /* Prediction Command */
 #define PRED_CMD_IBPB			(1 << 0)   /* Indirect Branch Prediction Barrier */
@@ -70,10 +70,10 @@
 #define MSR_IA32_ARCH_CAPABILITIES	0x0000010a
 #define ARCH_CAP_RDCL_NO		(1 << 0)   /* Not susceptible to Meltdown */
 #define ARCH_CAP_IBRS_ALL		(1 << 1)   /* Enhanced IBRS support */
-#define ARCH_CAP_RDS_NO			(1 << 4)   /*
+#define ARCH_CAP_SSBD_NO		(1 << 4)   /*
 						    * Not susceptible to Speculative Store Bypass
-						    * attack, so no Reduced Data Speculation control
-						    * required.
+						    * attack, so no Speculative Store Bypass
+						    * control required.
 						    */
 
 #define MSR_IA32_BBL_CR_CTL		0x00000119
diff --git a/arch/x86/include/asm/spec-ctrl.h b/arch/x86/include/asm/spec-ctrl.h
index 45ef00ad5105..dc21209790bf 100644
--- a/arch/x86/include/asm/spec-ctrl.h
+++ b/arch/x86/include/asm/spec-ctrl.h
@@ -17,20 +17,20 @@ extern void x86_spec_ctrl_restore_host(u64);
 
 /* AMD specific Speculative Store Bypass MSR data */
 extern u64 x86_amd_ls_cfg_base;
-extern u64 x86_amd_ls_cfg_rds_mask;
+extern u64 x86_amd_ls_cfg_ssbd_mask;
 
 /* The Intel SPEC CTRL MSR base value cache */
 extern u64 x86_spec_ctrl_base;
 
-static inline u64 rds_tif_to_spec_ctrl(u64 tifn)
+static inline u64 ssbd_tif_to_spec_ctrl(u64 tifn)
 {
-	BUILD_BUG_ON(TIF_RDS < SPEC_CTRL_RDS_SHIFT);
-	return (tifn & _TIF_RDS) >> (TIF_RDS - SPEC_CTRL_RDS_SHIFT);
+	BUILD_BUG_ON(TIF_SSBD < SPEC_CTRL_SSBD_SHIFT);
+	return (tifn & _TIF_SSBD) >> (TIF_SSBD - SPEC_CTRL_SSBD_SHIFT);
 }
 
-static inline u64 rds_tif_to_amd_ls_cfg(u64 tifn)
+static inline u64 ssbd_tif_to_amd_ls_cfg(u64 tifn)
 {
-	return (tifn & _TIF_RDS) ? x86_amd_ls_cfg_rds_mask : 0ULL;
+	return (tifn & _TIF_SSBD) ? x86_amd_ls_cfg_ssbd_mask : 0ULL;
 }
 
 extern void speculative_store_bypass_update(void);
diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h
index e5c26cc59619..2ff2a30a264f 100644
--- a/arch/x86/include/asm/thread_info.h
+++ b/arch/x86/include/asm/thread_info.h
@@ -79,7 +79,7 @@ struct thread_info {
 #define TIF_SIGPENDING		2	/* signal pending */
 #define TIF_NEED_RESCHED	3	/* rescheduling necessary */
 #define TIF_SINGLESTEP		4	/* reenable singlestep on user return*/
-#define TIF_RDS			5	/* Reduced data speculation */
+#define TIF_SSBD			5	/* Reduced data speculation */
 #define TIF_SYSCALL_EMU		6	/* syscall emulation active */
 #define TIF_SYSCALL_AUDIT	7	/* syscall auditing active */
 #define TIF_SECCOMP		8	/* secure computing */
@@ -106,7 +106,7 @@ struct thread_info {
 #define _TIF_SIGPENDING		(1 << TIF_SIGPENDING)
 #define _TIF_NEED_RESCHED	(1 << TIF_NEED_RESCHED)
 #define _TIF_SINGLESTEP		(1 << TIF_SINGLESTEP)
-#define _TIF_RDS		(1 << TIF_RDS)
+#define _TIF_SSBD		(1 << TIF_SSBD)
 #define _TIF_SYSCALL_EMU	(1 << TIF_SYSCALL_EMU)
 #define _TIF_SYSCALL_AUDIT	(1 << TIF_SYSCALL_AUDIT)
 #define _TIF_SECCOMP		(1 << TIF_SECCOMP)
@@ -146,7 +146,7 @@ struct thread_info {
 
 /* flags to check in __switch_to() */
 #define _TIF_WORK_CTXSW							\
-	(_TIF_IO_BITMAP|_TIF_NOCPUID|_TIF_NOTSC|_TIF_BLOCKSTEP|_TIF_RDS)
+	(_TIF_IO_BITMAP|_TIF_NOCPUID|_TIF_NOTSC|_TIF_BLOCKSTEP|_TIF_SSBD)
 
 #define _TIF_WORK_CTXSW_PREV (_TIF_WORK_CTXSW|_TIF_USER_RETURN_NOTIFY)
 #define _TIF_WORK_CTXSW_NEXT (_TIF_WORK_CTXSW)
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 18efc33a8d2e..7bde990b0385 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -567,12 +567,12 @@ static void bsp_init_amd(struct cpuinfo_x86 *c)
 		}
 		/*
 		 * Try to cache the base value so further operations can
-		 * avoid RMW. If that faults, do not enable RDS.
+		 * avoid RMW. If that faults, do not enable SSBD.
 		 */
 		if (!rdmsrl_safe(MSR_AMD64_LS_CFG, &x86_amd_ls_cfg_base)) {
-			setup_force_cpu_cap(X86_FEATURE_RDS);
-			setup_force_cpu_cap(X86_FEATURE_AMD_RDS);
-			x86_amd_ls_cfg_rds_mask = 1ULL << bit;
+			setup_force_cpu_cap(X86_FEATURE_SSBD);
+			setup_force_cpu_cap(X86_FEATURE_AMD_SSBD);
+			x86_amd_ls_cfg_ssbd_mask = 1ULL << bit;
 		}
 	}
 }
@@ -920,9 +920,9 @@ static void init_amd(struct cpuinfo_x86 *c)
 	if (!cpu_has(c, X86_FEATURE_XENPV))
 		set_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS);
 
-	if (boot_cpu_has(X86_FEATURE_AMD_RDS)) {
-		set_cpu_cap(c, X86_FEATURE_RDS);
-		set_cpu_cap(c, X86_FEATURE_AMD_RDS);
+	if (boot_cpu_has(X86_FEATURE_AMD_SSBD)) {
+		set_cpu_cap(c, X86_FEATURE_SSBD);
+		set_cpu_cap(c, X86_FEATURE_AMD_SSBD);
 	}
 }
 
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 563d8e54c863..09b116b7f3bf 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -45,10 +45,10 @@ static u64 __ro_after_init x86_spec_ctrl_mask = ~SPEC_CTRL_IBRS;
 
 /*
  * AMD specific MSR info for Speculative Store Bypass control.
- * x86_amd_ls_cfg_rds_mask is initialized in identify_boot_cpu().
+ * x86_amd_ls_cfg_ssbd_mask is initialized in identify_boot_cpu().
  */
 u64 __ro_after_init x86_amd_ls_cfg_base;
-u64 __ro_after_init x86_amd_ls_cfg_rds_mask;
+u64 __ro_after_init x86_amd_ls_cfg_ssbd_mask;
 
 void __init check_bugs(void)
 {
@@ -146,7 +146,7 @@ u64 x86_spec_ctrl_get_default(void)
 	u64 msrval = x86_spec_ctrl_base;
 
 	if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL)
-		msrval |= rds_tif_to_spec_ctrl(current_thread_info()->flags);
+		msrval |= ssbd_tif_to_spec_ctrl(current_thread_info()->flags);
 	return msrval;
 }
 EXPORT_SYMBOL_GPL(x86_spec_ctrl_get_default);
@@ -159,7 +159,7 @@ void x86_spec_ctrl_set_guest(u64 guest_spec_ctrl)
 		return;
 
 	if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL)
-		host |= rds_tif_to_spec_ctrl(current_thread_info()->flags);
+		host |= ssbd_tif_to_spec_ctrl(current_thread_info()->flags);
 
 	if (host != guest_spec_ctrl)
 		wrmsrl(MSR_IA32_SPEC_CTRL, guest_spec_ctrl);
@@ -174,18 +174,18 @@ void x86_spec_ctrl_restore_host(u64 guest_spec_ctrl)
 		return;
 
 	if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL)
-		host |= rds_tif_to_spec_ctrl(current_thread_info()->flags);
+		host |= ssbd_tif_to_spec_ctrl(current_thread_info()->flags);
 
 	if (host != guest_spec_ctrl)
 		wrmsrl(MSR_IA32_SPEC_CTRL, host);
 }
 EXPORT_SYMBOL_GPL(x86_spec_ctrl_restore_host);
 
-static void x86_amd_rds_enable(void)
+static void x86_amd_ssb_disable(void)
 {
-	u64 msrval = x86_amd_ls_cfg_base | x86_amd_ls_cfg_rds_mask;
+	u64 msrval = x86_amd_ls_cfg_base | x86_amd_ls_cfg_ssbd_mask;
 
-	if (boot_cpu_has(X86_FEATURE_AMD_RDS))
+	if (boot_cpu_has(X86_FEATURE_AMD_SSBD))
 		wrmsrl(MSR_AMD64_LS_CFG, msrval);
 }
 
@@ -473,7 +473,7 @@ static enum ssb_mitigation_cmd __init __ssb_select_mitigation(void)
 	enum ssb_mitigation mode = SPEC_STORE_BYPASS_NONE;
 	enum ssb_mitigation_cmd cmd;
 
-	if (!boot_cpu_has(X86_FEATURE_RDS))
+	if (!boot_cpu_has(X86_FEATURE_SSBD))
 		return mode;
 
 	cmd = ssb_parse_cmdline();
@@ -507,7 +507,7 @@ static enum ssb_mitigation_cmd __init __ssb_select_mitigation(void)
 	/*
 	 * We have three CPU feature flags that are in play here:
 	 *  - X86_BUG_SPEC_STORE_BYPASS - CPU is susceptible.
-	 *  - X86_FEATURE_RDS - CPU is able to turn off speculative store bypass
+	 *  - X86_FEATURE_SSBD - CPU is able to turn off speculative store bypass
 	 *  - X86_FEATURE_SPEC_STORE_BYPASS_DISABLE - engage the mitigation
 	 */
 	if (mode == SPEC_STORE_BYPASS_DISABLE) {
@@ -518,12 +518,12 @@ static enum ssb_mitigation_cmd __init __ssb_select_mitigation(void)
 		 */
 		switch (boot_cpu_data.x86_vendor) {
 		case X86_VENDOR_INTEL:
-			x86_spec_ctrl_base |= SPEC_CTRL_RDS;
-			x86_spec_ctrl_mask &= ~SPEC_CTRL_RDS;
-			x86_spec_ctrl_set(SPEC_CTRL_RDS);
+			x86_spec_ctrl_base |= SPEC_CTRL_SSBD;
+			x86_spec_ctrl_mask &= ~SPEC_CTRL_SSBD;
+			x86_spec_ctrl_set(SPEC_CTRL_SSBD);
 			break;
 		case X86_VENDOR_AMD:
-			x86_amd_rds_enable();
+			x86_amd_ssb_disable();
 			break;
 		}
 	}
@@ -556,16 +556,16 @@ static int ssb_prctl_set(struct task_struct *task, unsigned long ctrl)
 		if (task_spec_ssb_force_disable(task))
 			return -EPERM;
 		task_clear_spec_ssb_disable(task);
-		update = test_and_clear_tsk_thread_flag(task, TIF_RDS);
+		update = test_and_clear_tsk_thread_flag(task, TIF_SSBD);
 		break;
 	case PR_SPEC_DISABLE:
 		task_set_spec_ssb_disable(task);
-		update = !test_and_set_tsk_thread_flag(task, TIF_RDS);
+		update = !test_and_set_tsk_thread_flag(task, TIF_SSBD);
 		break;
 	case PR_SPEC_FORCE_DISABLE:
 		task_set_spec_ssb_disable(task);
 		task_set_spec_ssb_force_disable(task);
-		update = !test_and_set_tsk_thread_flag(task, TIF_RDS);
+		update = !test_and_set_tsk_thread_flag(task, TIF_SSBD);
 		break;
 	default:
 		return -ERANGE;
@@ -635,7 +635,7 @@ void x86_spec_ctrl_setup_ap(void)
 		x86_spec_ctrl_set(x86_spec_ctrl_base & ~x86_spec_ctrl_mask);
 
 	if (ssb_mode == SPEC_STORE_BYPASS_DISABLE)
-		x86_amd_rds_enable();
+		x86_amd_ssb_disable();
 }
 
 #ifdef CONFIG_SYSFS
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index e0517bcee446..9fbb388fadac 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -959,7 +959,7 @@ static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
 		rdmsrl(MSR_IA32_ARCH_CAPABILITIES, ia32_cap);
 
 	if (!x86_match_cpu(cpu_no_spec_store_bypass) &&
-	   !(ia32_cap & ARCH_CAP_RDS_NO))
+	   !(ia32_cap & ARCH_CAP_SSBD_NO))
 		setup_force_cpu_bug(X86_BUG_SPEC_STORE_BYPASS);
 
 	if (x86_match_cpu(cpu_no_speculation))
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index ef3f9c01c274..0eab6c89c8d9 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -189,7 +189,7 @@ static void early_init_intel(struct cpuinfo_x86 *c)
 		setup_clear_cpu_cap(X86_FEATURE_STIBP);
 		setup_clear_cpu_cap(X86_FEATURE_SPEC_CTRL);
 		setup_clear_cpu_cap(X86_FEATURE_INTEL_STIBP);
-		setup_clear_cpu_cap(X86_FEATURE_RDS);
+		setup_clear_cpu_cap(X86_FEATURE_SSBD);
 	}
 
 	/*
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 397342725046..b77a091bf3b8 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -283,11 +283,11 @@ static __always_inline void __speculative_store_bypass_update(unsigned long tifn
 {
 	u64 msr;
 
-	if (static_cpu_has(X86_FEATURE_AMD_RDS)) {
-		msr = x86_amd_ls_cfg_base | rds_tif_to_amd_ls_cfg(tifn);
+	if (static_cpu_has(X86_FEATURE_AMD_SSBD)) {
+		msr = x86_amd_ls_cfg_base | ssbd_tif_to_amd_ls_cfg(tifn);
 		wrmsrl(MSR_AMD64_LS_CFG, msr);
 	} else {
-		msr = x86_spec_ctrl_base | rds_tif_to_spec_ctrl(tifn);
+		msr = x86_spec_ctrl_base | ssbd_tif_to_spec_ctrl(tifn);
 		wrmsrl(MSR_IA32_SPEC_CTRL, msr);
 	}
 }
@@ -329,7 +329,7 @@ void __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p,
 	if ((tifp ^ tifn) & _TIF_NOCPUID)
 		set_cpuid_faulting(!!(tifn & _TIF_NOCPUID));
 
-	if ((tifp ^ tifn) & _TIF_RDS)
+	if ((tifp ^ tifn) & _TIF_SSBD)
 		__speculative_store_bypass_update(tifn);
 }
 
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 376ac9a2a2b9..865c9a769864 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -407,7 +407,7 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
 
 	/* cpuid 7.0.edx*/
 	const u32 kvm_cpuid_7_0_edx_x86_features =
-		F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) | F(RDS) |
+		F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) | F(SSBD) |
 		F(ARCH_CAPABILITIES);
 
 	/* all calls to cpuid_count() should be made on the same cpu */
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 16a111e44691..9b8d80bf3889 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -3525,7 +3525,7 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 		if (!msr_info->host_initiated &&
 		    !guest_cpuid_has(vcpu, X86_FEATURE_IBRS) &&
 		    !guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL) &&
-		    !guest_cpuid_has(vcpu, X86_FEATURE_RDS))
+		    !guest_cpuid_has(vcpu, X86_FEATURE_SSBD))
 			return 1;
 
 		msr_info->data = to_vmx(vcpu)->spec_ctrl;
@@ -3645,11 +3645,11 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 		if (!msr_info->host_initiated &&
 		    !guest_cpuid_has(vcpu, X86_FEATURE_IBRS) &&
 		    !guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL) &&
-		    !guest_cpuid_has(vcpu, X86_FEATURE_RDS))
+		    !guest_cpuid_has(vcpu, X86_FEATURE_SSBD))
 			return 1;
 
 		/* The STIBP bit doesn't fault even if it's not advertised */
-		if (data & ~(SPEC_CTRL_IBRS | SPEC_CTRL_STIBP | SPEC_CTRL_RDS))
+		if (data & ~(SPEC_CTRL_IBRS | SPEC_CTRL_STIBP | SPEC_CTRL_SSBD))
 			return 1;
 
 		vmx->spec_ctrl = data;
-- 
cgit v1.2.3-70-g09d2


From e7c587da125291db39ddf1f49b18e5970adbac17 Mon Sep 17 00:00:00 2001
From: Borislav Petkov <bp@suse.de>
Date: Wed, 2 May 2018 18:15:14 +0200
Subject: x86/speculation: Use synthetic bits for IBRS/IBPB/STIBP
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Intel and AMD have different CPUID bits hence for those use synthetic bits
which get set on the respective vendor's in init_speculation_control(). So
that debacles like what the commit message of

  c65732e4f721 ("x86/cpu: Restore CPUID_8000_0008_EBX reload")

talks about don't happen anymore.

Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Tested-by: Jörg Otte <jrg.otte@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Link: https://lkml.kernel.org/r/20180504161815.GG9257@pd.tnic
---
 arch/x86/include/asm/cpufeatures.h | 10 ++++++----
 arch/x86/kernel/cpu/common.c       | 14 ++++++++++----
 arch/x86/kvm/cpuid.c               | 10 +++++-----
 arch/x86/kvm/svm.c                 |  6 +++---
 arch/x86/kvm/vmx.c                 |  9 ++-------
 5 files changed, 26 insertions(+), 23 deletions(-)

(limited to 'arch/x86/kernel/cpu/common.c')

diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index 4e1c747acbf8..cb9bca8cecdc 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -198,7 +198,6 @@
 #define X86_FEATURE_CAT_L2		( 7*32+ 5) /* Cache Allocation Technology L2 */
 #define X86_FEATURE_CDP_L3		( 7*32+ 6) /* Code and Data Prioritization L3 */
 #define X86_FEATURE_INVPCID_SINGLE	( 7*32+ 7) /* Effectively INVPCID && CR4.PCIDE=1 */
-
 #define X86_FEATURE_HW_PSTATE		( 7*32+ 8) /* AMD HW-PState */
 #define X86_FEATURE_PROC_FEEDBACK	( 7*32+ 9) /* AMD ProcFeedbackInterface */
 #define X86_FEATURE_SME			( 7*32+10) /* AMD Secure Memory Encryption */
@@ -216,6 +215,9 @@
 #define X86_FEATURE_USE_IBRS_FW		( 7*32+22) /* "" Use IBRS during runtime firmware calls */
 #define X86_FEATURE_SPEC_STORE_BYPASS_DISABLE	( 7*32+23) /* "" Disable Speculative Store Bypass. */
 #define X86_FEATURE_AMD_SSBD		( 7*32+24)  /* "" AMD SSBD implementation */
+#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 */
 
 /* Virtualization flags: Linux defined, word 8 */
 #define X86_FEATURE_TPR_SHADOW		( 8*32+ 0) /* Intel TPR Shadow */
@@ -276,9 +278,9 @@
 #define X86_FEATURE_CLZERO		(13*32+ 0) /* CLZERO instruction */
 #define X86_FEATURE_IRPERF		(13*32+ 1) /* Instructions Retired Count */
 #define X86_FEATURE_XSAVEERPTR		(13*32+ 2) /* Always save/restore FP error pointers */
-#define X86_FEATURE_IBPB		(13*32+12) /* Indirect Branch Prediction Barrier */
-#define X86_FEATURE_IBRS		(13*32+14) /* Indirect Branch Restricted Speculation */
-#define X86_FEATURE_STIBP		(13*32+15) /* Single Thread Indirect Branch Predictors */
+#define X86_FEATURE_AMD_IBPB		(13*32+12) /* "" Indirect Branch Prediction Barrier */
+#define X86_FEATURE_AMD_IBRS		(13*32+14) /* "" Indirect Branch Restricted Speculation */
+#define X86_FEATURE_AMD_STIBP		(13*32+15) /* "" Single Thread Indirect Branch Predictors */
 
 /* Thermal and Power Management Leaf, CPUID level 0x00000006 (EAX), word 14 */
 #define X86_FEATURE_DTHERM		(14*32+ 0) /* Digital Thermal Sensor */
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 9fbb388fadac..e6cd38b20375 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -757,17 +757,23 @@ static void init_speculation_control(struct cpuinfo_x86 *c)
 	 * and they also have a different bit for STIBP support. Also,
 	 * a hypervisor might have set the individual AMD bits even on
 	 * Intel CPUs, for finer-grained selection of what's available.
-	 *
-	 * We use the AMD bits in 0x8000_0008 EBX as the generic hardware
-	 * features, which are visible in /proc/cpuinfo and used by the
-	 * kernel. So set those accordingly from the Intel bits.
 	 */
 	if (cpu_has(c, X86_FEATURE_SPEC_CTRL)) {
 		set_cpu_cap(c, X86_FEATURE_IBRS);
 		set_cpu_cap(c, X86_FEATURE_IBPB);
 	}
+
 	if (cpu_has(c, X86_FEATURE_INTEL_STIBP))
 		set_cpu_cap(c, X86_FEATURE_STIBP);
+
+	if (cpu_has(c, X86_FEATURE_AMD_IBRS))
+		set_cpu_cap(c, X86_FEATURE_IBRS);
+
+	if (cpu_has(c, X86_FEATURE_AMD_IBPB))
+		set_cpu_cap(c, X86_FEATURE_IBPB);
+
+	if (cpu_has(c, X86_FEATURE_AMD_STIBP))
+		set_cpu_cap(c, X86_FEATURE_STIBP);
 }
 
 void get_cpu_cap(struct cpuinfo_x86 *c)
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 865c9a769864..e5ba48599428 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -379,7 +379,7 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
 
 	/* cpuid 0x80000008.ebx */
 	const u32 kvm_cpuid_8000_0008_ebx_x86_features =
-		F(IBPB) | F(IBRS);
+		F(AMD_IBPB) | F(AMD_IBRS);
 
 	/* cpuid 0xC0000001.edx */
 	const u32 kvm_cpuid_C000_0001_edx_x86_features =
@@ -648,10 +648,10 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
 		entry->eax = g_phys_as | (virt_as << 8);
 		entry->edx = 0;
 		/* IBRS and IBPB aren't necessarily present in hardware cpuid */
-		if (boot_cpu_has(X86_FEATURE_IBPB))
-			entry->ebx |= F(IBPB);
-		if (boot_cpu_has(X86_FEATURE_IBRS))
-			entry->ebx |= F(IBRS);
+		if (boot_cpu_has(X86_FEATURE_AMD_IBPB))
+			entry->ebx |= F(AMD_IBPB);
+		if (boot_cpu_has(X86_FEATURE_AMD_IBRS))
+			entry->ebx |= F(AMD_IBRS);
 		entry->ebx &= kvm_cpuid_8000_0008_ebx_x86_features;
 		cpuid_mask(&entry->ebx, CPUID_8000_0008_EBX);
 		break;
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index fa891c8af842..1a7a811118a8 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -4108,7 +4108,7 @@ static int svm_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 		break;
 	case MSR_IA32_SPEC_CTRL:
 		if (!msr_info->host_initiated &&
-		    !guest_cpuid_has(vcpu, X86_FEATURE_IBRS))
+		    !guest_cpuid_has(vcpu, X86_FEATURE_AMD_IBRS))
 			return 1;
 
 		msr_info->data = svm->spec_ctrl;
@@ -4203,7 +4203,7 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)
 		break;
 	case MSR_IA32_SPEC_CTRL:
 		if (!msr->host_initiated &&
-		    !guest_cpuid_has(vcpu, X86_FEATURE_IBRS))
+		    !guest_cpuid_has(vcpu, X86_FEATURE_AMD_IBRS))
 			return 1;
 
 		/* The STIBP bit doesn't fault even if it's not advertised */
@@ -4230,7 +4230,7 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)
 		break;
 	case MSR_IA32_PRED_CMD:
 		if (!msr->host_initiated &&
-		    !guest_cpuid_has(vcpu, X86_FEATURE_IBPB))
+		    !guest_cpuid_has(vcpu, X86_FEATURE_AMD_IBPB))
 			return 1;
 
 		if (data & ~PRED_CMD_IBPB)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 9b8d80bf3889..210e1b63d4b5 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -3523,9 +3523,7 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 		return kvm_get_msr_common(vcpu, msr_info);
 	case MSR_IA32_SPEC_CTRL:
 		if (!msr_info->host_initiated &&
-		    !guest_cpuid_has(vcpu, X86_FEATURE_IBRS) &&
-		    !guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL) &&
-		    !guest_cpuid_has(vcpu, X86_FEATURE_SSBD))
+		    !guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL))
 			return 1;
 
 		msr_info->data = to_vmx(vcpu)->spec_ctrl;
@@ -3643,9 +3641,7 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 		break;
 	case MSR_IA32_SPEC_CTRL:
 		if (!msr_info->host_initiated &&
-		    !guest_cpuid_has(vcpu, X86_FEATURE_IBRS) &&
-		    !guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL) &&
-		    !guest_cpuid_has(vcpu, X86_FEATURE_SSBD))
+		    !guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL))
 			return 1;
 
 		/* The STIBP bit doesn't fault even if it's not advertised */
@@ -3675,7 +3671,6 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 		break;
 	case MSR_IA32_PRED_CMD:
 		if (!msr_info->host_initiated &&
-		    !guest_cpuid_has(vcpu, X86_FEATURE_IBPB) &&
 		    !guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL))
 			return 1;
 
-- 
cgit v1.2.3-70-g09d2


From 7eb8956a7fec3c1f0abc2a5517dada99ccc8a961 Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Thu, 10 May 2018 19:13:18 +0200
Subject: x86/cpufeatures: Disentangle MSR_SPEC_CTRL enumeration from IBRS

The availability of the SPEC_CTRL MSR is enumerated by a CPUID bit on
Intel and implied by IBRS or STIBP support on AMD. That's just confusing
and in case an AMD CPU has IBRS not supported because the underlying
problem has been fixed but has another bit valid in the SPEC_CTRL MSR,
the thing falls apart.

Add a synthetic feature bit X86_FEATURE_MSR_SPEC_CTRL to denote the
availability on both Intel and AMD.

While at it replace the boot_cpu_has() checks with static_cpu_has() where
possible. This prevents late microcode loading from exposing SPEC_CTRL, but
late loading is already very limited as it does not reevaluate the
mitigation options and other bits and pieces. Having static_cpu_has() is
the simplest and least fragile solution.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
---
 arch/x86/include/asm/cpufeatures.h |  1 +
 arch/x86/kernel/cpu/bugs.c         | 18 +++++++++++-------
 arch/x86/kernel/cpu/common.c       |  9 +++++++--
 arch/x86/kernel/cpu/intel.c        |  1 +
 4 files changed, 20 insertions(+), 9 deletions(-)

(limited to 'arch/x86/kernel/cpu/common.c')

diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index cb9bca8cecdc..7d34eb0d3715 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -206,6 +206,7 @@
 #define X86_FEATURE_RETPOLINE_AMD	( 7*32+13) /* "" AMD Retpoline mitigation for Spectre variant 2 */
 #define X86_FEATURE_INTEL_PPIN		( 7*32+14) /* Intel Processor Inventory Number */
 #define X86_FEATURE_CDP_L2		( 7*32+15) /* Code and Data Prioritization L2 */
+#define X86_FEATURE_MSR_SPEC_CTRL	( 7*32+16) /* "" MSR SPEC_CTRL is implemented */
 
 #define X86_FEATURE_MBA			( 7*32+18) /* Memory Bandwidth Allocation */
 #define X86_FEATURE_RSB_CTXSW		( 7*32+19) /* "" Fill RSB on context switches */
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index bab05913f864..316cb24092a3 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -64,7 +64,7 @@ void __init check_bugs(void)
 	 * have unknown values. AMD64_LS_CFG MSR is cached in the early AMD
 	 * init code as it is not enumerated and depends on the family.
 	 */
-	if (boot_cpu_has(X86_FEATURE_IBRS))
+	if (boot_cpu_has(X86_FEATURE_MSR_SPEC_CTRL))
 		rdmsrl(MSR_IA32_SPEC_CTRL, x86_spec_ctrl_base);
 
 	/* Select the proper spectre mitigation before patching alternatives */
@@ -145,7 +145,7 @@ u64 x86_spec_ctrl_get_default(void)
 {
 	u64 msrval = x86_spec_ctrl_base;
 
-	if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL)
+	if (static_cpu_has(X86_FEATURE_SPEC_CTRL))
 		msrval |= ssbd_tif_to_spec_ctrl(current_thread_info()->flags);
 	return msrval;
 }
@@ -155,10 +155,12 @@ void x86_spec_ctrl_set_guest(u64 guest_spec_ctrl)
 {
 	u64 host = x86_spec_ctrl_base;
 
-	if (!boot_cpu_has(X86_FEATURE_IBRS))
+	/* Is MSR_SPEC_CTRL implemented ? */
+	if (!static_cpu_has(X86_FEATURE_MSR_SPEC_CTRL))
 		return;
 
-	if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL)
+	/* Intel controls SSB in MSR_SPEC_CTRL */
+	if (static_cpu_has(X86_FEATURE_SPEC_CTRL))
 		host |= ssbd_tif_to_spec_ctrl(current_thread_info()->flags);
 
 	if (host != guest_spec_ctrl)
@@ -170,10 +172,12 @@ void x86_spec_ctrl_restore_host(u64 guest_spec_ctrl)
 {
 	u64 host = x86_spec_ctrl_base;
 
-	if (!boot_cpu_has(X86_FEATURE_IBRS))
+	/* Is MSR_SPEC_CTRL implemented ? */
+	if (!static_cpu_has(X86_FEATURE_MSR_SPEC_CTRL))
 		return;
 
-	if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL)
+	/* Intel controls SSB in MSR_SPEC_CTRL */
+	if (static_cpu_has(X86_FEATURE_SPEC_CTRL))
 		host |= ssbd_tif_to_spec_ctrl(current_thread_info()->flags);
 
 	if (host != guest_spec_ctrl)
@@ -631,7 +635,7 @@ int arch_prctl_spec_ctrl_get(struct task_struct *task, unsigned long which)
 
 void x86_spec_ctrl_setup_ap(void)
 {
-	if (boot_cpu_has(X86_FEATURE_IBRS))
+	if (boot_cpu_has(X86_FEATURE_MSR_SPEC_CTRL))
 		x86_spec_ctrl_set(x86_spec_ctrl_base & ~x86_spec_ctrl_mask);
 
 	if (ssb_mode == SPEC_STORE_BYPASS_DISABLE)
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index e6cd38b20375..af54dbe2df9a 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -761,19 +761,24 @@ static void init_speculation_control(struct cpuinfo_x86 *c)
 	if (cpu_has(c, X86_FEATURE_SPEC_CTRL)) {
 		set_cpu_cap(c, X86_FEATURE_IBRS);
 		set_cpu_cap(c, X86_FEATURE_IBPB);
+		set_cpu_cap(c, X86_FEATURE_MSR_SPEC_CTRL);
 	}
 
 	if (cpu_has(c, X86_FEATURE_INTEL_STIBP))
 		set_cpu_cap(c, X86_FEATURE_STIBP);
 
-	if (cpu_has(c, X86_FEATURE_AMD_IBRS))
+	if (cpu_has(c, X86_FEATURE_AMD_IBRS)) {
 		set_cpu_cap(c, X86_FEATURE_IBRS);
+		set_cpu_cap(c, X86_FEATURE_MSR_SPEC_CTRL);
+	}
 
 	if (cpu_has(c, X86_FEATURE_AMD_IBPB))
 		set_cpu_cap(c, X86_FEATURE_IBPB);
 
-	if (cpu_has(c, X86_FEATURE_AMD_STIBP))
+	if (cpu_has(c, X86_FEATURE_AMD_STIBP)) {
 		set_cpu_cap(c, X86_FEATURE_STIBP);
+		set_cpu_cap(c, X86_FEATURE_MSR_SPEC_CTRL);
+	}
 }
 
 void get_cpu_cap(struct cpuinfo_x86 *c)
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 0eab6c89c8d9..dd37244c587a 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -188,6 +188,7 @@ static void early_init_intel(struct cpuinfo_x86 *c)
 		setup_clear_cpu_cap(X86_FEATURE_IBPB);
 		setup_clear_cpu_cap(X86_FEATURE_STIBP);
 		setup_clear_cpu_cap(X86_FEATURE_SPEC_CTRL);
+		setup_clear_cpu_cap(X86_FEATURE_MSR_SPEC_CTRL);
 		setup_clear_cpu_cap(X86_FEATURE_INTEL_STIBP);
 		setup_clear_cpu_cap(X86_FEATURE_SSBD);
 	}
-- 
cgit v1.2.3-70-g09d2


From 52817587e706686fcdb27f14c1b000c92f266c96 Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Thu, 10 May 2018 20:21:36 +0200
Subject: x86/cpufeatures: Disentangle SSBD enumeration

The SSBD enumeration is similarly to the other bits magically shared
between Intel and AMD though the mechanisms are different.

Make X86_FEATURE_SSBD synthetic and set it depending on the vendor specific
features or family dependent setup.

Change the Intel bit to X86_FEATURE_SPEC_CTRL_SSBD to denote that SSBD is
controlled via MSR_SPEC_CTRL and fix up the usage sites.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
---
 arch/x86/include/asm/cpufeatures.h |  7 +++----
 arch/x86/kernel/cpu/amd.c          |  7 +------
 arch/x86/kernel/cpu/bugs.c         | 10 +++++-----
 arch/x86/kernel/cpu/common.c       |  3 +++
 arch/x86/kernel/cpu/intel.c        |  1 +
 arch/x86/kernel/process.c          |  2 +-
 6 files changed, 14 insertions(+), 16 deletions(-)

(limited to 'arch/x86/kernel/cpu/common.c')

diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index 7d34eb0d3715..61c34c1a525c 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -207,15 +207,14 @@
 #define X86_FEATURE_INTEL_PPIN		( 7*32+14) /* Intel Processor Inventory Number */
 #define X86_FEATURE_CDP_L2		( 7*32+15) /* Code and Data Prioritization L2 */
 #define X86_FEATURE_MSR_SPEC_CTRL	( 7*32+16) /* "" MSR SPEC_CTRL is implemented */
-
+#define X86_FEATURE_SSBD		( 7*32+17) /* Speculative Store Bypass Disable */
 #define X86_FEATURE_MBA			( 7*32+18) /* Memory Bandwidth Allocation */
 #define X86_FEATURE_RSB_CTXSW		( 7*32+19) /* "" Fill RSB on context switches */
 #define X86_FEATURE_SEV			( 7*32+20) /* AMD Secure Encrypted Virtualization */
-
 #define X86_FEATURE_USE_IBPB		( 7*32+21) /* "" Indirect Branch Prediction Barrier enabled */
 #define X86_FEATURE_USE_IBRS_FW		( 7*32+22) /* "" Use IBRS during runtime firmware calls */
 #define X86_FEATURE_SPEC_STORE_BYPASS_DISABLE	( 7*32+23) /* "" Disable Speculative Store Bypass. */
-#define X86_FEATURE_AMD_SSBD		( 7*32+24)  /* "" AMD SSBD implementation */
+#define X86_FEATURE_LS_CFG_SSBD		( 7*32+24)  /* "" AMD SSBD implementation via LS_CFG MSR */
 #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 */
@@ -339,7 +338,7 @@
 #define X86_FEATURE_SPEC_CTRL		(18*32+26) /* "" Speculation Control (IBRS + IBPB) */
 #define X86_FEATURE_INTEL_STIBP		(18*32+27) /* "" Single Thread Indirect Branch Predictors */
 #define X86_FEATURE_ARCH_CAPABILITIES	(18*32+29) /* IA32_ARCH_CAPABILITIES MSR (Intel) */
-#define X86_FEATURE_SSBD		(18*32+31) /* Speculative Store Bypass Disable */
+#define X86_FEATURE_SPEC_CTRL_SSBD	(18*32+31) /* "" Speculative Store Bypass Disable */
 
 /*
  * BUG word(s)
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 7bde990b0385..2d2d8985654b 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -570,8 +570,8 @@ static void bsp_init_amd(struct cpuinfo_x86 *c)
 		 * avoid RMW. If that faults, do not enable SSBD.
 		 */
 		if (!rdmsrl_safe(MSR_AMD64_LS_CFG, &x86_amd_ls_cfg_base)) {
+			setup_force_cpu_cap(X86_FEATURE_LS_CFG_SSBD);
 			setup_force_cpu_cap(X86_FEATURE_SSBD);
-			setup_force_cpu_cap(X86_FEATURE_AMD_SSBD);
 			x86_amd_ls_cfg_ssbd_mask = 1ULL << bit;
 		}
 	}
@@ -919,11 +919,6 @@ static void init_amd(struct cpuinfo_x86 *c)
 	/* AMD CPUs don't reset SS attributes on SYSRET, Xen does. */
 	if (!cpu_has(c, X86_FEATURE_XENPV))
 		set_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS);
-
-	if (boot_cpu_has(X86_FEATURE_AMD_SSBD)) {
-		set_cpu_cap(c, X86_FEATURE_SSBD);
-		set_cpu_cap(c, X86_FEATURE_AMD_SSBD);
-	}
 }
 
 #ifdef CONFIG_X86_32
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 316cb24092a3..7ebd6373fc31 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -159,8 +159,8 @@ void x86_spec_ctrl_set_guest(u64 guest_spec_ctrl)
 	if (!static_cpu_has(X86_FEATURE_MSR_SPEC_CTRL))
 		return;
 
-	/* Intel controls SSB in MSR_SPEC_CTRL */
-	if (static_cpu_has(X86_FEATURE_SPEC_CTRL))
+	/* SSBD controlled in MSR_SPEC_CTRL */
+	if (static_cpu_has(X86_FEATURE_SPEC_CTRL_SSBD))
 		host |= ssbd_tif_to_spec_ctrl(current_thread_info()->flags);
 
 	if (host != guest_spec_ctrl)
@@ -176,8 +176,8 @@ void x86_spec_ctrl_restore_host(u64 guest_spec_ctrl)
 	if (!static_cpu_has(X86_FEATURE_MSR_SPEC_CTRL))
 		return;
 
-	/* Intel controls SSB in MSR_SPEC_CTRL */
-	if (static_cpu_has(X86_FEATURE_SPEC_CTRL))
+	/* SSBD controlled in MSR_SPEC_CTRL */
+	if (static_cpu_has(X86_FEATURE_SPEC_CTRL_SSBD))
 		host |= ssbd_tif_to_spec_ctrl(current_thread_info()->flags);
 
 	if (host != guest_spec_ctrl)
@@ -189,7 +189,7 @@ static void x86_amd_ssb_disable(void)
 {
 	u64 msrval = x86_amd_ls_cfg_base | x86_amd_ls_cfg_ssbd_mask;
 
-	if (boot_cpu_has(X86_FEATURE_AMD_SSBD))
+	if (boot_cpu_has(X86_FEATURE_LS_CFG_SSBD))
 		wrmsrl(MSR_AMD64_LS_CFG, msrval);
 }
 
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index af54dbe2df9a..68282514c025 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -767,6 +767,9 @@ static void init_speculation_control(struct cpuinfo_x86 *c)
 	if (cpu_has(c, X86_FEATURE_INTEL_STIBP))
 		set_cpu_cap(c, X86_FEATURE_STIBP);
 
+	if (cpu_has(c, X86_FEATURE_SPEC_CTRL_SSBD))
+		set_cpu_cap(c, X86_FEATURE_SSBD);
+
 	if (cpu_has(c, X86_FEATURE_AMD_IBRS)) {
 		set_cpu_cap(c, X86_FEATURE_IBRS);
 		set_cpu_cap(c, X86_FEATURE_MSR_SPEC_CTRL);
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index dd37244c587a..577e7f7ae273 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -191,6 +191,7 @@ static void early_init_intel(struct cpuinfo_x86 *c)
 		setup_clear_cpu_cap(X86_FEATURE_MSR_SPEC_CTRL);
 		setup_clear_cpu_cap(X86_FEATURE_INTEL_STIBP);
 		setup_clear_cpu_cap(X86_FEATURE_SSBD);
+		setup_clear_cpu_cap(X86_FEATURE_SPEC_CTRL_SSBD);
 	}
 
 	/*
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index b77a091bf3b8..d71ef7eaa7ef 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -283,7 +283,7 @@ static __always_inline void __speculative_store_bypass_update(unsigned long tifn
 {
 	u64 msr;
 
-	if (static_cpu_has(X86_FEATURE_AMD_SSBD)) {
+	if (static_cpu_has(X86_FEATURE_LS_CFG_SSBD)) {
 		msr = x86_amd_ls_cfg_base | ssbd_tif_to_amd_ls_cfg(tifn);
 		wrmsrl(MSR_AMD64_LS_CFG, msr);
 	} else {
-- 
cgit v1.2.3-70-g09d2


From bc226f07dcd3c9ef0b7f6236fe356ea4a9cb4769 Mon Sep 17 00:00:00 2001
From: Tom Lendacky <thomas.lendacky@amd.com>
Date: Thu, 10 May 2018 22:06:39 +0200
Subject: KVM: SVM: Implement VIRT_SPEC_CTRL support for SSBD

Expose the new virtualized architectural mechanism, VIRT_SSBD, for using
speculative store bypass disable (SSBD) under SVM.  This will allow guests
to use SSBD on hardware that uses non-architectural mechanisms for enabling
SSBD.

[ tglx: Folded the migration fixup from Paolo Bonzini ]

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 arch/x86/include/asm/kvm_host.h |  2 +-
 arch/x86/kernel/cpu/common.c    |  3 ++-
 arch/x86/kvm/cpuid.c            | 11 +++++++++--
 arch/x86/kvm/svm.c              | 21 +++++++++++++++++++--
 arch/x86/kvm/vmx.c              | 18 +++++++++++++++---
 arch/x86/kvm/x86.c              | 13 ++++---------
 6 files changed, 50 insertions(+), 18 deletions(-)

(limited to 'arch/x86/kernel/cpu/common.c')

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index c25775fad4ed..f4b2588865e9 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -924,7 +924,7 @@ struct kvm_x86_ops {
 	int (*hardware_setup)(void);               /* __init */
 	void (*hardware_unsetup)(void);            /* __exit */
 	bool (*cpu_has_accelerated_tpr)(void);
-	bool (*cpu_has_high_real_mode_segbase)(void);
+	bool (*has_emulated_msr)(int index);
 	void (*cpuid_update)(struct kvm_vcpu *vcpu);
 
 	struct kvm *(*vm_alloc)(void);
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 68282514c025..b4247ed0c81e 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -767,7 +767,8 @@ static void init_speculation_control(struct cpuinfo_x86 *c)
 	if (cpu_has(c, X86_FEATURE_INTEL_STIBP))
 		set_cpu_cap(c, X86_FEATURE_STIBP);
 
-	if (cpu_has(c, X86_FEATURE_SPEC_CTRL_SSBD))
+	if (cpu_has(c, X86_FEATURE_SPEC_CTRL_SSBD) ||
+	    cpu_has(c, X86_FEATURE_VIRT_SSBD))
 		set_cpu_cap(c, X86_FEATURE_SSBD);
 
 	if (cpu_has(c, X86_FEATURE_AMD_IBRS)) {
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index e5ba48599428..ced851169730 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -379,7 +379,7 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
 
 	/* cpuid 0x80000008.ebx */
 	const u32 kvm_cpuid_8000_0008_ebx_x86_features =
-		F(AMD_IBPB) | F(AMD_IBRS);
+		F(AMD_IBPB) | F(AMD_IBRS) | F(VIRT_SSBD);
 
 	/* cpuid 0xC0000001.edx */
 	const u32 kvm_cpuid_C000_0001_edx_x86_features =
@@ -647,13 +647,20 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
 			g_phys_as = phys_as;
 		entry->eax = g_phys_as | (virt_as << 8);
 		entry->edx = 0;
-		/* IBRS and IBPB aren't necessarily present in hardware cpuid */
+		/*
+		 * IBRS, IBPB and VIRT_SSBD aren't necessarily present in
+		 * hardware cpuid
+		 */
 		if (boot_cpu_has(X86_FEATURE_AMD_IBPB))
 			entry->ebx |= F(AMD_IBPB);
 		if (boot_cpu_has(X86_FEATURE_AMD_IBRS))
 			entry->ebx |= F(AMD_IBRS);
+		if (boot_cpu_has(X86_FEATURE_VIRT_SSBD))
+			entry->ebx |= F(VIRT_SSBD);
 		entry->ebx &= kvm_cpuid_8000_0008_ebx_x86_features;
 		cpuid_mask(&entry->ebx, CPUID_8000_0008_EBX);
+		if (boot_cpu_has(X86_FEATURE_LS_CFG_SSBD))
+			entry->ebx |= F(VIRT_SSBD);
 		break;
 	}
 	case 0x80000019:
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index c07dbcc6d449..26110c202b19 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -4120,6 +4120,13 @@ static int svm_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 
 		msr_info->data = svm->spec_ctrl;
 		break;
+	case MSR_AMD64_VIRT_SPEC_CTRL:
+		if (!msr_info->host_initiated &&
+		    !guest_cpuid_has(vcpu, X86_FEATURE_VIRT_SSBD))
+			return 1;
+
+		msr_info->data = svm->virt_spec_ctrl;
+		break;
 	case MSR_F15H_IC_CFG: {
 
 		int family, model;
@@ -4251,6 +4258,16 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)
 			break;
 		set_msr_interception(svm->msrpm, MSR_IA32_PRED_CMD, 0, 1);
 		break;
+	case MSR_AMD64_VIRT_SPEC_CTRL:
+		if (!msr->host_initiated &&
+		    !guest_cpuid_has(vcpu, X86_FEATURE_VIRT_SSBD))
+			return 1;
+
+		if (data & ~SPEC_CTRL_SSBD)
+			return 1;
+
+		svm->virt_spec_ctrl = data;
+		break;
 	case MSR_STAR:
 		svm->vmcb->save.star = data;
 		break;
@@ -5791,7 +5808,7 @@ static bool svm_cpu_has_accelerated_tpr(void)
 	return false;
 }
 
-static bool svm_has_high_real_mode_segbase(void)
+static bool svm_has_emulated_msr(int index)
 {
 	return true;
 }
@@ -7017,7 +7034,7 @@ static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
 	.hardware_enable = svm_hardware_enable,
 	.hardware_disable = svm_hardware_disable,
 	.cpu_has_accelerated_tpr = svm_cpu_has_accelerated_tpr,
-	.cpu_has_high_real_mode_segbase = svm_has_high_real_mode_segbase,
+	.has_emulated_msr = svm_has_emulated_msr,
 
 	.vcpu_create = svm_create_vcpu,
 	.vcpu_free = svm_free_vcpu,
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 5d733a03a6fa..0c57fb4df2d1 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -9477,9 +9477,21 @@ static void vmx_handle_external_intr(struct kvm_vcpu *vcpu)
 }
 STACK_FRAME_NON_STANDARD(vmx_handle_external_intr);
 
-static bool vmx_has_high_real_mode_segbase(void)
+static bool vmx_has_emulated_msr(int index)
 {
-	return enable_unrestricted_guest || emulate_invalid_guest_state;
+	switch (index) {
+	case MSR_IA32_SMBASE:
+		/*
+		 * We cannot do SMM unless we can run the guest in big
+		 * real mode.
+		 */
+		return enable_unrestricted_guest || emulate_invalid_guest_state;
+	case MSR_AMD64_VIRT_SPEC_CTRL:
+		/* This is AMD only.  */
+		return false;
+	default:
+		return true;
+	}
 }
 
 static bool vmx_mpx_supported(void)
@@ -12625,7 +12637,7 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
 	.hardware_enable = hardware_enable,
 	.hardware_disable = hardware_disable,
 	.cpu_has_accelerated_tpr = report_flexpriority,
-	.cpu_has_high_real_mode_segbase = vmx_has_high_real_mode_segbase,
+	.has_emulated_msr = vmx_has_emulated_msr,
 
 	.vm_init = vmx_vm_init,
 	.vm_alloc = vmx_vm_alloc,
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 51ecd381793b..421a39e40d5e 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1058,6 +1058,7 @@ static u32 emulated_msrs[] = {
 	MSR_SMI_COUNT,
 	MSR_PLATFORM_INFO,
 	MSR_MISC_FEATURES_ENABLES,
+	MSR_AMD64_VIRT_SPEC_CTRL,
 };
 
 static unsigned num_emulated_msrs;
@@ -2903,7 +2904,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 		 * fringe case that is not enabled except via specific settings
 		 * of the module parameters.
 		 */
-		r = kvm_x86_ops->cpu_has_high_real_mode_segbase();
+		r = kvm_x86_ops->has_emulated_msr(MSR_IA32_SMBASE);
 		break;
 	case KVM_CAP_VAPIC:
 		r = !kvm_x86_ops->cpu_has_accelerated_tpr();
@@ -4603,14 +4604,8 @@ static void kvm_init_msr_list(void)
 	num_msrs_to_save = j;
 
 	for (i = j = 0; i < ARRAY_SIZE(emulated_msrs); i++) {
-		switch (emulated_msrs[i]) {
-		case MSR_IA32_SMBASE:
-			if (!kvm_x86_ops->cpu_has_high_real_mode_segbase())
-				continue;
-			break;
-		default:
-			break;
-		}
+		if (!kvm_x86_ops->has_emulated_msr(emulated_msrs[i]))
+			continue;
 
 		if (j < i)
 			emulated_msrs[j] = emulated_msrs[i];
-- 
cgit v1.2.3-70-g09d2


From 240da953fcc6a9008c92fae5b1f727ee5ed167ab Mon Sep 17 00:00:00 2001
From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Date: Wed, 16 May 2018 23:18:09 -0400
Subject: x86/bugs: Rename SSBD_NO to SSB_NO

The "336996 Speculative Execution Side Channel Mitigations" from
May defines this as SSB_NO, hence lets sync-up.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 arch/x86/include/asm/msr-index.h | 2 +-
 arch/x86/kernel/cpu/common.c     | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

(limited to 'arch/x86/kernel/cpu/common.c')

diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index 562414d5b834..fda2114197b3 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -70,7 +70,7 @@
 #define MSR_IA32_ARCH_CAPABILITIES	0x0000010a
 #define ARCH_CAP_RDCL_NO		(1 << 0)   /* Not susceptible to Meltdown */
 #define ARCH_CAP_IBRS_ALL		(1 << 1)   /* Enhanced IBRS support */
-#define ARCH_CAP_SSBD_NO		(1 << 4)   /*
+#define ARCH_CAP_SSB_NO			(1 << 4)   /*
 						    * Not susceptible to Speculative Store Bypass
 						    * attack, so no Speculative Store Bypass
 						    * control required.
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index b4247ed0c81e..78decc3e3067 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -974,7 +974,7 @@ static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
 		rdmsrl(MSR_IA32_ARCH_CAPABILITIES, ia32_cap);
 
 	if (!x86_match_cpu(cpu_no_spec_store_bypass) &&
-	   !(ia32_cap & ARCH_CAP_SSBD_NO))
+	   !(ia32_cap & ARCH_CAP_SSB_NO))
 		setup_force_cpu_bug(X86_BUG_SPEC_STORE_BYPASS);
 
 	if (x86_match_cpu(cpu_no_speculation))
-- 
cgit v1.2.3-70-g09d2


From 8ecc4979b1bd9c94168e6fc92960033b7a951336 Mon Sep 17 00:00:00 2001
From: Dominik Brodowski <linux@dominikbrodowski.net>
Date: Tue, 22 May 2018 11:05:39 +0200
Subject: x86/speculation: Simplify the CPU bug detection logic

Only CPUs which speculate can speculate. Therefore, it seems prudent
to test for cpu_no_speculation first and only then determine whether
a specific speculating CPU is susceptible to store bypass speculation.
This is underlined by all CPUs currently listed in cpu_no_speculation
were present in cpu_no_spec_store_bypass as well.

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: bp@suse.de
Cc: konrad.wilk@oracle.com
Link: https://lkml.kernel.org/r/20180522090539.GA24668@light.dominikbrodowski.net
---
 arch/x86/kernel/cpu/common.c | 22 +++++++---------------
 1 file changed, 7 insertions(+), 15 deletions(-)

(limited to 'arch/x86/kernel/cpu/common.c')

diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 78decc3e3067..38276f58d3bf 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -942,12 +942,8 @@ static const __initconst struct x86_cpu_id cpu_no_meltdown[] = {
 	{}
 };
 
+/* Only list CPUs which speculate but are non susceptible to SSB */
 static const __initconst struct x86_cpu_id cpu_no_spec_store_bypass[] = {
-	{ X86_VENDOR_INTEL,	6,	INTEL_FAM6_ATOM_PINEVIEW	},
-	{ X86_VENDOR_INTEL,	6,	INTEL_FAM6_ATOM_LINCROFT	},
-	{ X86_VENDOR_INTEL,	6,	INTEL_FAM6_ATOM_PENWELL		},
-	{ X86_VENDOR_INTEL,	6,	INTEL_FAM6_ATOM_CLOVERVIEW	},
-	{ X86_VENDOR_INTEL,	6,	INTEL_FAM6_ATOM_CEDARVIEW	},
 	{ X86_VENDOR_INTEL,	6,	INTEL_FAM6_ATOM_SILVERMONT1	},
 	{ X86_VENDOR_INTEL,	6,	INTEL_FAM6_ATOM_AIRMONT		},
 	{ X86_VENDOR_INTEL,	6,	INTEL_FAM6_ATOM_SILVERMONT2	},
@@ -955,14 +951,10 @@ static const __initconst struct x86_cpu_id cpu_no_spec_store_bypass[] = {
 	{ X86_VENDOR_INTEL,	6,	INTEL_FAM6_CORE_YONAH		},
 	{ X86_VENDOR_INTEL,	6,	INTEL_FAM6_XEON_PHI_KNL		},
 	{ X86_VENDOR_INTEL,	6,	INTEL_FAM6_XEON_PHI_KNM		},
-	{ X86_VENDOR_CENTAUR,	5,					},
-	{ X86_VENDOR_INTEL,	5,					},
-	{ X86_VENDOR_NSC,	5,					},
 	{ X86_VENDOR_AMD,	0x12,					},
 	{ X86_VENDOR_AMD,	0x11,					},
 	{ X86_VENDOR_AMD,	0x10,					},
 	{ X86_VENDOR_AMD,	0xf,					},
-	{ X86_VENDOR_ANY,	4,					},
 	{}
 };
 
@@ -970,6 +962,12 @@ static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
 {
 	u64 ia32_cap = 0;
 
+	if (x86_match_cpu(cpu_no_speculation))
+		return;
+
+	setup_force_cpu_bug(X86_BUG_SPECTRE_V1);
+	setup_force_cpu_bug(X86_BUG_SPECTRE_V2);
+
 	if (cpu_has(c, X86_FEATURE_ARCH_CAPABILITIES))
 		rdmsrl(MSR_IA32_ARCH_CAPABILITIES, ia32_cap);
 
@@ -977,12 +975,6 @@ static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
 	   !(ia32_cap & ARCH_CAP_SSB_NO))
 		setup_force_cpu_bug(X86_BUG_SPEC_STORE_BYPASS);
 
-	if (x86_match_cpu(cpu_no_speculation))
-		return;
-
-	setup_force_cpu_bug(X86_BUG_SPECTRE_V1);
-	setup_force_cpu_bug(X86_BUG_SPECTRE_V2);
-
 	if (x86_match_cpu(cpu_no_meltdown))
 		return;
 
-- 
cgit v1.2.3-70-g09d2