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authorBorislav Petkov <bp@suse.de>2018-05-02 18:15:14 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-12-17 21:55:14 +0100
commit3e3a1c2ee031cd3d1a8fe9a990b61c8f17a6dd83 (patch)
tree5715866ad6c6e02856753fc35edc45562b6e6cde
parentb5ec2b3f11993d843f75c2d2954ece20af96dc88 (diff)
x86/speculation: Use synthetic bits for IBRS/IBPB/STIBP
commit e7c587da125291db39ddf1f49b18e5970adbac17 upstream. 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 Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [bwh: Backported to 4.4: This was partly applied before; apply just the missing bits] Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--arch/x86/kvm/cpuid.c10
-rw-r--r--arch/x86/kvm/cpuid.h4
2 files changed, 7 insertions, 7 deletions
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 6b20e0a823da..b0371a77cbc8 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -343,7 +343,7 @@ 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_supported_word5_x86_features =
@@ -596,10 +596,10 @@ 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/cpuid.h b/arch/x86/kvm/cpuid.h
index 31ff5d2d0536..ba8988707e9d 100644
--- a/arch/x86/kvm/cpuid.h
+++ b/arch/x86/kvm/cpuid.h
@@ -164,7 +164,7 @@ static inline bool guest_cpuid_has_ibpb(struct kvm_vcpu *vcpu)
struct kvm_cpuid_entry2 *best;
best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0);
- if (best && (best->ebx & bit(X86_FEATURE_IBPB)))
+ if (best && (best->ebx & bit(X86_FEATURE_AMD_IBPB)))
return true;
best = kvm_find_cpuid_entry(vcpu, 7, 0);
return best && (best->edx & bit(X86_FEATURE_SPEC_CTRL));
@@ -175,7 +175,7 @@ static inline bool guest_cpuid_has_spec_ctrl(struct kvm_vcpu *vcpu)
struct kvm_cpuid_entry2 *best;
best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0);
- if (best && (best->ebx & bit(X86_FEATURE_IBRS)))
+ if (best && (best->ebx & bit(X86_FEATURE_AMD_IBRS)))
return true;
best = kvm_find_cpuid_entry(vcpu, 7, 0);
return best && (best->edx & (bit(X86_FEATURE_SPEC_CTRL) | bit(X86_FEATURE_SPEC_CTRL_SSBD)));