* [PATCH] Fix SSBD not being exposed to guests. (v1)
@ 2018-05-21 21:54 Konrad Rzeszutek Wilk
2018-05-21 21:54 ` [PATCH] KVM: VMX: Expose SSBD properly to guests Konrad Rzeszutek Wilk
0 siblings, 1 reply; 5+ messages in thread
From: Konrad Rzeszutek Wilk @ 2018-05-21 21:54 UTC (permalink / raw)
To: x86, kvm, linux-kernel
Hi,
Without this patch, when launching QEMU with -cpu +ssbd I ended up
with a warning seeing that the CPU does not support - which in fact it does.
The issue was the X86_FEATURE_ - the kvm_cpuid_7_0_edx_x86_features
had bit 17 set (X86_FEATURE_SSBD), while the right bit should have been
bit 31 ( X86_FEATURE_SPEC_CTRL_SSBD). That meant the masking:
entry->edx &= kvm_cpuid_7_0_edx_x86_features;
would nicely clear the SSBD bit.
This fixes:
Fixes: 52817587e706 ("x86/cpufeatures: Disentangle SSBD enumeration")
arch/x86/kvm/cpuid.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
Konrad Rzeszutek Wilk (1):
KVM: VMX: Expose SSBD properly to guests.
^ permalink raw reply [flat|nested] 5+ messages in thread* [PATCH] KVM: VMX: Expose SSBD properly to guests. 2018-05-21 21:54 [PATCH] Fix SSBD not being exposed to guests. (v1) Konrad Rzeszutek Wilk @ 2018-05-21 21:54 ` Konrad Rzeszutek Wilk 2018-05-22 23:50 ` Ben Hutchings 2018-05-23 9:00 ` [tip:x86/pti] KVM/VMX: " tip-bot for Konrad Rzeszutek Wilk 0 siblings, 2 replies; 5+ messages in thread From: Konrad Rzeszutek Wilk @ 2018-05-21 21:54 UTC (permalink / raw) To: x86, kvm, linux-kernel Cc: Konrad Rzeszutek Wilk, Paolo Bonzini, Radim Krčmář, Thomas Gleixner, Ingo Molnar, H. Peter Anvin, stable The X86_FEATURE_SSBD is an synthetic CPU feature - that is it bit location has no relevance to the real CPUID 0x7.EBX[31] bit position. For that we need the new CPU feature name. Fixes: 52817587e706 ("x86/cpufeatures: Disentangle SSBD enumeration") CC: Paolo Bonzini <pbonzini@redhat.com> Cc: "Radim Krčmář" <rkrcmar@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: stable@vger.kernel.org Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> --- arch/x86/kvm/cpuid.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index ced851169730..598461e24be3 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -407,8 +407,8 @@ 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(SSBD) | - F(ARCH_CAPABILITIES); + F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) | + F(SPEC_CTRL_SSBD) | F(ARCH_CAPABILITIES); /* all calls to cpuid_count() should be made on the same cpu */ get_cpu(); -- 2.13.4 ^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH] KVM: VMX: Expose SSBD properly to guests. 2018-05-21 21:54 ` [PATCH] KVM: VMX: Expose SSBD properly to guests Konrad Rzeszutek Wilk @ 2018-05-22 23:50 ` Ben Hutchings 2018-06-07 13:14 ` Thomas Voegtle 2018-05-23 9:00 ` [tip:x86/pti] KVM/VMX: " tip-bot for Konrad Rzeszutek Wilk 1 sibling, 1 reply; 5+ messages in thread From: Ben Hutchings @ 2018-05-22 23:50 UTC (permalink / raw) To: Konrad Rzeszutek Wilk, x86, kvm, linux-kernel Cc: Paolo Bonzini, Radim Krčmář, Thomas Gleixner, Ingo Molnar, H. Peter Anvin, stable [-- Attachment #1: Type: text/plain, Size: 1550 bytes --] On Mon, 2018-05-21 at 17:54 -0400, Konrad Rzeszutek Wilk wrote: > The X86_FEATURE_SSBD is an synthetic CPU feature - that is > it bit location has no relevance to the real CPUID 0x7.EBX[31] > bit position. For that we need the new CPU feature name. > > Fixes: 52817587e706 ("x86/cpufeatures: Disentangle SSBD enumeration") > > CC: Paolo Bonzini <pbonzini@redhat.com> > Cc: "Radim Krčmář" <rkrcmar@redhat.com> > Cc: Thomas Gleixner <tglx@linutronix.de> > Cc: Ingo Molnar <mingo@redhat.com> > Cc: "H. Peter Anvin" <hpa@zytor.com> > Cc: stable@vger.kernel.org > Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> > --- > arch/x86/kvm/cpuid.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c > index ced851169730..598461e24be3 100644 > --- a/arch/x86/kvm/cpuid.c > +++ b/arch/x86/kvm/cpuid.c > @@ -407,8 +407,8 @@ 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(SSBD) | > - F(ARCH_CAPABILITIES); > + F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) | > + F(SPEC_CTRL_SSBD) | F(ARCH_CAPABILITIES); > > /* all calls to cpuid_count() should be made on the same cpu */ > get_cpu(); For 4.9-stable, guest_cpuid_has_spec_ctrl() needs a similar fix. Ben. -- Ben Hutchings It is easier to change the specification to fit the program than vice versa. [-- Attachment #2: This is a digitally signed message part --] [-- Type: application/pgp-signature, Size: 833 bytes --] ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] KVM: VMX: Expose SSBD properly to guests. 2018-05-22 23:50 ` Ben Hutchings @ 2018-06-07 13:14 ` Thomas Voegtle 0 siblings, 0 replies; 5+ messages in thread From: Thomas Voegtle @ 2018-06-07 13:14 UTC (permalink / raw) To: Ben Hutchings Cc: Konrad Rzeszutek Wilk, x86, kvm, linux-kernel, Paolo Bonzini, Radim Krčmář, Thomas Gleixner, Ingo Molnar, H. Peter Anvin, stable [-- Attachment #1: Type: text/plain, Size: 2086 bytes --] On Wed, 23 May 2018, Ben Hutchings wrote: > On Mon, 2018-05-21 at 17:54 -0400, Konrad Rzeszutek Wilk wrote: >> The X86_FEATURE_SSBD is an synthetic CPU feature - that is >> it bit location has no relevance to the real CPUID 0x7.EBX[31] >> bit position. For that we need the new CPU feature name. >> >> Fixes: 52817587e706 ("x86/cpufeatures: Disentangle SSBD enumeration") >> >> CC: Paolo Bonzini <pbonzini@redhat.com> >> Cc: "Radim Krčmář" <rkrcmar@redhat.com> >> Cc: Thomas Gleixner <tglx@linutronix.de> >> Cc: Ingo Molnar <mingo@redhat.com> >> Cc: "H. Peter Anvin" <hpa@zytor.com> >> Cc: stable@vger.kernel.org >> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> >> --- >> arch/x86/kvm/cpuid.c | 4 ++-- >> 1 file changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c >> index ced851169730..598461e24be3 100644 >> --- a/arch/x86/kvm/cpuid.c >> +++ b/arch/x86/kvm/cpuid.c >> @@ -407,8 +407,8 @@ 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(SSBD) | >> - F(ARCH_CAPABILITIES); >> + F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) | >> + F(SPEC_CTRL_SSBD) | F(ARCH_CAPABILITIES); >> >> /* all calls to cpuid_count() should be made on the same cpu */ >> get_cpu(); > > For 4.9-stable, guest_cpuid_has_spec_ctrl() needs a similar fix. > > Ben. Do you mean something like this? --- a/arch/x86/kvm/cpuid.h +++ b/arch/x86/kvm/cpuid.h @@ -179,7 +179,7 @@ static inline bool guest_cpuid_has_spec_ctrl(struct kvm_vcpu *vcpu) 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_SSBD))); + return best && (best->edx & (bit(X86_FEATURE_SPEC_CTRL) | bit(X86_FEATURE_SPEC_CTRL_SSBD))); } static inline bool guest_cpuid_has_arch_capabilities(struct kvm_vcpu *vcpu) ^ permalink raw reply [flat|nested] 5+ messages in thread
* [tip:x86/pti] KVM/VMX: Expose SSBD properly to guests 2018-05-21 21:54 ` [PATCH] KVM: VMX: Expose SSBD properly to guests Konrad Rzeszutek Wilk 2018-05-22 23:50 ` Ben Hutchings @ 2018-05-23 9:00 ` tip-bot for Konrad Rzeszutek Wilk 1 sibling, 0 replies; 5+ messages in thread From: tip-bot for Konrad Rzeszutek Wilk @ 2018-05-23 9:00 UTC (permalink / raw) To: linux-tip-commits Cc: hpa, rkrcmar, konrad.wilk, linux-kernel, tglx, mingo, pbonzini Commit-ID: 0aa48468d00959c8a37cd3ac727284f4f7359151 Gitweb: https://git.kernel.org/tip/0aa48468d00959c8a37cd3ac727284f4f7359151 Author: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> AuthorDate: Mon, 21 May 2018 17:54:49 -0400 Committer: Thomas Gleixner <tglx@linutronix.de> CommitDate: Wed, 23 May 2018 10:55:52 +0200 KVM/VMX: Expose SSBD properly to guests The X86_FEATURE_SSBD is an synthetic CPU feature - that is it bit location has no relevance to the real CPUID 0x7.EBX[31] bit position. For that we need the new CPU feature name. Fixes: 52817587e706 ("x86/cpufeatures: Disentangle SSBD enumeration") Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: kvm@vger.kernel.org Cc: "Radim Krčmář" <rkrcmar@redhat.com> Cc: stable@vger.kernel.org Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Link: https://lkml.kernel.org/r/20180521215449.26423-2-konrad.wilk@oracle.com --- arch/x86/kvm/cpuid.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index ced851169730..598461e24be3 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -407,8 +407,8 @@ 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(SSBD) | - F(ARCH_CAPABILITIES); + F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) | + F(SPEC_CTRL_SSBD) | F(ARCH_CAPABILITIES); /* all calls to cpuid_count() should be made on the same cpu */ get_cpu(); ^ permalink raw reply related [flat|nested] 5+ messages in thread
end of thread, other threads:[~2018-06-07 13:25 UTC | newest] Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2018-05-21 21:54 [PATCH] Fix SSBD not being exposed to guests. (v1) Konrad Rzeszutek Wilk 2018-05-21 21:54 ` [PATCH] KVM: VMX: Expose SSBD properly to guests Konrad Rzeszutek Wilk 2018-05-22 23:50 ` Ben Hutchings 2018-06-07 13:14 ` Thomas Voegtle 2018-05-23 9:00 ` [tip:x86/pti] KVM/VMX: " tip-bot for Konrad Rzeszutek Wilk
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for NNTP newsgroup(s).