65 lines
2.3 KiB
Diff
65 lines
2.3 KiB
Diff
From foo@baz Mon May 21 21:56:07 CEST 2018
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From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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Date: Wed, 25 Apr 2018 22:04:25 -0400
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Subject: x86/KVM/VMX: Expose SPEC_CTRL Bit(2) to the guest
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From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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commit da39556f66f5cfe8f9c989206974f1cb16ca5d7c upstream
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Expose the CPUID.7.EDX[31] bit to the guest, and also guard against various
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combinations of SPEC_CTRL MSR values.
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The handling of the MSR (to take into account the host value of SPEC_CTRL
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Bit(2)) is taken care of in patch:
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KVM/SVM/VMX/x86/spectre_v2: Support the combination of guest and host IBRS
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Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Reviewed-by: Ingo Molnar <mingo@kernel.org>
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Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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---
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arch/x86/kvm/cpuid.c | 2 +-
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arch/x86/kvm/vmx.c | 8 +++++---
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2 files changed, 6 insertions(+), 4 deletions(-)
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--- a/arch/x86/kvm/cpuid.c
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+++ b/arch/x86/kvm/cpuid.c
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@@ -402,7 +402,7 @@ static inline int __do_cpuid_ent(struct
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/* cpuid 7.0.edx*/
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const u32 kvm_cpuid_7_0_edx_x86_features =
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- F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) |
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+ F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) | F(RDS) |
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F(ARCH_CAPABILITIES);
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/* all calls to cpuid_count() should be made on the same cpu */
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--- a/arch/x86/kvm/vmx.c
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+++ b/arch/x86/kvm/vmx.c
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@@ -3270,7 +3270,8 @@ static int vmx_get_msr(struct kvm_vcpu *
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case MSR_IA32_SPEC_CTRL:
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if (!msr_info->host_initiated &&
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!guest_cpuid_has(vcpu, X86_FEATURE_IBRS) &&
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- !guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL))
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+ !guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL) &&
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+ !guest_cpuid_has(vcpu, X86_FEATURE_RDS))
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return 1;
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msr_info->data = to_vmx(vcpu)->spec_ctrl;
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@@ -3391,11 +3392,12 @@ static int vmx_set_msr(struct kvm_vcpu *
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case MSR_IA32_SPEC_CTRL:
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if (!msr_info->host_initiated &&
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!guest_cpuid_has(vcpu, X86_FEATURE_IBRS) &&
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- !guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL))
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+ !guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL) &&
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+ !guest_cpuid_has(vcpu, X86_FEATURE_RDS))
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return 1;
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/* The STIBP bit doesn't fault even if it's not advertised */
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- if (data & ~(SPEC_CTRL_IBRS | SPEC_CTRL_STIBP))
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+ if (data & ~(SPEC_CTRL_IBRS | SPEC_CTRL_STIBP | SPEC_CTRL_RDS))
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return 1;
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vmx->spec_ctrl = data;
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