Add direct access to speculation control MSRs for KVM guests. This allows the guest to protect itself against Spectre V2 using IBRS+IBPB instead of a retpoline+IBPB based approach.
It also exposes the ARCH_CAPABILITIES MSR which is going to be used by future Intel processors to indicate RDCL_NO and IBRS_ALL. v4: - Add IBRS passthrough for SVM (5/5). - Handle nested guests properly. - expose F(IBRS) in kvm_cpuid_8000_0008_ebx_x86_features Ashok Raj (1): KVM: x86: Add IBPB support KarimAllah Ahmed (4): KVM: x86: Update the reverse_cpuid list to include CPUID_7_EDX KVM: VMX: Emulate MSR_IA32_ARCH_CAPABILITIES KVM: VMX: Allow direct access to MSR_IA32_SPEC_CTRL KVM: SVM: Allow direct access to MSR_IA32_SPEC_CTRL arch/x86/kvm/cpuid.c | 22 +++++++--- arch/x86/kvm/cpuid.h | 1 + arch/x86/kvm/svm.c | 85 ++++++++++++++++++++++++++++++++++++++ arch/x86/kvm/vmx.c | 114 ++++++++++++++++++++++++++++++++++++++++++++++++++- arch/x86/kvm/x86.c | 1 + 5 files changed, 216 insertions(+), 7 deletions(-) Cc: Andi Kleen <a...@linux.intel.com> Cc: Andrea Arcangeli <aarca...@redhat.com> Cc: Andy Lutomirski <l...@kernel.org> Cc: Arjan van de Ven <ar...@linux.intel.com> Cc: Ashok Raj <ashok....@intel.com> Cc: Asit Mallick <asit.k.mall...@intel.com> Cc: Borislav Petkov <b...@suse.de> Cc: Dan Williams <dan.j.willi...@intel.com> Cc: Dave Hansen <dave.han...@intel.com> Cc: David Woodhouse <d...@amazon.co.uk> Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org> Cc: H. Peter Anvin <h...@zytor.com> Cc: Ingo Molnar <mi...@redhat.com> Cc: Janakarajan Natarajan <janakarajan.natara...@amd.com> Cc: Joerg Roedel <j...@8bytes.org> Cc: Jun Nakajima <jun.nakaj...@intel.com> Cc: Laura Abbott <labb...@redhat.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Masami Hiramatsu <mhira...@kernel.org> Cc: Paolo Bonzini <pbonz...@redhat.com> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Radim Krčmář <rkrc...@redhat.com> Cc: Thomas Gleixner <t...@linutronix.de> Cc: Tim Chen <tim.c.c...@linux.intel.com> Cc: Tom Lendacky <thomas.lenda...@amd.com> Cc: k...@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: x...@kernel.org -- 2.7.4
