Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755474AbeAIMDf (ORCPT + 1 other); Tue, 9 Jan 2018 07:03:35 -0500 Received: from mail-wm0-f68.google.com ([74.125.82.68]:45907 "EHLO mail-wm0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754235AbeAIMDa (ORCPT ); Tue, 9 Jan 2018 07:03:30 -0500 X-Google-Smtp-Source: ACJfBotyVp/fHWPu40YY/mtYPc5arotz3xUQpeKFXghOGWsM4nToJhWVYYP0gsFk50rG6UJVpEaSVA== From: Paolo Bonzini To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: rkrcmar@redhat.com, liran.alon@oracle.com, jmattson@google.com, aliguori@amazon.com, thomas.lendacky@amd.com, dwmw@amazon.co.uk, bp@alien8.de, x86@kernel.org Subject: [PATCH 8/8] KVM: x86: add SPEC_CTRL and IBPB_SUPPORT to MSR and CPUID lists Date: Tue, 9 Jan 2018 13:03:10 +0100 Message-Id: <20180109120311.27565-9-pbonzini@redhat.com> X-Mailer: git-send-email 2.14.3 In-Reply-To: <20180109120311.27565-1-pbonzini@redhat.com> References: <20180109120311.27565-1-pbonzini@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: Expose them to userspace, now that guests can use them. I am not adding cpufeatures here to avoid having a kernel that shows spec_ctrl in /proc/cpuinfo and actually has no support whatsoever for IBRS/IBPB. Keep the ugly special-casing for now, and clean it up once the generic arch/x86/ code learns about them. Reviewed-by: Liran Alon Reviewed-by: Jim Mattson Signed-off-by: Paolo Bonzini --- arch/x86/kvm/cpuid.c | 24 +++++++++++++++++++++--- arch/x86/kvm/x86.c | 1 + 2 files changed, 22 insertions(+), 3 deletions(-) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 767af697c20c..5f43a5940275 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -397,7 +397,12 @@ 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 = - KF(AVX512_4VNNIW) | KF(AVX512_4FMAPS); + KF(AVX512_4VNNIW) | KF(AVX512_4FMAPS) | + KF(SPEC_CTRL) | KF(STIBP); + + /* cpuid 0x80000008.edx */ + const u32 kvm_cpuid_80000008_ebx_x86_features = + KF(IBPB_SUPPORT); /* all calls to cpuid_count() should be made on the same cpu */ get_cpu(); @@ -483,7 +488,14 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, if (!tdp_enabled || !boot_cpu_has(X86_FEATURE_OSPKE)) entry->ecx &= ~F(PKU); entry->edx &= kvm_cpuid_7_0_edx_x86_features; - entry->edx &= get_scattered_cpuid_leaf(7, 0, CPUID_EDX); + /* + * FIXME: the special casing of SPEC_CTRL and STIBP + * can be removed once they become regular + * cpufeatures. + */ + entry->edx &= ( + get_scattered_cpuid_leaf(7, 0, CPUID_EDX) | + KF(SPEC_CTRL) | KF(STIBP)); } else { entry->ebx = 0; entry->ecx = 0; @@ -651,7 +663,13 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, if (!g_phys_as) g_phys_as = phys_as; entry->eax = g_phys_as | (virt_as << 8); - entry->ebx = entry->edx = 0; + /* + * FIXME: mask against cpufeatures, with + * get_scattered_cpuid_leaf(0x80000008, 0, CPUID_EBX), + * once IBPB_SUPPORT becomes a regular cpufeature. + */ + entry->ebx &= kvm_cpuid_80000008_ebx_x86_features; + entry->edx = 0; break; } case 0x80000019: diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index daa1918031df..4abb37d9f4d8 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1032,6 +1032,7 @@ unsigned int kvm_get_pt_addr_cnt(void) MSR_IA32_RTIT_ADDR1_A, MSR_IA32_RTIT_ADDR1_B, MSR_IA32_RTIT_ADDR2_A, MSR_IA32_RTIT_ADDR2_B, MSR_IA32_RTIT_ADDR3_A, MSR_IA32_RTIT_ADDR3_B, + MSR_IA32_SPEC_CTRL, }; static unsigned num_msrs_to_save; -- 1.8.3.1