From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751630AbeB0BVU (ORCPT ); Mon, 26 Feb 2018 20:21:20 -0500 Received: from mail-ot0-f196.google.com ([74.125.82.196]:34268 "EHLO mail-ot0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751445AbeB0BVS (ORCPT ); Mon, 26 Feb 2018 20:21:18 -0500 X-Google-Smtp-Source: AG47ELsKMxw5Jnj8IA8UrKlZCMgK7r5jC8URWnz2X+u49TjcZw692I3Z18QDjIuEXxoizAndbr5Xzqi5m3qLQ8eC9Mc= MIME-Version: 1.0 In-Reply-To: <469812b9-d003-249a-d6d3-de74c24e4146@redhat.com> References: <1519640239-4428-1-git-send-email-wanpengli@tencent.com> <469812b9-d003-249a-d6d3-de74c24e4146@redhat.com> From: Wanpeng Li Date: Tue, 27 Feb 2018 09:21:17 +0800 Message-ID: Subject: Re: [PATCH v2] KVM: X86: Allow userspace to define the microcode version To: Paolo Bonzini Cc: LKML , kvm , =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= , Liran Alon Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by mail.home.local id w1R1LOZl007620 2018-02-26 19:42 GMT+08:00 Paolo Bonzini : > On 26/02/2018 11:17, Wanpeng Li wrote: >> From: Wanpeng Li >> >> Linux (among the others) has checks to make sure that certain features >> aren't enabled on a certain family/model/stepping if the microcode version >> isn't greater than or equal to a known good version. >> >> By exposing the real microcode version, we're preventing buggy guests that >> don't check that they are running virtualized (i.e., they should trust the >> hypervisor) from disabling features that are effectively not buggy. >> >> Suggested-by: Filippo Sironi >> Cc: Paolo Bonzini >> Cc: Radim Krčmář >> Cc: Liran Alon >> Signed-off-by: Wanpeng Li >> --- >> v1 -> v2: >> * add MSR_IA32_UCODE_REV to emulated_msrs >> >> arch/x86/include/asm/kvm_host.h | 1 + >> arch/x86/kvm/x86.c | 9 +++++++-- >> 2 files changed, 8 insertions(+), 2 deletions(-) >> >> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h >> index 938d453..6e13f2f 100644 >> --- a/arch/x86/include/asm/kvm_host.h >> +++ b/arch/x86/include/asm/kvm_host.h >> @@ -507,6 +507,7 @@ struct kvm_vcpu_arch { >> u64 smi_count; >> bool tpr_access_reporting; >> u64 ia32_xss; >> + u32 microcode_version; >> >> /* >> * Paging state of the vcpu >> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c >> index 1a3ed81..4ae9517 100644 >> --- a/arch/x86/kvm/x86.c >> +++ b/arch/x86/kvm/x86.c >> @@ -1047,6 +1047,7 @@ static u32 emulated_msrs[] = { >> MSR_SMI_COUNT, >> MSR_PLATFORM_INFO, >> MSR_MISC_FEATURES_ENABLES, >> + MSR_IA32_UCODE_REV, >> }; >> >> static unsigned num_emulated_msrs; >> @@ -2247,7 +2248,6 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) >> >> switch (msr) { >> case MSR_AMD64_NB_CFG: >> - case MSR_IA32_UCODE_REV: >> case MSR_IA32_UCODE_WRITE: >> case MSR_VM_HSAVE_PA: >> case MSR_AMD64_PATCH_LOADER: >> @@ -2255,6 +2255,10 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) >> case MSR_AMD64_DC_CFG: >> break; >> >> + case MSR_IA32_UCODE_REV: >> + if (msr_info->host_initiated) >> + vcpu->arch.microcode_version = data >> 32; > > Please remove the shifts, and add the MSR_IA32_UCODE_REV version to the > "feature MSRs" recently added by Tom Lendacky. Do it in v3, thanks for the review. :) Regards, Wanpeng Li > > Thanks, > > Paolo > >> + break; >> case MSR_EFER: >> return set_efer(vcpu, data); >> case MSR_K7_HWCR: >> @@ -2550,7 +2554,7 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) >> msr_info->data = 0; >> break; >> case MSR_IA32_UCODE_REV: >> - msr_info->data = 0x100000000ULL; >> + msr_info->data = (u64)vcpu->arch.microcode_version << 32; >> break; >> case MSR_MTRRcap: >> case 0x200 ... 0x2ff: >> @@ -8232,6 +8236,7 @@ void kvm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event) >> vcpu->arch.regs_dirty = ~0; >> >> vcpu->arch.ia32_xss = 0; >> + vcpu->arch.microcode_version = 0x1; >> >> kvm_x86_ops->vcpu_reset(vcpu, init_event); >> } >> >