From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6D0A7C43381 for ; Mon, 11 Mar 2019 15:22:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 38CB0206BA for ; Mon, 11 Mar 2019 15:22:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727592AbfCKPWC (ORCPT ); Mon, 11 Mar 2019 11:22:02 -0400 Received: from mx1.redhat.com ([209.132.183.28]:17731 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726000AbfCKPWB (ORCPT ); Mon, 11 Mar 2019 11:22:01 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 0D25481F31; Mon, 11 Mar 2019 15:22:01 +0000 (UTC) Received: from [10.36.112.64] (ovpn-112-64.ams2.redhat.com [10.36.112.64]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 686E35D706; Mon, 11 Mar 2019 15:21:59 +0000 (UTC) Subject: Re: [PATCH v4 17/17] kvm: vmx: Emulate TEST_CTL MSR To: Xiaoyao Li Cc: linux-kernel , x86 , kvm@vger.kernel.org References: <1551494711-213533-1-git-send-email-fenghua.yu@intel.com> <1551494711-213533-18-git-send-email-fenghua.yu@intel.com> <58653d477d78b2a69927d8707522d91f091bcb52.camel@linux.intel.com> <7a10bb11-e9bf-f49c-6575-25c3da08cfac@redhat.com> From: Paolo Bonzini Openpgp: preference=signencrypt Autocrypt: addr=pbonzini@redhat.com; prefer-encrypt=mutual; keydata= mQHhBFRCcBIBDqDGsz4K0zZun3jh+U6Z9wNGLKQ0kSFyjN38gMqU1SfP+TUNQepFHb/Gc0E2 CxXPkIBTvYY+ZPkoTh5xF9oS1jqI8iRLzouzF8yXs3QjQIZ2SfuCxSVwlV65jotcjD2FTN04 hVopm9llFijNZpVIOGUTqzM4U55sdsCcZUluWM6x4HSOdw5F5Utxfp1wOjD/v92Lrax0hjiX DResHSt48q+8FrZzY+AUbkUS+Jm34qjswdrgsC5uxeVcLkBgWLmov2kMaMROT0YmFY6A3m1S P/kXmHDXxhe23gKb3dgwxUTpENDBGcfEzrzilWueOeUWiOcWuFOed/C3SyijBx3Av/lbCsHU Vx6pMycNTdzU1BuAroB+Y3mNEuW56Yd44jlInzG2UOwt9XjjdKkJZ1g0P9dwptwLEgTEd3Fo UdhAQyRXGYO8oROiuh+RZ1lXp6AQ4ZjoyH8WLfTLf5g1EKCTc4C1sy1vQSdzIRu3rBIjAvnC tGZADei1IExLqB3uzXKzZ1BZ+Z8hnt2og9hb7H0y8diYfEk2w3R7wEr+Ehk5NQsT2MPI2QBd wEv1/Aj1DgUHZAHzG1QN9S8wNWQ6K9DqHZTBnI1hUlkp22zCSHK/6FwUCuYp1zcAEQEAAbQj UGFvbG8gQm9uemluaSA8cGJvbnppbmlAcmVkaGF0LmNvbT6JAg0EEwECACMFAlRCcBICGwMH CwkIBwMCAQYVCAIJCgsEFgIDAQIeAQIXgAAKCRB+FRAMzTZpsbceDp9IIN6BIA0Ol7MoB15E 11kRz/ewzryFY54tQlMnd4xxfH8MTQ/mm9I482YoSwPMdcWFAKnUX6Yo30tbLiNB8hzaHeRj jx12K+ptqYbg+cevgOtbLAlL9kNgLLcsGqC2829jBCUTVeMSZDrzS97ole/YEez2qFpPnTV0 VrRWClWVfYh+JfzpXmgyhbkuwUxNFk421s4Ajp3d8nPPFUGgBG5HOxzkAm7xb1cjAuJ+oi/K CHfkuN+fLZl/u3E/fw7vvOESApLU5o0icVXeakfSz0LsygEnekDbxPnE5af/9FEkXJD5EoYG SEahaEtgNrR4qsyxyAGYgZlS70vkSSYJ+iT2rrwEiDlo31MzRo6Ba2FfHBSJ7lcYdPT7bbk9 AO3hlNMhNdUhoQv7M5HsnqZ6unvSHOKmReNaS9egAGdRN0/GPDWr9wroyJ65ZNQsHl9nXBqE AukZNr5oJO5vxrYiAuuTSd6UI/xFkjtkzltG3mw5ao2bBpk/V/YuePrJsnPFHG7NhizrxttB nTuOSCMo45pfHQ+XYd5K1+Cv/NzZFNWscm5htJ0HznY+oOsZvHTyGz3v91pn51dkRYN0otqr bQ4tlFFuVjArBZcapSIe6NV8C4cEiSS5AQ0EVEJxcwEIAK+nUrsUz3aP2aBjIrX3a1+C+39R nctpNIPcJjFJ/8WafRiwcEuLjbvJ/4kyM6K7pWUIQftl1P8Woxwb5nqL7zEFHh5I+hKS3haO 5pgco//V0tWBGMKinjqntpd4U4Dl299dMBZ4rRbPvmI8rr63sCENxTnHhTECyHdGFpqSzWzy 97rH68uqMpxbUeggVwYkYihZNd8xt1+lf7GWYNEO/QV8ar/qbRPG6PEfiPPHQd/sldGYavmd //o6TQLSJsvJyJDt7KxulnNT8Q2X/OdEuVQsRT5glLaSAeVAABcLAEnNgmCIGkX7TnQF8a6w gHGrZIR9ZCoKvDxAr7RP6mPeS9sAEQEAAYkDEgQYAQIACQUCVEJxcwIbAgEpCRB+FRAMzTZp scBdIAQZAQIABgUCVEJxcwAKCRC/+9JfeMeug/SlCACl7QjRnwHo/VzENWD9G2VpUOd9eRnS DZGQmPo6Mp3Wy8vL7snGFBfRseT9BevXBSkxvtOnUUV2YbyLmolAODqUGzUI8ViF339poOYN i6Ffek0E19IMQ5+CilqJJ2d5ZvRfaq70LA/Ly9jmIwwX4auvXrWl99/2wCkqnWZI+PAepkcX JRD4KY2fsvRi64/aoQmcxTiyyR7q3/52Sqd4EdMfj0niYJV0Xb9nt8G57Dp9v3Ox5JeWZKXS krFqy1qyEIypIrqcMbtXM7LSmiQ8aJRM4ZHYbvgjChJKR4PsKNQZQlMWGUJO4nVFSkrixc9R Z49uIqQK3b3ENB1QkcdMg9cxsB0Onih8zR+Wp1uDZXnz1ekto+EivLQLqvTjCCwLxxJafwKI bqhQ+hGR9jF34EFur5eWt9jJGloEPVv0GgQflQaE+rRGe+3f5ZDgRe5Y/EJVNhBhKcafcbP8 MzmLRh3UDnYDwaeguYmxuSlMdjFL96YfhRBXs8tUw6SO9jtCgBvoOIBDCxxAJjShY4KIvEpK b2hSNr8KxzelKKlSXMtB1bbHbQxiQcerAipYiChUHq1raFc3V0eOyCXK205rLtknJHhM5pfG 6taABGAMvJgm/MrVILIxvBuERj1FRgcgoXtiBmLEJSb7akcrRlqe3MoPTntSTNvNzAJmfWhd SvP0G1WDLolqvX0OtKMppI91AWVu72f1kolJg43wbaKpRJg1GMkKEI3H+jrrlTBrNl/8e20m TElPRDKzPiowmXeZqFSS1A6Azv0TJoo9as+lWF+P4zCXt40+Zhh5hdHO38EV7vFAVG3iuay6 7ToF8Uy7tgc3mdH98WQSmHcn/H5PFYk3xTP3KHB7b0FZPdFPQXBZb9+tJeZBi9gMqcjMch+Y R8dmTcQRQX14bm5nXlBF7VpSOPZMR392LY7wzAvRdhz7aeIUkdO7VelaspFk2nT7wOj1Y6uL nRxQlLkBDQRUQnHuAQgAx4dxXO6/Zun0eVYOnr5GRl76+2UrAAemVv9Yfn2PbDIbxXqLff7o yVJIkw4WdhQIIvvtu5zH24iYjmdfbg8iWpP7NqxUQRUZJEWbx2CRwkMHtOmzQiQ2tSLjKh/c HeyFH68xjeLcinR7jXMrHQK+UCEw6jqi1oeZzGvfmxarUmS0uRuffAb589AJW50kkQK9VD/9 QC2FJISSUDnRC0PawGSZDXhmvITJMdD4TjYrePYhSY4uuIV02v028TVAaYbIhxvDY0hUQE4r 8ZbGRLn52bEzaIPgl1p/adKfeOUeMReg/CkyzQpmyB1TSk8lDMxQzCYHXAzwnGi8WU9iuE1P 0wARAQABiQHzBBgBAgAJBQJUQnHuAhsMAAoJEH4VEAzNNmmxp1EOoJy0uZggJm7gZKeJ7iUp eX4eqUtqelUw6gU2daz2hE/jsxsTbC/w5piHmk1H1VWDKEM4bQBTuiJ0bfo55SWsUNN+c9hh IX+Y8LEe22izK3w7mRpvGcg+/ZRG4DEMHLP6JVsv5GMpoYwYOmHnplOzCXHvmdlW0i6SrMsB Dl9rw4AtIa6bRwWLim1lQ6EM3PWifPrWSUPrPcw4OLSwFk0CPqC4HYv/7ZnASVkR5EERFF3+ 6iaaVi5OgBd81F1TCvCX2BEyIDRZLJNvX3TOd5FEN+lIrl26xecz876SvcOb5SL5SKg9/rCB ufdPSjojkGFWGziHiFaYhbuI2E+NfWLJtd+ZvWAAV+O0d8vFFSvriy9enJ8kxJwhC0ECbSKF Y+W1eTIhMD3aeAKY90drozWEyHhENf4l/V+Ja5vOnW+gCDQkGt2Y1lJAPPSIqZKvHzGShdh8 DduC0U3xYkfbGAUvbxeepjgzp0uEnBXfPTy09JGpgWbg0w91GyfT/ujKaGd4vxG2Ei+MMNDm S1SMx7wu0evvQ5kT9NPzyq8R2GIhVSiAd2jioGuTjX6AZCFv3ToO53DliFMkVTecLptsXaes uUHgL9dKIfvpm+rNXRn9wAwGjk0X/A== Message-ID: <330cd5ec-813b-8835-2178-32e14190b9e6@redhat.com> Date: Mon, 11 Mar 2019 16:21:56 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.4.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Mon, 11 Mar 2019 15:22:01 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/03/19 16:10, Xiaoyao Li wrote: > On Mon, 2019-03-11 at 14:31 +0100, Paolo Bonzini wrote: >> On 09/03/19 03:31, Xiaoyao Li wrote: >>> Hi, Paolo, >>> >>> Do you have any comments on this patch? >>> >>> We are preparing v5 patches for split lock detection, if you have any >>> comments >>> about this one, please let me know. >> >> No, my only comment is that it should be placed _before_ the other two >> for bisectability. I think I have already sent that small remark. >> >> Thanks, >> >> Paolo > > I cannot find the small remark you sent before. Maybe I missed something. > But I'am confused why it should be placed _before_ the other two. This patch > just use the vmx->core_capability that defined it the previous patch. Because otherwise the guest can see core_capability != 0 and will #GP when trying to use split lock detection. But you are right, this patch must be the last. Instead, kvm-get_core_capability() should always return 0 until the previous patch. Then in this patch you add the rdmsr and boot_cpu_has() tests. Paolo >>>> + if (!(vmx->core_capability & CORE_CAP_SPLIT_LOCK_DETECT)) >>>> + return 1; >>>> + >>>> + if (data & ~TEST_CTL_ENABLE_SPLIT_LOCK_DETECT) >>>> + return 1; >>>> + vmx->msr_test_ctl = data; >>>> + break; >>>> case MSR_EFER: >>>> ret = kvm_set_msr_common(vcpu, msr_info); >>>> break; >>>> @@ -4108,6 +4122,9 @@ static void vmx_vcpu_setup(struct vcpu_vmx *vmx) >>>> >>>> vmx->arch_capabilities = kvm_get_arch_capabilities(); >>>> >>>> + /* disable AC split lock by default */ >>>> + vmx->msr_test_ctl = 0; >>>> + >>>> vm_exit_controls_init(vmx, vmx_vmexit_ctrl()); >>>> >>>> /* 22.2.1, 20.8.1 */ >>>> @@ -4145,6 +4162,7 @@ static void vmx_vcpu_reset(struct kvm_vcpu *vcpu, >>>> bool >>>> init_event) >>>> >>>> vmx->rmode.vm86_active = 0; >>>> vmx->spec_ctrl = 0; >>>> + vmx->msr_test_ctl = 0; >>>> >>>> vcpu->arch.microcode_version = 0x100000000ULL; >>>> vmx->vcpu.arch.regs[VCPU_REGS_RDX] = get_rdx_init_val(); >>>> @@ -6344,6 +6362,21 @@ static void atomic_switch_perf_msrs(struct vcpu_vmx >>>> *vmx) >>>> msrs[i].host, false); >>>> } >>>> >>>> +static void atomic_switch_msr_test_ctl(struct vcpu_vmx *vmx) >>>> +{ >>>> + u64 host_msr_test_ctl; >>>> + >>>> + if (!boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT)) >>>> + return; >>>> + >>>> + rdmsrl(MSR_TEST_CTL, host_msr_test_ctl); >>>> + if (host_msr_test_ctl == vmx->msr_test_ctl) >>>> + clear_atomic_switch_msr(vmx, MSR_TEST_CTL); >>>> + else >>>> + add_atomic_switch_msr(vmx, MSR_TEST_CTL, vmx->msr_test_ctl, >>>> + host_msr_test_ctl, false); >>>> +} >>>> + >>>> static void vmx_arm_hv_timer(struct vcpu_vmx *vmx, u32 val) >>>> { >>>> vmcs_write32(VMX_PREEMPTION_TIMER_VALUE, val); >>>> @@ -6585,6 +6618,8 @@ static void vmx_vcpu_run(struct kvm_vcpu *vcpu) >>>> >>>> atomic_switch_perf_msrs(vmx); >>>> >>>> + atomic_switch_msr_test_ctl(vmx); >>>> + >>>> vmx_update_hv_timer(vcpu); >>>> >>>> /* >>>> diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h >>>> index cc22379991f3..e8831609c6c3 100644 >>>> --- a/arch/x86/kvm/vmx/vmx.h >>>> +++ b/arch/x86/kvm/vmx/vmx.h >>>> @@ -191,6 +191,7 @@ struct vcpu_vmx { >>>> u64 msr_guest_kernel_gs_base; >>>> #endif >>>> >>>> + u64 msr_test_ctl; >>>> u64 core_capability; >>>> u64 arch_capabilities; >>>> u64 spec_ctrl; >> >> >