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=-16.6 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_IN_DEF_DKIM_WL autolearn=unavailable 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 94B67C433E1 for ; Wed, 5 Aug 2020 19:12:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 72D6720842 for ; Wed, 5 Aug 2020 19:12:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="WItl9UdE" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728914AbgHETMD (ORCPT ); Wed, 5 Aug 2020 15:12:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34714 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729240AbgHESaT (ORCPT ); Wed, 5 Aug 2020 14:30:19 -0400 Received: from mail-io1-xd43.google.com (mail-io1-xd43.google.com [IPv6:2607:f8b0:4864:20::d43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ED207C061757 for ; Wed, 5 Aug 2020 11:29:53 -0700 (PDT) Received: by mail-io1-xd43.google.com with SMTP id j8so34590113ioe.9 for ; Wed, 05 Aug 2020 11:29:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=SARuME9J10v3sen/Xni7v/xI7rOWv9gm7Kfl7nu9RLM=; b=WItl9UdE0b5ZGEHl6FjMKa0TRpIq4jGrjQhEgOYt0YHvs9S5QQiQGmiNiMibXYZytI GlLaeTtgReLvgxx7eFCaUDO97I7kX3GxfsEGfCW8jK1xTXKGGXoDchsKQXrHRm7zD97O FwrRkSbLKze3NLeC8B/aDYLbtdZxP39VNzEpqMAbIBPpVyzlsaej1GiNOGlMNZZvM1Nl 5vtKO6OXlX4yDKKesarf6WlOoBq+mpke9JtvhHDVXX/wz1jOsLyf3tlHPUSt7WzUmSTA WuulOuN2AySeK690OH2U7Ya0L5v7hjAuauIfjr3AcMB+rgJWNEAn2oR4OwHP6ZVGxv3u Nq3g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=SARuME9J10v3sen/Xni7v/xI7rOWv9gm7Kfl7nu9RLM=; b=dT2/iugvoFu52cnHAyfTl+G1tZ0UGRJb/0LSOfaWEVK0FLH1SilPYrujdjbG7SlPQG vU+9+pHHzWkE3zSoOia7qtVKN4fci0zZTg+UDsbHB0+mwiM7u5kjoD2I1+QR4ubR/H/o rBDDq14fcuXVVsMTpv5jxdKNqfuuFZhLrJak4phldYaxSxkPgO8wSA1bePXNIHaJ6y+C TNtEugX2PORoNvb4qiOK0WyHYVXh0XGKLJAU8BcCDILLGOuY7MwPiqa8CVVGgC1o2tIH WkKnXj2ca5828CQghDsWQHcZQQqsJlDJR03i+pOkpC0U8LQZ0DlV+sTXEVsVUVt11N6T vXfA== X-Gm-Message-State: AOAM533qheTaDVGj5fr90HeR8sNRevwC77FVNLyvxGcPKpJ+h/gtSiM5 R6j+D1ob9GrFtmyBR/Z2Ggxd8o+ogWYoBVdOSXZoXg== X-Google-Smtp-Source: ABdhPJw1/ZX6Zxh2XqOSuKBSOqZgN3PrB8R6jBBj96SVyIceT6wdrGYeKyoldLvl1/EFlU0fL4yHu4e2fd8Q3Pyy6+I= X-Received: by 2002:a6b:4e0e:: with SMTP id c14mr4490564iob.8.1596652193001; Wed, 05 Aug 2020 11:29:53 -0700 (PDT) MIME-Version: 1.0 References: <20200518190708.GA7929@ashkalra_ubuntu_server> <20200603221428.GA6511@ashkalra_ubuntu_server> In-Reply-To: <20200603221428.GA6511@ashkalra_ubuntu_server> From: Steve Rutherford Date: Wed, 5 Aug 2020 11:29:17 -0700 Message-ID: Subject: Re: [PATCH v8 00/18] Add AMD SEV guest live migration support To: Ashish Kalra Cc: Paolo Bonzini , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Joerg Roedel , Borislav Petkov , Tom Lendacky , X86 ML , KVM list , LKML , David Rientjes , Venu Busireddy , Brijesh Singh Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Are these likely to get merged into 5.9? On Wed, Jun 3, 2020 at 3:14 PM Ashish Kalra wrote: > > Hello Steve, > > On Mon, Jun 01, 2020 at 01:02:23PM -0700, Steve Rutherford wrote: > > On Mon, May 18, 2020 at 12:07 PM Ashish Kalra wr= ote: > > > > > > Hello All, > > > > > > Any other feedback, review or comments on this patch-set ? > > > > > > Thanks, > > > Ashish > > > > > > On Tue, May 05, 2020 at 09:13:49PM +0000, Ashish Kalra wrote: > > > > From: Ashish Kalra > > > > > > > > The series add support for AMD SEV guest live migration commands. T= o protect the > > > > confidentiality of an SEV protected guest memory while in transit w= e need to > > > > use the SEV commands defined in SEV API spec [1]. > > > > > > > > SEV guest VMs have the concept of private and shared memory. Privat= e memory > > > > is encrypted with the guest-specific key, while shared memory may b= e encrypted > > > > with hypervisor key. The commands provided by the SEV FW are meant = to be used > > > > for the private memory only. The patch series introduces a new hype= rcall. > > > > The guest OS can use this hypercall to notify the page encryption s= tatus. > > > > If the page is encrypted with guest specific-key then we use SEV co= mmand during > > > > the migration. If page is not encrypted then fallback to default. > > > > > > > > The patch adds new ioctls KVM_{SET,GET}_PAGE_ENC_BITMAP. The ioctl = can be used > > > > by the qemu to get the page encrypted bitmap. Qemu can consult this= bitmap > > > > during the migration to know whether the page is encrypted. > > > > > > > > This section descibes how the SEV live migration feature is negotia= ted > > > > between the host and guest, the host indicates this feature support= via > > > > KVM_FEATURE_CPUID. The guest firmware (OVMF) detects this feature a= nd > > > > sets a UEFI enviroment variable indicating OVMF support for live > > > > migration, the guest kernel also detects the host support for this > > > > feature via cpuid and in case of an EFI boot verifies if OVMF also > > > > supports this feature by getting the UEFI enviroment variable and i= f it > > > > set then enables live migration feature on host by writing to a cus= tom > > > > MSR, if not booted under EFI, then it simply enables the feature by > > > > again writing to the custom MSR. The host returns error as part of > > > > SET_PAGE_ENC_BITMAP ioctl if guest has not enabled live migration. > > > > > > > > A branch containing these patches is available here: > > > > https://nam11.safelinks.protection.outlook.com/?url=3Dhttps%3A%2F%2= Fgithub.com%2FAMDESE%2Flinux%2Ftree%2Fsev-migration-v8&data=3D02%7C01%7= Cashish.kalra%40amd.com%7Cb7da54c6f7784a548ed208d80666c99b%7C3dd8961fe4884e= 608e11a82d994e183d%7C0%7C0%7C637266386411473155&sdata=3DigztZXTZl1i18e5= T4DTlNJw07h6z3aBNCAD6%2BE7r9Ik%3D&reserved=3D0 > > > > > > > > [1] https://nam11.safelinks.protection.outlook.com/?url=3Dhttps%3A%= 2F%2Fdeveloper.amd.com%2Fwp-content%2Fresources%2F55766.PDF&data=3D02%7= C01%7Cashish.kalra%40amd.com%7Cb7da54c6f7784a548ed208d80666c99b%7C3dd8961fe= 4884e608e11a82d994e183d%7C0%7C0%7C637266386411473155&sdata=3DGBgV6HAd2A= XZzjK3hp%2F396tDaHlYtN%2FL3Zfny3GaSoU%3D&reserved=3D0 > > > > > > > > Changes since v7: > > > > - Removed the hypervisor specific hypercall/paravirt callback for > > > > SEV live migration and moved back to calling kvm_sev_hypercall3 > > > > directly. > > > > - Fix build errors as > > > > Reported-by: kbuild test robot , specifically fixe= d > > > > build error when CONFIG_HYPERVISOR_GUEST=3Dy and > > > > CONFIG_AMD_MEM_ENCRYPT=3Dn. > > > > - Implicitly enabled live migration for incoming VM(s) to handle > > > > A->B->C->... VM migrations. > > > > - Fixed Documentation as per comments on v6 patches. > > > > - Fixed error return path in sev_send_update_data() as per comments > > > > on v6 patches. > > > > > > > > Changes since v6: > > > > - Rebasing to mainline and refactoring to the new split SVM > > > > infrastructre. > > > > - Move to static allocation of the unified Page Encryption bitmap > > > > instead of the dynamic resizing of the bitmap, the static allocat= ion > > > > is done implicitly by extending kvm_arch_commit_memory_region() c= allack > > > > to add svm specific x86_ops which can read the userspace provided= memory > > > > region/memslots and calculate the amount of guest RAM managed by = the KVM > > > > and grow the bitmap. > > > > - Fixed KVM_SET_PAGE_ENC_BITMAP ioctl to set the whole bitmap inste= ad > > > > of simply clearing specific bits. > > > > - Removed KVM_PAGE_ENC_BITMAP_RESET ioctl, which is now performed u= sing > > > > KVM_SET_PAGE_ENC_BITMAP. > > > > - Extended guest support for enabling Live Migration feature by add= ing a > > > > check for UEFI environment variable indicating OVMF support for L= ive > > > > Migration feature and additionally checking for KVM capability fo= r the > > > > same feature. If not booted under EFI, then we simply check for K= VM > > > > capability. > > > > - Add hypervisor specific hypercall for SEV live migration by addin= g > > > > a new paravirt callback as part of x86_hyper_runtime. > > > > (x86 hypervisor specific runtime callbacks) > > > > - Moving MSR handling for MSR_KVM_SEV_LIVE_MIG_EN into svm/sev code > > > > and adding check for SEV live migration enabled by guest in the > > > > KVM_GET_PAGE_ENC_BITMAP ioctl. > > > > - Instead of the complete __bss_decrypted section, only specific va= riables > > > > such as hv_clock_boot and wall_clock are marked as decrypted in t= he > > > > page encryption bitmap > > > > > > > > Changes since v5: > > > > - Fix build errors as > > > > Reported-by: kbuild test robot > > > > > > > > Changes since v4: > > > > - Host support has been added to extend KVM capabilities/feature bi= ts to > > > > include a new KVM_FEATURE_SEV_LIVE_MIGRATION, which the guest can > > > > query for host-side support for SEV live migration and a new cust= om MSR > > > > MSR_KVM_SEV_LIVE_MIG_EN is added for guest to enable the SEV live > > > > migration feature. > > > > - Ensure that _bss_decrypted section is marked as decrypted in the > > > > page encryption bitmap. > > > > - Fixing KVM_GET_PAGE_ENC_BITMAP ioctl to return the correct bitmap > > > > as per the number of pages being requested by the user. Ensure th= at > > > > we only copy bmap->num_pages bytes in the userspace buffer, if > > > > bmap->num_pages is not byte aligned we read the trailing bits > > > > from the userspace and copy those bits as is. This fixes guest > > > > page(s) corruption issues observed after migration completion. > > > > - Add kexec support for SEV Live Migration to reset the host's > > > > page encryption bitmap related to kernel specific page encryption > > > > status settings before we load a new kernel by kexec. We cannot > > > > reset the complete page encryption bitmap here as we need to > > > > retain the UEFI/OVMF firmware specific settings. > > > > > > > > Changes since v3: > > > > - Rebasing to mainline and testing. > > > > - Adding a new KVM_PAGE_ENC_BITMAP_RESET ioctl, which resets the > > > > page encryption bitmap on a guest reboot event. > > > > - Adding a more reliable sanity check for GPA range being passed to > > > > the hypercall to ensure that guest MMIO ranges are also marked > > > > in the page encryption bitmap. > > > > > > > > Changes since v2: > > > > - reset the page encryption bitmap on vcpu reboot > > > > > > > > Changes since v1: > > > > - Add support to share the page encryption between the source and = target > > > > machine. > > > > - Fix review feedbacks from Tom Lendacky. > > > > - Add check to limit the session blob length. > > > > - Update KVM_GET_PAGE_ENC_BITMAP icotl to use the base_gfn instead= of > > > > the memory slot when querying the bitmap. > > > > > > > > Ashish Kalra (7): > > > > KVM: SVM: Add support for static allocation of unified Page Encry= ption > > > > Bitmap. > > > > KVM: x86: Introduce new KVM_FEATURE_SEV_LIVE_MIGRATION feature & > > > > Custom MSR. > > > > EFI: Introduce the new AMD Memory Encryption GUID. > > > > KVM: x86: Add guest support for detecting and enabling SEV Live > > > > Migration feature. > > > > KVM: x86: Mark _bss_decrypted section variables as decrypted in p= age > > > > encryption bitmap. > > > > KVM: x86: Add kexec support for SEV Live Migration. > > > > KVM: SVM: Enable SEV live migration feature implicitly on Incomin= g > > > > VM(s). > > > > > > > > Brijesh Singh (11): > > > > KVM: SVM: Add KVM_SEV SEND_START command > > > > KVM: SVM: Add KVM_SEND_UPDATE_DATA command > > > > KVM: SVM: Add KVM_SEV_SEND_FINISH command > > > > KVM: SVM: Add support for KVM_SEV_RECEIVE_START command > > > > KVM: SVM: Add KVM_SEV_RECEIVE_UPDATE_DATA command > > > > KVM: SVM: Add KVM_SEV_RECEIVE_FINISH command > > > > KVM: x86: Add AMD SEV specific Hypercall3 > > > > KVM: X86: Introduce KVM_HC_PAGE_ENC_STATUS hypercall > > > > KVM: x86: Introduce KVM_GET_PAGE_ENC_BITMAP ioctl > > > > mm: x86: Invoke hypercall when page encryption status is changed > > > > KVM: x86: Introduce KVM_SET_PAGE_ENC_BITMAP ioctl > > > > > > > > .../virt/kvm/amd-memory-encryption.rst | 120 +++ > > > > Documentation/virt/kvm/api.rst | 71 ++ > > > > Documentation/virt/kvm/cpuid.rst | 5 + > > > > Documentation/virt/kvm/hypercalls.rst | 15 + > > > > Documentation/virt/kvm/msr.rst | 10 + > > > > arch/x86/include/asm/kvm_host.h | 7 + > > > > arch/x86/include/asm/kvm_para.h | 12 + > > > > arch/x86/include/asm/mem_encrypt.h | 11 + > > > > arch/x86/include/asm/paravirt.h | 10 + > > > > arch/x86/include/asm/paravirt_types.h | 2 + > > > > arch/x86/include/uapi/asm/kvm_para.h | 5 + > > > > arch/x86/kernel/kvm.c | 90 +++ > > > > arch/x86/kernel/kvmclock.c | 12 + > > > > arch/x86/kernel/paravirt.c | 1 + > > > > arch/x86/kvm/svm/sev.c | 732 ++++++++++++++= +++- > > > > arch/x86/kvm/svm/svm.c | 21 + > > > > arch/x86/kvm/svm/svm.h | 9 + > > > > arch/x86/kvm/vmx/vmx.c | 1 + > > > > arch/x86/kvm/x86.c | 35 + > > > > arch/x86/mm/mem_encrypt.c | 68 +- > > > > arch/x86/mm/pat/set_memory.c | 7 + > > > > include/linux/efi.h | 1 + > > > > include/linux/psp-sev.h | 8 +- > > > > include/uapi/linux/kvm.h | 52 ++ > > > > include/uapi/linux/kvm_para.h | 1 + > > > > 25 files changed, 1297 insertions(+), 9 deletions(-) > > > > > > > > -- > > > > 2.17.1 > > > > > > > > Hey all, > > These patches look pretty reasonable at this point. What's the next > > step for getting them merged? > > I believe i have incorporated all your main comments and feedback, for > example, no more dynamic resizing of the page encryption bitmap and > static allocation of the same, fixing SET_PAGE_ENC_BITMAP ioctl to set > the whole bitmap and also merging RESET_PAGE_ENC_BITMAP ioctl into it > and other stuff like kexec support, etc. > > I know you have some additional comments and i am waiting for some more > feedback and comments from others on the mailing list. > > But otherwise i believe these patches are fully ready to be merged at > this point and i am looking forward to the same. > > Thanks, > Ashish > > > Thanks, > > Steve