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=-23.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,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 05916C433E6 for ; Fri, 15 Jan 2021 00:33:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CB1A523AAA for ; Fri, 15 Jan 2021 00:33:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731328AbhAOAdS (ORCPT ); Thu, 14 Jan 2021 19:33:18 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54030 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731209AbhAOAdQ (ORCPT ); Thu, 14 Jan 2021 19:33:16 -0500 Received: from mail-io1-xd2b.google.com (mail-io1-xd2b.google.com [IPv6:2607:f8b0:4864:20::d2b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 60E6EC061757 for ; Thu, 14 Jan 2021 16:32:36 -0800 (PST) Received: by mail-io1-xd2b.google.com with SMTP id u17so15049571iow.1 for ; Thu, 14 Jan 2021 16:32:36 -0800 (PST) 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; bh=VOQ/AhgJ3E0EhA15ZI14xotoZTAklFRTxP5RiI0pr4w=; b=ZKqirSc1RXxGZk9m5C1Q/rMeYrWTjUtba1m3HeBthnH0Q+DkrD/47pIHau7E42QcG0 QlHkz/g7VIe6SAqB7J4f2opMv3QT5kSoqCxxCcWR/pv9KOyrtrqvotn63RsCS7DpyDkH nbmJPf1tn6pkcO2yIqk4rvEX91Zp9+iBKf1uFwKuz+w6NFs5U0owMt4o9Rn2jfVpGVQ9 MMmfSi0SacqZMIU07He0glcF8l+in5ianV+FHe+F6kRz17NYwXcGFIAGvBWLQ6TxOb7s Xpg2OT2vsqbXYIGXZzP1ZpUNxv6A6pkMhSf5cepMH0caIl7QocPIyQ+3Zu0tcz4r04ZD T7qw== 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; bh=VOQ/AhgJ3E0EhA15ZI14xotoZTAklFRTxP5RiI0pr4w=; b=Y8PDNi3SLcD13wVmLg52Ij16vi1YWkiS9btpk74tRYWKCMKL9gUVy/JL1Bj2XN6CjQ GW9I1GwYBHD4bzQVoKAvTg5lFS3mucDCXR/4psN11uw94GXZDdYGXLSI96kP7t5tjVm4 0e0xYEyM8txpAwGKDje9gQX94dvWcou5mH59183/cVITcqdVekMOEPKN8h6galqFov+7 8iJ+oZMdAYL73ywkGBeOpTl9O7gh2kOeOqycEFXIkvXvHT4c/eeK0kOfProlpTq0IGGw r2sJNqOVDWVA6jx/LcQlz0lla03Yh9uSHkcV75L8wW/UsA4a6AK4k4sC9ZeJdjPUv7y1 feoA== X-Gm-Message-State: AOAM5327HdnfWbBZGUzfOEfcXSp9JYj42s5A2XdlLXzNa3zNP/HOY/gz QdgHImt2xAzr972khK3fwIL42Wx8YZqGno2CfG9sQQ== X-Google-Smtp-Source: ABdhPJxbNAzWVOVJfbEBY8T6GsiM6dkRxLPzdspE3E1+d0gUbNlqrmg6Px5WqEFTvbpRjjACRkEjKVw73nzyq7Vc/Yo= X-Received: by 2002:a02:4b42:: with SMTP id q63mr8126963jaa.77.1610670755423; Thu, 14 Jan 2021 16:32:35 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: From: Steve Rutherford Date: Thu, 14 Jan 2021 16:31:59 -0800 Message-ID: Subject: Re: [PATCH v9 00/18] Add AMD SEV guest live migration support To: Ashish Kalra Cc: Paolo Bonzini , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= , Joerg Roedel , Borislav Petkov , Tom Lendacky , X86 ML , KVM list , LKML , Venu Busireddy , Brijesh Singh Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Forgot to ask this: is there an intention to support SEND_CANCEL in a follow up patch? On Tue, Dec 8, 2020 at 2:03 PM Ashish Kalra wrote: > > From: Ashish Kalra > > The series add support for AMD SEV guest live migration commands. To protect the > confidentiality of an SEV protected guest memory while in transit we need to > use the SEV commands defined in SEV API spec [1]. > > SEV guest VMs have the concept of private and shared memory. Private memory > is encrypted with the guest-specific key, while shared memory may be 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 hypercall. > The guest OS can use this hypercall to notify the page encryption status. > If the page is encrypted with guest specific-key then we use SEV command 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 negotiated > between the host and guest, the host indicates this feature support via > KVM_FEATURE_CPUID. The guest firmware (OVMF) detects this feature and > 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 if it > set then enables live migration feature on host by writing to a custom > 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://github.com/AMDESE/linux/tree/sev-migration-v9 > > [1] https://developer.amd.com/wp-content/resources/55766.PDF > > Changes since v8: > - Rebasing to kvm next branch. > - Fixed and added comments as per review feedback on v8 patches. > - Removed implicitly enabling live migration for incoming VMs in > in KVM_SET_PAGE_ENC_BITMAP, it is now done via KVM_SET_MSR ioctl. > - Adds support for bypassing unencrypted guest memory regions for > DBG_DECRYPT API calls, guest memory region encryption status in > sev_dbg_decrypt() is referenced using the page encryption bitmap. > > 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 fixed > build error when CONFIG_HYPERVISOR_GUEST=y and > CONFIG_AMD_MEM_ENCRYPT=n. > - 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 allocation > is done implicitly by extending kvm_arch_commit_memory_region() callack > 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 instead > of simply clearing specific bits. > - Removed KVM_PAGE_ENC_BITMAP_RESET ioctl, which is now performed using > KVM_SET_PAGE_ENC_BITMAP. > - Extended guest support for enabling Live Migration feature by adding a > check for UEFI environment variable indicating OVMF support for Live > Migration feature and additionally checking for KVM capability for the > same feature. If not booted under EFI, then we simply check for KVM > capability. > - Add hypervisor specific hypercall for SEV live migration by adding > 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 variables > such as hv_clock_boot and wall_clock are marked as decrypted in the > 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 bits 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 custom 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 that > 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 Encryption > 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 page > encryption bitmap. > KVM: x86: Add kexec support for SEV Live Migration. > KVM: SVM: Enable SEV live migration feature implicitly on Incoming > 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 > > Ashish Kalra (7): > KVM: SVM: Add support for static allocation of unified Page Encryption > 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 page > encryption bitmap. > KVM: x86: Add kexec support for SEV Live Migration. > KVM: SVM: Bypass DBG_DECRYPT API calls for unecrypted guest memory. > > 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 | 16 + > 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 | 790 ++++++++++++++++++ > 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, 1365 insertions(+), 5 deletions(-) > > -- > 2.17.1 >