From patchwork Sat Mar 11 00:22:45 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Christopherson X-Patchwork-Id: 67879 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a5d:5915:0:0:0:0:0 with SMTP id v21csp43825wrd; Fri, 10 Mar 2023 16:25:55 -0800 (PST) X-Google-Smtp-Source: AK7set+tK09XUB61Q+hy10egpp+vwj8gtyzonT55P0Ro0OHca4rTAonoNs9ttiAFTvyiqlRhKdLS X-Received: by 2002:a05:6a20:548b:b0:be:e450:69b3 with SMTP id i11-20020a056a20548b00b000bee45069b3mr34786295pzk.0.1678494355134; Fri, 10 Mar 2023 16:25:55 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1678494355; cv=none; d=google.com; s=arc-20160816; b=ALocSu3odWKdl8Es9avNn0FnpDE+iIfnPG/PgCaUIeGnALFZ4+phwV95XHE/b6txlz nUlIeW3QR82Wan+wH7I5goAy47pIIi9ruttU84BhcBzEAwZYQbaVzimLftYjiqlAqUJg eDeKh5F+FOVhgacwYjKBbSdpzSV0FqmzPZ83gggOa8vwEpInBGgdO1GUuRVb8wEISXxP jf7zKqb50br4c5tO/4q3tmQxJUaCKnSk+Ch2RQMInudCcC8FBjKkpFIB70K/XBsOtOyN AnJAfsXCOsBHP105XgxIdPvVdJsWoxazYNz3UC4nV3oIt8ICbv+Em4xG7K0wmOwLi2c6 c90g== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:cc:to:from:subject:message-id:references :mime-version:in-reply-to:date:reply-to:dkim-signature; bh=Rm109LqJljTWMnqiCeQQyQd+NmHilpchibDoYyZB3Pk=; b=r7R6XSsdozenmMNiRzTOlZ1u//BJerO4flyeexLGlex3dxUCzAbmCxNw12JIAfV5Bm g+7ZWPBwdho0R4reFkj3FCijVIufeuctFr6pfKBZRsgTEnNX3hnvz45I5o4nm30j5Fna QljR566TPx9mSnkvg5kD38JuHqdAQbH8btjDuxQnfhhint4COs8lMAIr8g8TD0RdB2mg 6SsuQ5PTRMAEsAyHZHjPy6fKTjR/cb7z+WfKG6wTUwvE7ThGKM8gaoK9/DVOn/h72TD6 mlabHg4S1DnBiZUqbq0mQ70FcHNCLobvg8V20RHDAlrvOhe4bK+MJyXwR6Mfoz/kC4Yb qbCg== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@google.com header.s=20210112 header.b=nbQyCIoi; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id o9-20020a656149000000b004fb98a13f1csi953522pgv.140.2023.03.10.16.25.41; Fri, 10 Mar 2023 16:25:55 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@google.com header.s=20210112 header.b=nbQyCIoi; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231232AbjCKAYn (ORCPT + 99 others); Fri, 10 Mar 2023 19:24:43 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47114 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231171AbjCKAYH (ORCPT ); Fri, 10 Mar 2023 19:24:07 -0500 Received: from mail-pf1-x449.google.com (mail-pf1-x449.google.com [IPv6:2607:f8b0:4864:20::449]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7B94180E16 for ; Fri, 10 Mar 2023 16:23:33 -0800 (PST) Received: by mail-pf1-x449.google.com with SMTP id bw25-20020a056a00409900b005a9d0e66a7aso3597648pfb.5 for ; Fri, 10 Mar 2023 16:23:33 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; t=1678494212; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:from:to:cc:subject:date:message-id:reply-to; bh=Rm109LqJljTWMnqiCeQQyQd+NmHilpchibDoYyZB3Pk=; b=nbQyCIoiLIM7RQJY0KwsZy4MzALtUvpTVM0wdA1nSuVn+9c9kcDfgfjPsaslp3h104 zCUflGcnq2a5vqfNqA7G619cjYvpnP0xZenQN8Zu1a1rSrPcdxhIboj4sIXYcbKgkKZF 1HiHk172uv/TS/YsLBJ8VPH5ev9KwCQ+n0xy/R2NBWQfRgme2yPjjL66yaKvoymjOp98 H7bh6xdjI+pIQvZVpqHMbBcMVNwAe8eRczAgZZ12yOdlAdRqTGG+BqDD+VS/2ZFU4HsK WCauxqGyQpSRdb6mw3BfyWNp7bQTtspy/V2CMSt8fyQjpFLp47jZ/M0grWgr3WRYJApx 659g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1678494212; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=Rm109LqJljTWMnqiCeQQyQd+NmHilpchibDoYyZB3Pk=; b=Yr8DyAJd3A+994Glx/ExrF+7PxpZ9OI9wfIbRhbm1Sa+ya2KnUvORZ/8x/m9MYAtWN fXvHNdxqZgZZeGVCLvGbUCSF9jZxXNvuKDP0e9Mcbf9TKC7Wug6PULXkUdioNtnLV+rI Px+7wKQcEjtlSCOQwFr+ON5dHlRGkM6IOCekVYk55uthQBHIVNBYyw9XdVr+yzDyngcr saiwJuESuaOH4rAP+ri+JOHjrf3n6hTjI3rqg9mXZPCSAKG555UJ+IXaa6MHJNOYuXa/ w5qDGiujiTObtLOs5AiYNRnG5EKSW8bnpei3QdyE73xnNicaMF0l9sbdNXAB4KDRHCW/ wb2w== X-Gm-Message-State: AO0yUKU87tgJTz9XUHccgS+KSJOSUQB2IqX1Q1hdhNPe1Qu8mf9fAMM7 w1TAgx6Xq0i5BqbmPzvDWkhZarkQmHk= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a63:7515:0:b0:503:20b9:5d88 with SMTP id q21-20020a637515000000b0050320b95d88mr8959180pgc.4.1678494212241; Fri, 10 Mar 2023 16:23:32 -0800 (PST) Reply-To: Sean Christopherson Date: Fri, 10 Mar 2023 16:22:45 -0800 In-Reply-To: <20230311002258.852397-1-seanjc@google.com> Mime-Version: 1.0 References: <20230311002258.852397-1-seanjc@google.com> X-Mailer: git-send-email 2.40.0.rc1.284.g88254d51c5-goog Message-ID: <20230311002258.852397-15-seanjc@google.com> Subject: [PATCH v2 14/27] KVM: x86: Reject memslot MOVE operations if KVMGT is attached From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini , Zhenyu Wang , Zhi Wang Cc: kvm@vger.kernel.org, intel-gvt-dev@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org, Yan Zhao , Ben Gardon X-Spam-Status: No, score=-9.6 required=5.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE, SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1760028897029691031?= X-GMAIL-MSGID: =?utf-8?q?1760028897029691031?= Disallow moving memslots if the VM has external page-track users, i.e. if KVMGT is being used to expose a virtual GPU to the guest, as KVM doesn't correctly handle moving memory regions. Note, this is potential ABI breakage! E.g. userspace could move regions that aren't shadowed by KVMGT without harming the guest. However, the only known user of KVMGT is QEMU, and QEMU doesn't move generic memory regions. KVM's own support for moving memory regions was also broken for multiple years (albeit for an edge case, but arguably moving RAM is itself an edge case), e.g. see commit edd4fa37baa6 ("KVM: x86: Allocate new rmap and large page tracking when moving memslot"). Signed-off-by: Sean Christopherson Reviewed-by: Yan Zhao --- arch/x86/include/asm/kvm_page_track.h | 3 +++ arch/x86/kvm/mmu/page_track.c | 5 +++++ arch/x86/kvm/x86.c | 7 +++++++ 3 files changed, 15 insertions(+) diff --git a/arch/x86/include/asm/kvm_page_track.h b/arch/x86/include/asm/kvm_page_track.h index 0d65ae203fd6..6a287bcbe8a9 100644 --- a/arch/x86/include/asm/kvm_page_track.h +++ b/arch/x86/include/asm/kvm_page_track.h @@ -77,4 +77,7 @@ kvm_page_track_unregister_notifier(struct kvm *kvm, void kvm_page_track_write(struct kvm_vcpu *vcpu, gpa_t gpa, const u8 *new, int bytes); void kvm_page_track_flush_slot(struct kvm *kvm, struct kvm_memory_slot *slot); + +bool kvm_page_track_has_external_user(struct kvm *kvm); + #endif diff --git a/arch/x86/kvm/mmu/page_track.c b/arch/x86/kvm/mmu/page_track.c index 39a0863af8b4..1cfc0a0ccc23 100644 --- a/arch/x86/kvm/mmu/page_track.c +++ b/arch/x86/kvm/mmu/page_track.c @@ -321,3 +321,8 @@ enum pg_level kvm_page_track_max_mapping_level(struct kvm *kvm, gfn_t gfn, return max_level; } EXPORT_SYMBOL_GPL(kvm_page_track_max_mapping_level); + +bool kvm_page_track_has_external_user(struct kvm *kvm) +{ + return hlist_empty(&kvm->arch.track_notifier_head.track_notifier_list); +} diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 29dd6c97d145..47ac9291cd43 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -12484,6 +12484,13 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm, struct kvm_memory_slot *new, enum kvm_mr_change change) { + /* + * KVM doesn't support moving memslots when there are external page + * trackers attached to the VM, i.e. if KVMGT is in use. + */ + if (change == KVM_MR_MOVE && kvm_page_track_has_external_user(kvm)) + return -EINVAL; + if (change == KVM_MR_CREATE || change == KVM_MR_MOVE) { if ((new->base_gfn + new->npages - 1) > kvm_mmu_max_gfn()) return -EINVAL;