From patchwork Mon Feb 24 23:55:41 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Christopherson X-Patchwork-Id: 13989141 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E7632C021A4 for ; Tue, 25 Feb 2025 00:06:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:Reply-To:List-Subscribe:List-Help: List-Post:List-Archive:List-Unsubscribe:List-Id:Cc:To:From:Subject:Message-ID :References:Mime-Version:In-Reply-To:Date:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=kpeIjzjgUksRfpZqkPpX2yoaUgHaMdnHZ225MRqWdPQ=; b=fSRs8MvBLlTva9 Z8nLSdynTpVNwlkNUWYGSSloRNgIVtEF97M/T8TEDzddAAUyz6PfRpeZjVjYjkTGDn0IPySa8Izmf QGnFF5mHLEI2H5mYl2imd7Rv4KU3epq6TxGQjS2363+httPGkxF+3KUgmvUyWo+P4q6SW/gElCRrw GLXu7WZsX8yVkh3AAUisn8gYmYlVww+4/2ohzip02JqMnYCjriutjgXveOLOt6Rrmbjx770PeisQt 5UbpH1Dpfdd1P4ERa5/nSyuBaZa2gV2lch4GrKRoyNOMqJlswGzByULJZlZ7wdDVcoHIX2vJRGm9F BBM96Bj6zL/i0Een270g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tmiTH-0000000FaKb-10LY; Tue, 25 Feb 2025 00:06:47 +0000 Received: from mail-pl1-x64a.google.com ([2607:f8b0:4864:20::64a]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tmiIn-0000000FY1L-1PGE for linux-riscv@lists.infradead.org; Mon, 24 Feb 2025 23:55:58 +0000 Received: by mail-pl1-x64a.google.com with SMTP id d9443c01a7336-220e62c4fc2so108951975ad.3 for ; Mon, 24 Feb 2025 15:55:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1740441356; x=1741046156; darn=lists.infradead.org; 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=TJTgZNhYY30nXxMYJRDXX1rx/rqsWdUW6nwlsEZr+Zo=; b=s/EKz2bmKg1x/EOX4H7mnARQb/HNhdfz2Clx6VAHIYBvMOFInSfPKZO62yu6Gi/OXT 8pKnKCgi7yk+L7mIkmAUENtj2hQvYXTp5PXjcfKoUs1qTqEcrCjPrktvoUFm1Sd6s4GX xkAMz5fkd8UXe19MxbGMO6n/o1sccehqi88yR0P+Vxo6le6VHO4w4w4hEcfqvhDa/qzN JDhIIGV4ekYTmeoBTcu1uTCGPb+Jw2kzETYBHiXsxgx1p0FXP1NwwxuQRqSxjzyAVo+y +5yeagx0x8UcTsSJ5lyMNO8pxmZwyXyHjwzfNerBllGmK+DhwNdL9T+NmBupkJc4IcOY /NqQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1740441356; x=1741046156; 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=TJTgZNhYY30nXxMYJRDXX1rx/rqsWdUW6nwlsEZr+Zo=; b=Gmax//LLSE+XsOCT41VLqvLTEKfwVV1LFamaeAxw9CfhXDGeIK5CKPumJud/W7mryn pNFUQPTAyxJdGocsBZvz+dxsYAB79pRtiiwjM/dp/5tKh7j6WJ//aJYVMPBMdsU646L3 gBn1ErnmPkPkrRhpjwdpysrQaw+ZCkL6lpr5VTMrun9vEdJMHfQNdqZdJA0DJpONxkkV Gx+6WsIJGRlA9D2Kg+kOkx5TU5/Qmcf2V76Q9MNh1BvLCaOHF1K74W41FSvsgNyeavw2 Cj4UtIf+ODy4zLuQK2dEEekHr/NYkvNCEtBWw2mA69XqLz1dmxUfF0TEgMXNE6KktjIu /tPA== X-Forwarded-Encrypted: i=1; AJvYcCVL8OMamN0+yQPcGO4eAxO7mNSGgVbiLtNGYgQ2FaTgFp6vdxWdGZR1/asETDNZoDTtVKXTAj/UB3E+qQ==@lists.infradead.org X-Gm-Message-State: AOJu0YwC7rIoRbt7WbRhZgaIXxs98SYFPV5tQKynQLDImedotUyvC4Wc lzTatXL0LuP/cOUHnwXxwBdVO20wuWij1enc5QOUZSAMUUU/U38XqMS7LtYsmMiUXc43S+pNnUL UCg== X-Google-Smtp-Source: AGHT+IHgthprmvsK7rAfh+PsqOM1pat7xQuGm72FmKpfdI+qTOt1cCxKN5aFSZszJT1EFJi9jy4pNoVXfJY= X-Received: from pfbig2.prod.google.com ([2002:a05:6a00:8b82:b0:730:7c03:35e1]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a00:1947:b0:732:623e:2bdc with SMTP id d2e1a72fcca58-73426c84885mr24369761b3a.2.1740441355733; Mon, 24 Feb 2025 15:55:55 -0800 (PST) Date: Mon, 24 Feb 2025 15:55:41 -0800 In-Reply-To: <20250224235542.2562848-1-seanjc@google.com> Mime-Version: 1.0 References: <20250224235542.2562848-1-seanjc@google.com> X-Mailer: git-send-email 2.48.1.658.g4767266eb4-goog Message-ID: <20250224235542.2562848-7-seanjc@google.com> Subject: [PATCH 6/7] KVM: x86: Fold guts of kvm_arch_sync_events() into kvm_arch_pre_destroy_vm() From: Sean Christopherson To: Marc Zyngier , Oliver Upton , Tianrui Zhao , Bibo Mao , Huacai Chen , Madhavan Srinivasan , Anup Patel , Paul Walmsley , Palmer Dabbelt , Albert Ou , Christian Borntraeger , Janosch Frank , Claudio Imbrenda , Sean Christopherson , Paolo Bonzini Cc: linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, kvm@vger.kernel.org, loongarch@lists.linux.dev, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, Aaron Lewis , Jim Mattson , Yan Zhao , Rick P Edgecombe , Kai Huang , Isaku Yamahata X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250224_155557_370990_DEF846E0 X-CRM114-Status: UNSURE ( 8.69 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Sean Christopherson Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org Fold the guts of kvm_arch_sync_events() into kvm_arch_pre_destroy_vm(), as the kvmclock and PIT background workers only need to be stopped before destroying vCPUs (to avoid accessing vCPUs as they are being freed); it's a-ok for them to be running while the VM is visible on the global vm_list. Note, the PIT also needs to be stopped before IRQ routing is freed (because KVM's IRQ routing is garbage and assumes there is always non-NULL routing). Opportunistically add comments to explain why KVM stops/frees certain assets early. Signed-off-by: Sean Christopherson --- arch/x86/kvm/x86.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index a61dbd1f0d01..ea445e6579f1 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -12772,9 +12772,7 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) void kvm_arch_sync_events(struct kvm *kvm) { - cancel_delayed_work_sync(&kvm->arch.kvmclock_sync_work); - cancel_delayed_work_sync(&kvm->arch.kvmclock_update_work); - kvm_free_pit(kvm); + } /** @@ -12855,6 +12853,17 @@ EXPORT_SYMBOL_GPL(__x86_set_memory_region); void kvm_arch_pre_destroy_vm(struct kvm *kvm) { + /* + * Stop all background workers and kthreads before destroying vCPUs, as + * iterating over vCPUs in a different task while vCPUs are being freed + * is unsafe, i.e. will lead to use-after-free. The PIT also needs to + * be stopped before IRQ routing is freed. + */ + cancel_delayed_work_sync(&kvm->arch.kvmclock_sync_work); + cancel_delayed_work_sync(&kvm->arch.kvmclock_update_work); + + kvm_free_pit(kvm); + kvm_mmu_pre_destroy_vm(kvm); }