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 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 E8120C021B8 for ; Wed, 26 Feb 2025 18:40:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=Po4dipnmwfGs5ho6Uar/3eIBvd8Wea1v5VEnmsiU7UA=; b=0tWjD8LMgw0qE5A14q4q4N34qn auMzSSqAxpGZAXfVjYsUaKcdgNPhRS5CTRCQtLpEAW7uA7C6HzBId7xHWQYxCdlpcM5lPugWKUAGC Su4Uk2CR5EgVOPwCy/ySGOHk9K8jmY8Yowub17jWHQRsyJDm0No6kMSD022a4pVVr4BAJVKFdwR+x yBScz5MjzTiNJoqH5b/j/gOLJTeVFhclBRbdURwJtcKzw5MEHLjkbFsPiuyhX0cXRgQJZyaR4g7yj AFHJfUFvvwSvGWnkylzdnExRY/Ec90R/IuK3TgZNzGkgLLR5wb9w6CJ6cz1qGj1PmYM6WEbOAFQhJ a0mHWKAQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tnMKI-00000004zCw-3ZpS; Wed, 26 Feb 2025 18:40:10 +0000 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tnMIk-00000004yu8-0N4k for linux-arm-kernel@lists.infradead.org; Wed, 26 Feb 2025 18:38:35 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1740595113; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=Po4dipnmwfGs5ho6Uar/3eIBvd8Wea1v5VEnmsiU7UA=; b=GosU4Ei3WXlSDR8RMr8yh+LUCsf9Ur77lNAwH3tp1ksChhTahazwmUy4HYa/r9wXjZSpCM +XWGkFxjGw8vlb4F6dymDJdkc5AkP0UaJ1PZpxmOg2X2g4TZNoIG9xWuURQy5RNtFGYVMI sAzLKE2F7FJKtm2hGr0gTD92DtRWATw= Received: from mail-ej1-f69.google.com (mail-ej1-f69.google.com [209.85.218.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-479-Zb_Fo3NuNvWBlEeECxqpsg-1; Wed, 26 Feb 2025 13:38:31 -0500 X-MC-Unique: Zb_Fo3NuNvWBlEeECxqpsg-1 X-Mimecast-MFC-AGG-ID: Zb_Fo3NuNvWBlEeECxqpsg_1740595110 Received: by mail-ej1-f69.google.com with SMTP id a640c23a62f3a-abb9d1c8113so7345666b.0 for ; Wed, 26 Feb 2025 10:38:30 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1740595109; x=1741199909; h=content-transfer-encoding:in-reply-to:autocrypt:content-language :from:references:cc:to:subject:user-agent:mime-version:date :message-id:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=Po4dipnmwfGs5ho6Uar/3eIBvd8Wea1v5VEnmsiU7UA=; b=gknYcyTs9B2DI5S/n6qDnETyrZhyUG1xGYf1u8ft4SRtqAdpUrSHH01znDYrSFTilX g/0oo+L3kwmsfSi1dtYmlMHjRFU/O7Kh2W3Q8U4ljDEpnb7rX7nhyUj7eWaGNGkT/eAU Vx/qDdRTf/BBLpgJHuzigXhSbafWQP5Vfgdz3QN6K+jB0/C4YOaYJxWVMXhfV5NQt4rk hUb82FgJe/FONW/a7sk6lObYI+5pnQ0p+NRwQHXmV1lVGr9cadjWWpMOfEVZrOkp8VVA amqb9zy0kmHW2zhPKHzWapAgf90s/niqd/r+7kjXz8eALOspdMaicX5WhbNz2g9oUFT4 ZvyA== X-Gm-Message-State: AOJu0YzzS7RSkf0oElzRzaZx0lfShuoKFX5Fu+D5E1f0w9b1/GAhUhqb VPkjGCnBqXOyHdxgF0Pyb3E/0mrUKTikPk9ZLxbU01WW748DdudmeacBc6CM76xQVqh/eUTA6ab SQnQyN2Z9ApzmYfxZnoDeI8rYXLwx+3TsCis5Jxon5WLyfeI8V0wi8M4VbHzRMujPW9v2S7vW X-Gm-Gg: ASbGnctKN4K5HaQFbxDtLnfuqCCnx9HgUU6KQ8FOcKXoVWMzPrO02FHjX3tDaSsyTiJ s0XztXLnNhnNVdK3/acv7UyqSAwduqPlnqp+pYgCJ55JAqT00ufAGf1saVJaaSFEDn6CTPx3YDU BlKSJMxf4qROIGX+oUx4GYpiXV0xl9TE3dCSXjGo/UJjrRShY0841RjR6XkYbYCGJM/bv3QjZA1 F7l83HrFKPqno/233tQfro3wBpxo/yVnSYAWQjd+hKWQe4n8QRfshNBP5J+w1HMrfDWyuxGdJTm bOpSvjvy1kHgl2SG0cLD X-Received: by 2002:a17:906:6185:b0:ab7:c1d5:14f9 with SMTP id a640c23a62f3a-abeeecf6f63mr518735466b.10.1740595109600; Wed, 26 Feb 2025 10:38:29 -0800 (PST) X-Google-Smtp-Source: AGHT+IGCDnvlNLlcOiBeBNB6S3TtqOxMTUK/PR46JW7lLq0KgREP2FusBvOHa60dTZ6MWayPAjFhrw== X-Received: by 2002:a17:906:6185:b0:ab7:c1d5:14f9 with SMTP id a640c23a62f3a-abeeecf6f63mr518730666b.10.1740595109199; Wed, 26 Feb 2025 10:38:29 -0800 (PST) Received: from [192.168.10.81] ([176.206.102.52]) by smtp.googlemail.com with ESMTPSA id a640c23a62f3a-abed20ac11bsm364226166b.163.2025.02.26.10.38.23 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 26 Feb 2025 10:38:28 -0800 (PST) Message-ID: Date: Wed, 26 Feb 2025 19:38:21 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 0/7] KVM: x86: nVMX IRQ fix and VM teardown cleanups To: Sean Christopherson , 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 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 References: <20250224235542.2562848-1-seanjc@google.com> From: Paolo Bonzini Autocrypt: addr=pbonzini@redhat.com; keydata= xsEhBFRCcBIBDqDGsz4K0zZun3jh+U6Z9wNGLKQ0kSFyjN38gMqU1SfP+TUNQepFHb/Gc0E2 CxXPkIBTvYY+ZPkoTh5xF9oS1jqI8iRLzouzF8yXs3QjQIZ2SfuCxSVwlV65jotcjD2FTN04 hVopm9llFijNZpVIOGUTqzM4U55sdsCcZUluWM6x4HSOdw5F5Utxfp1wOjD/v92Lrax0hjiX DResHSt48q+8FrZzY+AUbkUS+Jm34qjswdrgsC5uxeVcLkBgWLmov2kMaMROT0YmFY6A3m1S P/kXmHDXxhe23gKb3dgwxUTpENDBGcfEzrzilWueOeUWiOcWuFOed/C3SyijBx3Av/lbCsHU Vx6pMycNTdzU1BuAroB+Y3mNEuW56Yd44jlInzG2UOwt9XjjdKkJZ1g0P9dwptwLEgTEd3Fo UdhAQyRXGYO8oROiuh+RZ1lXp6AQ4ZjoyH8WLfTLf5g1EKCTc4C1sy1vQSdzIRu3rBIjAvnC tGZADei1IExLqB3uzXKzZ1BZ+Z8hnt2og9hb7H0y8diYfEk2w3R7wEr+Ehk5NQsT2MPI2QBd wEv1/Aj1DgUHZAHzG1QN9S8wNWQ6K9DqHZTBnI1hUlkp22zCSHK/6FwUCuYp1zcAEQEAAc0j UGFvbG8gQm9uemluaSA8cGJvbnppbmlAcmVkaGF0LmNvbT7CwU0EEwECACMFAlRCcBICGwMH 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 bQ4tlFFuVjArBZcapSIe6NV8C4cEiSTOwE0EVEJx7gEIAMeHcVzuv2bp9HlWDp6+RkZe+vtl KwAHplb/WH59j2wyG8V6i33+6MlSSJMOFnYUCCL77bucx9uImI5nX24PIlqT+zasVEEVGSRF m8dgkcJDB7Tps0IkNrUi4yof3B3shR+vMY3i3Ip0e41zKx0CvlAhMOo6otaHmcxr35sWq1Jk tLkbn3wG+fPQCVudJJECvVQ//UAthSSEklA50QtD2sBkmQ14ZryEyTHQ+E42K3j2IUmOLriF dNr9NvE1QGmGyIcbw2NIVEBOK/GWxkS5+dmxM2iD4Jdaf2nSn3jlHjEXoPwpMs0KZsgdU0pP JQzMUMwmB1wM8JxovFlPYrhNT9MAEQEAAcLBMwQYAQIACQUCVEJx7gIbDAAKCRB+FRAMzTZp sadRDqCctLmYICZu4GSnie4lKXl+HqlLanpVMOoFNnWs9oRP47MbE2wv8OaYh5pNR9VVgyhD OG0AU7oidG36OeUlrFDTfnPYYSF/mPCxHttosyt8O5kabxnIPv2URuAxDByz+iVbL+RjKaGM GDph56ZTswlx75nZVtIukqzLAQ5fa8OALSGum0cFi4ptZUOhDNz1onz61klD6z3MODi0sBZN Aj6guB2L/+2ZwElZEeRBERRd/uommlYuToAXfNRdUwrwl9gRMiA0WSyTb190zneRRDfpSK5d usXnM/O+kr3Dm+Ui+UioPf6wgbn3T0o6I5BhVhs4h4hWmIW7iNhPjX1iybXfmb1gAFfjtHfL xRUr64svXpyfJMScIQtBAm0ihWPltXkyITA92ngCmPdHa6M1hMh4RDX+Jf1fiWubzp1voAg0 JBrdmNZSQDz0iKmSrx8xkoXYfA3bgtFN8WJH2xgFL28XnqY4M6dLhJwV3z08tPSRqYFm4NMP dRsn0/7oymhneL8RthIvjDDQ5ktUjMe8LtHr70OZE/TT88qvEdhiIVUogHdo4qBrk41+gGQh b906Dudw5YhTJFU3nC6bbF2nrLlB4C/XSiH76ZvqzV0Z/cAMBo5NF/w= In-Reply-To: <20250224235542.2562848-1-seanjc@google.com> X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: dyrllkNwU0QAce6kkmUsGE1p3WIrG4pCklLpBiI73co_1740595110 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250226_103834_193359_BE78DAB8 X-CRM114-Status: GOOD ( 14.36 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 2/25/25 00:55, Sean Christopherson wrote: > This was _supposed_ to be a tiny one-off patch to fix a nVMX bug where KVM > fails to detect that, after nested VM-Exit, L1 has a pending IRQ (or NMI). > But because x86's nested teardown flows are garbage (KVM simply forces a > nested VM-Exit to put the vCPU back into L1), that simple fix snowballed. > > The immediate issue is that checking for a pending interrupt accesses the > legacy PIC, and x86's kvm_arch_destroy_vm() currently frees the PIC before > destroying vCPUs, i.e. checking for IRQs during the forced nested VM-Exit > results in a NULL pointer deref (or use-after-free if KVM didn't nullify > the PIC pointer). That's patch 1. > > Patch 2 is the original nVMX fix. > > The remaining patches attempt to bring a bit of sanity to x86's VM > teardown code, which has accumulated a lot of cruft over the years. E.g. > KVM currently unloads each vCPU's MMUs in a separate operation from > destroying vCPUs, all because when guest SMP support was added, KVM had a > kludgy MMU teardown flow that broken when a VM had more than one 1 vCPU. > And that oddity lived on, for 18 years... Queued patches 1 and 2 to kvm/master, and everything to kvm/queue (pending a little more testing and the related TDX change). Paolo