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 lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (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 29003D15DA5 for ; Mon, 21 Oct 2024 15:09:07 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.823660.1237688 (Exim 4.92) (envelope-from ) id 1t2u1e-0006Vy-Oe; Mon, 21 Oct 2024 15:08:54 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 823660.1237688; Mon, 21 Oct 2024 15:08:54 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1t2u1e-0006Vr-M4; Mon, 21 Oct 2024 15:08:54 +0000 Received: by outflank-mailman (input) for mailman id 823660; Mon, 21 Oct 2024 15:08:53 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1t2u1c-0006Vh-Up for xen-devel@lists.xenproject.org; Mon, 21 Oct 2024 15:08:52 +0000 Received: from mail-ej1-x62a.google.com (mail-ej1-x62a.google.com [2a00:1450:4864:20::62a]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id 613ee9cb-8fbe-11ef-99a3-01e77a169b0f; Mon, 21 Oct 2024 17:08:51 +0200 (CEST) Received: by mail-ej1-x62a.google.com with SMTP id a640c23a62f3a-a7aa086b077so533322666b.0 for ; Mon, 21 Oct 2024 08:08:51 -0700 (PDT) Received: from [10.125.226.166] ([185.25.67.249]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-a9a9155a1c9sm212970066b.129.2024.10.21.08.08.49 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 21 Oct 2024 08:08:50 -0700 (PDT) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 613ee9cb-8fbe-11ef-99a3-01e77a169b0f DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=citrix.com; s=google; t=1729523330; x=1730128130; darn=lists.xenproject.org; h=content-transfer-encoding:in-reply-to:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:from:to:cc:subject:date:message-id:reply-to; bh=E5ZZ1ZGwLNfx5yh4T1bZZfcgIUaSUikY7n52pslz2Y8=; b=TfrflGPddnkA2k+eUPLSj3bgj6mktjzkWk8HlTh49UdOwDL8FNfMuZcHBgh8+Vj9C2 rP8zFUtleg3rqRoDTQlYDyBZMZwgESj1zHF3hfkYlGr50ZQrK35WXbAFmQ/1tar0vVFZ f53bftP9qCQfhxBQlA6tBl7PtDen1eQ8EcX/Q= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1729523330; x=1730128130; h=content-transfer-encoding:in-reply-to:autocrypt:from :content-language: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=E5ZZ1ZGwLNfx5yh4T1bZZfcgIUaSUikY7n52pslz2Y8=; b=tqDfgulnGLRhXqUDCEg8jluxwHbAmFUvvzc2O95LrjjJpkZMuyvlPfNmXwV5VaWQV9 vFSj4YMoONnyWPgDuFQaknmSF48hMW7aIth84xtnW2EJj+9lIqNbWjbn8sL5w4MCuUK3 Q0doJokzBwZPDfFrlrGsWpFhkXxVqJmDsWLK3mfA8BbzpGHPHd6WB2XI6Diu5giWrqhH RA0Lat8UcRlWz3rMfi47BbcMKNO53ljsxPtTE2HWfy5Kvtdp/sqrN+BlUCSeN0zhP8MO Znck02U6tY5/Rm8B1kRXlitejH759juBEBPbbZR6oxitLlLe/6Dcooju5yEhCXlzzMed aXAQ== X-Gm-Message-State: AOJu0YzyPEQeajXY5gx7hD78ZPuigSS/A8AKh84ulRx9feBXb60TlhPf sZZ6DkyLecIrMlkLdeXHyWJ6tJc+tG9WWSP27DRK2VG1WmhUpK4pkXkyWIQA6+w= X-Google-Smtp-Source: AGHT+IGuzF+pfvTHUY9k+H0C++iUwOl+kj7Czq0vqGssig8KcYLa7nR+bErcQZZdDkTMI0BsWrxX5A== X-Received: by 2002:a17:907:9450:b0:a9a:139:5ef3 with SMTP id a640c23a62f3a-a9aa8a41db6mr30109566b.55.1729523330538; Mon, 21 Oct 2024 08:08:50 -0700 (PDT) Message-ID: Date: Mon, 21 Oct 2024 16:08:48 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] x86/io-apic: fix directed EOI when using AMd-Vi interrupt remapping To: Alejandro Vallejo , =?UTF-8?Q?Roger_Pau_Monn=C3=A9?= , David Woodhouse Cc: xen-devel@lists.xenproject.org, Jan Beulich , Willi Junga References: <20241018080813.45759-1-roger.pau@citrix.com> <10e0f567ab3be0eae4c6473326da3a6d369ba8ff.camel@infradead.org> <5970c852-8800-414a-83f9-66392bdbe016@citrix.com> Content-Language: en-GB From: Andrew Cooper Autocrypt: addr=andrew.cooper3@citrix.com; keydata= xsFNBFLhNn8BEADVhE+Hb8i0GV6mihnnr/uiQQdPF8kUoFzCOPXkf7jQ5sLYeJa0cQi6Penp VtiFYznTairnVsN5J+ujSTIb+OlMSJUWV4opS7WVNnxHbFTPYZVQ3erv7NKc2iVizCRZ2Kxn srM1oPXWRic8BIAdYOKOloF2300SL/bIpeD+x7h3w9B/qez7nOin5NzkxgFoaUeIal12pXSR Q354FKFoy6Vh96gc4VRqte3jw8mPuJQpfws+Pb+swvSf/i1q1+1I4jsRQQh2m6OTADHIqg2E ofTYAEh7R5HfPx0EXoEDMdRjOeKn8+vvkAwhviWXTHlG3R1QkbE5M/oywnZ83udJmi+lxjJ5 YhQ5IzomvJ16H0Bq+TLyVLO/VRksp1VR9HxCzItLNCS8PdpYYz5TC204ViycobYU65WMpzWe LFAGn8jSS25XIpqv0Y9k87dLbctKKA14Ifw2kq5OIVu2FuX+3i446JOa2vpCI9GcjCzi3oHV e00bzYiHMIl0FICrNJU0Kjho8pdo0m2uxkn6SYEpogAy9pnatUlO+erL4LqFUO7GXSdBRbw5 gNt25XTLdSFuZtMxkY3tq8MFss5QnjhehCVPEpE6y9ZjI4XB8ad1G4oBHVGK5LMsvg22PfMJ ISWFSHoF/B5+lHkCKWkFxZ0gZn33ju5n6/FOdEx4B8cMJt+cWwARAQABzSlBbmRyZXcgQ29v cGVyIDxhbmRyZXcuY29vcGVyM0BjaXRyaXguY29tPsLBegQTAQgAJAIbAwULCQgHAwUVCgkI CwUWAgMBAAIeAQIXgAUCWKD95wIZAQAKCRBlw/kGpdefoHbdD/9AIoR3k6fKl+RFiFpyAhvO 59ttDFI7nIAnlYngev2XUR3acFElJATHSDO0ju+hqWqAb8kVijXLops0gOfqt3VPZq9cuHlh IMDquatGLzAadfFx2eQYIYT+FYuMoPZy/aTUazmJIDVxP7L383grjIkn+7tAv+qeDfE+txL4 SAm1UHNvmdfgL2/lcmL3xRh7sub3nJilM93RWX1Pe5LBSDXO45uzCGEdst6uSlzYR/MEr+5Z JQQ32JV64zwvf/aKaagSQSQMYNX9JFgfZ3TKWC1KJQbX5ssoX/5hNLqxMcZV3TN7kU8I3kjK mPec9+1nECOjjJSO/h4P0sBZyIUGfguwzhEeGf4sMCuSEM4xjCnwiBwftR17sr0spYcOpqET ZGcAmyYcNjy6CYadNCnfR40vhhWuCfNCBzWnUW0lFoo12wb0YnzoOLjvfD6OL3JjIUJNOmJy RCsJ5IA/Iz33RhSVRmROu+TztwuThClw63g7+hoyewv7BemKyuU6FTVhjjW+XUWmS/FzknSi dAG+insr0746cTPpSkGl3KAXeWDGJzve7/SBBfyznWCMGaf8E2P1oOdIZRxHgWj0zNr1+ooF /PzgLPiCI4OMUttTlEKChgbUTQ+5o0P080JojqfXwbPAyumbaYcQNiH1/xYbJdOFSiBv9rpt TQTBLzDKXok86M7BTQRS4TZ/ARAAkgqudHsp+hd82UVkvgnlqZjzz2vyrYfz7bkPtXaGb9H4 Rfo7mQsEQavEBdWWjbga6eMnDqtu+FC+qeTGYebToxEyp2lKDSoAsvt8w82tIlP/EbmRbDVn 7bhjBlfRcFjVYw8uVDPptT0TV47vpoCVkTwcyb6OltJrvg/QzV9f07DJswuda1JH3/qvYu0p vjPnYvCq4NsqY2XSdAJ02HrdYPFtNyPEntu1n1KK+gJrstjtw7KsZ4ygXYrsm/oCBiVW/OgU g/XIlGErkrxe4vQvJyVwg6YH653YTX5hLLUEL1NS4TCo47RP+wi6y+TnuAL36UtK/uFyEuPy wwrDVcC4cIFhYSfsO0BumEI65yu7a8aHbGfq2lW251UcoU48Z27ZUUZd2Dr6O/n8poQHbaTd 6bJJSjzGGHZVbRP9UQ3lkmkmc0+XCHmj5WhwNNYjgbbmML7y0fsJT5RgvefAIFfHBg7fTY/i kBEimoUsTEQz+N4hbKwo1hULfVxDJStE4sbPhjbsPCrlXf6W9CxSyQ0qmZ2bXsLQYRj2xqd1 bpA+1o1j2N4/au1R/uSiUFjewJdT/LX1EklKDcQwpk06Af/N7VZtSfEJeRV04unbsKVXWZAk uAJyDDKN99ziC0Wz5kcPyVD1HNf8bgaqGDzrv3TfYjwqayRFcMf7xJaL9xXedMcAEQEAAcLB XwQYAQgACQUCUuE2fwIbDAAKCRBlw/kGpdefoG4XEACD1Qf/er8EA7g23HMxYWd3FXHThrVQ HgiGdk5Yh632vjOm9L4sd/GCEACVQKjsu98e8o3ysitFlznEns5EAAXEbITrgKWXDDUWGYxd pnjj2u+GkVdsOAGk0kxczX6s+VRBhpbBI2PWnOsRJgU2n10PZ3mZD4Xu9kU2IXYmuW+e5KCA vTArRUdCrAtIa1k01sPipPPw6dfxx2e5asy21YOytzxuWFfJTGnVxZZSCyLUO83sh6OZhJkk b9rxL9wPmpN/t2IPaEKoAc0FTQZS36wAMOXkBh24PQ9gaLJvfPKpNzGD8XWR5HHF0NLIJhgg 4ZlEXQ2fVp3XrtocHqhu4UZR4koCijgB8sB7Tb0GCpwK+C4UePdFLfhKyRdSXuvY3AHJd4CP 4JzW0Bzq/WXY3XMOzUTYApGQpnUpdOmuQSfpV9MQO+/jo7r6yPbxT7CwRS5dcQPzUiuHLK9i nvjREdh84qycnx0/6dDroYhp0DFv4udxuAvt1h4wGwTPRQZerSm4xaYegEFusyhbZrI0U9tJ B8WrhBLXDiYlyJT6zOV2yZFuW47VrLsjYnHwn27hmxTC/7tvG3euCklmkn9Sl9IAKFu29RSo d5bD8kMSCYsTqtTfT6W4A3qHGvIDta3ptLYpIAOD2sY3GYq2nf3Bbzx81wZK14JdDDHUX2Rs 6+ahAA== In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 21/10/2024 4:03 pm, Alejandro Vallejo wrote: > On Mon Oct 21, 2024 at 3:51 PM BST, Andrew Cooper wrote: >> On 21/10/2024 3:06 pm, Roger Pau Monné wrote: >>> On Mon, Oct 21, 2024 at 12:34:37PM +0100, David Woodhouse wrote: >>>> On Fri, 2024-10-18 at 10:08 +0200, Roger Pau Monne wrote: >>>>> When using AMD-VI interrupt remapping the vector field in the IO-APIC RTE is >>>>> repurposed to contain part of the offset into the remapping table.  Previous to >>>>> 2ca9fbd739b8 Xen had logic so that the offset into the interrupt remapping >>>>> table would match the vector.  Such logic was mandatory for end of interrupt to >>>>> work, since the vector field (even when not containing a vector) is used by the >>>>> IO-APIC to find for which pin the EOI must be performed. >>>>> >>>>> Introduce a table to store the EOI handlers when using interrupt remapping, so >>>>> that the IO-APIC driver can translate pins into EOI handlers without having to >>>>> read the IO-APIC RTE entry.  Note that to simplify the logic such table is used >>>>> unconditionally when interrupt remapping is enabled, even if strictly it would >>>>> only be required for AMD-Vi. >>>>> >>>>> Reported-by: Willi Junga >>>>> Suggested-by: David Woodhouse >>>>> Fixes: 2ca9fbd739b8 ('AMD IOMMU: allocate IRTE entries instead of using a static mapping') >>>>> Signed-off-by: Roger Pau Monné >>>> Hm, couldn't we just have used the pin#? >>> Yes, but that would require a much bigger change that what's currently >>> presented here, and for backport purposes I think it's better done >>> this way for fixing this specific bug. >>> >>> Changing to use pin# as the IR offset is worthwhile, but IMO needs to >>> be done separated from the bugfix here. >>> >>>> The AMD IOMMU has per-device IRTE, so you *know* you can just use IRTE >>>> indices 0-23 for the I/O APIC pins. >>> Aren't there IO-APICs with more than 24 pins? >> Recent Intel SoCs have a single IO-APIC with 120 pins. >> >> ~Andrew > I can't say I understand why though. > > In practice you have the legacy ISA IRQs and the 4 legacy PCI INTx. If you have > a weird enough system you might have more than one PCIe bus, but even that fits > more than nicely in 24 "pins". Does ACPI give more than 4 IRQs these days after > an adequate blood sacrifice to the gods of AML? There's a whole bunch of pins for misc non-PCI(e) things, including plain GPIO lines. ~Andrew