From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=209.85.218.45 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792757800; b=ej8o2SVbs5hmnKS1lI8ZMkC44mNGI44X+WaLHFs0bvjM3r54ThGlKBUl/oWuiTpYKa4F kB9ri9N1bhKIoSfLX2xcBPRN7mkHJEaZlsZKfSZZORZi7rXGo3+rQlBM5yre0b/LZLlc6 KHXcXm7MByrvwQ5ZUFQ+2z9LcXUwtoFtu2bVfB0s7ilLBZfoZ6d5Ol+uvIT0+Ie8K2yK9 EGmvQ2QoQn16yssqajtd3rDVmW4Bev2BkI5tJ4obGtouE7w0s/sNinZLMtg50WzuI6EFA S0C30NaSYzDT75Fug2owyf0yeGsO5OoB5Ca/1iqlMerYaiP/KLXA7YcnyYzZVMQMW1g== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792757800; h=DMARC-Filter:Received:DKIM-Signature:X-Google-DKIM-Signature: X-Forwarded-Encrypted:X-Gm-Message-State:X-Gm-Gg:X-Received:Received: From:To:Cc:Subject:Date:Message-ID:X-Mailer:In-Reply-To:References: MIME-Version:Content-Transfer-Encoding; bh=pH7C+Ic+skXIiL+8yDLrJvoIJ/Xi8EZtJUFQlV0QBE0=; b=vMHebYO3AgdMo3e2mFcihcZVudb04A+T/NoBLKTGNzmT3kg3B763ZVk86O3qx/xF9NjP 1joNdePvhZ+znSj+Fnic2yZtMM35UVDuFzcoR93hdTpc+DYwtpfSfDd9X5RXvOIiBMCcd vJyJw37D+fFEav/68cYckvu9ezzSrjdRnEMqAtRI3s5FskoBeKAvEQrPpOHXpTFPWc9GF 8wurhKXofxcOG8B8TREBWmylLLJHVGmd3d6vd5IDo/uCI3LkB/54d1ykV0w3y3vA4MdwH u9j/47bPuC6Q6TQ25/lYzN4RannX5IdHvCS3yma6LA8VUKAibxGqTX/ohdvELeqO/8g== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20251104 header.b=KW995WiV; arc=none smtp.remote-ip=209.85.218.45 Received: from mail-ej1-f45.google.com (mail-ej1-f45.google.com [209.85.218.45]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B9FF7606A31B for ; Fri, 23 Oct 2026 12:16:39 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org B9FF7606A31B Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20251104 header.b=KW995WiV Received: by mail-ej1-f45.google.com with SMTP id a640c23a62f3a-c4322d310e7so122989666b.0 for ; Fri, 23 Oct 2026 05:16:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1792757798; x=1793362598; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=pH7C+Ic+skXIiL+8yDLrJvoIJ/Xi8EZtJUFQlV0QBE0=; b=KW995WiV+2FKvyP/wgDtPTisweGN15FcNyMcGyClqJusS2poI0hz2xccJKOyCiI8Pv MqChXnM36N3LKhLeA3IZ0Xk4pnF8RWFkyj8Q69NAruevjjSaB2ttKASmsWper5vSfGhD Jz55nnvno4+UoxIFirw6wrTT0NMXfzI0L1sUd9/cmYHESFmkqHBm0sTPd/Sq9yEv7JC8 8ZKUjFoprG35SN44ahrR4rNebW1k3645bCEZt+RAn4PufSpxNXeTdhzh32T8QTsaWlka twwdtrPXQaN7hhH/6wfANSkuq/zE28bvyJBU9X+tGSK0eSoVl7zYGk2/bhim0dny6MOx KiDA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1792757798; x=1793362598; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=pH7C+Ic+skXIiL+8yDLrJvoIJ/Xi8EZtJUFQlV0QBE0=; b=gaVyvZQlXdm5sL/Hw/wk9+jzoBITMOduXkrBptm7ZaUTnOwUiCwPf82EGAk8AlGJZ0 8787h6Lw2xeojDSXHRISlbTwel31ms81cqDNx+SNGMFtLqXmTDcuYNvvJ4nxPp1McOP3 HveXKMYXfO3naYeTiUqiuUE0VqVkLxPPCRcr7YS+y9EArpGNSThZ7oa8ToVTjhNgR+7q BPo+lI4mwtaxidrjzfl/re29A+2sF2HE64SbD/Y5buUc13dxL/t6HnO3Tw3jmfnwBZ+F jtAbIbQjA9P3sYjygmVCXQmxxIeUsnqyTSVcMqi56Nv0VfJ3C2XMpNvXtNUWyuSyv244 6dqw== X-Forwarded-Encrypted: i=1; AKwUvBxmXJPKf57b7RYnpRB5SEtCCMUU+2PtNKNuiySTJ76psB1Rrm4+DW62GU0J3WxAAWi9fVZmNng=@vger.kernel.org X-Gm-Message-State: AFq9FYI5TSCjnpvvh1MIbpy6OrtmC2LlzR+6BVr5pm9YmzPw3sD2h1Qe zUQgIG1JxlpIXB5Vbs+UVVpnO3dTz5doLm02EDhWsi3L51+wsQER1mQ4 X-Gm-Gg: AYBFou3D+gir1be3g4VgFK982bxaM30AanXsyZe4Rjoj0pJDWqhmD0lTTyl9ElUeYgE fOG3OufT3TwoVm9gRfYuVPNlvw7/2hLfSb/UZ6qRi0a8pD+LFUNSTMxySGAfzXOa+j0yUwq6hiP zAZmeioNCivswpunezZR6Mo2wDMSA/E/kbqR8rPWyJHcrsPTwg2um/yxxoX5oNbSofzQkWEQeRP 7CUOErAuE8HM/fx6RBWuV1sMow99UG6vA3vj4t5V/RvQRrospeWKU0tLLVb90zwpbRQrXP6Gf6m 4hlhkWmur4m9fBBVSHYB1iOW2J6cv/oAhIsFd4cKt2+BuvcIaQu6MxCXE4k7Mt8fgmS56SXz2WZ y+4xPfNkfyQ4BxA2OFkHvQQA645jIjkuxocR/n5GUBbPhDe4xNtjhK3qbNVCa7kc5HQpnlJX0TY brM4Aa85nG+3/D2hGhCSlE/Ay5APSlr7ldAVf/+qKEcNVP2ffZy2Izbm2nWQ3FvABmX4t3Sb2c0 nXvVzYm0DbuLrdH40sbewmetqdH8hwqna6cUbYKXQlju2+01Q== X-Received: by 2002:a17:907:9309:b0:c2e:63ba:1f90 with SMTP id a640c23a62f3a-c46a92d5849mr287640866b.48.1792757797774; Fri, 23 Oct 2026 05:16:37 -0700 (PDT) Received: from localhost ([2a03:2880:32ff:4f::]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-c46a5cf5540sm95824066b.78.2026.10.23.05.16.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 23 Oct 2026 05:16:37 -0700 (PDT) From: Vlad Poenaru To: Jinqian Yang , Thomas Gleixner , Marc Zyngier Cc: Lorenzo Pieralisi , Michael Chan , Pavan Chebbi , Jakub Kicinski , Breno Leitao , Andrew Preece , netdev@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, regressions@lists.linux.dev Subject: Re: [PATCH] irqchip/gic-v3-its: Enable dynamic MSI-X allocation Date: Fri, 23 Oct 2026 05:16:35 -0700 Message-ID: <20261023121635.2190639-1-vlad.wing@gmail.com> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261022193620.2152038-1-vlad.wing@gmail.com> References: <20261022193620.2152038-1-vlad.wing@gmail.com> X-Mailing-List: netdev@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Two updates on this report. First, a correction: it is not specific to our debug config. Our production config hits it as well, on every Grace + BCM57508 machine we tried, at the same point in boot. Second, the root cause is in bnxt_en, and this commit only exposes it. When the channel count is raised, bnxt_check_rings() allocates the extra MSI-X vectors before firmware has reserved them for the function. On BCM57508, writes to MSI-X table entries beyond the reserved IRQs don't stick, so the message written when the vectors are activated is lost, and the entries stay zero after the reservation. x86 never notices because GENERIC_IRQ_RESERVATION_MODE makes the PCI MSI domains MSI_FLAG_MUST_REACTIVATE and the message is written again at request_irq() time. With this commit, arm64 GICv3 takes the same dynamic path but writes the message only once, at allocation. Instrumenting the driver showed it directly. After the channel count went from 18 to 32, MSI-X entries 18-31 read back as all zero, while the cached msi_msg and the ITS LPI mapping were correct. Exactly the 14 rings on those vectors lost their completions. The fix is posted to netdev: https://lore.kernel.org/all/20261023121321.2127263-1-vlad.wing@gmail.com/ With it, the same machine runs cleanly through the channel change and the ring resize. I don't think the ITS change needs to be reverted. #regzbot monitor: https://lore.kernel.org/all/20261023121321.2127263-1-vlad.wing@gmail.com/ Thanks, Vlad