From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f54.google.com (mail-wm1-f54.google.com [209.85.128.54]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7535849DB99 for ; Fri, 9 Oct 2026 09:35:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.54 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791538520; cv=none; b=bHsVPUmLvg15962a+llUaxEwrTwFt/3LZFOFVctKjaY1yGMt8gP84g3Wp31b/QgcAyXHcJhNvVmfUOAIOknJLkhrgnwyOk14W7rhgiGkPxpugNm/ph+A3g29s8Jxf6hdnIuvpY1BEpxmdjm8QZADLh/RZRF6799C8Rasm3HXaAg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791538520; c=relaxed/simple; bh=/c8N48QbtXgR/eVlCX4e1X5WhhCM4Hemay3LC9ggKPk=; h=From:Date:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=YRiE8P9NZR80i188JWnwwASTfrrGsNXuWMCZ7f2Ir3ueRJtVHgaaowaye0Bb6io634FbRVi6WAMOVj5N2qvZjVNXxpc1Q3ONHIvW2VsdrrBMyGO5yww0OKzSF8pQGaqQDYISzdWBadca8HbrDdUn89aNQSkq3HZ4Iv+ApFzpUjY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=cloudflare.com; spf=pass smtp.mailfrom=cloudflare.com; dkim=pass (2048-bit key) header.d=cloudflare.com header.i=@cloudflare.com header.b=IGkscjq0; arc=none smtp.client-ip=209.85.128.54 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=cloudflare.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=cloudflare.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=cloudflare.com header.i=@cloudflare.com header.b="IGkscjq0" Received: by mail-wm1-f54.google.com with SMTP id 5b1f17b1804b1-4a1698ea378so33385665e9.2 for ; Fri, 09 Oct 2026 02:35:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cloudflare.com; s=google09082023; t=1791538510; x=1792143310; darn=vger.kernel.org; h=in-reply-to:content-disposition:content-type:mime-version :references:message-id:subject:cc:to:date:from:from:to:cc:subject :date:message-id:reply-to:content-type; bh=oJvujCG6Ef+ooO87W/Kfsk5ax+KDA0Y6he4rHd/9/6A=; b=IGkscjq05/VuTlEGylZ0tPumx/YjRJcVe+CMB584AsxZF7ioC1ojWkI+S9bDCmadGN 3oHbrjxTnv7iiCyYtEoFv36uKFDLWC5Ks+aHaqgwKE7NMq8aNdlbkW7I9PVjdKAcJCO5 ReK9hv9QVku9rm58f0EwKFMEbK8X2oAlDHPNkPF7vRDBmeGt6Zbh7J+XfO2eckYsPNaB 9T8meJ1AHhfiYFU9krpj0FKQc14PKjPzu/LQZXmx4wEKBLh2H8DULILBuDmwiiqN1l7A Mty11O2KjiKdmio2QApQxZXaEabmYonTxMpNUx26my94LdaMV9AgwUYFMn3gZNcerf/O WdgA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1791538510; x=1792143310; h=in-reply-to:content-disposition:content-type:mime-version :references:message-id:subject:cc:to:date:from:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=oJvujCG6Ef+ooO87W/Kfsk5ax+KDA0Y6he4rHd/9/6A=; b=MAFWkxWyVsbIrQiNhGg9kWoH7dULSD7JNgL0QWtJAlBc/D4Qm5WuSvu1shf9hWSGN8 Obzv7PR/hh+5JIQykVpqy0AtI8M219458h9ISy4LdPQJYRsglXuHKxclZhdn3gLpJpDD raCDY/qg9vkd52e4OtOhk/WTfcPyrSnb0P+WzlMgiXAaUd73WEbVNct4EMjGA4a6tDkN IvbaDX9GQorxJDp/Y6tN/Ob6RO0s41ZZ12aYEXmOwFINR2mhqltguPZ602LPfvBqzPfU hPEoVZbPu5kFZzDR+NyKpzQD+1Wx50hCx1WSNSoIWdlkuu1JX/hiiP+vG7ywI7pvOt+n nGGQ== X-Forwarded-Encrypted: i=1; AKwUvBwSS1UPoTVqUbxCZFcjzpkgNOx8cEW7+B1INZLF1ZA5o+bZDFQhGEqFq8hMz5gEOK9hNn1tj7g=@vger.kernel.org X-Gm-Message-State: AFuF++nTySntV0koVUssa89P7guN0a1Ydmmz27+zIObVOtjw0M1rwwEO AgDFZJxhsGl0U/8ljz/43Qlle/8nXf8FEKL1JTW5cc8QPIMhNa5PUrhwEsXxR+i9XMY= X-Gm-Gg: AYBFou2FghBJU0z2oQggEvW+g4VPTRSWUigHsrz3uswPofLCrtlDgu1X7AnwwnYIVCA A0NdmPfjhmDEbX++M8Mm19+0Uc4VsSUH71OrUJdMBR80NKQI+ghc2X/KDLjKh/zA0d4tqh5eRWq 8xsB182H/tL2eqQuNVtv2PiAWUDZ7HTn2m59k5vfhP4oxxRWzua8LPfJEJtBkWtxgp4bJbEqkFc g1pVdB94Qeyfink3UVAP0dvRyG/qA52FsRYxU/n7EzexAIeJKdUltbIz50wEYQIE+Ho9xwHTqy+ si3qED//d4OtCxSh9YqOQBZLuzYRyYVN8fWftmh0k3Wu4dVrHcPdy3Z3jPl5GpgBWW0ea/3oouH 9kWbgYWRIBhm6yuDkj9zJmBepbG9i7Lkm/ClZZwdCiL8J/X59U8JJ11bUBm39ZR33pzOb74I5fA ji/hj1YiSFbx6qfhomBBkxEd6L2c7t9ruYiTezZsuxuAvMIU1NyOWSE38= X-Received: by 2002:a05:600c:4f10:b0:4a0:d1f4:b1d1 with SMTP id 5b1f17b1804b1-4a18e4bff89mr26548565e9.24.1791538510535; Fri, 09 Oct 2026 02:35:10 -0700 (PDT) Received: from localhost ([2a09:bac6:37a8:2696::3d8:4]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4a18bea1021sm43339765e9.10.2026.10.09.02.35.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 09 Oct 2026 02:35:10 -0700 (PDT) From: Matt Fleming X-Google-Original-From: Matt Fleming Date: Fri, 9 Oct 2026 10:35:09 +0100 To: Joerg Roedel Cc: Suravee Suthikulpanit , Ashish Kalra , Vasant Hegde , Sairaj Kodilkar , Baoquan He , iommu@lists.linux.dev, linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@cloudflare.com Subject: Re: [PATCH 0/2] iommu/amd: Fix device table setup in kdump kernels Message-ID: References: <20261002133143.3628181-1-matt@readmodwrite.com> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261002133143.3628181-1-matt@readmodwrite.com> On Fri, Oct 02, 2026 at 02:31:41PM +0100, Matt Fleming wrote: > From: Matt Fleming > > An AMD kdump kernel booted with crashkernel=512M,high and > crashkernel=0,low fails to allocate its device table because there's no > memory below 4G. IOMMU init fails and, on our systems with an Intel > E810 NIC, the ice driver's TX queues time out, so the dump never gets > sent. > > Since commit 38e5f33ee359 ("iommu/amd: Reuse device table for kdump"), a > kdump kernel normally reuses the previous kernel's table. Patch 1 > programs the new table if reuse fails. Patch 2 drops GFP_DMA32 for > kdump kernels. Normal kernels still allocate below 4G, because that's > what the kdump kernel checks before reusing the table. > > On an AMD EPYC system with an E810 NIC, the kdump kernel without these > patches failed the order-9 GFP_DMA32 allocation and its TX queues timed > out. With these patches, the kdump kernel reused the old device table > and the dump was written over the network. > > Matt Fleming (2): > iommu/amd: Program device table when kdump reuse fails > iommu/amd: Don't allocate kdump device table from DMA32 > > drivers/iommu/amd/init.c | 23 ++++++++++++++++++++--- > 1 file changed, 20 insertions(+), 3 deletions(-) Hey Joerg, I know it was Plumbers and ksummit this week, but have you had chance to look at these two patches? Thanks, Matt