From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F2CE83D47A5; Thu, 15 Oct 2026 22:36:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792103814; cv=none; b=HSkqBPLSm8cuv9iqrug/4JcQ7he0D1K2r71EFmIIJidGXdx228sISrSAlyPn2RsPKWOgxwX/34vQ3EViUCZ1FIbcqGM53EsykELm1JlsVZIC8aNo1TYtNgoUkxb2Oaouw4e2b5AKaeIjXmjz2l41xzw4se1MO1PUKyjzSnYzxIA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792103814; c=relaxed/simple; bh=UvrediL3+glf+ZUnb7Hsv9YP2T7349slM7Ohgj8ctow=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=PYyFlP3OREHh0xNGBxS4sqKuWx6ouKXThsehUMPjtfFYYM/vJ5z+wsDYfD2ljX6tYu4SDbQhwoZF8ml1pThn1pwEME+0tKqcjPw41S8A6tNBfZS8zPXEUc2OGqEws3xb0lOYi0ci+5jrl30YKS1fQt+1GZ75WNdQeVBVcFl1wMw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=YwhwpnEH; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="YwhwpnEH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A7DDB1F000C4; Thu, 15 Oct 2026 22:36:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792103812; bh=UvrediL3+glf+ZUnb7Hsv9YP2T7349slM7Ohgj8ctow=; h=From:To:Cc:Subject:In-Reply-To:References:Date; b=YwhwpnEH00xhAOV/iRPgwBMT6Nl8PjM/y9nn/3iS4wy/lA0zwCoXN530gexuEQDnG LhGq7VCaFMXQMmLMVynH1KqKhV11e+ESm8OdpN3gLuXShXRM98r6hZolIke0tClgna t5tU6beBa4jMEV4trd6DEu8Wzvva9de5dBIjnzJ5Cjxhw8WOvPwiGlnnY6IKLqOdF5 +cpk3x2lOKgloe3pfmnhhMmXTNKNPL9LhoQu1OgJVVEKC48CE4XRrgSWY4rNW7Cw5W mBH8wSpGemI4s2sbqqjcH8ptWQ98bXW8mLJhR/TbJMyL5G+QtFR9LUxq3o/JnmXr9R bwztX8o6f8qyg== From: Thomas Gleixner To: Naman Jain , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H . Peter Anvin" , Wei Liu , "K . Y . Srinivasan" , Haiyang Zhang , Dexuan Cui , Michael Kelley Cc: Long Li , Nam Cao , Joerg Roedel , Suravee Suthikulpanit , Vasant Hegde , Will Deacon , Robin Murphy , Lorenzo Pieralisi , Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= , Manivannan Sadhasivam , Rob Herring , Bjorn Helgaas , Kees Cook , "Rafael J . Wysocki" , Radu Rendec , Sean Christopherson , Kai Huang , Dmitry Ilvokhin , Shradha Gupta , Christophe JAILLET , Thierry Reding , Jiri Wiesner , Daniel J Blueman , linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, iommu@lists.linux.dev, linux-pci@vger.kernel.org Subject: Re: [PATCH v6 0/4] x86/irq: Fix lost interrupts on CPU hot-unplug In-Reply-To: <20260923043023.3150498-1-namjain@linux.microsoft.com> References: <20260923043023.3150498-1-namjain@linux.microsoft.com> Date: Fri, 16 Oct 2026 00:36:49 +0200 Message-ID: <87ecdqd20u.ffs@fw13> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain On Wed, Sep 23 2026 at 04:30, Naman Jain wrote: > On CPU hot-unplug, fixup_irqs() re-injects interrupts that are still > pending in the outgoing CPU's IRR via the irqchip's irq_retrigger() > callback. The Hyper-V root partition PCI/MSI irqchip lost that callback > when it was converted to msi_create_parent_irq_domain(), so such a > pending interrupt is silently dropped, leading to lost interrupts, stalls > and "No irq handler for vector" messages. > > Patch 1 is the minimal, backportable fix (Fixes:/Cc: stable) that restores > irq_chip_retrigger_hierarchy() on the Hyper-V root partition PCI/MSI chip. > The equivalent guest pci-hyperv.c fix from the previous version is already > merged, so it is dropped here. > > Patch 2 then switches fixup_irqs() to call irq_chip_retrigger_hierarchy() > directly which ensures that this issue does not occur for chips that > miss adding this initialization. > > Patch 3 makes a similar change in msi_set_affinity() > > Patch 4 then drops the now-redundant irq_retrigger() initializations. > This way, patch 2-4 do not need to be backported. Reviewed-by: Thomas Gleixner