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 A6C5E37F8D7; Sat, 12 Sep 2026 19:33:54 +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=1789241635; cv=none; b=MOZt9mjH/k5m8q3tiyatELGYiFlL2tUlpaXmbYy7hfGW/zvSd9Yb6Nl8V2vq8CimnZp0b4sRe5CItZJbChhmcqP9r/5ThZyVjCkWlW/wPOmHYfZix6jWdsQ5nI6b0fC+3/AXPXsQTHU8m78G0bmqmcKd8ezvtu297bIqtbUYl/Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789241635; c=relaxed/simple; bh=WSTPgp/8VWm4JromrdtcGVvLXoOmomacCsxLRd/57iI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=MnKZleBQSBZFxD0DK1LgbnRzBMPvbOMrxtBxIxiAbocfZ1/o+sdv/mtFRyMZbaSgrpEK/pOipYYIkhD6cI9Yz29s5I88wtOJYAvavRg7UEpisryORIYjQiyiD0KFvtNKGJJD+4nhYEh64fueIVsS8EgHWvpDdyaQviRZZrQR+oA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=JuOLVhJA; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="JuOLVhJA" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AEDA81F000FF; Sat, 12 Sep 2026 19:33:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789241634; bh=6485rFL7Hgz3KllOUhlbIlkbqHoHf55vUTQ7ToiAbzM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=JuOLVhJAeB2TIJiZntpTMEE5frysViMCs/2OHXasoSitaD5v4PNluTxx+Ya90n3aj 6Xyd279ocU2JrAMRgypC4N9H8IUOWIZIuC8BFH5uYBnLyV5NmKslu/9bCQnoixAuds aYB2mfy1odoChbLFEfgb+zLAPRY/Fz70fi2T7zu8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Long Li , Thomas Gleixner , Aditya Garg , Shradha Gupta , Naman Jain , Michael Kelley , Wei Liu , Sasha Levin Subject: [PATCH 5.10 176/798] PCI: hv: Set irq_retrigger callback for the Hyper-V PCI MSI irqchip Date: Sat, 12 Sep 2026 08:56:44 +0200 Message-ID: <20260912065521.053595436@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065516.948645775@linuxfoundation.org> References: <20260912065516.948645775@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Naman Jain [ Upstream commit 86bdd16e8f390d51bae9e77a4bc4164ca2f580fe ] The Hyper-V vPCI MSI irqchip never installs an irq_retrigger() callback. On CPU hot-unplug fixup_irqs() migrates the interrupts which are affine to the outgoing CPU to a new target. If an interrupt still has its pending bit set in the outgoing CPU's IRR at that point, fixup_irqs() resends it on the new target through the irqchip's irq_retrigger() callback. As the Hyper-V PCI/MSI chip does not provide that callback, the pending interrupt is silently dropped, which can result in lost interrupts, stalls and "No irq handler for vector" messages during CPU hotplug. Install irq_chip_retrigger_hierarchy() as the irq_retrigger() callback for the Hyper-V PCI/MSI irqchip, so that a pending interrupt is resent on its new target CPU via the parent x86 vector domain. Fixes: 4daace0d8ce85 ("PCI: hv: Add paravirtual PCI front-end for Microsoft Hyper-V VMs") Cc: stable@vger.kernel.org Suggested-by: Long Li Suggested-by: Thomas Gleixner Reviewed-by: Aditya Garg Reviewed-by: Shradha Gupta Signed-off-by: Naman Jain Reviewed-by: Michael Kelley Signed-off-by: Wei Liu Signed-off-by: Sasha Levin --- drivers/pci/controller/pci-hyperv.c | 1 + 1 file changed, 1 insertion(+) --- a/drivers/pci/controller/pci-hyperv.c +++ b/drivers/pci/controller/pci-hyperv.c @@ -1595,6 +1595,7 @@ static struct irq_chip hv_msi_irq_chip = .irq_compose_msi_msg = hv_compose_msi_msg, .irq_set_affinity = hv_set_affinity, .irq_ack = irq_chip_ack_parent, + .irq_retrigger = irq_chip_retrigger_hierarchy, .irq_mask = hv_irq_mask, .irq_unmask = hv_irq_unmask, };