From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id BA9F04E80D2 for ; Thu, 3 Sep 2026 16:19:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788452370; cv=none; b=pw0P337zNJmZrl3q2Nsagpj8YRQ2lvxBsLoyZ9erLokgmUryriFD1iComOg6RBDyf+raO6unXSukFF3x4fwaZFLtmU+ob/nMVMIi8SY0U47D16MEIsqZZX6TGNpo6NKYcpoi94VRaFeoufwlg27T2DCePjdr+Qu63zjEDlUYv6M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788452370; c=relaxed/simple; bh=CRqQTsRO7q0L3GQFXL3KeEsDLCb6TvH1oEnTovBIEb4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=IAdiIxwyCaHPPvZlWckNlRa6U/A2f2W/49ei3netWCQDRH7aWwS57mxaXi/o7SALGbPJNRZQO3cJPUdP70hqlHP0pWk5i26ifrrk5jBsWKpO9H8TAgLJKN+rsXxkgyQQ0BvuUoBSS6UY8GavfGLkWA70vatclEPvUKZRJU2RNYU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=XHq8L4f6; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="XHq8L4f6" Received: from CPC-namja-026ON.localdomain (unknown [4.213.232.21]) by linux.microsoft.com (Postfix) with ESMTPSA id D40E120B712B; Thu, 3 Sep 2026 09:18:48 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com D40E120B712B DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1788452331; bh=ivCqi1+FwC0DdzIroEXthPMAlwue8gQTsCKALVC7SVU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XHq8L4f6mmGTss4DOAVLqQlDb1AzKGE/+Tyiq4QJpr7iy2pXXfPMnZ7gQopqcJdTv hJLWVyi8X98Pg7aLT8AYm7f1+QO/LKd/wytQdJBgA3ESB8cBDvbNSpgP9nkMcdGIqG aoWoe0QgsOIayTZKqb+DGLbVX02Sb4VnRxexSlPw= From: Naman Jain To: stable@vger.kernel.org Cc: gregkh@linuxfoundation.org, gargaditya@linux.microsoft.com, longli@microsoft.com, mhklinux@outlook.com, shradhagupta@linux.microsoft.com, tglx@kernel.org, wei.liu@kernel.org, namjain@linux.microsoft.com Subject: [PATCH 5.15.y] PCI: hv: Set irq_retrigger callback for the Hyper-V PCI MSI irqchip Date: Thu, 3 Sep 2026 16:19:22 +0000 Message-ID: <20260903161922.87232-1-namjain@linux.microsoft.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <2026090343-twirl-opt-bff6@gregkh> References: <2026090343-twirl-opt-bff6@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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 (cherry picked from commit 86bdd16e8f390d51bae9e77a4bc4164ca2f580fe) Signed-off-by: Naman Jain --- drivers/pci/controller/pci-hyperv.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c index 7917ed426f6a7..ef3beda509186 100644 --- a/drivers/pci/controller/pci-hyperv.c +++ b/drivers/pci/controller/pci-hyperv.c @@ -1655,6 +1655,7 @@ 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, }; -- 2.43.0