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 B4BCE3B895D; Wed, 9 Sep 2026 06:45:11 +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=1788936313; cv=none; b=a0PY2C73ztWrsUegwLBlEVxvO2U8Oj41ke/BQTquoIYua6k23XMpxOP2nkEdV/S2osy0Ud3Wpr+cX0VAZ0U8qbcOJEx5slD+jDWbeiFfBTVEhn/5mgdIXF8hIokEKw5v6dG36yHIW14RhAHYNuBa27Un+1dDjPfjCo6wkmSlc00= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788936313; c=relaxed/simple; bh=/DLIok3k4tdCoOMkF2K/QrJWNryia6Ild8zWY6ve8M4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=JfF5R01r2ahQzDSU6dJC4lkvaypxCaYVciC0bxGYNaCX4YXdYYFiuNOKZUB1Si+If325IeOyXILIyJkZQWR32QJKCbk+KSVLbM+sBf9lk7vXTDklJR5Dgy13pOy+Wpr0I5vEGFPKYhT2kK0/YmAcPYM8cxKa0F4XjHRM9UyckNI= 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=p/81C5N0; 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="p/81C5N0" Received: from CPC-namja-026ON.localdomain (unknown [4.213.232.16]) by linux.microsoft.com (Postfix) with ESMTPSA id B3D7220B712B; Tue, 8 Sep 2026 23:44:22 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com B3D7220B712B DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1788936271; bh=vKHuFOw8t4T9qpNBzxIJe+5gzUOU1w5bceovfgKqwGU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=p/81C5N0Nhb4PASLj2y38DpLCycOVHsXzvYXVoy+C9heCL77FlV2FBK67UJyIpUhA Z/H+GUgqQJ6QzQSGdt5CW8hlUULng9CBp/ttGnI8INXMgc0EAhjGIjcnwXhIApzALh gwU1rACPwIWjeDatrhC7Txe7TzHBNjAzBVMTiQGM= From: Naman Jain To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H . Peter Anvin" , Wei Liu , "K . Y . Srinivasan" , Haiyang Zhang , Dexuan Cui Cc: Michael Kelley , Long Li , Nam Cao , Joerg Roedel , Suravee Suthikulpanit , Vasant Hegde , Will Deacon , Robin Murphy , Lorenzo Pieralisi , =?UTF-8?q?Krzysztof=20Wilczy=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: [PATCH v4 1/4] x86/hyperv: Set irq_retrigger for root partition PCI/MSI irqchip Date: Wed, 9 Sep 2026 06:44:45 +0000 Message-ID: <20260909064448.1004-2-namjain@linux.microsoft.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260909064448.1004-1-namjain@linux.microsoft.com> References: <20260909064448.1004-1-namjain@linux.microsoft.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The Hyper-V root partition vPCI MSI irqchip lost its irq_retrigger() callback when it was converted to msi_create_parent_irq_domain(). The callback was present on the original irqchip and was dropped during that conversion. 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 root partition PCI/MSI chip no longer provides 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. Restore irq_chip_retrigger_hierarchy() as the irq_retrigger() callback for the root partition PCI/MSI irqchip, so that a pending interrupt is resent on its new target CPU via the parent x86 vector domain. Fixes: 4691db0704ac ("x86/hyperv: Switch to msi_create_parent_irq_domain()") Cc: stable@vger.kernel.org Reviewed-by: Michael Kelley Signed-off-by: Naman Jain --- arch/x86/hyperv/irqdomain.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/hyperv/irqdomain.c b/arch/x86/hyperv/irqdomain.c index b3ad50a874dca..6d790636c8b95 100644 --- a/arch/x86/hyperv/irqdomain.c +++ b/arch/x86/hyperv/irqdomain.c @@ -316,6 +316,7 @@ static bool hv_init_dev_msi_info(struct device *dev, struct irq_domain *domain, return false; chip->flags |= IRQCHIP_SKIP_SET_WAKE | IRQCHIP_MOVE_DEFERRED; + chip->irq_retrigger = irq_chip_retrigger_hierarchy; info->ops->msi_prepare = pci_msi_prepare; -- 2.43.0