Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753077AbbLCSgt (ORCPT ); Thu, 3 Dec 2015 13:36:49 -0500 Received: from mga14.intel.com ([192.55.52.115]:26069 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752972AbbLCSgq (ORCPT ); Thu, 3 Dec 2015 13:36:46 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.20,378,1444719600"; d="scan'208";a="7025551" From: Yunhong Jiang To: alex.williamson@redhat.com, pbonzini@redhat.com Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 0/5] Threaded MSI interrupt for VFIO PCI device Date: Thu, 3 Dec 2015 10:22:47 -0800 Message-Id: <1449166972-8894-1-git-send-email-yunhong.jiang@linux.intel.com> X-Mailer: git-send-email 1.8.3.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1653 Lines: 38 When assigning a VFIO device to a KVM guest with low latency requirement, it is better to handle the interrupt in the hard interrupt context, to reduce the context switch to/from the IRQ thread. Based on discussion on https://lkml.org/lkml/2015/10/26/764, the VFIO msi interrupt is changed to use request_threaded_irq(). The primary interrupt handler tries to set the guest interrupt atomically. If it fails to achieve it, a threaded interrupt handler will be invoked. The irq_bypass manager is extended for this purpose. The KVM eventfd will provide a irqbypass consumer to handle the interrupt at hard interrupt context. The producer will invoke the consumer's handler then. Yunhong Jiang (5): Extract the irqfd_wakeup_pollin/irqfd_wakeup_pollup Support runtime irq_bypass consumer Support threaded interrupt handling on VFIO Add the irq handling consumer Expose x86 kvm_arch_set_irq_inatomic() arch/x86/kvm/Kconfig | 1 + drivers/vfio/pci/vfio_pci_intrs.c | 39 ++++++++++-- include/linux/irqbypass.h | 8 +++ include/linux/kvm_host.h | 19 +++++- include/linux/kvm_irqfd.h | 1 + virt/kvm/Kconfig | 3 + virt/kvm/eventfd.c | 131 ++++++++++++++++++++++++++------------ virt/lib/irqbypass.c | 82 ++++++++++++++++++------ 8 files changed, 214 insertions(+), 70 deletions(-) -- 1.8.3.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/