From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: [PATCH] KVM: Use IRQF_ONESHOT for assigned device MSI interrupts Date: Fri, 01 Jun 2012 18:39:30 +0200 Message-ID: <4FC8F042.5050600@siemens.com> References: <20120601161521.26935.25606.stgit@bling.home> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: "kvm@vger.kernel.org" , "avi@redhat.com" , "mtosatti@redhat.com" , "linux-kernel@vger.kernel.org" , "yongjie.ren@intel.com" To: Alex Williamson Return-path: Received: from goliath.siemens.de ([192.35.17.28]:33836 "EHLO goliath.siemens.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965486Ab2FAQjj (ORCPT ); Fri, 1 Jun 2012 12:39:39 -0400 In-Reply-To: <20120601161521.26935.25606.stgit@bling.home> Sender: kvm-owner@vger.kernel.org List-ID: On 2012-06-01 18:16, Alex Williamson wrote: > The kernel no longer allows us to pass NULL for a hard interrupt > handler without IRQF_ONESHOT. Should have been using this flag > anyway. This make the IRQ handling tail a bit slower (due to irq_finalize_oneshot). MSIs are edge-triggered, so there was no need for masking in theory. Hmm, can't we trust the information that an IRQ grabbed here is really a MSI type? Jan > > Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=43328 > > Signed-off-by: Alex Williamson > --- > > virt/kvm/assigned-dev.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/virt/kvm/assigned-dev.c b/virt/kvm/assigned-dev.c > index 01f572c..e804d14 100644 > --- a/virt/kvm/assigned-dev.c > +++ b/virt/kvm/assigned-dev.c > @@ -347,7 +347,7 @@ static int assigned_device_enable_host_msi(struct kvm *kvm, > > dev->host_irq = dev->dev->irq; > if (request_threaded_irq(dev->host_irq, NULL, > - kvm_assigned_dev_thread_msi, 0, > + kvm_assigned_dev_thread_msi, IRQF_ONESHOT, > dev->irq_name, dev)) { > pci_disable_msi(dev->dev); > return -EIO; > @@ -375,7 +375,7 @@ static int assigned_device_enable_host_msix(struct kvm *kvm, > for (i = 0; i < dev->entries_nr; i++) { > r = request_threaded_irq(dev->host_msix_entries[i].vector, > NULL, kvm_assigned_dev_thread_msix, > - 0, dev->irq_name, dev); > + IRQF_ONESHOT, dev->irq_name, dev); > if (r) > goto err; > } > -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux