From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53414) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZepiD-00029x-8Z for qemu-devel@nongnu.org; Wed, 23 Sep 2015 15:28:18 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZepiA-0002ZT-28 for qemu-devel@nongnu.org; Wed, 23 Sep 2015 15:28:17 -0400 Received: from mx1.redhat.com ([209.132.183.28]:44567) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zepi9-0002Z7-T6 for qemu-devel@nongnu.org; Wed, 23 Sep 2015 15:28:13 -0400 Message-ID: <1443036490.23936.506.camel@redhat.com> From: Alex Williamson Date: Wed, 23 Sep 2015 13:28:10 -0600 In-Reply-To: <1442962830-7437-3-git-send-email-eric.auger@linaro.org> References: <1442962830-7437-1-git-send-email-eric.auger@linaro.org> <1442962830-7437-3-git-send-email-eric.auger@linaro.org> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 2/2] hw/vfio/platform: do not set resamplefd for edge-sensitive IRQS List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eric Auger Cc: peter.maydell@linaro.org, eric.auger@st.com, qemu-devel@nongnu.org, christoffer.dall@linaro.org, patches@linaro.org On Wed, 2015-09-23 at 00:00 +0100, Eric Auger wrote: > In irqfd mode, current code attempts to set a resamplefd whatever > the type of the IRQ. For an edge-sensitive IRQ this attempt fails > and as a consequence the whole irqfd setup fails and we fall back > to the slow mode. This patch bypasses the resamplefd setting for > non level-sentive IRQs. > > Signed-off-by: Eric Auger > --- > hw/vfio/platform.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/hw/vfio/platform.c b/hw/vfio/platform.c > index 38eaccf..2c91650 100644 > --- a/hw/vfio/platform.c > +++ b/hw/vfio/platform.c > @@ -352,6 +352,10 @@ static int vfio_set_resample_eventfd(VFIOINTp *intp) > int argsz, ret; > int32_t *pfd; > > + if (!(intp->flags & VFIO_IRQ_INFO_AUTOMASKED)) { > + return 0; > + } > + > argsz = sizeof(*irq_set) + sizeof(*pfd); > irq_set = g_malloc0(argsz); > irq_set->argsz = argsz; Aren't we also wasting a file descriptor for intp->unmask on edge IRQs as well? I'd be tempted to make a helper function that does this test and use it both to avoid calling this in vfio_start_irqfd_injection() and also to avoid creating the unused eventfd in vfio_init_intp(). Thanks, Alex