From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:41015) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Tt04F-0001Mx-RZ for qemu-devel@nongnu.org; Wed, 09 Jan 2013 13:08:01 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Tt04D-0001pX-PZ for qemu-devel@nongnu.org; Wed, 09 Jan 2013 13:07:59 -0500 Received: from mx1.redhat.com ([209.132.183.28]:25006) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Tt04D-0001pR-Ij for qemu-devel@nongnu.org; Wed, 09 Jan 2013 13:07:57 -0500 Message-ID: <1357754873.3224.777.camel@bling.home> From: Alex Williamson Date: Wed, 09 Jan 2013 11:07:53 -0700 In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 2/2] QEMU-AER: Qemu changes to support AER for VFIO-PCI devices List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Pandarathil, Vijaymohan R" Cc: Gleb Natapov , "kvm@vger.kernel.org" , "linux-pci@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "qemu-devel@nongnu.org" , Bjorn Helgaas On Wed, 2013-01-09 at 06:26 +0000, Pandarathil, Vijaymohan R wrote: > - Create eventfd per vfio device assigned to a guest and register an > event handler > > - This fd is passed to the vfio_pci driver through a new ioctl > > - When the device encounters an error, the eventfd is signaled > and the qemu eventfd handler gets invoked. > > - In the handler decide what action to take. Current action taken > is to terminate the guest. > > Signed-off-by: Vijay Mohan Pandarathil > --- > hw/vfio_pci.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++ > linux-headers/linux/vfio.h | 9 ++++++++ > 2 files changed, 65 insertions(+) > > diff --git a/hw/vfio_pci.c b/hw/vfio_pci.c > index 28c8303..9c3c28b 100644 > --- a/hw/vfio_pci.c > +++ b/hw/vfio_pci.c > @@ -38,6 +38,7 @@ > #include "qemu/error-report.h" > #include "qemu/queue.h" > #include "qemu/range.h" > +#include "sysemu/sysemu.h" > > /* #define DEBUG_VFIO */ > #ifdef DEBUG_VFIO > @@ -130,6 +131,8 @@ typedef struct VFIODevice { > QLIST_ENTRY(VFIODevice) next; > struct VFIOGroup *group; > bool reset_works; > + EventNotifier errfd; Misleading name, it's an EventNotifier not an fd. > + __u32 dev_info_flags; > } VFIODevice; > > typedef struct VFIOGroup { > @@ -1805,6 +1808,8 @@ static int vfio_get_device(VFIOGroup *group, const char *name, VFIODevice *vdev) > DPRINTF("Device %s flags: %u, regions: %u, irgs: %u\n", name, > dev_info.flags, dev_info.num_regions, dev_info.num_irqs); > > + vdev->dev_info_flags = dev_info.flags; > + We test the VFIO_DEVICE_FLAGS_RESET elsewhere by caching the bit into a variable, why not do that here too? > if (!(dev_info.flags & VFIO_DEVICE_FLAGS_PCI)) { > error_report("vfio: Um, this isn't a PCI device\n"); > goto error; > @@ -1900,6 +1905,55 @@ static void vfio_put_device(VFIODevice *vdev) > } > } > > +static void vfio_errfd_handler(void *opaque) > +{ > + VFIODevice *vdev = opaque; > + > + if (!event_notifier_test_and_clear(&vdev->errfd)) { > + return; > + } > + > + /* > + * TBD. Retrieve the error details and decide what action > + * needs to be taken. One of the actions could be to pass > + * the error to the guest and have the guest driver recover > + * the error. This requires that PCIe capabilities be > + * exposed to the guest. At present, we just terminate the > + * guest to contain the error. > + */ > + error_report("%s(%04x:%02x:%02x.%x) " > + "Unrecoverable error detected... Terminating guest\n", > + __func__, vdev->host.domain, vdev->host.bus, vdev->host.slot, > + vdev->host.function); > + > + qemu_system_shutdown_request(); I would have figured hw_error > + return; > +} > + > +static void vfio_register_errfd(VFIODevice *vdev) > +{ > + int32_t pfd; "pfd" is used elsewhere in vfio as "Pointer to FD", this is just a fd. > + int ret; > + > + if (!(vdev->dev_info_flags & VFIO_DEVICE_FLAGS_AER_NOTIFY)) { > + error_report("vfio: Warning: Error notification not supported for the device\n"); This should probably just be a debug print. > + return; > + } > + if (event_notifier_init(&vdev->errfd, 0)) { > + error_report("vfio: Warning: Unable to init event notifier for error detection\n"); > + return; > + } > + pfd = event_notifier_get_fd(&vdev->errfd); > + qemu_set_fd_handler(pfd, vfio_errfd_handler, NULL, vdev); > + > + ret = ioctl(vdev->fd, VFIO_DEVICE_SET_ERRFD, pfd); > + if (ret) { > + error_report("vfio: Warning: Failed to setup error fd: %d\n", ret); > + qemu_set_fd_handler(pfd, NULL, NULL, vdev); > + event_notifier_cleanup(&vdev->errfd); > + } > + return; > +} > static int vfio_initfn(PCIDevice *pdev) > { > VFIODevice *pvdev, *vdev = DO_UPCAST(VFIODevice, pdev, pdev); > @@ -2010,6 +2064,8 @@ static int vfio_initfn(PCIDevice *pdev) > } > } > > + vfio_register_errfd(vdev); > + No cleanup in exitfn?! Thanks, Alex > return 0; > > out_teardown: > diff --git a/linux-headers/linux/vfio.h b/linux-headers/linux/vfio.h > index 4758d1b..0ca4eeb 100644 > --- a/linux-headers/linux/vfio.h > +++ b/linux-headers/linux/vfio.h > @@ -147,6 +147,7 @@ struct vfio_device_info { > __u32 flags; > #define VFIO_DEVICE_FLAGS_RESET (1 << 0) /* Device supports reset */ > #define VFIO_DEVICE_FLAGS_PCI (1 << 1) /* vfio-pci device */ > +#define VFIO_DEVICE_FLAGS_AER_NOTIFY (1 << 2) /* Supports aer notification */ > __u32 num_regions; /* Max region index + 1 */ > __u32 num_irqs; /* Max IRQ index + 1 */ > }; > @@ -288,6 +289,14 @@ struct vfio_irq_set { > */ > #define VFIO_DEVICE_RESET _IO(VFIO_TYPE, VFIO_BASE + 11) > > +/** > + * VFIO_DEVICE_SET_ERRFD - _IO(VFIO_TYPE, VFIO_BASE + 12) > + * > + * Pass the eventfd to the vfio-pci driver for signalling any device > + * error notifications > + */ > +#define VFIO_DEVICE_SET_ERRFD _IO(VFIO_TYPE, VFIO_BASE + 12) > + > /* > * The VFIO-PCI bus driver makes use of the following fixed region and > * IRQ index mapping. Unimplemented regions return a size of zero.