| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <1360868919.25865.26.camel@ul30vt.home>
Date: Thu, 14 Feb 2013 12:08:39 -0700
From: Alex Williamson <alex.williamson@...hat.com>
To: Vijay Mohan Pandarathil <vijaymohan.pandarathil@...com>
Cc: gleb@...hat.com, bhelgaas@...gle.com, blauwirbel@...il.com,
lance.oritz@...com, kvm@...r.kernel.org, qemu-devel@...gnu.org,
linux-pci@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v4 3/3] QEMU-AER: Qemu changes to support AER for
VFIO-PCI devices
On Thu, 2013-02-14 at 04:41 -0600, Vijay Mohan Pandarathil 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 the SET_IRQ ioctl
>
> - When the device encounters an error, the eventfd is signalled
> and the qemu eventfd handler gets invoked.
>
> - In the handler decide what action to take. Current action taken
> is to stop the guest.
>
> Signed-off-by: Vijay Mohan Pandarathil <vijaymohan.pandarathil@...com>
> ---
> hw/vfio_pci.c | 112 +++++++++++++++++++++++++++++++++++++++++++++
> linux-headers/linux/vfio.h | 1 +
> 2 files changed, 113 insertions(+)
>
> diff --git a/hw/vfio_pci.c b/hw/vfio_pci.c
> index c51ae67..05da53b 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
> @@ -129,7 +130,9 @@ typedef struct VFIODevice {
> PCIHostDeviceAddress host;
> QLIST_ENTRY(VFIODevice) next;
> struct VFIOGroup *group;
> + EventNotifier err_notifier;
> bool reset_works;
> + bool pci_aer;
> } VFIODevice;
>
> typedef struct VFIOGroup {
> @@ -1802,6 +1805,7 @@ static int vfio_get_device(VFIOGroup *group, const char *name, VFIODevice *vdev)
> {
> struct vfio_device_info dev_info = { .argsz = sizeof(dev_info) };
> struct vfio_region_info reg_info = { .argsz = sizeof(reg_info) };
> + struct vfio_irq_info irq_info = { .argsz = sizeof(irq_info) };
> int ret, i;
>
> ret = ioctl(group->fd, VFIO_GROUP_GET_DEVICE_FD, name);
> @@ -1901,6 +1905,15 @@ static int vfio_get_device(VFIOGroup *group, const char *name, VFIODevice *vdev)
> vdev->config_size = reg_info.size;
> vdev->config_offset = reg_info.offset;
>
> + irq_info.index = VFIO_PCI_ERR_IRQ_INDEX;
> +
> + ret = ioctl(vdev->fd, VFIO_DEVICE_GET_IRQ_INFO, &irq_info);
> + if (ret) {
> + error_report("vfio: Error getting IRQ info: %m\n");
What if we're assigning a Legacy PCI device or running on an old kernel,
neither of these warrant an error_report.
> + goto error;
> + }
> + if (irq_info.count == 1)
> + vdev->pci_aer = true;
This is where I'd actually expect some kind of warning, you're getting
something back that you don't expect (if != 1).
> error:
> if (ret) {
> QLIST_REMOVE(vdev, next);
> @@ -1922,6 +1935,102 @@ static void vfio_put_device(VFIODevice *vdev)
> }
> }
>
> +static void vfio_err_notifier_handler(void *opaque)
> +{
> + VFIODevice *vdev = opaque;
> +
> + if (!event_notifier_test_and_clear(&vdev->err_notifier)) {
> + 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
> + * from the error. This requires that PCIe capabilities be
> + * exposed to the guest. For now, we just terminate the
> + * guest to contain the error.
> + */
> +
> + error_report("%s (%04x:%02x:%02x.%x)"
> + "Unrecoverable error detected...\n"
> + "Please inestigate/collect any data required and then kill the quest",
s/inestigate/investigate/
This seems like a lot to ask of a user.
> + __func__, vdev->host.domain, vdev->host.bus,
> + vdev->host.slot, vdev->host.function);
> +
> + vm_stop(RUN_STATE_IO_ERROR);
Gleb, were you looking for a new stop condition or is this one ok to
re-use?
> +}
> +
> +static void vfio_register_err_notifier(VFIODevice *vdev)
> +{
> + int ret;
> + int argsz;
> + struct vfio_irq_set *irq_set;
> + int32_t *pfd;
> +
> + if (!vdev->pci_aer) {
> + return;
> + }
> +
> + if (event_notifier_init(&vdev->err_notifier, 0)) {
> + error_report("vfio: Warning: Unable to init event notifier for error detection\n");
> + return;
> + }
> +
> + argsz = sizeof(*irq_set) + sizeof(*pfd);
> +
> + irq_set = g_malloc0(argsz);
> + irq_set->argsz = argsz;
> + irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD |
> + VFIO_IRQ_SET_ACTION_TRIGGER;
> + irq_set->index = VFIO_PCI_ERR_IRQ_INDEX;
> + irq_set->start = 0;
> + irq_set->count = 1;
> + pfd = (int32_t *)&irq_set->data;
> +
> + *pfd = event_notifier_get_fd(&vdev->err_notifier);
> + qemu_set_fd_handler(*pfd, vfio_err_notifier_handler, NULL, vdev);
> +
> + ret = ioctl(vdev->fd, VFIO_DEVICE_SET_IRQS, irq_set);
> + if (ret) {
> + error_report("vfio: Failed to set up error notification\n");
> + qemu_set_fd_handler(*pfd, NULL, NULL, vdev);
> + event_notifier_cleanup(&vdev->err_notifier);
> + }
> + g_free(irq_set);
> +}
Why does the register return void? If it's supported and fails, isn't
that a condition where we'd want to fail the initfn? Also, if the above
fails, there's nothing that prevents the below unreqister... isn't that
a bug?
> +static void vfio_unregister_err_notifier(VFIODevice *vdev)
> +{
> + int argsz;
> + struct vfio_irq_set *irq_set;
> + int32_t *pfd;
> + int ret;
> +
> + if (!vdev->pci_aer) {
> + return;
> + }
> +
> + argsz = sizeof(*irq_set) + sizeof(*pfd);
> +
> + irq_set = g_malloc0(argsz);
> + irq_set->argsz = argsz;
> + irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD |
> + VFIO_IRQ_SET_ACTION_TRIGGER;
> + irq_set->index = VFIO_PCI_ERR_IRQ_INDEX;
> + irq_set->start = 0;
> + irq_set->count = 1;
> + pfd = (int32_t *)&irq_set->data;
> + *pfd = -1;
> +
> + ret = ioctl(vdev->fd, VFIO_DEVICE_SET_IRQS, irq_set);
> + if (ret) {
> + error_report("vfio: Failed to de-assign error fd: %d\n", ret);
> + }
> + g_free(irq_set);
> + qemu_set_fd_handler(event_notifier_get_fd(&vdev->err_notifier),
> + NULL, NULL, vdev);
> + event_notifier_cleanup(&vdev->err_notifier);
> +}
> static int vfio_initfn(PCIDevice *pdev)
> {
> VFIODevice *pvdev, *vdev = DO_UPCAST(VFIODevice, pdev, pdev);
> @@ -2032,6 +2141,8 @@ static int vfio_initfn(PCIDevice *pdev)
> }
> }
>
> + vfio_register_err_notifier(vdev);
> +
> return 0;
>
> out_teardown:
> @@ -2049,6 +2160,7 @@ static void vfio_exitfn(PCIDevice *pdev)
> VFIODevice *vdev = DO_UPCAST(VFIODevice, pdev, pdev);
> VFIOGroup *group = vdev->group;
>
> + vfio_unregister_err_notifier(vdev);
> pci_device_set_intx_routing_notifier(&vdev->pdev, NULL);
> vfio_disable_interrupts(vdev);
> if (vdev->intx.mmap_timer) {
> diff --git a/linux-headers/linux/vfio.h b/linux-headers/linux/vfio.h
> index f787b72..6b20849 100644
> --- a/linux-headers/linux/vfio.h
> +++ b/linux-headers/linux/vfio.h
> @@ -310,6 +310,7 @@ enum {
> VFIO_PCI_INTX_IRQ_INDEX,
> VFIO_PCI_MSI_IRQ_INDEX,
> VFIO_PCI_MSIX_IRQ_INDEX,
> + VFIO_PCI_ERR_IRQ_INDEX,
> VFIO_PCI_NUM_IRQS
> };
>
Linux headers get updated via the scripts/update-linux-headers.sh
script. This will need to be done in a separate patch after the kernel
changes are upstream. Thanks,
Alex
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists