[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH v2 05/11] vfio: add check host bus reset is supp
From: |
Alex Williamson |
Subject: |
Re: [Qemu-devel] [PATCH v2 05/11] vfio: add check host bus reset is support or not |
Date: |
Tue, 8 Mar 2016 15:55:19 -0700 |
On Mon, 7 Mar 2016 11:22:58 +0800
Cao jin <address@hidden> wrote:
> From: Chen Fan <address@hidden>
>
> when boot up a VM that assigning vfio devices with aer enabled, we
> must check the vfio device whether support host bus reset. because
> when one error occur. OS driver always recover the device by do a
> bus reset, in order to recover the vfio device, qemu must to do a
> host bus reset to reset the device to default status. and for all
> affected devices by the bus reset. we must check them whether all
> are assigned to the VM.
>
> Signed-off-by: Chen Fan <address@hidden>
> ---
> hw/vfio/pci.c | 218
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++--
> hw/vfio/pci.h | 1 +
> 2 files changed, 212 insertions(+), 7 deletions(-)
>
> diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
> index 8ec9b25..0898e34 100644
> --- a/hw/vfio/pci.c
> +++ b/hw/vfio/pci.c
> @@ -1868,6 +1868,197 @@ static int vfio_add_std_cap(VFIOPCIDevice *vdev,
> uint8_t pos)
> return 0;
> }
>
> +static bool vfio_pci_host_slot_match(PCIHostDeviceAddress *host1,
> + PCIHostDeviceAddress *host2)
> +{
> + return (host1->domain == host2->domain && host1->bus == host2->bus &&
> + host1->slot == host2->slot);
> +}
> +
> +static bool vfio_pci_host_match(PCIHostDeviceAddress *host1,
> + PCIHostDeviceAddress *host2)
> +{
> + return (vfio_pci_host_slot_match(host1, host2) &&
> + host1->function == host2->function);
> +}
> +
> +struct VFIODeviceFind {
> + PCIDevice *pdev;
> + bool found;
> +};
> +
> +static void vfio_check_device_noreset(PCIBus *bus, PCIDevice *pdev,
> + void *opaque)
> +{
> + DeviceState *dev = DEVICE(pdev);
> + DeviceClass *dc = DEVICE_GET_CLASS(dev);
> + VFIOPCIDevice *vdev;
> + struct VFIODeviceFind *find = opaque;
> +
> + if (find->found) {
> + return;
> + }
> +
> + if (!object_dynamic_cast(OBJECT(dev), "vfio-pci")) {
> + if (!dc->reset) {
> + goto found;
> + }
> + return;
> + }
> + vdev = DO_UPCAST(VFIOPCIDevice, pdev, pdev);
> + if (!(vdev->features & VFIO_FEATURE_ENABLE_AER) &&
> + !vdev->vbasedev.reset_works) {
> + goto found;
> + }
> +
> + return;
> +found:
> + find->pdev = pdev;
> + find->found = true;
> +}
> +
> +static void vfio_check_host_bus_reset(VFIOPCIDevice *vdev, Error **errp)
> +{
> + PCIBus *bus = vdev->pdev.bus;
> + struct vfio_pci_hot_reset_info *info = NULL;
> + struct vfio_pci_dependent_device *devices;
> + VFIOGroup *group;
> + struct VFIODeviceFind find;
> + int ret, i;
> +
> + ret = vfio_get_hot_reset_info(vdev, &info);
> + if (ret) {
> + error_setg(errp, "vfio: Cannot enable AER for device %s,"
> + " device does not support hot reset.",
> + vdev->vbasedev.name);
> + return;
> + }
> +
> + /* List all affected devices by bus reset */
> + devices = &info->devices[0];
> +
> + /* Verify that we have all the groups required */
> + for (i = 0; i < info->count; i++) {
> + PCIHostDeviceAddress host;
> + VFIOPCIDevice *tmp;
> + VFIODevice *vbasedev_iter;
> + bool found = false;
> +
> + host.domain = devices[i].segment;
> + host.bus = devices[i].bus;
> + host.slot = PCI_SLOT(devices[i].devfn);
> + host.function = PCI_FUNC(devices[i].devfn);
> +
> + /* Skip the current device */
> + if (vfio_pci_host_match(&host, &vdev->host)) {
> + continue;
> + }
> +
> + /* Ensure we own the group of the affected device */
> + QLIST_FOREACH(group, &vfio_group_list, next) {
> + if (group->groupid == devices[i].group_id) {
> + break;
> + }
> + }
> +
> + if (!group) {
> + error_setg(errp, "vfio: Cannot enable AER for device %s, "
> + "depends on group %d which is not owned.",
> + vdev->vbasedev.name, devices[i].group_id);
> + goto out;
> + }
> +
> + /* Ensure affected devices for reset on the same slot */
> + QLIST_FOREACH(vbasedev_iter, &group->device_list, next) {
> + if (vbasedev_iter->type != VFIO_DEVICE_TYPE_PCI) {
> + continue;
> + }
> + tmp = container_of(vbasedev_iter, VFIOPCIDevice, vbasedev);
> + if (vfio_pci_host_match(&host, &tmp->host)) {
> + /*
> + * AER errors may be broadcast to all functions of a multi-
> + * function endpoint. If any of those sibling functions are
> + * also assigned, they need to have AER enabled or else an
> + * error may continue to cause a vm_stop condition. IOW,
> + * AER setup of this function would be pointless.
> + */
> + if (vfio_pci_host_slot_match(&vdev->host, &tmp->host) &&
> + !(tmp->features & VFIO_FEATURE_ENABLE_AER)) {
> + error_setg(errp, "vfio: Cannot enable AER for device %s,
> on same slot"
> + " the dependent device %s which does not
> enable AER.",
> + vdev->vbasedev.name, tmp->vbasedev.name);
> + goto out;
> + }
> +
> + if (tmp->pdev.bus != bus) {
> + error_setg(errp, "vfio: Cannot enable AER for device %s,
> "
> + "the dependent device %s is not on the same
> bus",
> + vdev->vbasedev.name, tmp->vbasedev.name);
> + goto out;
> + }
> + found = true;
> + break;
> + }
> + }
> +
> + /* Ensure all affected devices assigned to VM */
> + if (!found) {
> + error_setg(errp, "vfio: Cannot enable AER for device %s, "
> + "the dependent device %04x:%02x:%02x.%x "
> + "is not assigned to VM.",
> + vdev->vbasedev.name, host.domain, host.bus,
> + host.slot, host.function);
> + goto out;
> + }
> + }
> +
> + /*
> + * Check the all pci devices on or below the target bus
> + * have a reset mechanism at least.
> + */
> + find.pdev = NULL;
> + find.found = false;
> + pci_for_each_device(bus, pci_bus_num(bus),
I'm not fully convinced this does what it says that it does. Bus
numbers are under guest control, but using pci_bus_num(bus) here will
cause us to always take the path in pci_find_bus_nr() where it simply
returns bus. Thus we call pci_for_each_device_under_bus() with the bus
originally provided in pci_for_each_device(). But
pci_for_each_device_under_bus() only iterates the devfns immediately on
that bus, despite the name that would imply otherwise. So it seems
like the pci_for_each_device() callback would need to itself call
pci_for_each_device() if it finds a bridge. Am I missing something or
is that correct?
We could also just go on to require that there are no subordinate buses
to this bus, which seems like a reasonable thing to do. Thanks,
Alex
> + vfio_check_device_noreset, &find);
> + if (find.found) {
> + error_setg(errp, "vfio: Cannot enable AER for device %s, "
> + "the affected device %s does not have a reset mechanism.",
> + vdev->vbasedev.name, find.pdev->name);
> + goto out;
> + }
> +
> +out:
> + g_free(info);
> + return;
> +}
> +
> +static void vfio_check_devices_host_bus_reset(Error **errp)
> +{
> + VFIOGroup *group;
> + VFIODevice *vbasedev;
> + VFIOPCIDevice *vdev;
> + Error *local_err = NULL;
> +
> + /* Check All vfio-pci devices if have bus reset capability */
> + QLIST_FOREACH(group, &vfio_group_list, next) {
> + QLIST_FOREACH(vbasedev, &group->device_list, next) {
> + if (vbasedev->type != VFIO_DEVICE_TYPE_PCI) {
> + continue;
> + }
> + vdev = container_of(vbasedev, VFIOPCIDevice, vbasedev);
> + if (vdev->features & VFIO_FEATURE_ENABLE_AER) {
> + vfio_check_host_bus_reset(vdev, &local_err);
> + if (local_err) {
> + error_propagate(errp, local_err);
> + return;
> + }
> + }
> + }
> + }
> +
> + return;
> +}
> +
> static int vfio_setup_aer(VFIOPCIDevice *vdev, uint8_t cap_ver,
> int pos, uint16_t size)
> {
> @@ -2047,13 +2238,6 @@ static void vfio_pci_post_reset(VFIOPCIDevice *vdev)
> vfio_intx_enable(vdev);
> }
>
> -static bool vfio_pci_host_match(PCIHostDeviceAddress *host1,
> - PCIHostDeviceAddress *host2)
> -{
> - return (host1->domain == host2->domain && host1->bus == host2->bus &&
> - host1->slot == host2->slot && host1->function ==
> host2->function);
> -}
> -
> static int vfio_pci_hot_reset(VFIOPCIDevice *vdev, bool single)
> {
> VFIOGroup *group;
> @@ -2559,6 +2743,21 @@ static void vfio_unregister_req_notifier(VFIOPCIDevice
> *vdev)
> vdev->req_enabled = false;
> }
>
> +static void vfio_pci_machine_done_notify(Notifier *notifier, void *unused)
> +{
> + Error *local_err = NULL;
> +
> + vfio_check_devices_host_bus_reset(&local_err);
> + if (local_err) {
> + error_report_err(local_err);
> + exit(1);
> + }
> +}
> +
> +static Notifier machine_notifier = {
> + .notify = vfio_pci_machine_done_notify,
> +};
> +
> static int vfio_initfn(PCIDevice *pdev)
> {
> VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, pdev);
> @@ -2905,6 +3104,11 @@ static const TypeInfo vfio_pci_dev_info = {
> static void register_vfio_pci_dev_type(void)
> {
> type_register_static(&vfio_pci_dev_info);
> + /*
> + * Register notifier when machine init is done, since we need
> + * check the configration manner after all vfio device are inited.
> + */
> + qemu_add_machine_init_done_notifier(&machine_notifier);
> }
>
> type_init(register_vfio_pci_dev_type)
> diff --git a/hw/vfio/pci.h b/hw/vfio/pci.h
> index e0c53f2..aff46c2 100644
> --- a/hw/vfio/pci.h
> +++ b/hw/vfio/pci.h
> @@ -15,6 +15,7 @@
> #include "qemu-common.h"
> #include "exec/memory.h"
> #include "hw/pci/pci.h"
> +#include "hw/pci/pci_bus.h"
> #include "hw/pci/pci_bridge.h"
> #include "hw/vfio/vfio-common.h"
> #include "qemu/event_notifier.h"
- [Qemu-devel] [PATCH v2 Resend 00/11] vfio-pci: pass the aer error to guest, part2, Cao jin, 2016/03/06
- [Qemu-devel] [PATCH v2 03/11] vfio: add pcie extended capability support, Cao jin, 2016/03/06
- [Qemu-devel] [PATCH v2 01/11] vfio: extract vfio_get_hot_reset_info as a single function, Cao jin, 2016/03/06
- [Qemu-devel] [PATCH v2 02/11] vfio: squeeze out vfio_pci_do_hot_reset for support bus reset, Cao jin, 2016/03/06
- [Qemu-devel] [PATCH v2 04/11] vfio: add aer support for vfio device, Cao jin, 2016/03/06
- [Qemu-devel] [PATCH v2 05/11] vfio: add check host bus reset is support or not, Cao jin, 2016/03/06
- [Qemu-devel] [PATCH v2 07/11] vfio: add check aer functionality for hotplug device, Cao jin, 2016/03/06
- [Qemu-devel] [PATCH v2 10/11] vfio-pci: pass the aer error to guest, Cao jin, 2016/03/06
- [Qemu-devel] [PATCH v2 06/11] pci: add a is_valid_func callback to check device if complete, Cao jin, 2016/03/06