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Re: [Qemu-devel] [PATCH v2 09/11] vfio: vote a device to do host bus res
From: |
Michael S. Tsirkin |
Subject: |
Re: [Qemu-devel] [PATCH v2 09/11] vfio: vote a device to do host bus reset |
Date: |
Wed, 9 Mar 2016 19:31:17 +0200 |
On Wed, Mar 09, 2016 at 10:09:11AM -0700, Alex Williamson wrote:
> On Wed, 9 Mar 2016 18:39:51 +0200
> "Michael S. Tsirkin" <address@hidden> wrote:
>
> > On Mon, Mar 07, 2016 at 11:23:02AM +0800, Cao jin wrote:
> > > From: Chen Fan <address@hidden>
> > >
> > > Signed-off-by: Chen Fan <address@hidden>
> > > ---
> > > hw/vfio/pci.c | 57
> > > +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> > > hw/vfio/pci.h | 1 +
> > > 2 files changed, 58 insertions(+)
> > >
> > > diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
> > > index 24848c9..8e902d2 100644
> > > --- a/hw/vfio/pci.c
> > > +++ b/hw/vfio/pci.c
> > > @@ -1937,6 +1937,8 @@ static void vfio_check_host_bus_reset(VFIOPCIDevice
> > > *vdev, Error **errp)
> > > /* List all affected devices by bus reset */
> > > devices = &info->devices[0];
> > >
> > > + vdev->single_depend_dev = (info->count == 1);
> > > +
> > > /* Verify that we have all the groups required */
> > > for (i = 0; i < info->count; i++) {
> > > PCIHostDeviceAddress host;
> > > @@ -2998,6 +3000,49 @@ static void vfio_exitfn(PCIDevice *pdev)
> > > vfio_unregister_bars(vdev);
> > > }
> > >
> > > +static VFIOPCIDevice *vfio_pci_get_do_reset_device(VFIOPCIDevice *vdev)
> > > +{
> > > + struct vfio_pci_hot_reset_info *info = NULL;
> > > + struct vfio_pci_dependent_device *devices;
> > > + VFIOGroup *group;
> > > + VFIODevice *vbasedev_iter;
> > > + int ret;
> > > +
> > > + ret = vfio_get_hot_reset_info(vdev, &info);
> > > + if (ret) {
> > > + error_report("vfio: Cannot enable AER for device %s,"
> > > + " device does not support hot reset.",
> > > + vdev->vbasedev.name);
> > > + return NULL;
> > > + }
> > > +
> > > + devices = &info->devices[0];
> > > +
> > > + QLIST_FOREACH(group, &vfio_group_list, next) {
> > > + if (group->groupid == devices[0].group_id) {
> > > + break;
> > > + }
> > > + }
> > > +
> > > + if (!group) {
> > > + error_report("vfio: Cannot enable AER for device %s, "
> > > + "depends on group %d which is not owned.",
> > > + vdev->vbasedev.name, devices[0].group_id);
> > > + return NULL;
> > > + }
> > > +
> > > + QLIST_FOREACH(vbasedev_iter, &group->device_list, next) {
> > > + if (vbasedev_iter->type != VFIO_DEVICE_TYPE_PCI ||
> > > + !(vdev->features & VFIO_FEATURE_ENABLE_AER)) {
> > > + continue;
> > > + }
> > > +
> > > + return container_of(vbasedev_iter, VFIOPCIDevice, vbasedev);
> > > + }
> > > +
> > > + return NULL;
> > > +}
> > > +
> > > static void vfio_pci_reset(DeviceState *dev)
> > > {
> > > PCIDevice *pdev = DO_UPCAST(PCIDevice, qdev, dev);
> > > @@ -3005,6 +3050,18 @@ static void vfio_pci_reset(DeviceState *dev)
> > >
> > > trace_vfio_pci_reset(vdev->vbasedev.name);
> > >
> > > + if (pdev->bus->in_hot_reset) {
> >
> > After discussing this with Alex, I think what you
> > really are looking for is
> > if (dev->realized)
> > in order to skip hot reset when device is plugged-in
> > initially.
>
> Seems fragile, device_reset() also gets called via pci_device_reset()
> which would happen if we hooked up FLR to the device.
You can check that as well (through config space, no need
for new flags).
There's also PM reset.
> That's clearly
> intended to be a function local reset, as is I believe the dc->reset
> itself, so assuming behavior based on states like dev->realized is
> likely to break. Either we need some external hints, like what's added
> here, or we need a separate callback for a bus reset. Thanks,
>
> Alex
So I'm fine with a new flag is_bus_rst, or an API pci_is_bus_rst.
But it has to be set whenever bus is reset, *not* just on secondary bus reset.
> > > + VFIOPCIDevice *tmp;
> > > +
> > > + tmp = vfio_pci_get_do_reset_device(vdev);
> > > + if (tmp) {
> > > + if (tmp == vdev) {
> > > + vfio_pci_hot_reset(vdev, vdev->single_depend_dev);
> > > + }
> > > + return;
> > > + }
> > > + }
> > > +
> > > vfio_pci_pre_reset(vdev);
> > >
> > > if (vdev->resetfn && !vdev->resetfn(vdev)) {
> > > diff --git a/hw/vfio/pci.h b/hw/vfio/pci.h
> > > index aff46c2..32bd31f 100644
> > > --- a/hw/vfio/pci.h
> > > +++ b/hw/vfio/pci.h
> > > @@ -143,6 +143,7 @@ typedef struct VFIOPCIDevice {
> > > bool no_kvm_intx;
> > > bool no_kvm_msi;
> > > bool no_kvm_msix;
> > > + bool single_depend_dev;
> > > } VFIOPCIDevice;
> > >
> > > uint32_t vfio_pci_read_config(PCIDevice *pdev, uint32_t addr, int len);
> > > --
> > > 1.9.3
> > >
> > >
- Re: [Qemu-devel] [PATCH v2 06/11] pci: add a is_valid_func callback to check device if complete, (continued)
[Qemu-devel] [PATCH v2 08/11] pci: introduce pci bus pre reset, Cao jin, 2016/03/06
[Qemu-devel] [PATCH v2 11/11] vfio: add 'aer' property to expose aercap, Cao jin, 2016/03/06
[Qemu-devel] [PATCH v2 09/11] vfio: vote a device to do host bus reset, Cao jin, 2016/03/06