On Fri, Nov 22, 2019 at 06:12:57AM +0100, Greg Kurz wrote:
> On Thu, 21 Nov 2019 11:56:05 +1100
> David Gibson <david@xxxxxxxxxxxxxxxxxxxxx> wrote:
>
> > VFIO PCI devices already respond to the pci intx routing notifier, in order
> > to update kernel irqchip mappings when routing is updated. However this
> > won't handle the case where the irqchip itself is replaced by a different
> > model while retaining the same routing. This case can happen on
> > the pseries machine type due to PAPR feature negotiation.
> >
> > To handle that case, add a handler for the irqchip change notifier, which
> > does much the same thing as the routing notifier, but is unconditional,
> > rather than being a no-op when the routing hasn't changed.
> >
> > Cc: Alex Williamson <alex.williamson@xxxxxxxxxx>
> > Cc: Alexey Kardashevskiy <aik@xxxxxxxxx>
> >
> > Signed-off-by: David Gibson <david@xxxxxxxxxxxxxxxxxxxxx>
> > ---
> > hw/vfio/pci.c | 23 ++++++++++++++++++-----
> > hw/vfio/pci.h | 1 +
> > 2 files changed, 19 insertions(+), 5 deletions(-)
> >
> > diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
> > index 521289aa7d..95478c2c55 100644
> > --- a/hw/vfio/pci.c
> > +++ b/hw/vfio/pci.c
> > @@ -256,6 +256,14 @@ static void vfio_intx_routing_notifier(PCIDevice *pdev)
> > }
> > }
> >
> > +static void vfio_irqchip_change(Notifier *notify, void *data)
> > +{
> > + VFIOPCIDevice *vdev = container_of(notify, VFIOPCIDevice,
> > + irqchip_change_notifier);
> > +
> > + vfio_intx_update(vdev, &vdev->intx.route);
> > +}
> > +
> > static int vfio_intx_enable(VFIOPCIDevice *vdev, Error **errp)
> > {
> > uint8_t pin = vfio_pci_read_config(&vdev->pdev, PCI_INTERRUPT_PIN, 1);
> > @@ -2973,16 +2981,18 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
> > vfio_intx_mmap_enable, vdev);
> > pci_device_set_intx_routing_notifier(&vdev->pdev,
> > vfio_intx_routing_notifier);
> > + vdev->irqchip_change_notifier.notify = vfio_irqchip_change;
> > + kvm_irqchip_add_change_notifier(&vdev->irqchip_change_notifier);
> > ret = vfio_intx_enable(vdev, errp);
> > if (ret) {
> > - goto out_teardown;
> > + goto out_deregister;
> > }
> > }
> >
> > if (vdev->display != ON_OFF_AUTO_OFF) {
> > ret = vfio_display_probe(vdev, errp);
> > if (ret) {
> > - goto out_teardown;
> > + goto out_deregister;
> > }
> > }
> > if (vdev->enable_ramfb && vdev->dpy == NULL) {
> > @@ -2992,11 +3002,11 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
> > if (vdev->display_xres || vdev->display_yres) {
> > if (vdev->dpy == NULL) {
> > error_setg(errp, "xres and yres properties require display=on");
> > - goto out_teardown;
> > + goto out_deregister;
> > }
> > if (vdev->dpy->edid_regs == NULL) {
> > error_setg(errp, "xres and yres properties need edid support");
> > - goto out_teardown;
> > + goto out_deregister;
> > }
> > }
> >
>
> After this change, we end up with:
>
> if (vfio_pci_read_config(&vdev->pdev, PCI_INTERRUPT_PIN, 1)) {
> vdev->intx.mmap_timer = timer_new_ms(QEMU_CLOCK_VIRTUAL,
> vfio_intx_mmap_enable, vdev);
> pci_device_set_intx_routing_notifier(&vdev->pdev,
> vfio_intx_routing_notifier);
> vdev->irqchip_change_notifier.notify = vfio_irqchip_change;
> kvm_irqchip_add_change_notifier(&vdev->irqchip_change_notifier);
> ret = vfio_intx_enable(vdev, errp);
> if (ret) {
> goto out_deregister;
> }
> }
>
> if (vdev->display != ON_OFF_AUTO_OFF) {
> ret = vfio_display_probe(vdev, errp);
> if (ret) {
> goto out_deregister;
> }
> }
> if (vdev->enable_ramfb && vdev->dpy == NULL) {
> error_setg(errp, "ramfb=on requires display=on");
> goto out_teardown;
> ^^^^^^^^^^^^
>
> This should be out_deregister.
Oops, fixed in my tree.
> The enable_ramfb property belongs to the nohotplug variant. It
> means QEMU is going to terminate and we probably don't really
> care to leak notifiers, but this still looks weird and fragile,
> if enable_ramfb ever becomes usable by hotpluggable devices
> one day.
>
> }
> if (vdev->display_xres || vdev->display_yres) {
> if (vdev->dpy == NULL) {
> error_setg(errp, "xres and yres properties require display=on");
> goto out_deregister;
> }
> if (vdev->dpy->edid_regs == NULL) {
> error_setg(errp, "xres and yres properties need edid support");
> goto out_deregister;
> }
> }
>
>
> > @@ -3020,8 +3030,10 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
> >
> > return;
> >
> > -out_teardown:
> > +out_deregister:
> > pci_device_set_intx_routing_notifier(&vdev->pdev, NULL);
> > + kvm_irqchip_remove_change_notifier(&vdev->irqchip_change_notifier);
> > +out_teardown:
> > vfio_teardown_msi(vdev);
> > vfio_bars_exit(vdev);
> > error:
> > @@ -3064,6 +3076,7 @@ static void vfio_exitfn(PCIDevice *pdev)
> > vfio_unregister_req_notifier(vdev);
> > vfio_unregister_err_notifier(vdev);
> > pci_device_set_intx_routing_notifier(&vdev->pdev, NULL);
> > + kvm_irqchip_remove_change_notifier(&vdev->irqchip_change_notifier);
> > vfio_disable_interrupts(vdev);
> > if (vdev->intx.mmap_timer) {
> > timer_free(vdev->intx.mmap_timer);
> > diff --git a/hw/vfio/pci.h b/hw/vfio/pci.h
> > index b329d50338..35626cd63e 100644
> > --- a/hw/vfio/pci.h
> > +++ b/hw/vfio/pci.h
> > @@ -169,6 +169,7 @@ typedef struct VFIOPCIDevice {
> > bool enable_ramfb;
> > VFIODisplay *dpy;
> > Error *migration_blocker;
> > + Notifier irqchip_change_notifier;
> > } VFIOPCIDevice;
> >
> > uint32_t vfio_pci_read_config(PCIDevice *pdev, uint32_t addr, int len);
>
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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