On Thu, Apr 23, 2020 at 06:38:40PM +0100, Andre Przywara wrote: > At the moment the IRQ line for a virtio-mmio device is assigned in the > generic device__register() routine in devices.c, by calling back into > virtio-mmio.c. This does not only sound slightly convoluted, but also > breaks when we try to register an MMIO device that is not a virtio-mmio > device. In this case container_of will return a bogus pointer (as it > assumes a struct virtio_mmio), and the IRQ allocation routine will > corrupt some data in the device_header (for instance the first byte > of the "data" pointer). > > Simply assign the IRQ directly in virtio_mmio_init(), before calling > device__register(). This avoids the problem and looks actually much more > straightforward. > > Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx> > --- > devices.c | 4 ---- > include/kvm/virtio-mmio.h | 1 - > virtio/mmio.c | 10 ++-------- > 3 files changed, 2 insertions(+), 13 deletions(-) > > diff --git a/devices.c b/devices.c > index a7c666a7..2c8b2665 100644 > --- a/devices.c > +++ b/devices.c > @@ -1,7 +1,6 @@ > #include "kvm/devices.h" > #include "kvm/kvm.h" > #include "kvm/pci.h" > -#include "kvm/virtio-mmio.h" > > #include <linux/err.h> > #include <linux/rbtree.h> > @@ -33,9 +32,6 @@ int device__register(struct device_header *dev) > case DEVICE_BUS_PCI: > pci__assign_irq(dev); > break; > - case DEVICE_BUS_MMIO: > - virtio_mmio_assign_irq(dev); > - break; Hmm, but then it's a bit ugly to handle these differently to PCI. How difficult is it to add a new bus type instead? e.g. stick the virtio mmio devices on DEVICE_BUS_VIRTIO_MMIO and then add the non-virtio MMIO devices to DEVICE_BUS_MMIO? Will
