From: Prasad J Pandit USB Ehci emulation supports host controller capability registers. But its mmio '.write' function was missing, which lead to a null pointer dereference issue. Add a do nothing 'ehci_caps_write' definition to avoid it; Do nothing because capability registers are Read Only(RO). Reported-by: Zuozhi Fzz Signed-off-by: Prasad J Pandit --- hw/usb/hcd-ehci.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/hw/usb/hcd-ehci.c b/hw/usb/hcd-ehci.c index c40013e..b08ff62 100644 --- a/tools/qemu-xen/hw/usb/hcd-ehci.c +++ b/tools/qemu-xen/hw/usb/hcd-ehci.c @@ -893,6 +893,11 @@ static uint64_t ehci_caps_read(void *ptr, hwaddr addr, return s->caps[addr]; } +static void ehci_caps_write(void *ptr, hwaddr addr, + uint64_t val, unsigned size) +{ +} + static uint64_t ehci_opreg_read(void *ptr, hwaddr addr, unsigned size) { @@ -2313,6 +2318,7 @@ static void ehci_frame_timer(void *opaque) static const MemoryRegionOps ehci_mmio_caps_ops = { .read = ehci_caps_read, + .write = ehci_caps_write, .valid.min_access_size = 1, .valid.max_access_size = 4, .impl.min_access_size = 1, -- 2.5.0