Re: 'virtio DMA to IO ram' error

[Avi Kivity <avi@redhat.com>]

Passera, Pablo R wrote:
> Hi everybody,
>
>         I am trying to implement a new virtio device. I have implemented the new device in Qemu and I also have the correspondent virtio driver in the guest. But when I get data in the device and I try to put that into the virtqueue using virtqueue_pop, the qemu instance crash showing the error 'virtio DMA to IO ram'. This is in the virtio_map_gpa function in virtio.c. Does anyone knows what this means?
>
>         Here is the code from virtio_map_gpa
> .
> .
> static void *virtio_map_gpa(target_phys_addr_t addr, size_t size)
> {
>     ram_addr_t off;
>     target_phys_addr_t addr1;
>
>     off = cpu_get_physical_page_desc(addr);
>     if ((off & ~TARGET_PAGE_MASK) != IO_MEM_RAM) {
>         fprintf(stderr, "virtio DMA to IO ram 1\n");
>         exit(1);
>     }
>   

In means the virtio buffers point to memory that is not RAM, but is some 
memory-mapped I/O range or pehaps unmapped.  I suggest printing the 
physical addresses both in the guest and in qemu; something is likely 
garbled.



-- 
error compiling committee.c: too many arguments to function