Re: [Qemu-devel] qemu git (f03d07d46) / e100 / sending large packets causes SIGABRT

[Stefan Hajnoczi]

On Wed, Jul 24, 2013 at 01:17:29PM +0300, Oleksii Shevchuk wrote:
> 
> 1. qemu-kvm -sdl -nodefaults -name NP1-C1                           \
>   -uuid b71057e9-5705-420b-a780-52339afa6ed9                        \
>   -boot c                                                           \
>   -hda np1UD.disk                                                   \
>   -hdb fat:exchange                                                 \
>   -device i82559c,netdev=vin0,romfile="",mac="00:11:22:33:44:54"    \
>   -netdev tap,id=vin0,ifname=vin0,script=no                         \
>   -device cirrus-vga                                                \
>   -serial pty                                                       \
>   &
> 
> 2. ping -s 65000
> 
> 3. Program received signal SIGABRT, Aborted.

Here is an annotated backtrace:

> #7  tx_command (address@hidden) at 
> /tmp/portage/app-emulation/qemu-9999/work/qemu-9999/hw/net/eepro100.c:804
> #6  pci_dma_read (len=0x53f, buf=0x7f9a97ffe022, addr=0x86fa4000, 
> dev=0x7f9aac086820) at 
> /tmp/portage/app-emulation/qemu-9999/work/qemu-9999/include/hw/pci/pci.h:659

len=0x53f is an odd number: 1343

> #5  pci_dma_rw (dir=DMA_DIRECTION_TO_DEVICE, len=0x53f, buf=0x7f9a97ffe022, 
> addr=0x86fa4000, dev=0x7f9aac086820) at 
> /tmp/portage/app-emulation/qemu-9999/work/qemu-9999/include/hw/pci/pci.h:652
> #4  dma_memory_rw (dir=DMA_DIRECTION_TO_DEVICE, len=0x53f, 
> buf=0x7f9a97ffe022, addr=0x86fa4000, as=0x7f9aac086a40) at 
> /tmp/portage/app-emulation/qemu-9999/work/qemu-9999/include/sysemu/dma.h:112
> #3  0x00007f9aa96d6349 in dma_memory_rw_relaxed (dir=DMA_DIRECTION_TO_DEVICE, 
> len=0x53f, buf=0x7f9a97ffe022, addr=0x86fa4000, as=0x7f9aac086a40) at 
> /tmp/portage/app-emulation/qemu-9999/work/qemu-9999/include/sysemu/dma.h:90
> #2  0x00007f9aa97cb9ac in address_space_rw (address@hidden, addr=0x86fa453c, 
> address@hidden, buf=0x7f9a97ffe55e 
> "address@hidden:9\337\070\071\071\332G;:\340\071::\336H<;\341:;;\342I=<\342;<<\346J>=\343<==\352K?>\344=>>",
>  '\377' <repeats 92 times>..., address@hidden '\377' <repeats 200 times>..., 
> len=0x3, address@hidden, address@hidden) at 
> /tmp/portage/app-emulation/qemu-9999/work/qemu-9999/exec.c:2005

There are only a few bytes remaining: len=0x3.  The abort(3) comes from 
address_space_rw():

if (!memory_access_is_direct(mr, is_write)) {
    /* I/O case */
    l = memory_access_size(mr, l, addr1);
    switch (l) {
    case 8:
        ...
    case 4:
        ...
    case 2:
        ...
    case 1:
        ...
    default:
        abort();  <-- we abort here
}

Paolo: Do you know how the memory API is supposed to work here?

Stefan