On 03/03/2014 07:33 PM, Paolo Bonzini wrote: > Il 03/03/2014 02:58, Alexey Kardashevskiy ha scritto: >> On 03/02/2014 08:31 AM, Paolo Bonzini wrote: >>> Il 01/03/2014 13:30, Alexey Kardashevskiy ha scritto: >>>>>> >>>>>> Corrupted DMA buffer is 0x e00000 -- 0x7f15c313f000. >>>>>> The e1000 packet is at 0x12ffac2 -- 0x7f15c313eac2. >>>>>> >>>>>> (0x7f15c313f000 - 0x7f15c313eac2) = 0x53e which is less than 0x5aa and >>>>>> (0x5aa - 0x53e) = 0x6c bytes get corrupted. >>>>>> >>>>>> I see here buffer overrun from e1000 and I suspect that your patch just >>>>>> hides this problem. What did I miss? >>>> >>>> Ping, anyone? >>> >>> You missed that this is a Xen-specific problem. Xen maps things a page at >>> a time, so address_space_map/unmap/rw can operate only on a small part of >>> the requested [address, address+length) range. >> >> Sorry, I am not following you here. Does KVM map things not page-aligned? > > Look in exec.c for xen_enabled(). Xen's implementation of > address_space_map/unmap is completely different.
Honestly cannot see much difference in the current QEMU... > >>> So there is no overrun in e1000. The patch is incomplete, because it fixes >>> only address_space_rw, but the problem is indeed in exec.c. >> >> So you know what the problem is? We have a bunch of bugreports against >> e1000 breaking things... > > This one had been reported and fixed already. Any hint? :) Could not spot any related to overrun except: a0ae17a 8 months ago Andrew Jones e1000: cleanup process_tx_desc but commit message says "complaints are false positives"... -- Alexey
