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"...