On 29/04/15 12:05, Roger Pau Monné wrote:
El 29/04/15 a les 2.38, Andrew Cooper ha escrit:
+
+ if ( is_pvh_domain(d) )
+ {
+ for ( i = 0; i < 0x10000; i++ )
+ /* NB: 0xcf8 has special treatment so we need to trap it. */
Why? (and irrespective of my question, cf8 expects a 4 byte access, and
surely cfc would need similar treatment?)
0xcfc-0xcff is already added to ioports_deny_access in construct_dom0. I
have no idea why 0xcf8 needs this special treatment, but Linux PVH fails
to enumerate PCI devices if Xen is not set to trap accesses to 0xcf8
(FreeBSD seems to be fine, either with 0xcf8 trapped or not).
Sorry for the noise on v3. I replied before seeing this reply.
cf8/cfc are used as an indirect pair for access to PCI config space.
They must be strictly be controlled by a single entity in a system, or
dom0 and Xen can race and interfere with each other. As a result,
permissions for cf8/cfc must never be set in the IO bitmap.
There are other indirect pairs which need similar treatment. Please
make sure that they get altered appropriately. (see admin_io_ok(),
which I think you can now fold given the updates to the dom0 io
permission rangesets.)
~Andrew
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