for spurious write faults on mappings that have been
changed from read-only to writable. If a CPU has a stale
read-only entry in its TLB, it is allowed to fault on
the next write access without re-walking the page table.
Signed-off-by: Keir Fraser <keir@xensource.com>
for unprivileged domains (in any case, can fall back to swiotlb).
On non-privileged domain of Xen/IA64, this caused some trouble.
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
can sleep, we could race save/restore and end up with stale
machine addresses stores in pgd entries. Avoid this by
remembering virtuall addresses and translating to machine
addresses all at the end and protected by the pgd_lock.
Signed-off-by: Keir Fraser <keir@xensource.com>
when reconnecting to backend driver (e.g., after save/restore or migrate).
Two main reasons for this:
1. The retransmit code is broken for fragmented packets. It would need
a rewrite to cope with the new scatter-gather format.
2. We will drop packets anyway, in both directions (e.g., takes some
time for received packets to be redirected to new virtual interface;
also further transmitted packets from the network stack are dropped
after we call netif_carrier_off(), so even if we retransmite what's
already in the ring it is likely that some subsequent packets will
already be lost).
If this causes downtimes that are too long (particularly for live
relocation) then the whole strategy for buffering packets while the
frontend-backend connection is severed needs to be considered.
Signed-off-by: Keir Fraser <keir@xensource.com>
Moving the re-allocation to low memory into pgd_alloc() has several
advantages:
1. Avoids race with save/restore where pgdir may end up above 4GB after
save/restore.
2. If pgdir cannot be re-allocated we can return failure to the caller
rather than BUG().
3. Slightly reduces diff against native Linux code.
Signed-off-by: Keir Fraser <keir@xensource.com>
1. We must ensure gnttab callbacks are disabled and all work
flushed before tearing down device state. A new gnttab interface
call is added for this purpose.
2. blkif_free() must check for a request_queue before deref'ing it.
Signed-off-by: Keir Fraser <keir@xensource.com>
after the device-specific resume code has run. Also removed some unused /
usless code from netfront.c.
Signed-off-by: Steven Hand <steven@xensource.com>
There is a problem with the current implementation of stop_hz_timer in
arch/i386/kernel/time-xen.c where the hz timer can be stopped on a CPU
which has RCU callbacks pending.
This patch backports a new RCU API created to fix this problem for the
s390 implementation of stop_hz_timer and also updates the time-xen.c
implementation of stop_hz_timer to call the new API.
Signed-off-by: Harry Butterworth <butterwo@uk.ibm.com>
The logic now mimics native x86 behaviour: a request to change
affinity via /proc is held until the next interrupt on that
event channel. So /proc/irq/n/smp_affinity may not change
immediately!
Other notes:
1. CPU-specific interrupts silently ignore requests to change
affinity. For example, resched0, timer0, callfunc0, ...
2. Reading smp_affinity always returns a cpumask containing
a single cpu. An event channel can only be bound to a single
cpu at a time. Neither Xen nor XenLinux implement IRQ
balancing: requires a user-space balancing daemon.
Signed-off-by: Keir Fraser <keir@xensource.com>
xenbus_transaction_t -> struct xenbus_transaction, which just contains
a single u32. Also renamed XBT_NULL to XBT_NIL to emphasize that it
isn't a NULL pointer, but a NIL transaction ID. Compile and boot tested.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
[chrisw: updated for xen-unstable from patchqueue]
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
instead, since that's what it is there for. Similar to patch
in patchqueue started by Jeremy, and expanded by me to include all
relevant drivers in xen-unstable.
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
EXPORTs with functions, order includes, eliminate unsed macros, don't
initialize static data to NULL, etc. Cleanups from patchqueue.
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
While there rearrange the ring setup order slightly to simplify error
path since netif_free() will cleanup once ring_ref is valid. And use
get_zeroed_page() instead of __get_free_page()/memset(). Handle error if
bind_evtchn_to_irqhandler() fails, as bad info->irq value is likely to
cause oops later. In create_device(), gnttab_free_grant_references()
is accidentally called twice on tx_head during cleanup from failed
gnttab_alloc_grant_references() on rx_head, which could corrupt
gnttab_free_count.
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Here's a first pass at some sparse tree cleanups based on feedback
we've gotten on linux-ia64. I haven't taken all of the comments into
account yet, this is just a start. Specific changes:
- CONFIG_ARCH_XEN is no longer necessary
- simple is_running_on_xen() checks can be handled w/o CONFIG_XEN
- pulled forward a drivers/xen/Makefile change that broken make clean
- changed some comments from C++ style to C
- turned HYPERVISOR_ioremap into a macro for !CONFIG_XEN
- made hypervisor.h and privop.h include-able for !CONFIG_XEN
Signed-off-by: Alex Williamson <alex.williamson@hp.com>
As discussed previously, the these operations are not performance-sensitive, so
the additional cache footprint shouldn't be an issue.
Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>
