Currently if the balloon driver is unable to increase the guest's
reservation it assumes the failure was due to reaching its full
allocation, gives up on the ballooning operation and records the limit
it reached as the "hard limit". The driver will not try again until
the target is set again (even to the same value).

However it is possible that ballooning has in fact failed due to
memory pressure in the host and therefore it is desirable to keep
attempting to reach the target in case memory becomes available. The
most likely scenario is that some guests are ballooning down while
others are ballooning up and therefore there is temporary memory
pressure while things stabilise. You would not expect a well behaved
toolstack to ask a domain to balloon to more than its allocation nor
would you expect it to deliberately over-commit memory by setting
balloon targets which exceed the total host memory.

This patch drops the concept of a hard limit and causes the balloon
driver to retry increasing the reservation on a timer in the same
manner as when decreasing the reservation.

Also if we partially succeed in increasing the reservation
(i.e. receive less pages than we asked for) then we may as well keep
those pages rather than returning them to Xen.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: Stable Kernel <stable@kernel.org>

Change totalram_pages when a single page is added/removed to the
ballooned list. This avoid totalram_pages to be set erroneously to
max_pfn at boot.
Signed-off-by: Gianluca Guida <gianluca.guida@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>

I have observed cases where the implicit stop_machine_destroy() done by
stop_machine() hangs while destroying the workqueues, specifically in
kthread_stop(). This seems to be because timer ticks are not restarted
until after stop_machine() returns.

Fortunately stop_machine provides a facility to pre-create/post-destroy
the workqueues so use this to ensure that workqueues are only destroyed
after everything is really up and running again.

I only actually observed this failure with 2.6.30. It seems that newer
kernels are somehow more robust against doing kthread_stop() without timer
interrupts (I tried some backports of some likely looking candidates but
did not track down the commit which added this robustness). However this
change seems like a reasonable belt&braces thing to do.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>

The existing error handling has a few issues:
- If freeze_processes() fails it exits with shutting_down = SHUTDOWN_SUSPEND.
- If dpm_suspend_noirq() fails it exits without resuming xenbus.
- If stop_machine() fails it exits without resuming xenbus or calling
  dpm_resume_end().
- xs_suspend()/xs_resume() and dpm_suspend_noirq()/dpm_resume_noirq() were not
  nested in the obvious way.

Fix by ensuring each failure case goto's the correct label. Treat a failure of
stop_machine() as a cancelled suspend in order to follow the correct resume
path.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>

On resume irq_info[*].evtchn is reset to 0 since event channel mappings
are not preserved over suspend/resume. The other contents of irq_info
is preserved to allow rebind_evtchn_irq() to function.

However when a device resumes it will try to unbind from the
previous IRQ (e.g.  blkfront goes blkfront_resume() -> blkif_free() ->
unbind_from_irqhandler() -> unbind_from_irq()). This will fail due to the
check for VALID_EVTCHN in unbind_from_irq() and the IRQ is leaked. The
device will then continue to resume and allocate a new IRQ, eventually
leading to find_unbound_irq() panic()ing.

Fix this by changing unbind_from_irq() to handle teardown of interrupts
which have type!=IRQT_UNBOUND but are not currently bound to a specific
event channel.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>

tick_resume() is never called on secondary processors. Presumably this
is because they are offlined for suspend on native and so this is
normally taken care of in the CPU onlining path. Under Xen we keep all
CPUs online over a suspend.

This patch papers over the issue for me but I will investigate a more
generic, less hacky, way of doing to the same.

tick_suspend is also only called on the boot CPU which I presume should
be fixed too.
Signed-off-by: Ian Campbell <Ian.Campbell@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>

If Xen wants to return to a 32b usermode with sysret it must use the
right form.  When using VCGF_in_syscall to trigger this, it looks at
the code segment and does a 32b sysret if it is FLAT_USER_CS32.
However, this is different from __USER32_CS, so it fails to return
properly if we use the normal Linux segment.

So avoid the whole mess by dropping VCGF_in_syscall and simply use
plain iret to return to usermode.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: Jan Beulich <jbeulich@novell.com>
Cc: Stable Kernel <stable@kernel.org>

dpm_resume_noirq() takes a mutex, so it can't be called from a no-interrupt
context.  Don't call it from within the stop-machine function, but just
afterwards, since we're resuming anyway, regardless of what happened.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>

printk timestamping uses sched_clock, which in turn relies on runstate
info under Xen.  So make sure we set it up before any printks can
be called.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>

The commit "xen: re-register runstate area earlier on resume" caused us
to never try and setup the runstate area for secondary CPUs. Ensure that
we do this...
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>

Otherwise the timer is disabled by dpm_suspend_noirq() which in turn prevents
correct operation of stop_machine on multi-processor systems and breaks
suspend.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>

pvops kernels >= 2.6.30 can currently only be saved and restored once. The
second attempt to save results in:

    ERROR Internal error: Frame# in pfn-to-mfn frame list is not in pseudophys
    ERROR Internal error: entry 0: p2m_frame_list[0] is 0xf2c2c2c2, max 0x120000
    ERROR Internal error: Failed to map/save the p2m frame list

I finally narrowed it down to:

    commit cdaead6b
        Author: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
        Date:   Fri Feb 27 15:34:59 2009 -0800

            xen: split construction of p2m mfn tables from registration

            Build the p2m_mfn_list_list early with the rest of the p2m table, but
            register it later when the real shared_info structure is in place.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

The unforeseen side-effect of this change was to cause the mfn list list to not
be rebuilt on resume. Prior to this change it would have been rebuilt via
xen_post_suspend() -> xen_setup_shared_info() -> xen_setup_mfn_list_list().

Fix by explicitly calling xen_build_mfn_list_list() from xen_post_suspend().
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>

Even if have_vcpu_info_placement is not set, we still need to set up
the runstate area on each resumed vcpu.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>

This is necessary to ensure the runstate area is available to
xen_sched_clock before any calls to printk which will require it in
order to provide a timestamp.

I chose to pull the xen_setup_runstate_info out of xen_time_init into
the caller in order to maintain parity with calling
xen_setup_runstate_info separately from calling xen_time_resume.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>

Increases the device timeout from 10s to 5 minutes, giving the user a
visual indication during that time in case there are problems.  The patch
is a backport of changesets 144 and 150 in the Xenbits tree.

Cc: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

When printing a warning about a timed-out device, print the
current state of both ends of the device connection (i.e., backend as
well as frontend).  This backports half of changeset 146 from the
Xenbits tree.

Cc: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

The logic of is_disconnected_device/exists_disconnected_device is wrong
in that they are used to test whether a device is trying to connect (i.e.
connecting).  For this reason the patch fixes them to not consider a
Closing or Closed device to be connecting.  At the same time the patch
also renames the functions according to what they really do; you could
say a closed device is "disconnected" (the old name), but not "connecting"
(the new name).

This patch is a backport of changeset 909 from the Xenbits tree.

Cc: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

They don't need to be global, and may cause linker clashes.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>

A Xen guest never needs to know about extended topology, and knowing
would just confuse it.

This patch just zeros ebx in leaf 0xb which indicates no topology info,
preventing a crash under Xen on cpus which support this leaf.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>

We never want to rely on the hvc workqueue to emit output, because the
most interesting output is when the kernel is broken.  This will
improve oops/crash/console message for better debugging.

Instead, we force-poll until all output is emitted.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>

xen_setup_stackprotector() ends up trying to set page protections,
so we need to have vm_mmu_ops set up before trying to do so.
Failing to do so causes an early boot crash.

[ Impact: Fix early crash under Xen. ]
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
  move virtrng_remove to .devexit.text
  move virtballoon_remove to .devexit.text
  virtio_blk: Revert serial number support
  virtio: let header files include virtio_ids.h
  virtio_blk: revert QUEUE_FLAG_VIRT addition

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (21 commits)
  niu: VLAN_ETH_HLEN should be used to make sure that the whole MAC header was copied to the head buffer in the Vlan packets case
  KS8851: Fix ks8851_set_rx_mode() for IFF_MULTICAST
  KS8851: Fix MAC address write order
  KS8851: Add soft reset at probe time
  net: fix section mismatch in fec.c
  net: Fix struct inet_timewait_sock bitfield annotation
  tcp: Try to catch MSG_PEEK bug
  net: Fix IP_MULTICAST_IF
  bluetooth: static lock key fix
  bluetooth: scheduling while atomic bug fix
  tcp: fix TCP_DEFER_ACCEPT retrans calculation
  tcp: reduce SYN-ACK retrans for TCP_DEFER_ACCEPT
  tcp: accept socket after TCP_DEFER_ACCEPT period
  Revert "tcp: fix tcp_defer_accept to consider the timeout"
  AF_UNIX: Fix deadlock on connecting to shutdown socket
  ethoc: clear only pending irqs
  ethoc: inline regs access
  vmxnet3: use dev_dbg, fix build for CONFIG_BLOCK=n
  virtio_net: use dev_kfree_skb_any() in free_old_xmit_skbs()
  be2net: fix support for PCI hot plug
  ...

The function virtrng_remove is used only wrapped by __devexit_p so define
it using __devexit.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

The function virtballoon_remove is used only wrapped by __devexit_p so
define it using __devexit.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

This reverts "Add serial number support for virtio_blk, V4a".

Turns out that virtio_pci, lguest and s/390 all have an 8 bit limit
on virtio config space, so noone could ever use this.

This is coming back later in a cleaner form.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: john cooper <john.cooper@redhat.com>
Cc: Jens Axboe <jens.axboe@oracle.com>

Rusty,

commit 3ca4f5ca
    virtio: add virtio IDs file
moved all device IDs into a single file. While the change itself is
a very good one, it can break userspace applications. For example
if a userspace tool wanted to get the ID of virtio_net it used to
include virtio_net.h. This does no longer work, since virtio_net.h
does not include virtio_ids.h.
This patch moves all "#include <linux/virtio_ids.h>" from the C
files into the header files, making the header files compatible with
the old ones.

In addition, this patch exports virtio_ids.h to userspace.

CC: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

It seems like the addition of QUEUE_FLAG_VIRT caueses major performance
regressions for Fedora users:

	https://bugzilla.redhat.com/show_bug.cgi?id=509383
	https://bugzilla.redhat.com/show_bug.cgi?id=505695

while I can't reproduce those extreme regressions myself I think the flag
is wrong.

Rationale:

  QUEUE_FLAG_VIRT expands to QUEUE_FLAG_NONROT which casus the queue
  unplugged immediately.  This is not a good behaviour for at least
  qemu and kvm where we do have significant overhead for every
  I/O operations.  Even with all the latested speeups (native AIO,
  MSI support, zero copy) we can only get native speed for up to 128kb
  I/O requests we already are down to 66% of native performance for 4kb
  requests even on my laptop running the Intel X25-M SSD for which the
  QUEUE_FLAG_NONROT was designed.
  If we ever get virtio-blk overhead low enough that this flag makes
  sense it should only be set based on a feature flag set by the host.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

niu: VLAN_ETH_HLEN should be used to make sure that the whole MAC header was copied to the head buffer in the Vlan packets case
Signed-off-by: Joyce Yu <joyce.yu@sun.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

* 'for-linus' of git://git.infradead.org/users/eparis/notify:
  dnotify: ignore FS_EVENT_ON_CHILD
  inotify: fix coalesce duplicate events into a single event in special case
  inotify: deprecate the inotify kernel interface
  fsnotify: do not set group for a mark before it is on the i_list

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: hp_sdc_rtc - fix test in hp_sdc_rtc_read_rt()
  Input: atkbd - consolidate force release quirks for volume keys
  Input: logips2pp - model 73 is actually TrackMan FX
  Input: i8042 - add Sony Vaio VGN-FZ240E to the nomux list
  Input: fix locking issue in /proc/bus/input/ handlers
  Input: atkbd - postpone restoring LED/repeat rate at resume
  Input: atkbd - restore resetting LED state at startup
  Input: i8042 - make pnp_data_busted variable boolean instead of int
  Input: synaptics - add another Protege M300 to rate blacklist

* 'kvm-updates/2.6.32' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: Prevent kvm_init from corrupting debugfs structures
  KVM: MMU: fix pointer cast
  KVM: use proper hrtimer function to retrieve expiration time

* git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm:
  dm snapshot: allow chunk size to be less than page size
  dm snapshot: use unsigned integer chunk size
  dm snapshot: lock snapshot while supplying status
  dm exception store: fix failed set_chunk_size error path
  dm snapshot: require non zero chunk size by end of ctr
  dm: dec_pending needs locking to save error value
  dm: add missing del_gendisk to alloc_dev error path
  dm log: userspace fix incorrect luid cast in userspace_ctr
  dm snapshot: free exception store on init failure
  dm snapshot: sort by chunk size to fix race

Increase TEST_SUSPEND_SECONDS to 10 so the warning in
suspend_test_finish() doesn't annoy the users of slower systems so much.

Also, make the warning print the suspend-resume cycle time, so that we
know why the warning actually triggered.

Patch prepared during the hacking session at the Kernel Summit in Tokyo.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This fixes a compile bug introduced in

	6ef297f8 (ARM: 5720/1: Move MMCI header to amba include dir)

That commit moved arch/arm/include/asm/mach/mmc.h to
include/linux/amba/mmci.h.  Just removing the include was enough.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Bill Gatliff <bgat@billgatliff.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Pierre Ossman <drzeus@drzeus.cx>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'sh/for-2.6.32' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6:
  sh: Kill off stray HAVE_FTRACE_SYSCALLS reference.
  sh: Remove BKL from landisk gio.
  sh: disabled cache handling fix.
  sh: Fix up single page flushing to use PAGE_SIZE.

* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: aesni-intel - Fix irq_fpu_usable usage
  crypto: padlock-sha - Fix stack alignment

Fix a (small) memory leak in one of the error paths of the NFS mount
options parsing code.

Regression introduced in 2.6.30 by commit a67d18f8 (NFS: load the
rpc/rdma transport module automatically).
Reported-by: Yinghai Lu <yinghai@kernel.org>
Reported-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This patch fixes a null pointer exception in pipe_rdwr_open() which
generates the stack trace:

> Unable to handle kernel NULL pointer dereference at 0000000000000028 RIP:
>  [<ffffffff802899a5>] pipe_rdwr_open+0x35/0x70
>  [<ffffffff8028125c>] __dentry_open+0x13c/0x230
>  [<ffffffff8028143d>] do_filp_open+0x2d/0x40
>  [<ffffffff802814aa>] do_sys_open+0x5a/0x100
>  [<ffffffff8021faf3>] sysenter_do_call+0x1b/0x67

The failure mode is triggered by an attempt to open an anonymous
pipe via /proc/pid/fd/* as exemplified by this script:

=============================================================
while : ; do
   { echo y ; sleep 1 ; } | { while read ; do echo z$REPLY; done ; } &
   PID=$!
   OUT=$(ps -efl | grep 'sleep 1' | grep -v grep |
        { read PID REST ; echo $PID; } )
   OUT="${OUT%% *}"
   DELAY=$((RANDOM * 1000 / 32768))
   usleep $((DELAY * 1000 + RANDOM % 1000 ))
   echo n > /proc/$OUT/fd/1                 # Trigger defect
done
=============================================================

Note that the failure window is quite small and I could only
reliably reproduce the defect by inserting a small delay
in pipe_rdwr_open(). For example:

 static int
 pipe_rdwr_open(struct inode *inode, struct file *filp)
 {
       msleep(100);
       mutex_lock(&inode->i_mutex);

Although the defect was observed in pipe_rdwr_open(), I think it
makes sense to replicate the change through all the pipe_*_open()
functions.

The core of the change is to verify that inode->i_pipe has not
been released before attempting to manipulate it. If inode->i_pipe
is no longer present, return ENOENT to indicate so.

The comment about potentially using atomic_t for i_pipe->readers
and i_pipe->writers has also been removed because it is no longer
relevant in this context. The inode->i_mutex lock must be used so
that inode->i_pipe can be dealt with correctly.
Signed-off-by: Earl Chew <earl_chew@agilent.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

In ks8851_set_rx_mode() the case handling IFF_MULTICAST was also setting
the RXCR1_AE bit by accident. This meant that all unicast frames where
being accepted by the device. Remove RXCR1_AE from this case.

Note, RXCR1_AE was also masking a problem with setting the MAC address
properly, so needs to be applied after fixing the MAC write order.

Fixes a bug reported by Doong, Ping of Micrel. This version of the
patch avoids setting RXCR1_ME for all cases.
Signed-off-by: Ben Dooks <ben@simtec.co.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>