linux-stable.git/drivers/xen, branch v4.6.2

xen/events: Don't move disabled irqs

2016-06-08T01:23:39+00:00

commit f0f393877c71ad227d36705d61d1e4062bc29cf5 upstream.

Commit ff1e22e7a638 ("xen/events: Mask a moving irq") open-coded
irq_move_irq() but left out checking if the IRQ is disabled. This broke
resuming from suspend since it tries to move a (disabled) irq without
holding the IRQ's desc->lock. Fix it by adding in a check for disabled
IRQs.

The resulting stacktrace was:
kernel BUG at /build/linux-UbQGH5/linux-4.4.0/kernel/irq/migration.c:31!
invalid opcode: 0000 [#1] SMP
Modules linked in: xenfs xen_privcmd ...
CPU: 0 PID: 9 Comm: migration/0 Not tainted 4.4.0-22-generic #39-Ubuntu
Hardware name: Xen HVM domU, BIOS 4.6.1-xs125180 05/04/2016
task: ffff88003d75ee00 ti: ffff88003d7bc000 task.ti: ffff88003d7bc000
RIP: 0010:[]  [] irq_move_masked_irq+0xd2/0xe0
RSP: 0018:ffff88003d7bfc50  EFLAGS: 00010046
RAX: 0000000000000000 RBX: ffff88003d40ba00 RCX: 0000000000000001
RDX: 0000000000000001 RSI: 0000000000000100 RDI: ffff88003d40bad8
RBP: ffff88003d7bfc68 R08: 0000000000000000 R09: ffff88003d000000
R10: 0000000000000000 R11: 000000000000023c R12: ffff88003d40bad0
R13: ffffffff81f3a4a0 R14: 0000000000000010 R15: 00000000ffffffff
FS:  0000000000000000(0000) GS:ffff88003da00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd4264de624 CR3: 0000000037922000 CR4: 00000000003406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffff88003d40ba38 0000000000000024 0000000000000000 ffff88003d7bfca0
 ffffffff814c8d92 00000010813ef89d 00000000805ea732 0000000000000009
 0000000000000024 ffff88003cc39b80 ffff88003d7bfce0 ffffffff814c8f66
Call Trace:
 [] eoi_pirq+0xb2/0xf0
 [] __startup_pirq+0xe6/0x150
 [] xen_irq_resume+0x319/0x360
 [] xen_suspend+0xb5/0x180
 [] multi_cpu_stop+0xb5/0xe0
 [] ? cpu_stop_queue_work+0x80/0x80
 [] cpu_stopper_thread+0xb0/0x140
 [] ? finish_task_switch+0x76/0x220
 [] ? __raw_callee_save___pv_queued_spin_unlock+0x11/0x20
 [] smpboot_thread_fn+0x105/0x160
 [] ? sort_range+0x30/0x30
 [] kthread+0xd8/0xf0
 [] ? kthread_create_on_node+0x1e0/0x1e0
 [] ret_from_fork+0x3f/0x70
 [] ? kthread_create_on_node+0x1e0/0x1e0

Signed-off-by: Ross Lagerwall 
Reviewed-by: Boris Ostrovsky 
Signed-off-by: David Vrabel 
Signed-off-by: Greg Kroah-Hartman

xen/evtchn: fix ring resize when binding new events

2016-05-04T15:37:01+00:00

The copying of ring data was wrong for two cases: For a full ring
nothing got copied at all (as in that case the canonicalized producer
and consumer indexes are identical). And in case one or both of the
canonicalized (after the resize) indexes would point into the second
half of the buffer, the copied data ended up in the wrong (free) part
of the new buffer. In both cases uninitialized data would get passed
back to the caller.

Fix this by simply copying the old ring contents twice: Once to the
low half of the new buffer, and a second time to the high half.

This addresses the inability to boot a HVM guest with 64 or more
vCPUs.  This regression was caused by 8620015499101090 (xen/evtchn:
dynamically grow pending event channel ring).

Reported-by: Konrad Rzeszutek Wilk 
Signed-off-by: Jan Beulich 
Cc:  # 4.4+
Signed-off-by: David Vrabel

xen/balloon: Fix crash when ballooning on x86 32 bit PAE

2016-04-06T10:29:18+00:00

Commit 55b3da98a40dbb3776f7454daf0d95dde25c33d2 (xen/balloon: find
non-conflicting regions to place hotplugged memory) caused a
regression in 4.4.

When ballooning on an x86 32 bit PAE system with close to 64 GiB of
memory, the address returned by allocate_resource may be above 64 GiB.
When using CONFIG_SPARSEMEM, this setup is limited to using physical
addresses < 64 GiB.  When adding memory at this address, it runs off
the end of the mem_section array and causes a crash.  Instead, fail
the ballooning request.

Signed-off-by: Ross Lagerwall 
Cc:  # 4.4+
Signed-off-by: David Vrabel

xen/events: Mask a moving irq

2016-04-04T10:18:00+00:00

Moving an unmasked irq may result in irq handler being invoked on both
source and target CPUs.

With 2-level this can happen as follows:

On source CPU:
        evtchn_2l_handle_events() ->
            generic_handle_irq() ->
                handle_edge_irq() ->
                   eoi_pirq():
                       irq_move_irq(data);

                       /***** WE ARE HERE *****/

                       if (VALID_EVTCHN(evtchn))
                           clear_evtchn(evtchn);

If at this moment target processor is handling an unrelated event in
evtchn_2l_handle_events()'s loop it may pick up our event since target's
cpu_evtchn_mask claims that this event belongs to it *and* the event is
unmasked and still pending. At the same time, source CPU will continue
executing its own handle_edge_irq().

With FIFO interrupt the scenario is similar: irq_move_irq() may result
in a EVTCHNOP_unmask hypercall which, in turn, may make the event
pending on the target CPU.

We can avoid this situation by moving and clearing the event while
keeping event masked.

Signed-off-by: Boris Ostrovsky 
Cc: stable@vger.kernel.org
Signed-off-by: David Vrabel

Merge tag 'for-linus-4.6-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

2016-03-22T19:55:17+00:00

Pull xen updates from David Vrabel:
 "Features and fixes for 4.6:

  - Make earlyprintk=xen work for HVM guests

  - Remove module support for things never built as modules"

* tag 'for-linus-4.6-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  drivers/xen: make platform-pci.c explicitly non-modular
  drivers/xen: make sys-hypervisor.c explicitly non-modular
  drivers/xen: make xenbus_dev_[front/back]end explicitly non-modular
  drivers/xen: make [xen-]ballon explicitly non-modular
  xen: audit usages of module.h ; remove unnecessary instances
  xen/x86: Drop mode-selecting ifdefs in startup_xen()
  xen/x86: Zero out .bss for PV guests
  hvc_xen: make early_printk work with HVM guests
  hvc_xen: fix xenboot for DomUs
  hvc_xen: add earlycon support

Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending

2016-03-22T19:41:14+00:00

Pull SCSI target updates from Nicholas Bellinger:
 "The highlights this round include:

   - Add target_alloc_session() w/ callback helper for doing se_session
     allocation + tag + se_node_acl lookup.  (HCH + nab)

   - Tree-wide fabric driver conversion to use target_alloc_session()

   - Convert sbp-target to use percpu_ida tag pre-allocation, and
     TARGET_SCF_ACK_KREF I/O krefs (Chris Boot + nab)

   - Convert usb-gadget to use percpu_ida tag pre-allocation, and
     TARGET_SCF_ACK_KREF I/O krefs (Andrzej Pietrasiewicz + nab)

   - Convert xen-scsiback to use percpu_ida tag pre-allocation, and
     TARGET_SCF_ACK_KREF I/O krefs (Juergen Gross + nab)

   - Convert tcm_fc to use TARGET_SCF_ACK_KREF I/O + TMR krefs

   - Convert ib_srpt to use percpu_ida tag pre-allocation

   - Add DebugFS node for qla2xxx target sess list (Quinn)

   - Rework iser-target connection termination (Jenny + Sagi)

   - Convert iser-target to new CQ API (HCH)

   - Add pass-through WRITE_SAME support for IBLOCK (Mike Christie)

   - Introduce data_bitmap for asynchronous access of data area (Sheng
     Yang + Andy)

   - Fix target_release_cmd_kref shutdown comp leak (Himanshu Madhani)

  Also, there is a separate PULL request coming for cxgb4 NIC driver
  prerequisites for supporting hw iscsi segmentation offload (ISO), that
  will be the base for a number of v4.7 developments involving
  iscsi-target hw offloads"

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (36 commits)
  target: Fix target_release_cmd_kref shutdown comp leak
  target: Avoid DataIN transfers for non-GOOD SAM status
  target/user: Report capability of handling out-of-order completions to userspace
  target/user: Fix size_t format-spec build warning
  target/user: Don't free expired command when time out
  target/user: Introduce data_bitmap, replace data_length/data_head/data_tail
  target/user: Free data ring in unified function
  target/user: Use iovec[] to describe continuous area
  target: Remove enum transport_lunflags_table
  target/iblock: pass WRITE_SAME to device if possible
  iser-target: Kill the ->isert_cmd back pointer in struct iser_tx_desc
  iser-target: Kill struct isert_rdma_wr
  iser-target: Convert to new CQ API
  iser-target: Split and properly type the login buffer
  iser-target: Remove ISER_RECV_DATA_SEG_LEN
  iser-target: Remove impossible condition from isert_wait_conn
  iser-target: Remove redundant wait in release_conn
  iser-target: Rework connection termination
  iser-target: Separate flows for np listeners and connections cma events
  iser-target: Add new state ISER_CONN_BOUND to isert_conn
  ...

drivers/xen: make platform-pci.c explicitly non-modular

2016-03-21T15:14:04+00:00

The Kconfig currently controlling compilation of this code is:

arch/x86/xen/Kconfig:config XEN_PVHVM
arch/x86/xen/Kconfig:   def_bool y

...meaning that it currently is not being built as a module by anyone.

Lets remove the modular code that is essentially orphaned, so that
when reading the driver there is no doubt it is builtin-only.

Since module_init translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.

Also note that MODULE_DEVICE_TABLE is a no-op for non-modular code.

We also delete the MODULE_LICENSE tag etc. since all that information
was (or is now) contained at the top of the file in the comments.

In removing "module" from the init fcn name, we observe a namespace
collision with the probe function, so we use "probe" in the name of
the probe function, and "init" in the registration fcn, as per
standard convention, as suggested by Stefano.

Signed-off-by: Paul Gortmaker 
Reviewed-by: Stefano Stabellini 
Signed-off-by: David Vrabel

drivers/xen: make sys-hypervisor.c explicitly non-modular

2016-03-21T15:14:03+00:00

The Kconfig currently controlling compilation of this code is:

config XEN_SYS_HYPERVISOR
       bool "Create xen entries under /sys/hypervisor"

...meaning that it currently is not being built as a module by anyone.

Lets remove the modular code that is essentially orphaned, so that
when reading the driver there is no doubt it is builtin-only.

Since module_init translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.  However
one could argue that fs_initcall() might make more sense here.

This change means that the one line function xen_properties_destroy()
has only one user left, and since that is inside an #ifdef, we just
manually inline it there vs. adding more ifdeffery around the function
to avoid compile warnings about "defined but not used".

In order to be consistent we also manually inline the other _destroy
functions that are also just one line sysfs functions calls with only
one call site remaing, even though they wouldn't need #ifdeffery.

Signed-off-by: Paul Gortmaker 
Reviewed-by: Stefano Stabellini 
Signed-off-by: David Vrabel

drivers/xen: make xenbus_dev_[front/back]end explicitly non-modular

2016-03-21T15:13:55+00:00

The Makefile / Kconfig currently controlling compilation here is:

obj-y   += xenbus_dev_frontend.o
[...]
obj-$(CONFIG_XEN_BACKEND) += xenbus_dev_backend.o

...with:

drivers/xen/Kconfig:config XEN_BACKEND
drivers/xen/Kconfig:    bool "Backend driver support"

...meaning that they currently are not being built as modules by anyone.

Lets remove the modular code that is essentially orphaned, so that
when reading the driver there is no doubt it is builtin-only.

Since module_init translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.

We also delete the MODULE_LICENSE tag since all that information
is already contained at the top of the file in the comments.

Signed-off-by: Paul Gortmaker 
Reviewed-by: Stefano Stabellini 
Signed-off-by: David Vrabel

drivers/xen: make [xen-]ballon explicitly non-modular

2016-03-21T15:13:44+00:00

The Makefile / Kconfig currently controlling compilation here is:

obj-y   += grant-table.o features.o balloon.o manage.o preempt.o time.o
[...]
obj-$(CONFIG_XEN_BALLOON)               += xen-balloon.o

...with:

drivers/xen/Kconfig:config XEN_BALLOON
drivers/xen/Kconfig:    bool "Xen memory balloon driver"

...meaning that they currently are not being built as modules by anyone.

Lets remove the modular code that is essentially orphaned, so that
when reading the driver there is no doubt it is builtin-only.

In doing so we uncover two implict includes that were obtained
by module.h having such a wide include scope itself:

In file included from drivers/xen/xen-balloon.c:41:0:
include/xen/balloon.h:26:51: warning: ‘struct page’ declared inside parameter list [enabled by default]
 int alloc_xenballooned_pages(int nr_pages, struct page **pages);
                                                   ^
include/xen/balloon.h: In function ‘register_xen_selfballooning’:
include/xen/balloon.h:35:10: error: ‘ENOSYS’ undeclared (first use in this function)
  return -ENOSYS;
          ^

This is fixed by adding mm-types.h and errno.h to the list.

We also delete the MODULE_LICENSE tags since all that information
is already contained at the top of the file in the comments.

Signed-off-by: Paul Gortmaker 
Reviewed-by: Stefano Stabellini 
Signed-off-by: David Vrabel