Current snaphost code does not properly handle moving inode from one
empty snap realm to another empty snap realm. After changing inode's
snap realm, some dirty pages' snap context can be not equal to inode's
i_head_snap. This can trigger BUG() in ceph_put_wrbuffer_cap_refs()
The fix is introduce a global empty snap context for all empty snap
realm. This avoids triggering the BUG() for filesystem with no snapshot.
Fixes: http://tracker.ceph.com/issues/9928
Signed-off-by: Yan, Zheng <zyan@redhat.com>
Reviewed-by: Ilya Dryomov <idryomov@redhat.com>
There were two places we were assigning version in host byte order
instead of network byte order.
Also in MSG_CLIENT_SESSION we weren't setting compat_version in the
header to reflect continued compatability with older MDSs.
Fixes: http://tracker.ceph.com/issues/9945
Signed-off-by: John Spray <john.spray@redhat.com>
Reviewed-by: Sage Weil <sage@redhat.com>
2 bytes of what was reserved space is now used by userspace for the
compat_version field.
Signed-off-by: John Spray <john.spray@redhat.com>
Reviewed-by: Sage Weil <sage@redhat.com>
Session key is required when calculating message signature. Save the session
key in authorizer, this avoid lookup ticket handler for each message
Signed-off-by: Yan, Zheng <zyan@redhat.com>
The functions ceph_put_snap_context() and iput() test whether their
argument is NULL and then return immediately. Thus the test around the
call is not needed.
This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
[idryomov@redhat.com: squashed rbd.c hunk, changelog]
Signed-off-by: Ilya Dryomov <idryomov@redhat.com>
After creating/deleting/renaming file, offsets of sibling dentries may
change. So we can not use cached dentries to satisfy readdir. But we can
still use the cached dentries to conclude -ENOENT for lookup.
This patch introduces a new inode flag indicating if child dentries are
ordered. The flag is set at the same time marking a directory complete.
After creating/deleting/renaming file, we clear the flag on directory
inode. This prevents ceph_readdir() from using cached dentries to satisfy
readdir syscall.
Signed-off-by: Yan, Zheng <zyan@redhat.com>
Use kvfree() from linux/mm.h instead, which is identical. Also fix the
ceph_buffer comment: we will allocate with kmalloc() up to 32k - the
value of PAGE_ALLOC_COSTLY_ORDER, but that really is just an
implementation detail so don't mention it at all.
Signed-off-by: Ilya Dryomov <idryomov@redhat.com>
When a lock operation is interrupted, current code sends a unlock request to
MDS to undo the lock operation. This method does not work as expected because
the unlock request can drop locks that have already been acquired.
The fix is use the newly introduced CEPH_LOCK_FCNTL_INTR/CEPH_LOCK_FLOCK_INTR
requests to interrupt blocked file lock request. These requests do not drop
locks that have alread been acquired, they only interrupt blocked file lock
request.
Signed-off-by: Yan, Zheng <zyan@redhat.com>
Commit 80e96c5484 ("dm thin: do not allow thin device activation
while pool is suspended") delayed the initialization of a new thin
device's refcount and completion until after this new thin was added
to the pool's active_thins list and the pool lock is released. This
opens a race with a worker thread that walks the list and calls
thin_get/put, noticing that the refcount goes to 0 and calling
complete, freezing up the system and giving the oops below:
kernel: BUG: unable to handle kernel NULL pointer dereference at (null)
kernel: IP: [<ffffffff810d360b>] __wake_up_common+0x2b/0x90
kernel: Call Trace:
kernel: [<ffffffff810d3683>] __wake_up_locked+0x13/0x20
kernel: [<ffffffff810d3dc7>] complete+0x37/0x50
kernel: [<ffffffffa0595c50>] thin_put+0x20/0x30 [dm_thin_pool]
kernel: [<ffffffffa059aab7>] do_worker+0x667/0x870 [dm_thin_pool]
kernel: [<ffffffff816a8a4c>] ? __schedule+0x3ac/0x9a0
kernel: [<ffffffff810b1aef>] process_one_work+0x14f/0x400
kernel: [<ffffffff810b206b>] worker_thread+0x6b/0x490
kernel: [<ffffffff810b2000>] ? rescuer_thread+0x260/0x260
kernel: [<ffffffff810b6a7b>] kthread+0xdb/0x100
kernel: [<ffffffff810b69a0>] ? kthread_create_on_node+0x170/0x170
kernel: [<ffffffff816ad7ec>] ret_from_fork+0x7c/0xb0
kernel: [<ffffffff810b69a0>] ? kthread_create_on_node+0x170/0x170
Set the thin device's initial refcount and initialize the completion
before adding it to the pool's active_thins list in thin_ctr().
Signed-off-by: Marc Dionne <marc.dionne@your-file-system.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Packard Bell EasyNote MX65 with AD1986A codec needs a few fixups,
namely, the pin config overrides to set only the known I/O pins and
the EAPD has to be turned on. In addition, add stereo mix input
forcibly for avoiding the weird KDE behavior by this update.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=88251
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Discard bios and thin device deletion have the potential to release data
blocks. If the thin-pool is in out-of-data-space mode, and blocks were
released, transition the thin-pool back to full write mode.
The correct time to do this is just after the thin-pool metadata commit.
It cannot be done before the commit because the space maps will not
allow immediate reuse of the data blocks in case there's a rollback
following power failure.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
When the pool was in PM_OUT_OF_SPACE mode its process_prepared_discard
function pointer was incorrectly being set to
process_prepared_discard_passdown rather than process_prepared_discard.
This incorrect function pointer meant the discard was being passed down,
but not effecting the mapping. As such any discard that was issued, in
an attempt to reclaim blocks, would not successfully free data space.
Reported-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
This patch adds native DSD support for two XMOS based DACs from Matrix Audio:
- X-Sabre
- Mini-i Pro
Signed-off-by: Jurgen Kramer <gtmkramer@xs4all.nl>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The release_firmware() function tests whether its argument is NULL
and then returns immediately. Thus the test around the call is not needed.
This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Rob Clark <robdclark@gmail.com>
The functions framebuffer_release() and vunmap() perform also input
parameter validation. Thus the test around the call is not needed.
This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Rob Clark <robdclark@gmail.com>
Audio subsystem clocks are located in separate block. On Exynos 5420 if
clock for this block (from main clock domain) 'mau_epll' is gated then
any read or write to audss registers will block.
This kind of boot hang was observed on Arndale Octa and Peach Pi/Pit
after introducing runtime PM to pl330 DMA driver. After that commit the
'mau_epll' was gated, because the "amba" clock was disabled and there
were no more users of mau_epll.
The system hang on one of steps:
1. Disabling unused clocks from audss block.
2. During audss GPIO setup (just before probing i2s0 because
samsung_pinmux_setup() tried to access memory from audss block which was
gated.
Add a workaround for this by enabling the 'mau_epll' clock in probe.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Tested-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Tested-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
In filename__read_build_id, phdr points to memory in buf, which gets realloced
before a call to fseek that uses phdr->p_offset. This change stores the value
of p_offset before buf is realloced, so the fseek can use the value safely.
Signed-off-by: Mitchell Krome <mitchellkrome@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20141216021612.GA7199@mitchell
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To replace equivalent code used in the mmap_pages command line
parameter handling in tools/perf.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-i44zs02xt4zexfxywpklo7km@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
If /proc/sys/kernel/perf_event_mlock_kb is not (power of 2 + PAGE_SIZE_in_kb)
and we let the perf tools do mmap length autosizing based on that, then, for
non-CAP_IPC_LOCK users when /proc/sys/kernel/perf_event_paranoid is > -1, then
we get an -EINVAL that ends up in:
[acme@ssdandy linux]$ trace usleep 1
Invalid argument
[acme@ssdandy linux]$ perf record usleep 1
failed to mmap with 22 (Invalid argument)
After this fix:
[acme@ssdandy linux]$ trace usleep 1
<SNIP>
0.806 ( 0.006 ms): munmap(addr: 0x7f7e4740a000, len: 66467) = 0
0.869 ( 0.002 ms): brk( ) = 0x7bb000
0.873 ( 0.003 ms): brk(brk: 0x7dc000 ) = 0x7dc000
0.877 ( 0.001 ms): brk( ) = 0x7dc000
0.953 ( 0.058 ms): nanosleep(rqtp: 0x7fff26ab9420 ) = 0
0.959 ( 0.000 ms): exit_group(
[acme@ssdandy linux]$ perf record usleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.017 MB perf.data (~759 samples) ]
[acme@ssdandy linux]$
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-6p6l5ou6jev6o7ymc4nn1n2a@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Will be used to make sure we pass a power of two when automatically
setting up the perf_mmap addr range length, as the kernel code
validating input on /proc/sys/kernel/perf_event_mlock_kb accepts any
integer, if we plain use it to set up the mmap lenght, we may get an
EINVAL when passing a non power of two.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-zflvep0q01dmkruf4o291l4p@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Will be used when adopting rounddown_pow_of_two.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-9m0tt5300q1ygv51hejjas82@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
So that we better mirror the kernel sources and make it available for
other tools.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-mvfu6x753tksnto3t6412m93@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
In preparation for moving linux/bitops.h from tools/perf/util/ to
tools/include/.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-2wuk8vahl7voz0ie55f07c9k@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To match the Linux kernel source code structure from where this code came from.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-fkbma1h04ki0zzdmp0dpgfyy@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To match the Linux kernel source code structure from where this code came from.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-1ldjhvioch1uczilno5e1epl@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
From tools/perf/util/include/linux, so that it becomes accessible to
other tools/.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-uqohgzilp3ebd3cbybnf3luc@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To match the Linux kernel source code structure from where this code came from.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-gubysnp4a8hd98lxoeruak13@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
In finish pageflip, the driver was not selecting the root window when
dispatching events. This exposed a race where a plane update would
change the window selection and cause tegra_dc_finish_page_flip to check
the wrong base address.
This patch also protects access to the window selection register as well
as the registers affected by it.
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
If the requested buffer size wasn't a multiple of the page size, the
IOMMU code would round down the size to the next multiple of the page
size, thereby causing translation errors. To fix this we no longer pass
around the requested size but reuse the computed size of the GEM object.
This is already rounded to the next page boundary, so mapping that size
works out fine.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Buffers obtained via shmem may still have associated cachelines. If they
aren't properly flushed they may cause framebuffer corruption if the
cache gets flushed after the application has drawn to it.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Page-flip completion could race with page-flip submission, so extend the
critical section to include all accesses to page-flip related data.
Reported-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
The hardware pipe numbers don't always match the DRM CRTC indices. This
can happen for example if the first display controller defers probe,
causing it to be registered with DRM after the second display
controller. When that happens the hardware pipe numbers and DRM CRTC
indices become different. Make sure that the CRTC index is always used
when accessing per-CRTC VBLANK data. This can be ensured by using the
drm_crtc_vblank_*() API, which will do the right thing automatically
given a struct drm_crtc *.
Signed-off-by: Thierry Reding <treding@nvidia.com>
This function is the KMS native variant of drm_vblank_count(). It takes
a struct drm_crtc * instead of a struct drm_device * and an index of the
CRTC.
Eventually the goal is to access vblank data through the CRTC only so
that the per-CRTC data can be moved to struct drm_crtc.
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Thierry Reding <treding@nvidia.com>
This function is the KMS native variant of drm_handle_vblank(). It takes
a struct drm_crtc * instead of a struct drm_device * and an index of the
CRTC.
Eventually the goal is to access vblank data through the CRTC only so
that the per-CRTC data can be moved to struct drm_crtc.
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Thierry Reding <treding@nvidia.com>
This function is the KMS native variant of drm_send_vblank_event(). It
takes a struct drm_crtc * instead of a struct drm_device * and an index
of the CRTC.
Eventually the goal is to access vblank data through the CRTC only so
that the per-CRTC data can be moved to struct drm_crtc.
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Thierry Reding <treding@nvidia.com>
As we already show mountpoints relative to the root directory, thanks
to the change made back in 2000, change show_vfsmnt() and show_vfsstat()
to skip out-of-root mountpoints the same way as show_mountinfo() does.
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Starting with commit v3.2-rc4-1-g02125a8, seq_path_root() no longer
changes the value of its "struct path *root" argument.
Starting with commit v3.2-rc7-104-g8c9379e, the "struct path *root"
argument of seq_path_root() is const.
As result, the temporary variable "root" in show_mountinfo() that
holds a copy of struct path root is no longer needed.
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
If mount flags don't have MS_RDONLY, iso9660 returns EACCES without actually
checking if it's an iso image.
This tricks mount_block_root() into retrying with MS_RDONLY. This results
in a read-only root despite the "rw" boot parameter if the actual
filesystem was checked after iso9660.
I believe the behavior of iso9660 is okay, while that of mount_block_root()
is not. It should rather try all types without MS_RDONLY and only then
retry with MS_RDONLY.
This change also makes the code more robust against the case when EACCES is
returned despite MS_RDONLY, which would've resulted in a lockup.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
scanarg(s, del) never returns s; the empty field results in s + 1.
Restore the correct checks, and move NUL-termination into scanarg(),
while we are at it.
Incidentally, mixing "coding style cleanups" (for small values of cleanup)
with functional changes is a Bad Idea(tm)...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
the only instance this method has ever grown was one in kernfs -
one that call ->migrate() of another vm_ops if it exists.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
When writing the code to allow per-station GTKs, I neglected to
take into account the management frame keys (index 4 and 5) when
freeing the station and only added code to free the first four
data frame keys.
Fix this by iterating the array of keys over the right length.
Cc: stable@vger.kernel.org
Fixes: e31b82136d ("cfg80211/mac80211: allow per-station GTKs")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Currently the H_CONFER hcall is implemented in kernel virtual mode,
meaning that whenever a guest thread does an H_CONFER, all the threads
in that virtual core have to exit the guest. This is bad for
performance because it interrupts the other threads even if they
are doing useful work.
The H_CONFER hcall is called by a guest VCPU when it is spinning on a
spinlock and it detects that the spinlock is held by a guest VCPU that
is currently not running on a physical CPU. The idea is to give this
VCPU's time slice to the holder VCPU so that it can make progress
towards releasing the lock.
To avoid having the other threads exit the guest unnecessarily,
we add a real-mode implementation of H_CONFER that checks whether
the other threads are doing anything. If all the other threads
are idle (i.e. in H_CEDE) or trying to confer (i.e. in H_CONFER),
it returns H_TOO_HARD which causes a guest exit and allows the
H_CONFER to be handled in virtual mode.
Otherwise it spins for a short time (up to 10 microseconds) to give
other threads the chance to observe that this thread is trying to
confer. The spin loop also terminates when any thread exits the guest
or when all other threads are idle or trying to confer. If the
timeout is reached, the H_CONFER returns H_SUCCESS. In this case the
guest VCPU will recheck the spinlock word and most likely call
H_CONFER again.
This also improves the implementation of the H_CONFER virtual mode
handler. If the VCPU is part of a virtual core (vcore) which is
runnable, there will be a 'runner' VCPU which has taken responsibility
for running the vcore. In this case we yield to the runner VCPU
rather than the target VCPU.
We also introduce a check on the target VCPU's yield count: if it
differs from the yield count passed to H_CONFER, the target VCPU
has run since H_CONFER was called and may have already released
the lock. This check is required by PAPR.
Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
There are two ways in which a guest instruction can be obtained from
the guest in the guest exit code in book3s_hv_rmhandlers.S. If the
exit was caused by a Hypervisor Emulation interrupt (i.e. an illegal
instruction), the offending instruction is in the HEIR register
(Hypervisor Emulation Instruction Register). If the exit was caused
by a load or store to an emulated MMIO device, we load the instruction
from the guest by turning data relocation on and loading the instruction
with an lwz instruction.
Unfortunately, in the case where the guest has opposite endianness to
the host, these two methods give results of different endianness, but
both get put into vcpu->arch.last_inst. The HEIR value has been loaded
using guest endianness, whereas the lwz will load the instruction using
host endianness. The rest of the code that uses vcpu->arch.last_inst
assumes it was loaded using host endianness.
To fix this, we define a new vcpu field to store the HEIR value. Then,
in kvmppc_handle_exit_hv(), we transfer the value from this new field to
vcpu->arch.last_inst, doing a byte-swap if the guest and host endianness
differ.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
This removes the code that was added to enable HV KVM to work
on PPC970 processors. The PPC970 is an old CPU that doesn't
support virtualizing guest memory. Removing PPC970 support also
lets us remove the code for allocating and managing contiguous
real-mode areas, the code for the !kvm->arch.using_mmu_notifiers
case, the code for pinning pages of guest memory when first
accessed and keeping track of which pages have been pinned, and
the code for handling H_ENTER hypercalls in virtual mode.
Book3S HV KVM is now supported only on POWER7 and POWER8 processors.
The KVM_CAP_PPC_RMA capability now always returns 0.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
This patch adds trace points in the guest entry and exit code and also
for exceptions handled by the host in kernel mode - hypercalls and page
faults. The new events are added to /sys/kernel/debug/tracing/events
under a new subsystem called kvm_hv.
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Suresh Warrier <warrier@linux.vnet.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Ilya Dryomov