Despite being an old document, it contains lots of information
that could still be useful.
The document has a nice style with makes easy to convert to
ReST. So, let's convert it to ReST.
This patch does:
- Use proper markups for titles;
- Mark and proper indent literal blocks;
- don't use an 'o' character for lists;
- other minor changes required for the doc to be parsed.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add this file to a new kvm/arm index.rst, in order for it to
be shown as part of the virt book.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The check cpu->hv_clock.system_time < 0 is redundant since system_time
is a u64 and hence can never be less than zero. But what was actually
meant is to check that the result is positive, since kernel_ns and
v->kvm->arch.kvmclock_offset are both s64.
Reported-by: Colin King <colin.king@canonical.com>
Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com>
Addresses-Coverity: ("Macro compares unsigned to 0")
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
x86_register enum is not used, let's remove it.
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Suggested-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Define PT_MAX_FULL_LEVELS as PT64_ROOT_MAX_LEVEL, i.e. 5, to fix shadow
paging for 5-level guest page tables. PT_MAX_FULL_LEVELS is used to
size the arrays that track guest pages table information, i.e. using a
"max levels" of 4 causes KVM to access garbage beyond the end of an
array when querying state for level 5 entries. E.g. FNAME(gpte_changed)
will read garbage and most likely return %true for a level 5 entry,
soft-hanging the guest because FNAME(fetch) will restart the guest
instead of creating SPTEs because it thinks the guest PTE has changed.
Note, KVM doesn't yet support 5-level nested EPT, so PT_MAX_FULL_LEVELS
gets to stay "4" for the PTTYPE_EPT case.
Fixes: 855feb6736 ("KVM: MMU: Add 5 level EPT & Shadow page table support.")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Hardcode the EPT page-walk level for L2 to be 4 levels, as KVM's MMU
currently also hardcodes the page walk level for nested EPT to be 4
levels. The L2 guest is all but guaranteed to soft hang on its first
instruction when L1 is using EPT, as KVM will construct 4-level page
tables and then tell hardware to use 5-level page tables.
Fixes: 855feb6736 ("KVM: MMU: Add 5 level EPT & Shadow page table support.")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Fix some typos in the comments. Also fix coding style.
[Sean Christopherson rewrites the comment of write_fault_to_shadow_pgtable
field in struct kvm_vcpu_arch.]
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Wrap calls to ->page_fault() with a small shim to directly invoke the
TDP fault handler when the kernel is using retpolines and TDP is being
used. Single out the TDP fault handler and annotate the TDP path as
likely to coerce the compiler into preferring it over the indirect
function call.
Rename tdp_page_fault() to kvm_tdp_page_fault(), as it's exposed outside
of mmu.c to allow inlining the shim.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
kvm_make_request() provides smp_wmb() so pending_events changes are
guaranteed to be visible.
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The KVM_REQ_EVENT request is already made in kvm_set_rflags(). We should
not make it again.
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
L2 guest calls vmcall and L1 checks the exit status does
correspond.
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Tested-by: Wei Huang <wei.huang2@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add the basic infrastructure needed to test AMD nested SVM.
This is largely copied from the KVM unit test infrastructure.
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
get_gdt_base() and get_idt_base() only return the base address
of the descriptor tables. Soon we will need to get the size as well.
Change the prototype of those functions so that they return
the whole desc_ptr struct instead of the address field.
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Wei Huang <wei.huang2@amd.com>
Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
If a dentry was not initially looked up while we were holding a
delegation, then we do still need to revalidate that it still holds
the same name. If there are multiple hard links to the same file,
then all the hard links need validation.
Reported-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Tested-by: Benjamin Coddington <bcodding@redhat.com>
[Anna: Put nfs_unset_verifier_delegated() under CONFIG_NFS_V4]
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
This allows you to specify the type of rgmii-id that will enable phy
internal delay in ethernet phy-mode.
This adds all RGMII cases to all of get_pinmode() except LD11, because LD11
SoC doesn't support RGMII due to the constraint of the hardware. When RGMII
phy mode is specified in the devicetree for LD11, the driver will abort
with an error.
Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Recent months, our customer reported several kernel crashes all
preceding with following message:
NETDEV WATCHDOG: eth2 (enic): transmit queue 0 timed out
Error message of one of those crashes:
BUG: unable to handle kernel paging request at ffffffffa007e090
After analyzing severl vmcores, I found that most of crashes are
caused by memory corruption. And all the corrupted memory areas
are overwritten by data of network packets. Moreover, I also found
that the tx queues were enabled over watchdog reset.
After going through the source code, I found that in enic_stop(),
the tx queues stopped by netif_tx_disable() could be woken up over
a small time window between netif_tx_disable() and the
napi_disable() by the following code path:
napi_poll->
enic_poll_msix_wq->
vnic_cq_service->
enic_wq_service->
netif_wake_subqueue(enic->netdev, q_number)->
test_and_clear_bit(__QUEUE_STATE_DRV_XOFF, &txq->state)
In turn, upper netowrk stack could queue skb to ENIC NIC though
enic_hard_start_xmit(). And this might introduce some race condition.
Our customer comfirmed that this kind of kernel crash doesn't occur over
90 days since they applied this patch.
Signed-off-by: Firo Yang <firo.yang@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Originally it was planned to create device id directories under
UUID/devinfo, but it got under UUID/devices by mistake. We really want
it under definfo so the bare device node names are not mixed with device
ids and are easy to enumerate.
Fixes: 668e48af7a ("btrfs: sysfs, add devid/dev_state kobject and device attributes")
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Create directory /sys/fs/btrfs/UUID/devinfo to hold devices directories
by the id (unlike /devices).
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The arm64 time code is not a clock provider, and just needs to call
of_clk_init().
Hence it can include <linux/of_clk.h> instead of <linux/clk-provider.h>.
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Will Deacon <will@kernel.org>
When there is a fiemap executing in parallel with a shrinking truncate
we can end up in a situation where we have extent maps for which we no
longer have corresponding file extent items. This is generally harmless
and at the moment the only consequences are missing file extent items
representing holes after we expand the file size again after the
truncate operation removed the prealloc extent items, and stale
information for future fiemap calls (reporting extents that no longer
exist or may have been reallocated to other files for example).
Consider the following example:
1) Our inode has a size of 128KiB, one 128KiB extent at file offset 0
and a 1MiB prealloc extent at file offset 128KiB;
2) Task A starts doing a shrinking truncate of our inode to reduce it to
a size of 64KiB. Before it searches the subvolume tree for file
extent items to delete, it drops all the extent maps in the range
from 64KiB to (u64)-1 by calling btrfs_drop_extent_cache();
3) Task B starts doing a fiemap against our inode. When looking up for
the inode's extent maps in the range from 128KiB to (u64)-1, it
doesn't find any in the inode's extent map tree, since they were
removed by task A. Because it didn't find any in the extent map
tree, it scans the inode's subvolume tree for file extent items, and
it finds the 1MiB prealloc extent at file offset 128KiB, then it
creates an extent map based on that file extent item and adds it to
inode's extent map tree (this ends up being done by
btrfs_get_extent() <- btrfs_get_extent_fiemap() <-
get_extent_skip_holes());
4) Task A then drops the prealloc extent at file offset 128KiB and
shrinks the 128KiB extent file offset 0 to a length of 64KiB. The
truncation operation finishes and we end up with an extent map
representing a 1MiB prealloc extent at file offset 128KiB, despite we
don't have any more that extent;
After this the two types of problems we have are:
1) Future calls to fiemap always report that a 1MiB prealloc extent
exists at file offset 128KiB. This is stale information, no longer
correct;
2) If the size of the file is increased, by a truncate operation that
increases the file size or by a write into a file offset > 64KiB for
example, we end up not inserting file extent items to represent holes
for any range between 128KiB and 128KiB + 1MiB, since the hole
expansion function, btrfs_cont_expand() will skip hole insertion for
any range for which an extent map exists that represents a prealloc
extent. This causes fsck to complain about missing file extent items
when not using the NO_HOLES feature.
The second issue could be often triggered by test case generic/561 from
fstests, which runs fsstress and duperemove in parallel, and duperemove
does frequent fiemap calls.
Essentially the problems happens because fiemap does not acquire the
inode's lock while truncate does, and fiemap locks the file range in the
inode's iotree while truncate does not. So fix the issue by making
btrfs_truncate_inode_items() lock the file range from the new file size
to (u64)-1, so that it serializes with fiemap.
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
A remount to a read-write filesystem is not safe when there's tree-log
to be replayed. Files that could be opened until now might be affected
by the changes in the tree-log.
A regular mount is needed to replay the log so the filesystem presents
the consistent view with the pending changes included.
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There's no logged information about tree-log replay although this is
something that points to previous unclean unmount. Other filesystems
report that as well.
Suggested-by: Chris Murphy <lists@colorremedies.com>
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We have a few cases where we allow an extent map that is in an extent map
tree to be merged with other extents in the tree. Such cases include the
unpinning of an extent after the respective ordered extent completed or
after logging an extent during a fast fsync. This can lead to subtle and
dangerous problems because when doing the merge some other task might be
using the same extent map and as consequence see an inconsistent state of
the extent map - for example sees the new length but has seen the old start
offset.
With luck this triggers a BUG_ON(), and not some silent bug, such as the
following one in __do_readpage():
$ cat -n fs/btrfs/extent_io.c
3061 static int __do_readpage(struct extent_io_tree *tree,
3062 struct page *page,
(...)
3127 em = __get_extent_map(inode, page, pg_offset, cur,
3128 end - cur + 1, get_extent, em_cached);
3129 if (IS_ERR_OR_NULL(em)) {
3130 SetPageError(page);
3131 unlock_extent(tree, cur, end);
3132 break;
3133 }
3134 extent_offset = cur - em->start;
3135 BUG_ON(extent_map_end(em) <= cur);
(...)
Consider the following example scenario, where we end up hitting the
BUG_ON() in __do_readpage().
We have an inode with a size of 8KiB and 2 extent maps:
extent A: file offset 0, length 4KiB, disk_bytenr = X, persisted on disk by
a previous transaction
extent B: file offset 4KiB, length 4KiB, disk_bytenr = X + 4KiB, not yet
persisted but writeback started for it already. The extent map
is pinned since there's writeback and an ordered extent in
progress, so it can not be merged with extent map A yet
The following sequence of steps leads to the BUG_ON():
1) The ordered extent for extent B completes, the respective page gets its
writeback bit cleared and the extent map is unpinned, at that point it
is not yet merged with extent map A because it's in the list of modified
extents;
2) Due to memory pressure, or some other reason, the MM subsystem releases
the page corresponding to extent B - btrfs_releasepage() is called and
returns 1, meaning the page can be released as it's not dirty, not under
writeback anymore and the extent range is not locked in the inode's
iotree. However the extent map is not released, either because we are
not in a context that allows memory allocations to block or because the
inode's size is smaller than 16MiB - in this case our inode has a size
of 8KiB;
3) Task B needs to read extent B and ends up __do_readpage() through the
btrfs_readpage() callback. At __do_readpage() it gets a reference to
extent map B;
4) Task A, doing a fast fsync, calls clear_em_loggin() against extent map B
while holding the write lock on the inode's extent map tree - this
results in try_merge_map() being called and since it's possible to merge
extent map B with extent map A now (the extent map B was removed from
the list of modified extents), the merging begins - it sets extent map
B's start offset to 0 (was 4KiB), but before it increments the map's
length to 8KiB (4kb + 4KiB), task A is at:
BUG_ON(extent_map_end(em) <= cur);
The call to extent_map_end() sees the extent map has a start of 0
and a length still at 4KiB, so it returns 4KiB and 'cur' is 4KiB, so
the BUG_ON() is triggered.
So it's dangerous to modify an extent map that is in the tree, because some
other task might have got a reference to it before and still using it, and
needs to see a consistent map while using it. Generally this is very rare
since most paths that lookup and use extent maps also have the file range
locked in the inode's iotree. The fsync path is pretty much the only
exception where we don't do it to avoid serialization with concurrent
reads.
Fix this by not allowing an extent map do be merged if if it's being used
by tasks other then the one attempting to merge the extent map (when the
reference count of the extent map is greater than 2).
Reported-by: ryusuke1925 <st13s20@gm.ibaraki-ct.ac.jp>
Reported-by: Koki Mitani <koki.mitani.xg@hco.ntt.co.jp>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=206211
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In btrfs_ref_tree_mod(), 'ref' and 'ra' are allocated through kzalloc() and
kmalloc(), respectively. In the following code, if an error occurs, the
execution will be redirected to 'out' or 'out_unlock' and the function will
be exited. However, on some of the paths, 'ref' and 'ra' are not
deallocated, leading to memory leaks. For example, if 'action' is
BTRFS_ADD_DELAYED_EXTENT, add_block_entry() will be invoked. If the return
value indicates an error, the execution will be redirected to 'out'. But,
'ref' is not deallocated on this path, causing a memory leak.
To fix the above issues, deallocate both 'ref' and 'ra' before exiting from
the function when an error is encountered.
CC: stable@vger.kernel.org # 4.15+
Signed-off-by: Wenwen Wang <wenwen@cs.uga.edu>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
To pick up the changes from:
7de3f1423f ("KVM: s390: Add new reset vcpu API")
So far we're ignoring those arch specific ioctls, we need to revisit
this at some time to have arch specific tables, etc:
$ grep S390 tools/perf/trace/beauty/kvm_ioctl.sh
egrep -v " ((ARM|PPC|S390)_|[GS]ET_(DEBUGREGS|PIT2|XSAVE|TSC_KHZ)|CREATE_SPAPR_TCE_64)" | \
$
This addresses these tools/perf build warnings:
Warning: Kernel ABI header at 'tools/arch/arm/include/uapi/asm/kvm.h' differs from latest version at 'arch/arm/include/uapi/asm/kvm.h'
diff -u tools/arch/arm/include/uapi/asm/kvm.h arch/arm/include/uapi/asm/kvm.h
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To pick up the changes from:
290a6bb06d ("arm64: KVM: Add UAPI notes for swapped registers")
No tools changes are caused by this.
This addresses these tools/perf build warnings:
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andrew Jones <drjones@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To pick up the changes from:
85c17291e2 ("x86/cpufeatures: Add flag to track whether MSR IA32_FEAT_CTL is configured")
f444a5ff95 ("x86/cpufeatures: Add support for fast short REP; MOVSB")
These don't cause any changes in tooling, just silences this perf build
warning:
Warning: Kernel ABI header at 'tools/arch/x86/include/asm/cpufeatures.h' differs from latest version at 'arch/x86/include/asm/cpufeatures.h'
diff -u tools/arch/x86/include/asm/cpufeatures.h arch/x86/include/asm/cpufeatures.h
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To silence the following tools/perf build warning:
Warning: Kernel ABI header at 'tools/arch/x86/include/asm/disabled-features.h' differs from latest version at 'arch/x86/include/asm/disabled-features.h'
diff -u tools/arch/x86/include/asm/disabled-features.h arch/x86/include/asm/disabled-features.h
Picking up the changes in:
45fc24e89b ("x86/mpx: remove MPX from arch/x86")
that didn't entail any functionality change in the tooling side.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Keep the rq->fence.flags consistent with the status of the
rq->sched.link, and clear the associated bits when decoupling the link
on retirement (as we may wish to inspect those flags independent of
other state).
Fixes: c3f1ed90e6 ("drm/i915/gt: Allow temporary suspension of inflight requests")
References: https://gitlab.freedesktop.org/drm/intel/issues/997
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200122140243.495621-3-chris@chris-wilson.co.uk
(cherry picked from commit b4a9a149f9)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
If we encounter a hang on a virtual engine, as we process the hang the
request may already have been moved back to the virtual engine (we are
processing the hang on the physical engine). We need to reclaim the
request from the virtual engine so that the locking is consistent and
local to the real engine on which we will hold the request for error
state capturing.
v2: Pull the reclamation into execlists_hold() and assert that cannot be
called from outside of the reset (i.e. with the tasklet disabled).
v3: Added selftest
v4: Drop the reference owned by the virtual engine
Fixes: ad18ba7b5e ("drm/i915/execlists: Offline error capture")
Testcase: igt/gem_exec_balancer/hang
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200122140243.495621-2-chris@chris-wilson.co.uk
(cherry picked from commit 989df3a7bd)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Thanks to preempt-to-busy, we leave the request on the HW as we submit
the preemption request. This means that the request may complete at any
moment as we process HW events, and in particular the request may be
retired as we are planning to capture it for a preemption timeout.
Be more careful while obtaining the request to capture after a
preemption timeout, and check to see if it completed before we were able
to put it on the on-hold list. If we do see it did complete just before
we capture the request, proclaim the preemption-timeout a false positive
and pardon the reset as we should hit an arbitration point momentarily
and so be able to process the preemption.
Note that even after we move the request to be on hold it may be retired
(as the reset to stop the HW comes after), so we do require to hold our
own reference as we work on the request for capture (and all of the
peeking at state within the request needs to be carefully protected).
Fixes: c3f1ed90e6 ("drm/i915/gt: Allow temporary suspension of inflight requests")
Closes: https://gitlab.freedesktop.org/drm/intel/issues/997
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200122140243.495621-1-chris@chris-wilson.co.uk
(cherry picked from commit 4ba5c086a1)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Currently, we skip error capture upon forced preemption. We apply forced
preemption when there is a higher priority request that should be
running but is being blocked, and we skip inline error capture so that
the preemption request is not further delayed by a user controlled
capture -- extending the denial of service.
However, preemption reset is also used for heartbeats and regular GPU
hangs. By skipping the error capture, we remove the ability to debug GPU
hangs.
In order to capture the error without delaying the preemption request
further, we can do an out-of-line capture by removing the guilty request
from the execution queue and scheduling a worker to dump that request.
When removing a request, we need to remove the entire context and all
descendants from the execution queue, so that they do not jump past.
Closes: https://gitlab.freedesktop.org/drm/intel/issues/738
Fixes: 3a7a92aba8 ("drm/i915/execlists: Force preemption")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200116184754.2860848-3-chris@chris-wilson.co.uk
(cherry picked from commit 748317386a)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
In order to support out-of-line error capture, we need to remove the
active request from HW and put it to one side while a worker compresses
and stores all the details associated with that request. (As that
compression may take an arbitrary user-controlled amount of time, we
want to let the engine continue running on other workloads while the
hanging request is dumped.) Not only do we need to remove the active
request, but we also have to remove its context and all requests that
were dependent on it (both in flight, queued and future submission).
Finally once the capture is complete, we need to be able to resubmit the
request and its dependents and allow them to execute.
v2: Replace stack recursion with a simple list.
v3: Check all the parents, not just the first, when searching for a
stuck ancestor!
References: https://gitlab.freedesktop.org/drm/intel/issues/738
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200116184754.2860848-2-chris@chris-wilson.co.uk
(cherry picked from commit 32ff621fd7)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
If we keep track of when the i915_request.sched.link is on the HW
runlist, or in the priority queue we can simplify our interactions with
the request (such as during rescheduling). This also simplifies the next
patch where we introduce a new in-between list, for requests that are
ready but neither on the run list or in the queue.
v2: Update i915_sched_node.link explanation for current usage where it
is a link on both the queue and on the runlists.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200116184754.2860848-1-chris@chris-wilson.co.uk
(cherry picked from commit 672c368f93)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Picking the changes from:
46b770f720 ("ALSA: uapi: Fix sparse warning")
a103a39899 ("ALSA: control: Fix incompatible protocol error")
bd3eb4e87e ("ALSA: ctl: bump protocol version up to v2.1.0")
ff16351e3f ("ALSA: ctl: remove dimen member from elem_info structure")
5422835666 ("ALSA: ctl: remove unused macro for timestamping of elem_value")
7fd7d6c504 ("ALSA: uapi: Fix typos and header inclusion in asound.h")
1cfaef9617 ("ALSA: bump uapi version numbers")
80fe7430c7 ("ALSA: add new 32-bit layout for snd_pcm_mmap_status/control")
07094ae6f9 ("ALSA: Avoid using timespec for struct snd_timer_tread")
d9e5582c4b ("ALSA: Avoid using timespec for struct snd_rawmidi_status")
3ddee7f88a ("ALSA: Avoid using timespec for struct snd_pcm_status")
a4e7dd35b9 ("ALSA: Avoid using timespec for struct snd_ctl_elem_value")
a07804cc74 ("ALSA: Avoid using timespec for struct snd_timer_status")
Which entails no changes in the tooling side.
To silence this perf tools build warning:
Warning: Kernel ABI header at 'tools/include/uapi/sound/asound.h' differs from latest version at 'include/uapi/sound/asound.h'
diff -u tools/include/uapi/sound/asound.h include/uapi/sound/asound.h
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Baolin Wang <baolin.wang@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To pick the changes from:
d41938d2cb ("mm: Reserve asm-generic prot flags 0x10 and 0x20 for arch use")
No changes in tooling, just a rebuild as files needed got touched.
This addresses the following perf build warning:
Warning: Kernel ABI header at 'tools/include/uapi/asm-generic/mman-common.h' differs from latest version at 'include/uapi/asm-generic/mman-common.h'
diff -u tools/include/uapi/asm-generic/mman-common.h include/uapi/asm-generic/mman-common.h
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Dave Martin <Dave.Martin@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Add an arm64 version of get_cpuid(), which is used for various annotation
and headers - for example, I now get the CPUID in "perf report --header",
as shown in this snippet:
# hostname : ubuntu
# os release : 5.5.0-rc1-dirty
# perf version : 5.5.rc1.gbf8a13dc9851
# arch : aarch64
# nrcpus online : 96
# nrcpus avail : 96
# cpuid : 0x00000000480fd010
Since much of the code to read the MIDR is already in get_cpuid_str(),
factor out this code.
Tester notes:
I tested this patch on my new ARM64 Kunpeng 920 server.
[root@node1 zsk]# ./perf --version
perf version 5.6.rc1.g2cdb955b7252
Both perf list and perf stat can work.
Signed-off-by: John Garry <john.garry@huawei.com>
Tested-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linuxarm@huawei.com
Link: http://lore.kernel.org/lkml/1576245255-210926-1-git-send-email-john.garry@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To pick the change in:
cc662126b4 ("drm/i915: Introduce DRM_I915_GEM_MMAP_OFFSET")
That don't result in any changes in tooling, just silences this perf
build warning:
Warning: Kernel ABI header at 'tools/include/uapi/drm/i915_drm.h' differs from latest version at 'include/uapi/drm/i915_drm.h'
diff -u tools/include/uapi/drm/i915_drm.h include/uapi/drm/i915_drm.h
Cc: Abdiel Janulgue <abdiel.janulgue@linux.intel.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To pick the changes from:
e933adde6f ("fscrypt: include <linux/ioctl.h> in UAPI header")
93edd392ca ("fscrypt: support passing a keyring key to FS_IOC_ADD_ENCRYPTION_KEY")
That don't trigger any changes in tooling.
This silences this perf build warning:
Warning: Kernel ABI header at 'tools/include/uapi/linux/fscrypt.h' differs from latest version at 'include/uapi/linux/fscrypt.h'
diff -u tools/include/uapi/linux/fscrypt.h include/uapi/linux/fscrypt.h
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
KVM allows the deferral of exception payloads when a vCPU is in guest
mode to allow the L1 hypervisor to intercept certain events (#PF, #DB)
before register state has been modified. However, this behavior is
incompatible with the KVM_{GET,SET}_VCPU_EVENTS ABI, as userspace
expects register state to have been immediately modified. Userspace may
opt-in for the payload deferral behavior with the
KVM_CAP_EXCEPTION_PAYLOAD per-VM capability. As such,
kvm_multiple_exception() will immediately manipulate guest registers if
the capability hasn't been requested.
Since the deferral is only necessary if a userspace ioctl were to be
serviced at the same as a payload bearing exception is recognized, this
behavior can be relaxed. Instead, opportunistically defer the payload
from kvm_multiple_exception() and deliver the payload before completing
a KVM_GET_VCPU_EVENTS ioctl.
Signed-off-by: Oliver Upton <oupton@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
SDM 27.3.4 states that the 'pending debug exceptions' VMCS field will
be populated if a VM-exit caused by an INIT signal takes priority over a
debug-trap. Emulate this behavior when synthesizing an INIT signal
VM-exit into L1.
Fixes: 4b9852f4f3 ("KVM: x86: Fix INIT signal handling in various CPU states")
Signed-off-by: Oliver Upton <oupton@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM defines the #DB payload as compatible with the 'pending debug
exceptions' field under VMX, not DR6. Mask off bit 12 when applying the
payload to DR6, as it is reserved on DR6 but not the 'pending debug
exceptions' field.
Fixes: f10c729ff9 ("kvm: vmx: Defer setting of DR6 until #DB delivery")
Signed-off-by: Oliver Upton <oupton@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Only the first and the last nodes were being added to
ref->preallocated_barriers.
Renaming variables to make it more easy to read.
Fixes: 8413502238 ("drm/i915/gt: Drop mutex serialisation between context pin/unpin")
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20200129232345.84512-1-jose.souza@intel.com
(cherry picked from commit d4c3c0b822)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
As we use a mutex to serialise the first acquire (as it may be a lengthy
operation), but only an atomic decrement for the release, we have to
be careful in case a second thread races and completes both
acquire/release as the first finishes its acquire.
Thread A Thread B
i915_active_acquire i915_active_acquire
atomic_read() == 0 atomic_read() == 0
mutex_lock() mutex_lock()
atomic_read() == 0
ref->active();
atomic_inc()
mutex_unlock()
atomic_read() == 1
i915_active_release
atomic_dec_and_test() -> 0
ref->retire()
atomic_inc() -> 1
mutex_unlock()
So thread A has acquired the ref->active_count but since the ref was
still active at the time, it did not initialise it. By switching the
check inside the mutex to an atomic increment only if already active, we
close the race.
Fixes: c9ad602fea ("drm/i915: Split i915_active.mutex into an irq-safe spinlock for the rbtree")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200126102346.1877661-3-chris@chris-wilson.co.uk
(cherry picked from commit ac0e331a62)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
i915_gpu_coreddump_put is currently only defined if
CONFIG_DRM_I915_CAPTURE_ERROR is enabled, provide a stub otherwise.
Reported-by: Mike Lothian <mike@fireburn.co.uk>
Fixes: 742379c0c4 ("drm/i915: Start chopping up the GPU error capture")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mike Lothian <mike@fireburn.co.uk>
Cc: Andi Shyti <andi.shyti@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200124192255.541355-1-chris@chris-wilson.co.uk
(cherry picked from commit 7e36505d0c)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Accessing a per-cpu variable only makes sense when preemption is
disabled (and the kernel does check this when the right debug options
are switched on).
For kvm_get_running_vcpu(), it is fine to return the value after
re-enabling preemption, as the preempt notifiers will make sure that
this is kept consistent across task migration (the comment above the
function hints at it, but lacks the crucial preemption management).
While we're at it, move the comment from the ARM code, which explains
why the whole thing works.
Fixes: 7495e22bb1 ("KVM: Move running VCPU from ARM to common code").
Cc: Paolo Bonzini <pbonzini@redhat.com>
Reported-by: Zenghui Yu <yuzenghui@huawei.com>
Tested-by: Zenghui Yu <yuzenghui@huawei.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/318984f6-bc36-33a3-abc6-bf2295974b06@huawei.com
Message-id: <20200207163410.31276-1-maz@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Mauro Carvalho Chehab