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2014-12-18mnt: Fix a memory stomp in umountEric W. Biederman1-0/+2
While reviewing the code of umount_tree I realized that when we append to a preexisting unmounted list we do not change pprev of the former first item in the list. Which means later in namespace_unlock hlist_del_init(&mnt->mnt_hash) on the former first item of the list will stomp unmounted.first leaving it set to some random mount point which we are likely to free soon. This isn't likely to hit, but if it does I don't know how anyone could track it down. [ This happened because we don't have all the same operations for hlist's as we do for normal doubly-linked lists. In particular, list_splice() is easy on our standard doubly-linked lists, while hlist_splice() doesn't exist and needs both start/end entries of the hlist. And commit 38129a13e6e7 incorrectly open-coded that missing hlist_splice(). We should think about making these kinds of "mindless" conversions easier to get right by adding the missing hlist helpers - Linus ] Fixes: 38129a13e6e71f666e0468e99fdd932a687b4d7e switch mnt_hash to hlist Cc: stable@vger.kernel.org Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-18be2net: Fix incorrect setting of tunnel offload flag in netdev featuresSriharsha Basavapatna1-0/+2
An earlier commit to resolve an issue with encapsulation offloads missed setting a bit in the outer netdev features flag. This results in loss of TSO feature on a VxLAN interface. Fixes: 630f4b70 ("Export tunnel offloads only when a VxLAN tunnel is created") Signed-off-by: Sriharsha Basavapatna <sriharsha.basavapatna@emulex.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-18bnx2x: fix typos in "configure"Jiri Benc2-4/+4
Noticed when debugging ptp. Signed-off-by: Jiri Benc <jbenc@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-18xen-netback: support frontends without feature-rx-notify againDavid Vrabel4-18/+29
Commit bc96f648df1bbc2729abbb84513cf4f64273a1f1 (xen-netback: make feature-rx-notify mandatory) incorrectly assumed that there were no frontends in use that did not support this feature. But the frontend driver in MiniOS does not and since this is used by (qemu) stubdoms, these stopped working. Netback sort of works as-is in this mode except: - If there are no Rx requests and the internal Rx queue fills, only the drain timeout will wake the thread. The default drain timeout of 10 s would give unacceptable pauses. - If an Rx stall was detected and the internal Rx queue is drained, then the Rx thread would never wake. Handle these two cases (when feature-rx-notify is disabled) by: - Reducing the drain timeout to 30 ms. - Disabling Rx stall detection. Reported-by: John <jw@nuclearfallout.net> Tested-by: John <jw@nuclearfallout.net> Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-18sparc32: destroy_context() and switch_mm() needs to disable interrupts.Andreas Larsson1-4/+7
Load balancing can be triggered in the critical sections protected by srmmu_context_spinlock in destroy_context() and switch_mm() and can hang the cpu waiting for the rq lock of another cpu that in turn has called switch_mm hangning on srmmu_context_spinlock leading to deadlock. So, disable interrupt while taking srmmu_context_spinlock in destroy_context() and switch_mm() so we don't deadlock. See also commit 77b838fa1ef0 ("[SPARC64]: destroy_context() needs to disable interrupts.") Signed-off-by: Andreas Larsson <andreas@gaisler.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-18MAINTAINERS: changes for wirelessJohn W. Linville1-11/+8
http://marc.info/?l=linux-wireless&m=141883202530292&w=2 This makes it official... :-) Signed-off-by: John W. Linville <linville@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-18cxgb4: Fix decoding QSA module for ethtool get settingsHariprasad Shenai2-2/+2
QSA module was getting decoded as QSFP module in ethtool get settings, this patch fixes it. Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-18geneve: Fix races between socket add and release.Jesse Gross1-6/+7
Currently, searching for a socket to add a reference to is not synchronized with deletion of sockets. This can result in use after free if there is another operation that is removing a socket at the same time. Solving this requires both holding the appropriate lock and checking the refcount to ensure that it has not already hit zero. Inspired by a related (but not exactly the same) issue in the VXLAN driver. Fixes: 0b5e8b8e ("net: Add Geneve tunneling protocol driver") CC: Andy Zhou <azhou@nicira.com> Signed-off-by: Jesse Gross <jesse@nicira.com> Acked-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-18geneve: Remove socket and offload handlers at destruction.Jesse Gross1-0/+17
Sockets aren't currently removed from the the global list when they are destroyed. In addition, offload handlers need to be cleaned up as well. Fixes: 0b5e8b8e ("net: Add Geneve tunneling protocol driver") CC: Andy Zhou <azhou@nicira.com> Signed-off-by: Jesse Gross <jesse@nicira.com> Acked-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-18netlink: Don't reorder loads/stores before marking mmap netlink frame as availableThomas Graf1-1/+1
Each mmap Netlink frame contains a status field which indicates whether the frame is unused, reserved, contains data or needs to be skipped. Both loads and stores may not be reordeded and must complete before the status field is changed and another CPU might pick up the frame for use. Use an smp_mb() to cover needs of both types of callers to netlink_set_status(), callers which have been reading data frame from the frame, and callers which have been filling or releasing and thus writing to the frame. - Example code path requiring a smp_rmb(): memcpy(skb->data, (void *)hdr + NL_MMAP_HDRLEN, hdr->nm_len); netlink_set_status(hdr, NL_MMAP_STATUS_UNUSED); - Example code path requiring a smp_wmb(): hdr->nm_uid = from_kuid(sk_user_ns(sk), NETLINK_CB(skb).creds.uid); hdr->nm_gid = from_kgid(sk_user_ns(sk), NETLINK_CB(skb).creds.gid); netlink_frame_flush_dcache(hdr); netlink_set_status(hdr, NL_MMAP_STATUS_VALID); Fixes: f9c228 ("netlink: implement memory mapped recvmsg()") Reported-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-18netlink: Always copy on mmap TX.David Miller1-36/+16
Checking the file f_count and the nlk->mapped count is not completely sufficient to prevent the mmap'd area contents from changing from under us during netlink mmap sendmsg() operations. Be careful to sample the header's length field only once, because this could change from under us as well. Fixes: 5fd96123ee19 ("netlink: implement memory mapped sendmsg()") Signed-off-by: David S. Miller <davem@davemloft.net> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Thomas Graf <tgraf@suug.ch>
2014-12-18KVM: move APIC types to arch/x86/Paolo Bonzini3-27/+27
They are not used anymore by IA64, move them away. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-17Ceph: remove left-over reject fileLinus Torvalds1-10/+0
Neither Sage nor I noticed that Zheng Yan had mistakenly committed fs/ceph/super.h.rej as part of commit 31c542a199d7 ("ceph: add inline data to pagecache"). Remove it. Requested-by: Yan, Zheng <ukernel@gmail.com> Cc: Sage Weil <sweil@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-17KVM: PPC: Book3S: Enable in-kernel XICS emulation by defaultAnton Blanchard1-0/+1
The in-kernel XICS emulation is faster than doing it all in QEMU and it has got a lot of testing, so enable it by default. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-12-17Bluetooth: Fix bug with filter in service discovery optimizationMarcel Holtmann1-5/+9
The optimization for filtering out extended inquiry results, advertising reports or scan response data based on provided UUID list has a logic bug. In case no match is found in the advertising data, the scan response is ignored and not checked against the filter. This will lead to events being filtered wrongly. Change the code to actually only drop the events when the scan response data is not present. If it is present, it needs to be checked against the provided filter. The patch is a bit more complex than it needs to be. That is because it also fixes this compiler warning that some gcc versions produce. CC net/bluetooth/mgmt.o net/bluetooth/mgmt.c: In function ‘mgmt_device_found’: net/bluetooth/mgmt.c:7028:7: warning: ‘match’ may be used uninitialized in this function [-Wmaybe-uninitialized] bool match; ^ It seems that gcc can not clearly figure out the context of the match variable. So just change the branches for the extended inquiry response and advertising data around so that it is clear. Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Marcel Holtmann <marcel@holtmann.org> Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
2014-12-17mmu_gather: fix over-eager tlb_flush_mmu_free() callingLinus Torvalds1-3/+3
Dave Hansen reports that commit fb7332a9fedf ("mmu_gather: move minimal range calculations into generic code") caused a performance problem: "tlb_finish_mmu() goes up about 9x in the profiles (~0.4%->3.6%) and tlb_flush_mmu_free() takes about 3.1% of CPU time with the patch applied, but does not show up at all on the commit before" and the reason is that Will moved the test for whether we need to flush from tlb_flush_mmu() into tlb_flush_mmu_tlbonly(). But that meant that tlb_flush_mmu_free() basically lost that check. Move it back into tlb_flush_mmu() where it belongs, so that it covers both tlb_flush_mmu_tlbonly() _and_ tlb_flush_mmu_free(). Reported-and-tested-by: Dave Hansen <dave@sr71.net> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-17x86: mm: fix VM_FAULT_RETRY handlingLinus Torvalds1-1/+1
My commit 26178ec11ef3 ("x86: mm: consolidate VM_FAULT_RETRY handling") had a really stupid typo: the FAULT_FLAG_USER bit is in the 'flags' variable, not the 'fault' variable. Duh, The one silver lining in this is that Dave finding this at least confirms that trinity actually triggers this special path easily, in a way normal use does not. Reported-by: Dave Jones <davej@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-17ceph: fix setting empty extended attributeYan, Zheng1-2/+5
make sure 'value' is not null. otherwise __ceph_setxattr will remove the extended attribute. Signed-off-by: Yan, Zheng <zyan@redhat.com> Reviewed-by: Sage Weil <sage@redhat.com>
2014-12-17ceph: fix mksnap crashYan, Zheng1-1/+3
mksnap reply only contain 'target', does not contain 'dentry'. So it's wrong to use req->r_reply_info.head->is_dentry to detect traceless reply. Signed-off-by: Yan, Zheng <zyan@redhat.com> Reviewed-by: Sage Weil <sage@redhat.com>
2014-12-17ceph: do_sync is never initializedDan Carpenter1-1/+1
Probably this code was syncing a lot more often then intended because the do_sync variable wasn't set to zero. Cc: stable@vger.kernel.org # v3.11+ Fixes: c62988ec0910 ('ceph: avoid meaningless calling ceph_caps_revoking if sync_mode == WB_SYNC_ALL.') Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Ilya Dryomov <idryomov@redhat.com>
2014-12-17libceph: fixup includes in pagelist.hIlya Dryomov1-1/+3
pagelist.h needs to include linux/types.h and asm/byteorder.h and not rely on other headers pulling yet another set of headers. Signed-off-by: Ilya Dryomov <idryomov@redhat.com>
2014-12-17ceph: support inline data featureYan, Zheng1-1/+2
Signed-off-by: Yan, Zheng <zyan@redhat.com>
2014-12-17ceph: flush inline versionYan, Zheng3-4/+23
After converting inline data to normal data, client need to flush the new i_inline_version (CEPH_INLINE_NONE) to MDS. This commit makes cap messages (sent to MDS) contain inline_version and inline_data. Client always converts inline data to normal data before data write, so the inline data length part is always zero. Signed-off-by: Yan, Zheng <zyan@redhat.com>
2014-12-17ceph: convert inline data to normal data before data writeYan, Zheng3-3/+161
Before any data write, convert inline data to normal data and set i_inline_version to CEPH_INLINE_NONE. The OSD request that saves inline data to object contains 3 operations (CMPXATTR, WRITE and SETXATTR). It compares a xattr named 'inline_version' to prevent old data overwrites newer data. Signed-off-by: Yan, Zheng <zyan@redhat.com>
2014-12-17ceph: sync read inline dataYan, Zheng2-13/+116
we can't use getattr to fetch inline data while holding Fr cap, because it can cause deadlock. If we need to sync read inline data, drop cap refs first, then use getattr to fetch inline data. Signed-off-by: Yan, Zheng <zyan@redhat.com>
2014-12-17ceph: fetch inline data when getting Fcr cap refsYan, Zheng3-18/+63
we can't use getattr to fetch inline data after getting Fcr caps, because it can cause deadlock. The solution is try bringing inline data to page cache when not holding any cap, and hope the inline data page is still there after getting the Fcr caps. If the page is still there, pin it in page cache for later IO. Signed-off-by: Yan, Zheng <zyan@redhat.com>
2014-12-17ceph: use getattr request to fetch inline dataYan, Zheng4-10/+34
Add a new parameter 'locked_page' to ceph_do_getattr(). If inline data in getattr reply will be copied to the page. Signed-off-by: Yan, Zheng <zyan@redhat.com>
2014-12-17ceph: add inline data to pagecacheYan, Zheng6-1/+85
Request reply and cap message can contain inline data. add inline data to the page cache if there is Fc cap. Signed-off-by: Yan, Zheng <zyan@redhat.com>
2014-12-17ceph: parse inline data in MClientReply and MClientCapsYan, Zheng3-11/+36
Signed-off-by: Yan, Zheng <zyan@redhat.com>
2014-12-17libceph: specify position of extent operationYan, Zheng4-20/+19
allow specifying position of extent operation in multi-operations osd request. This is required for cephfs to convert inline data to normal data (compare xattr, then write object). Signed-off-by: Yan, Zheng <zyan@redhat.com> Reviewed-by: Ilya Dryomov <idryomov@redhat.com>
2014-12-17libceph: add CREATE osd operation supportYan, Zheng1-20/+22
Add CEPH_OSD_OP_CREATE support. Also change libceph to not treat CEPH_OSD_OP_DELETE as an extent op and add an assert to that end. Signed-off-by: Yan, Zheng <zyan@redhat.com> Reviewed-by: Ilya Dryomov <idryomov@redhat.com>
2014-12-17libceph: add SETXATTR/CMPXATTR osd operations supportYan, Zheng2-0/+57
Signed-off-by: Yan, Zheng <zyan@redhat.com> Reviewed-by: Ilya Dryomov <idryomov@redhat.com>
2014-12-17rbd: don't treat CEPH_OSD_OP_DELETE as extent opIlya Dryomov1-2/+6
CEPH_OSD_OP_DELETE is not an extent op, stop treating it as such. This sneaked in with discard patches - it's one of the three osd ops (the other two are CEPH_OSD_OP_TRUNCATE and CEPH_OSD_OP_ZERO) that discard is implemented with. Signed-off-by: Ilya Dryomov <idryomov@redhat.com> Reviewed-by: Alex Elder <elder@linaro.org>
2014-12-17ceph: remove unused stringification macrosIlya Dryomov1-3/+0
These were used to report git versions a long time ago. Signed-off-by: Ilya Dryomov <idryomov@redhat.com>
2014-12-17libceph: require cephx message signature by defaultYan, Zheng2-0/+14
Signed-off-by: Yan, Zheng <zyan@redhat.com> Reviewed-by: Ilya Dryomov <idryomov@redhat.com>
2014-12-17ceph: introduce global empty snap contextYan, Zheng3-3/+35
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>
2014-12-17ceph: message versioning fixesJohn Spray1-2/+5
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>
2014-12-17libceph: update ceph_msg_header structureJohn Spray1-1/+2
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>
2014-12-17libceph: message signature supportYan, Zheng8-4/+162
Signed-off-by: Yan, Zheng <zyan@redhat.com>
2014-12-17libceph: store session key in cephx authorizerYan, Zheng2-7/+12
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>
2014-12-17ceph, rbd: delete unnecessary checks before two function callsSF Markus Elfring4-14/+7
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>
2014-12-17ceph: introduce a new inode flag indicating if cached dentries are orderedYan, Zheng3-19/+55
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>
2014-12-17libceph: nuke ceph_kvfree()Ilya Dryomov5-14/+4
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>
2014-12-17ceph: fix file lock interruptionYan, Zheng4-12/+67
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>
2014-12-17mac80211: free management frame keys when removing stationJohannes Berg1-1/+1
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: e31b82136d1a ("cfg80211/mac80211: allow per-station GTKs") Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2014-12-17KVM: PPC: Book3S HV: Improve H_CONFER implementationSam Bobroff4-2/+74
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>
2014-12-17KVM: PPC: Book3S HV: Fix endianness of instruction obtained from HEIR registerPaul Mackerras4-2/+9
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>
2014-12-17KVM: PPC: Book3S HV: Remove code for PPC970 processorsPaul Mackerras13-955/+70
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>
2014-12-17KVM: PPC: Book3S HV: Tracepoints for KVM HV guest interactionsSuresh E. Warrier5-27/+539
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>
2014-12-17KVM: PPC: Book3S HV: Simplify locking around stolen time calculationsPaul Mackerras2-29/+32
Currently the calculations of stolen time for PPC Book3S HV guests uses fields in both the vcpu struct and the kvmppc_vcore struct. The fields in the kvmppc_vcore struct are protected by the vcpu->arch.tbacct_lock of the vcpu that has taken responsibility for running the virtual core. This works correctly but confuses lockdep, because it sees that the code takes the tbacct_lock for a vcpu in kvmppc_remove_runnable() and then takes another vcpu's tbacct_lock in vcore_stolen_time(), and it thinks there is a possibility of deadlock, causing it to print reports like this: ============================================= [ INFO: possible recursive locking detected ] 3.18.0-rc7-kvm-00016-g8db4bc6 #89 Not tainted --------------------------------------------- qemu-system-ppc/6188 is trying to acquire lock: (&(&vcpu->arch.tbacct_lock)->rlock){......}, at: [<d00000000ecb1fe8>] .vcore_stolen_time+0x48/0xd0 [kvm_hv] but task is already holding lock: (&(&vcpu->arch.tbacct_lock)->rlock){......}, at: [<d00000000ecb25a0>] .kvmppc_remove_runnable.part.3+0x30/0xd0 [kvm_hv] other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(&vcpu->arch.tbacct_lock)->rlock); lock(&(&vcpu->arch.tbacct_lock)->rlock); *** DEADLOCK *** May be due to missing lock nesting notation 3 locks held by qemu-system-ppc/6188: #0: (&vcpu->mutex){+.+.+.}, at: [<d00000000eb93f98>] .vcpu_load+0x28/0xe0 [kvm] #1: (&(&vcore->lock)->rlock){+.+...}, at: [<d00000000ecb41b0>] .kvmppc_vcpu_run_hv+0x530/0x1530 [kvm_hv] #2: (&(&vcpu->arch.tbacct_lock)->rlock){......}, at: [<d00000000ecb25a0>] .kvmppc_remove_runnable.part.3+0x30/0xd0 [kvm_hv] stack backtrace: CPU: 40 PID: 6188 Comm: qemu-system-ppc Not tainted 3.18.0-rc7-kvm-00016-g8db4bc6 #89 Call Trace: [c000000b2754f3f0] [c000000000b31b6c] .dump_stack+0x88/0xb4 (unreliable) [c000000b2754f470] [c0000000000faeb8] .__lock_acquire+0x1878/0x2190 [c000000b2754f600] [c0000000000fbf0c] .lock_acquire+0xcc/0x1a0 [c000000b2754f6d0] [c000000000b2954c] ._raw_spin_lock_irq+0x4c/0x70 [c000000b2754f760] [d00000000ecb1fe8] .vcore_stolen_time+0x48/0xd0 [kvm_hv] [c000000b2754f7f0] [d00000000ecb25b4] .kvmppc_remove_runnable.part.3+0x44/0xd0 [kvm_hv] [c000000b2754f880] [d00000000ecb43ec] .kvmppc_vcpu_run_hv+0x76c/0x1530 [kvm_hv] [c000000b2754f9f0] [d00000000eb9f46c] .kvmppc_vcpu_run+0x2c/0x40 [kvm] [c000000b2754fa60] [d00000000eb9c9a4] .kvm_arch_vcpu_ioctl_run+0x54/0x160 [kvm] [c000000b2754faf0] [d00000000eb94538] .kvm_vcpu_ioctl+0x498/0x760 [kvm] [c000000b2754fcb0] [c000000000267eb4] .do_vfs_ioctl+0x444/0x770 [c000000b2754fd90] [c0000000002682a4] .SyS_ioctl+0xc4/0xe0 [c000000b2754fe30] [c0000000000092e4] syscall_exit+0x0/0x98 In order to make the locking easier to analyse, we change the code to use a spinlock in the kvmppc_vcore struct to protect the stolen_tb and preempt_tb fields. This lock needs to be an irq-safe lock since it is used in the kvmppc_core_vcpu_load_hv() and kvmppc_core_vcpu_put_hv() functions, which are called with the scheduler rq lock held, which is an irq-safe lock. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>