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* Drivers: hv: hv_balloon: correctly handle num_pages>INT_MAX caseVitaly Kuznetsov2015-04-031-6/+7
| | | | | | | | | | | | | | | | | balloon_wrk.num_pages is __u32 and it comes from host in struct dm_balloon where it is also __u32. We, however, use 'int' in balloon_up() and in case we happen to receive num_pages>INT_MAX request we'll end up allocating zero pages as 'num_pages < alloc_unit' check in alloc_balloon_pages() will pass. Change num_pages type to unsigned int. In real life ballooning request come with num_pages in [512, 32768] range so this is more a future-proof/cleanup. Reported-by: Laszlo Ersek <lersek@redhat.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Laszlo Ersek <lersek@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: hv_balloon: correctly handle val.freeram<num_pages caseVitaly Kuznetsov2015-04-031-1/+1
| | | | | | | | | | | | | | | | | 'Drivers: hv: hv_balloon: refuse to balloon below the floor' fix does not correctly handle the case when val.freeram < num_pages as val.freeram is __kernel_ulong_t and the 'val.freeram - num_pages' value will be a huge positive value instead of being negative. Usually host doesn't ask us to balloon more than val.freeram but in case he have a memory hog started after we post the last pressure report we can get into troubles. Suggested-by: Laszlo Ersek <lersek@redhat.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Laszlo Ersek <lersek@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* hv_vmbus: Add gradually increased delay for retries in vmbus_post_msg()Haiyang Zhang2015-04-031-2/+5
| | | | | | | | | | | | | Most of the retries can be done within a millisecond successfully, so we sleep 1ms before the first retry, then gradually increase the retry interval to 2^n with max value of 2048ms. Doing so, we will have shorter overall delay time, because most of the cases succeed within 1-2 attempts. Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com> Reviewed-by: K. Y. Srinivasan <kys@microsoft.com> Reviewed-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: hv_balloon: survive ballooning request with num_pages=0Vitaly Kuznetsov2015-04-031-13/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ... and simplify alloc_balloon_pages() interface by removing redundant alloc_error from it. If we happen to enter balloon_up() with balloon_wrk.num_pages = 0 we will enter infinite 'while (!done)' loop as alloc_balloon_pages() will be always returning 0 and not setting alloc_error. We will also be sending a meaningless message to the host on every iteration. The 'alloc_unit == 1 && alloc_error -> num_ballooned == 0' change and alloc_error elimination requires a special comment. We do alloc_balloon_pages() with 2 different alloc_unit values and there are 4 different alloc_balloon_pages() results, let's check them all. alloc_unit = 512: 1) num_ballooned = 0, alloc_error = 0: we do 'alloc_unit=1' and retry pre- and post-patch. 2) num_ballooned > 0, alloc_error = 0: we check 'num_ballooned == num_pages' and act accordingly, pre- and post-patch. 3) num_ballooned > 0, alloc_error > 0: we report this chunk and remain within the loop, no changes here. 4) num_ballooned = 0, alloc_error > 0: we do 'alloc_unit=1' and retry pre- and post-patch. alloc_unit = 1: 1) num_ballooned = 0, alloc_error = 0: this can happen in two cases: when we passed 'num_pages=0' to alloc_balloon_pages() or when there was no space in bl_resp to place a single response. The second option is not possible as bl_resp is of PAGE_SIZE size and single response 'union dm_mem_page_range' is 8 bytes, but the first one is (in theory, I think that Hyper-V host never places such requests). Pre-patch code loops forever, post-patch code sends a reply with more_pages = 0 and finishes. 2) num_ballooned > 0, alloc_error = 0: we ran out of space in bl_resp, we report partial success and remain within the loop, no changes pre- and post-patch. 3) num_ballooned > 0, alloc_error > 0: pre-patch code finishes, post-patch code does one more try and if there is no progress (we finish with 'num_ballooned = 0') we finish. So we try a bit harder with this patch. 4) num_ballooned = 0, alloc_error > 0: both pre- and post-patch code enter 'more_pages = 0' branch and finish. So this patch has two real effects: 1) We reply with an empty response to 'num_pages=0' request. 2) We try a bit harder on alloc_unit=1 allocations (and reply with an empty tail reply in case we fail). An empty reply should be supported by host as we were able to send it even with pre-patch code when we were not able to allocate a single page. Suggested-by: Laszlo Ersek <lersek@redhat.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: hv_balloon: eliminate jumps in piecewiese linear floor functionVitaly Kuznetsov2015-04-031-4/+4
| | | | | | | | | | | | | | | | | | | | | Commit 79208c57da53 ("Drivers: hv: hv_balloon: Make adjustments in computing the floor") was inacurate as it introduced a jump in our piecewiese linear 'floor' function: At 2048MB we have: Left limit: 104 + 2048/8 = 360 Right limit: 256 + 2048/16 = 384 (so the right value is 232) We now have to make an adjustment at 8192 boundary: 232 + 8192/16 = 744 512 + 8192/32 = 768 (so the right value is 488) Suggested-by: Laszlo Ersek <lersek@redhat.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: hv_balloon: do not online pages in offline blocksVitaly Kuznetsov2015-04-031-1/+11
| | | | | | | | | | | | | | | | | | | Currently we add memory in 128Mb blocks but the request from host can be aligned differently. In such case we add a partially backed block and when this block goes online we skip onlining pages which are not backed (hv_online_page() callback serves this purpose). When we receive next request for the same host add region we online pages which were not backed before with hv_bring_pgs_online(). However, we don't check if the the block in question was onlined and online this tail unconditionally. This is bad as we avoid all online_pages() logic: these pages are not accounted, we don't send notifications (and hv_balloon is not the only receiver of them),... And, first of all, nobody asked as to online these pages. Solve the issue by checking if the last previously backed page was onlined and onlining the tail only in case it was. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* hv: remove the per-channel workqueueDexuan Cui2015-04-031-29/+1
| | | | | | | | | | It's not necessary any longer, since we can safely run the blocking message handlers in vmbus_connection.work_queue now. Signed-off-by: Dexuan Cui <decui@microsoft.com> Cc: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* hv: don't schedule new works in vmbus_onoffer()/vmbus_onoffer_rescind()Dexuan Cui2015-04-033-135/+30
| | | | | | | | | | | | | Since the 2 fucntions can safely run in vmbus_connection.work_queue without hang, we don't need to schedule new work items into the per-channel workqueue. Actally we can even remove the per-channel workqueue now -- we'll do it in the next patch. Signed-off-by: Dexuan Cui <decui@microsoft.com> Cc: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* hv: run non-blocking message handlers in the dispatch taskletDexuan Cui2015-04-033-26/+53
| | | | | | | | | | | | | | | | | | | | | | | A work item in vmbus_connection.work_queue can sleep, waiting for a new host message (usually it is some kind of "completion" message). Currently the new message will be handled in the same workqueue, but since work items in the workqueue is serialized, we actually have no chance to handle the new message if the current work item is sleeping -- as as result, the current work item will hang forever. K. Y. has posted the below fix to resolve the issue: Drivers: hv: vmbus: Perform device register in the per-channel work element Actually we can simplify the fix by directly running non-blocking message handlers in the dispatch tasklet (inspired by K. Y.). This patch is the fundamental change. The following 2 patches will simplify the message offering and rescind-offering handling a lot. Signed-off-by: Dexuan Cui <decui@microsoft.com> Cc: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: vmbus: Don't wait after requesting offersK. Y. Srinivasan2015-03-261-11/+0
| | | | | | | | | Don't wait after sending request for offers to the host. This wait is unnecessary and simply adds 5 seconds to the boot time. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Cc: <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: vmbus: Fix a siganlling host signalling issueK. Y. Srinivasan2015-03-251-2/+26
| | | | | | | | | | Handle the case when the write to the ringbuffer fails. In this case, unconditionally signal the host. Since we may have deferred signalling the host based on the kick_q parameter, signalling the host unconditionally in this case deals with the issue. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: vmbus: Export the vmbus_sendpacket_pagebuffer_ctl()K. Y. Srinivasan2015-03-251-0/+1
| | | | | | | | Export the vmbus_sendpacket_pagebuffer_ctl() interface. This export will be used by the netvsc driver. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: vmbus: Fix a bug in rescind processing in vmbus_close_internal()K. Y. Srinivasan2015-03-251-9/+6
| | | | | | | | | | | | | | When a channel has been rescinded, the close operation is a noop. Restructure the code so we deal with the rescind condition after we properly cleanup the channel. I would like to thank Dexuan Cui <decui@microsoft.com> for observing this problem. The current code leaks memory when the channel is rescinded. The current char-next branch is broken and this patch fixes the bug. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* hv: vmbus: missing curly braces in vmbus_process_offer()Dan Carpenter2015-03-251-1/+2
| | | | | | | | | The indenting makes it clear that there were curly braces intended here. Fixes: 2dd37cb81580 ('Drivers: hv: vmbus: Handle both rescind and offer messages in the same context') Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: vmbus: Correcting truncation error for constant ↵Nick Meier2015-03-251-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | HV_CRASH_CTL_CRASH_NOTIFY HV_CRASH_CTL_CRASH_NOTIFY is a 64 bit number. Depending on the usage context, the value may be truncated. This patch is in response from the following email from Wu Fengguang <fengguang.wu@intel.com>: From: Wu Fengguang <fengguang.wu@intel.com> Subject: [char-misc:char-misc-testing 25/45] drivers/hv/vmbus_drv.c:67:9: sparse: constant 0x8000000000000000 is so big it is unsigned long tree: git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git char-misc-testing head: b3de8e3719e582f3182bb504295e4a8e43c8c96f commit: 96c1d0581d00f7abe033350edb021a9d947d8d81 [25/45] Drivers: hv: vmbus: Add support for VMBus panic notifier handler reproduce: # apt-get install sparse git checkout 96c1d0581d00f7abe033350edb021a9d947d8d81 make ARCH=x86_64 allmodconfig make C=1 CF=-D__CHECK_ENDIAN__ sparse warnings: (new ones prefixed by >>) drivers/hv/vmbus_drv.c:67:9: sparse: constant 0x8000000000000000 is so big it is unsigned long ... Signed-off-by: Nick Meier <nmeier@microsoft.com> Reported-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: hv_balloon: don't lose memory when onlining order is not naturalVitaly Kuznetsov2015-03-251-10/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Memory blocks can be onlined in random order. When this order is not natural some memory pages are not onlined because of the redundant check in hv_online_page(). Here is a real world scenario: 1) Host tries to hot-add the following (process_hot_add): pg_start=rg_start=0x48000, pfn_cnt=111616, rg_size=262144 2) This results in adding 4 memory blocks: [ 109.057866] init_memory_mapping: [mem 0x48000000-0x4fffffff] [ 114.102698] init_memory_mapping: [mem 0x50000000-0x57ffffff] [ 119.168039] init_memory_mapping: [mem 0x58000000-0x5fffffff] [ 124.233053] init_memory_mapping: [mem 0x60000000-0x67ffffff] The last one is incomplete but we have special has->covered_end_pfn counter to avoid onlining non-backed frames and hv_bring_pgs_online() function to bring them online later on. 3) Now we have 4 offline memory blocks: /sys/devices/system/memory/memory9-12 $ for f in /sys/devices/system/memory/memory*/state; do echo $f `cat $f`; done | grep -v onlin /sys/devices/system/memory/memory10/state offline /sys/devices/system/memory/memory11/state offline /sys/devices/system/memory/memory12/state offline /sys/devices/system/memory/memory9/state offline 4) We bring them online in non-natural order: $grep MemTotal /proc/meminfo MemTotal: 966348 kB $echo online > /sys/devices/system/memory/memory12/state && grep MemTotal /proc/meminfo MemTotal: 1019596 kB $echo online > /sys/devices/system/memory/memory11/state && grep MemTotal /proc/meminfo MemTotal: 1150668 kB $echo online > /sys/devices/system/memory/memory9/state && grep MemTotal /proc/meminfo MemTotal: 1150668 kB As you can see memory9 block gives us zero additional memory. We can also observe a huge discrepancy between host- and guest-reported memory sizes. The root cause of the issue is the redundant pg >= covered_start_pfn check (and covered_start_pfn advancing) in hv_online_page(). When upper memory block in being onlined before the lower one (memory12 and memory11 in the above case) we advance the covered_start_pfn pointer and all memory9 pages do not pass the check. If the assumption that host always gives us requests in sequential order and pg_start always equals rg_start when the first request for the new HA region is received (that's the case in my testing) is correct than we can get rid of covered_start_pfn and pg >= start_pfn check in hv_online_page() is sufficient. The current char-next branch is broken and this patch fixes the bug. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: hv_balloon: keep locks balanced on add_memory() failureVitaly Kuznetsov2015-03-251-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | When add_memory() fails the following BUG is observed: [ 743.646107] hv_balloon: hot_add memory failed error is -17 [ 743.679973] [ 743.680930] ===================================== [ 743.680930] [ BUG: bad unlock balance detected! ] [ 743.680930] 3.19.0-rc5_bug1131426+ #552 Not tainted [ 743.680930] ------------------------------------- [ 743.680930] kworker/0:2/255 is trying to release lock (&dm_device.ha_region_mutex) at: [ 743.680930] [<ffffffff81aae5fe>] mutex_unlock+0xe/0x10 [ 743.680930] but there are no more locks to release! This happens as we don't acquire ha_region_mutex and hot_add_req() expects us to as it does unconditional mutex_unlock(). Acquire the lock on the error path. The current char-next branch is broken and this patch fixes the bug. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: vmbus: Perform device register in the per-channel work elementK. Y. Srinivasan2015-03-253-44/+107
| | | | | | | | | | | | | This patch is a continuation of the rescind handling cleanup work. We cannot block in the global message handling work context especially if we are blocking waiting for the host to wake us up. I would like to thank Dexuan Cui <decui@microsoft.com> for observing this problem. The current char-next branch is broken and this patch fixes the bug. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* mei: bus: () can be statickbuild test robot2015-03-011-1/+1
| | | | | | | | | | drivers/hv/vmbus_drv.c:51:5: sparse: symbol 'hyperv_panic_event' was not declared. Should it be static? drivers/hv/vmbus_drv.c:51:5: sparse: symbol 'hyperv_panic_event' was not declared. Should it be static? drivers/hv/vmbus_drv.c:51:5: sparse: symbol 'hyperv_panic_event' was not declared. Should it be static? drivers/hv/vmbus_drv.c:51:5: sparse: symbol 'hyperv_panic_event' was not declared. Should it be static? Signed-off-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: vmbus: Suport an API to send packet with additional controlK. Y. Srinivasan2015-03-011-17/+26
| | | | | | | | | Implement an API that gives additional control on the what VMBUS flags will be set as well as if the host needs to be signalled. This API will be useful for clients that want to batch up requests to the host. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: vmbus: Suport an API to send pagebuffers with additional controlK. Y. Srinivasan2015-03-011-6/+27
| | | | | | | | | Implement an API for sending pagebuffers that gives more control to the client in terms of setting the vmbus flags as well as deciding when to notify the host. This will be useful for enabling batch processing. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: vmbus: Use a round-robin algorithm for picking the outgoing channelK. Y. Srinivasan2015-03-011-15/+15
| | | | | | | | | | The current algorithm for picking an outgoing channel was not distributing the load well. Implement a simple round-robin scheme to ensure good distribution of the outgoing traffic. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Reviewed-by: Long Li <longli@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: vmbus: Add support for VMBus panic notifier handlerNick Meier2015-03-012-0/+47
| | | | | | | | | | | | | | | | | | | | Hyper-V allows a guest to notify the Hyper-V host that a panic condition occured. This notification can include up to five 64 bit values. These 64 bit values are written into crash MSRs. Once the data has been written into the crash MSRs, the host is then notified by writing into a Crash Control MSR. On the Hyper-V host, the panic notification data is captured in the Windows Event log as a 18590 event. Crash MSRs are defined in appendix H of the Hypervisor Top Level Functional Specification. At the time of this patch, v4.0 is the current functional spec. The URL for the v4.0 document is: http://download.microsoft.com/download/A/B/4/AB43A34E-BDD0-4FA6-BDEF-79EEF16E880B/Hypervisor Top Level Functional Specification v4.0.docx Signed-off-by: Nick Meier <nmeier@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: hv_balloon: refuse to balloon below the floorVitaly Kuznetsov2015-03-011-0/+11
| | | | | | | | | | When host asks us to balloon up we need to be sure we're not committing suicide by overballooning. Use already existent 'floor' metric as our lowest possible value for free ram. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: hv_balloon: report offline pages as being usedVitaly Kuznetsov2015-03-011-9/+24
| | | | | | | | | | | | | When hot-added memory pages are not brought online or when some memory blocks are sent offline the subsequent ballooning process kills the guest with OOM killer. This happens as we don't report these pages as neither used nor free and apparently host algorithm considers them as being unused. Keep track of all online/offline operations and report all currently offline pages as being used so host won't try to balloon them out. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: hv_balloon: eliminate the trylock path in ↵Vitaly Kuznetsov2015-03-011-29/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | acquire/release_region_mutex When many memory regions are being added and automatically onlined the following lockup is sometimes observed: INFO: task udevd:1872 blocked for more than 120 seconds. ... Call Trace: [<ffffffff816ec0bc>] schedule_timeout+0x22c/0x350 [<ffffffff816eb98f>] wait_for_common+0x10f/0x160 [<ffffffff81067650>] ? default_wake_function+0x0/0x20 [<ffffffff816eb9fd>] wait_for_completion+0x1d/0x20 [<ffffffff8144cb9c>] hv_memory_notifier+0xdc/0x120 [<ffffffff816f298c>] notifier_call_chain+0x4c/0x70 ... When several memory blocks are going online simultaneously we got several hv_memory_notifier() trying to acquire the ha_region_mutex. When this mutex is being held by hot_add_req() all these competing acquire_region_mutex() do mutex_trylock, fail, and queue themselves into wait_for_completion(..). However when we do complete() from release_region_mutex() only one of them wakes up. This could be solved by changing complete() -> complete_all() memory onlining can be delayed as well, in that case we can still get several hv_memory_notifier() runners at the same time trying to grab the mutex. Only one of them will succeed and the others will hang for forever as complete() is not being called. We don't see this issue often because we have 5sec onlining timeout in hv_mem_hot_add() and usually all udev events arrive in this time frame. Get rid of the trylock path, waiting on the mutex is supposed to provide the required serialization. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: vmbus: Get rid of some unnecessary messagesK. Y. Srinivasan2015-03-011-6/+1
| | | | | | | | | | Currently we log messages when either we are not able to map an ID to a channel or when the channel does not have a callback associated (in the channel interrupt handling path). These messages don't add any value, get rid of them. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: util: On device remove, close the channel after de-initializing ↵K. Y. Srinivasan2015-03-011-1/+1
| | | | | | | | | | the service When the offer is rescinded, vmbus_close() can free up the channel; deinitialize the service before closing the channel. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: vmbus: Remove the channel from the channel list(s) on failureK. Y. Srinivasan2015-03-011-5/+16
| | | | | | | Properly rollback state in vmbus_pocess_offer() in the failure paths. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: vmbus: Handle both rescind and offer messages in the same contextK. Y. Srinivasan2015-03-011-53/+62
| | | | | | | | Execute both ressind and offer messages in the same work context. This serializes these operations and naturally addresses the various corner cases. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: vmbus: Introduce a function to remove a rescinded offerK. Y. Srinivasan2015-03-013-20/+49
| | | | | | | | | In response to a rescind message, we need to remove the channel and the corresponding device. Cleanup this code path by factoring out the code to remove a channel. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: vmbus: Properly handle child device removeK. Y. Srinivasan2015-03-011-6/+9
| | | | | | | | Handle the case when the device may be removed when the device has no driver attached to it. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: vmbus: Add support for the NetworkDirect GUIDK. Y. Srinivasan2015-03-011-0/+2
| | | | | | | | NetworkDirect is a service that supports guest RDMA. Define the GUID for this service. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: vmbus: Fix a bug in the error path in vmbus_open()K. Y. Srinivasan2015-03-011-2/+5
| | | | | | | | | Correctly rollback state if the failure occurs after we have handed over the ownership of the buffer to the host. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* hv: hv_balloon: match var type to return type of wait_for_completionNicholas Mc Guire2015-03-011-1/+2
| | | | | | | | | return type of wait_for_completion_timeout is unsigned long not int, this patch changes the type of t from int to unsigned long. Signed-off-by: Nicholas Mc Guire <der.herr@hofr.at> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* hv: channel_mgmt: match var type to return type of wait_for_completionNicholas Mc Guire2015-03-011-1/+2
| | | | | | | | | return type of wait_for_completion_timeout is unsigned long not int, this patch changes the type of t from int to unsigned long. Signed-off-by: Nicholas Mc Guire <der.herr@hofr.at> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* hv: channel: match var type to return type of wait_for_completionNicholas Mc Guire2015-03-011-1/+2
| | | | | | | | | return type of wait_for_completion_timeout is unsigned long not int, this patch changes the type of t from int to unsigned long. Signed-off-by: Nicholas Mc Guire <der.herr@hofr.at> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* hv: vmbus_open(): reset the channel state on ENOMEMDexuan Cui2015-03-011-3/+5
| | | | | | | | | | | | Without this patch, the state is put to CHANNEL_OPENING_STATE, and when the driver is loaded next time, vmbus_open() will fail immediately due to newchannel->state != CHANNEL_OPEN_STATE. CC: "K. Y. Srinivasan" <kys@microsoft.com> Signed-off-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Jason Wang <jasowang@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* hv: vmbus_post_msg: retry the hypercall on some transient errorsDexuan Cui2015-03-011-2/+9
| | | | | | | | | | | | | | | | | | | I got HV_STATUS_INVALID_CONNECTION_ID on Hyper-V 2008 R2 when keeping running "rmmod hv_netvsc; modprobe hv_netvsc; rmmod hv_utils; modprobe hv_utils" in a Linux guest. Looks the host has some kind of throttling mechanism if some kinds of hypercalls are sent too frequently. Without the patch, the driver can occasionally fail to load. Also let's retry HV_STATUS_INSUFFICIENT_MEMORY, though we didn't get it before. Removed 'case -ENOMEM', since the hypervisor doesn't return this. CC: "K. Y. Srinivasan" <kys@microsoft.com> Reviewed-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* hv: hv_util: move vmbus_open() to a later placeDexuan Cui2015-03-011-5/+6
| | | | | | | | | | | | | | Before the line vmbus_open() returns, srv->util_cb can be already running and the variables, like util_fw_version, are needed by the srv->util_cb. So we have to make sure the variables are initialized before the vmbus_open(). CC: "K. Y. Srinivasan" <kys@microsoft.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: vmbus: Teardown clockevent devices on module unloadVitaly Kuznetsov2015-03-013-1/+27
| | | | | | | | | | | | | | | | | | Newly introduced clockevent devices made it impossible to unload hv_vmbus module as clockevents_config_and_register() takes additional reverence to the module. To make it possible again we do the following: - avoid setting dev->owner for clockevent devices; - implement hv_synic_clockevents_cleanup() doing clockevents_unbind_device(); - call it from vmbus_exit(). In theory hv_synic_clockevents_cleanup() can be merged with hv_synic_cleanup(), however, we call hv_synic_cleanup() from smp_call_function_single() and this doesn't work for clockevents_unbind_device() as it does such call on its own. I opted for a separate function. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* drivers: hv: vmbus: Teardown synthetic interrupt controllers on module unloadVitaly Kuznetsov2015-03-012-2/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | SynIC has to be switched off when we unload the module, otherwise registered memory pages can get corrupted after (as Hyper-V host still writes there) and we see the following crashes for random processes: [ 89.116774] BUG: Bad page map in process sh pte:4989c716 pmd:36f81067 [ 89.159454] addr:0000000000437000 vm_flags:00000875 anon_vma: (null) mapping:ffff88007bba55a0 index:37 [ 89.226146] vma->vm_ops->fault: filemap_fault+0x0/0x410 [ 89.257776] vma->vm_file->f_op->mmap: generic_file_mmap+0x0/0x60 [ 89.297570] CPU: 0 PID: 215 Comm: sh Tainted: G B 3.19.0-rc5_bug923184+ #488 [ 89.353738] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS 090006 05/23/2012 [ 89.409138] 0000000000000000 000000004e083d7b ffff880036e9fa18 ffffffff81a68d31 [ 89.468724] 0000000000000000 0000000000437000 ffff880036e9fa68 ffffffff811a1e3a [ 89.519233] 000000004989c716 0000000000000037 ffffea0001edc340 0000000000437000 [ 89.575751] Call Trace: [ 89.591060] [<ffffffff81a68d31>] dump_stack+0x45/0x57 [ 89.625164] [<ffffffff811a1e3a>] print_bad_pte+0x1aa/0x250 [ 89.667234] [<ffffffff811a2c95>] vm_normal_page+0x55/0xa0 [ 89.703818] [<ffffffff811a3105>] unmap_page_range+0x425/0x8a0 [ 89.737982] [<ffffffff811a3601>] unmap_single_vma+0x81/0xf0 [ 89.780385] [<ffffffff81184320>] ? lru_deactivate_fn+0x190/0x190 [ 89.820130] [<ffffffff811a4131>] unmap_vmas+0x51/0xa0 [ 89.860168] [<ffffffff811ad12c>] exit_mmap+0xac/0x1a0 [ 89.890588] [<ffffffff810763c3>] mmput+0x63/0x100 [ 89.919205] [<ffffffff811eba48>] flush_old_exec+0x3f8/0x8b0 [ 89.962135] [<ffffffff8123b5bb>] load_elf_binary+0x32b/0x1260 [ 89.998581] [<ffffffff811a14f2>] ? get_user_pages+0x52/0x60 hv_synic_cleanup() function exists but noone calls it now. Do the following: - call hv_synic_cleanup() on each cpu from vmbus_exit(); - write global disable bit through MSR; - use hv_synic_free_cpu() to avoid memory leask and code duplication. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: vmbus: teardown hv_vmbus_con workqueue and vmbus_connection ↵Vitaly Kuznetsov2015-03-013-5/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | pages on shutdown We need to destroy hv_vmbus_con on module shutdown, otherwise the following crash is sometimes observed: [ 76.569845] hv_vmbus: Hyper-V Host Build:9600-6.3-17-0.17039; Vmbus version:3.0 [ 82.598859] BUG: unable to handle kernel paging request at ffffffffa0003480 [ 82.599287] IP: [<ffffffffa0003480>] 0xffffffffa0003480 [ 82.599287] PGD 1f34067 PUD 1f35063 PMD 3f72d067 PTE 0 [ 82.599287] Oops: 0010 [#1] SMP [ 82.599287] Modules linked in: [last unloaded: hv_vmbus] [ 82.599287] CPU: 0 PID: 26 Comm: kworker/0:1 Not tainted 3.19.0-rc5_bug923184+ #488 [ 82.599287] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v1.0 11/26/2012 [ 82.599287] Workqueue: hv_vmbus_con 0xffffffffa0003480 [ 82.599287] task: ffff88007b6ddfa0 ti: ffff88007f8f8000 task.ti: ffff88007f8f8000 [ 82.599287] RIP: 0010:[<ffffffffa0003480>] [<ffffffffa0003480>] 0xffffffffa0003480 [ 82.599287] RSP: 0018:ffff88007f8fbe00 EFLAGS: 00010202 ... To avoid memory leaks we need to free monitor_pages and int_page for vmbus_connection. Implement vmbus_disconnect() function by separating cleanup path from vmbus_connect(). As we use hv_vmbus_con to release channels (see free_channel() in channel_mgmt.c) we need to make sure the work was done before we remove the queue, do that with drain_workqueue(). We also need to avoid handling messages which can (potentially) create new channels, so set vmbus_connection.conn_state = DISCONNECTED at the very beginning of vmbus_exit() and check for that in vmbus_onmessage_work(). Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: vmbus: avoid double kfree for device_objVitaly Kuznetsov2015-03-011-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | On driver shutdown device_obj is being freed twice: 1) In vmbus_free_channels() 2) vmbus_device_release() (which is being triggered by device_unregister() in vmbus_device_unregister(). This double kfree leads to the following sporadic crash on driver unload: [ 23.469876] general protection fault: 0000 [#1] SMP [ 23.470036] Modules linked in: hv_vmbus(-) [ 23.470036] CPU: 2 PID: 213 Comm: rmmod Not tainted 3.19.0-rc5_bug923184+ #488 [ 23.470036] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS 090006 05/23/2012 [ 23.470036] task: ffff880036ef1cb0 ti: ffff880036ce8000 task.ti: ffff880036ce8000 [ 23.470036] RIP: 0010:[<ffffffff811d2e1b>] [<ffffffff811d2e1b>] __kmalloc_node_track_caller+0xdb/0x1e0 [ 23.470036] RSP: 0018:ffff880036cebcc8 EFLAGS: 00010246 ... When this crash does not happen on driver unload the similar one is expected if we try to load hv_vmbus again. Remove kfree from vmbus_free_channels() as freeing it from vmbus_device_release() seems right. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: vmbus: rename channel work queuesVitaly Kuznetsov2015-03-012-5/+6
| | | | | | | | | | | All channel work queues are named 'hv_vmbus_ctl', this makes them indistinguishable in ps output and makes it hard to link to the corresponding vmbus device. Rename them to hv_vmbus_ctl/N and make vmbus device names match, e.g. now vmbus_1 device is served by hv_vmbus_ctl/1 work queue. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Drivers: hv: vmbus: prevent cpu offlining on newer hypervisorsVitaly Kuznetsov2015-03-011-0/+36
| | | | | | | | | | | | | | | | | | | When an SMP Hyper-V guest is running on top of 2012R2 Server and secondary cpus are sent offline (with echo 0 > /sys/devices/system/cpu/cpu$cpu/online) the system freeze is observed. This happens due to the fact that on newer hypervisors (Win8, WS2012R2, ...) vmbus channel handlers are distributed across all cpus (see init_vp_index() function in drivers/hv/channel_mgmt.c) and on cpu offlining nobody reassigns them to CPU0. Prevent cpu offlining when vmbus is loaded until the issue is fixed host-side. This patch also disables hibernation but it is OK as it is also broken (MCE error is hit on resume). Suspend still works. Tested with WS2008R2 and WS2012R2. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge tag 'char-misc-3.20-rc1' of ↵Linus Torvalds2015-02-158-42/+323
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc Pull char / misc patches from Greg KH: "Here's the big char/misc driver update for 3.20-rc1. Lots of little things in here, all described in the changelog. Nothing major or unusual, except maybe the binder selinux stuff, which was all acked by the proper selinux people and they thought it best to come through this tree. All of this has been in linux-next with no reported issues for a while" * tag 'char-misc-3.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (90 commits) coresight: fix function etm_writel_cp14() parameter order coresight-etm: remove check for unknown Kconfig macro coresight: fixing CPU hwid lookup in device tree coresight: remove the unnecessary function coresight_is_bit_set() coresight: fix the debug AMBA bus name coresight: remove the extra spaces coresight: fix the link between orphan connection and newly added device coresight: remove the unnecessary replicator property coresight: fix the replicator subtype value pdfdocs: Fix 'make pdfdocs' failure for 'uio-howto.tmpl' mcb: Fix error path of mcb_pci_probe virtio/console: verify device has config space ti-st: clean up data types (fix harmless memory corruption) mei: me: release hw from reset only during the reset flow mei: mask interrupt set bit on clean reset bit extcon: max77693: Constify struct regmap_config extcon: adc-jack: Release IIO channel on driver remove extcon: Remove duplicated include from extcon-class.c Drivers: hv: vmbus: hv_process_timer_expiration() can be static Drivers: hv: vmbus: serialize Offer and Rescind offer ...
| * Drivers: hv: vmbus: hv_process_timer_expiration() can be statickbuild test robot2015-01-251-1/+1
| | | | | | | | | | | | | | | | | | | | drivers/hv/vmbus_drv.c:582:6: sparse: symbol 'hv_process_timer_expiration' was not declared. Should it be static? Signed-off-by: Fengguang Wu <fengguang.wu@intel.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * Drivers: hv: vmbus: serialize Offer and Rescind offerVitaly Kuznetsov2015-01-251-8/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 4b2f9abea52a ("staging: hv: convert channel_mgmt.c to not call osd_schedule_callback")' was written under an assumption that we never receive Rescind offer while we're still processing the initial Offer request. However, the issue we fixed in 04a258c162a8 could be caused by this assumption not always being true. In particular, we need to protect against the following: 1) Receiving a Rescind offer after we do queue_work() for processing an Offer request and before we actually enter vmbus_process_offer(). work.func points to vmbus_process_offer() at this moment and in vmbus_onoffer_rescind() we do another queue_work() without a check so we'll enter vmbus_process_offer() twice. 2) Receiving a Rescind offer after we enter vmbus_process_offer() and especially after we set >state = CHANNEL_OPEN_STATE. Many things can go wrong in that case, e.g. we can call free_channel() while we're still using it. Implement the required protection by changing work->func at the very end of vmbus_process_offer() and checking work->func in vmbus_onoffer_rescind(). In case we receive rescind offer during or before vmbus_process_offer() is done we set rescind flag to true and we check it at the end of vmbus_process_offer() so such offer will not get lost. Suggested-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * Drivers: hv: rename sc_lock to the more generic lockVitaly Kuznetsov2015-01-252-8/+8
| | | | | | | | | | | | | | | | | | | | | | | | sc_lock spinlock in struct vmbus_channel is being used to not only protect the sc_list field, e.g. vmbus_open() function uses it to implement test-and-set access to the state field. Rename it to the more generic 'lock' and add the description. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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