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2017-08-31xen/events: events_fifo: Don't use {get,put}_cpu() in xen_evtchn_fifo_init()Julien Grall1-4/+3
When booting Linux as Xen guest with CONFIG_DEBUG_ATOMIC, the following splat appears: [ 0.002323] Mountpoint-cache hash table entries: 1024 (order: 1, 8192 bytes) [ 0.019717] ASID allocator initialised with 65536 entries [ 0.020019] xen:grant_table: Grant tables using version 1 layout [ 0.020051] Grant table initialized [ 0.020069] BUG: sleeping function called from invalid context at /data/src/linux/mm/page_alloc.c:4046 [ 0.020100] in_atomic(): 1, irqs_disabled(): 0, pid: 1, name: swapper/0 [ 0.020123] no locks held by swapper/0/1. [ 0.020143] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.13.0-rc5 #598 [ 0.020166] Hardware name: FVP Base (DT) [ 0.020182] Call trace: [ 0.020199] [<ffff00000808a5c0>] dump_backtrace+0x0/0x270 [ 0.020222] [<ffff00000808a95c>] show_stack+0x24/0x30 [ 0.020244] [<ffff000008c1ef20>] dump_stack+0xb8/0xf0 [ 0.020267] [<ffff0000081128c0>] ___might_sleep+0x1c8/0x1f8 [ 0.020291] [<ffff000008112948>] __might_sleep+0x58/0x90 [ 0.020313] [<ffff0000082171b8>] __alloc_pages_nodemask+0x1c0/0x12e8 [ 0.020338] [<ffff00000827a110>] alloc_page_interleave+0x38/0x88 [ 0.020363] [<ffff00000827a904>] alloc_pages_current+0xdc/0xf0 [ 0.020387] [<ffff000008211f38>] __get_free_pages+0x28/0x50 [ 0.020411] [<ffff0000086566a4>] evtchn_fifo_alloc_control_block+0x2c/0xa0 [ 0.020437] [<ffff0000091747b0>] xen_evtchn_fifo_init+0x38/0xb4 [ 0.020461] [<ffff0000091746c0>] xen_init_IRQ+0x44/0xc8 [ 0.020484] [<ffff000009128adc>] xen_guest_init+0x250/0x300 [ 0.020507] [<ffff000008083974>] do_one_initcall+0x44/0x130 [ 0.020531] [<ffff000009120df8>] kernel_init_freeable+0x120/0x288 [ 0.020556] [<ffff000008c31ca8>] kernel_init+0x18/0x110 [ 0.020578] [<ffff000008083710>] ret_from_fork+0x10/0x40 [ 0.020606] xen:events: Using FIFO-based ABI [ 0.020658] Xen: initializing cpu0 [ 0.027727] Hierarchical SRCU implementation. [ 0.036235] EFI services will not be available. [ 0.043810] smp: Bringing up secondary CPUs ... This is because get_cpu() in xen_evtchn_fifo_init() will disable preemption, but __get_free_page() might sleep (GFP_ATOMIC is not set). xen_evtchn_fifo_init() will always be called before SMP is initialized, so {get,put}_cpu() could be replaced by a simple smp_processor_id(). This also avoid to modify evtchn_fifo_alloc_control_block that will be called in other context. Signed-off-by: Julien Grall <julien.grall@arm.com> Reported-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Fixes: 1fe565517b57 ("xen/events: use the FIFO-based ABI if available") Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2017-01-05Merge tag 'for-linus-4.10-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tipLinus Torvalds1-2/+1
Pull xen fixes and cleanups from Juergen Gross: - small fixes for xenbus driver - one fix for xen dom0 boot on huge system - small cleanups * tag 'for-linus-4.10-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: Xen: ARM: Zero reserved fields of xatp before making hypervisor call xen: events: Replace BUG() with BUG_ON() xen: remove stale xs_input_avail() from header xen: return xenstore command failures via response instead of rc xen: xenbus driver must not accept invalid transaction ids xen/evtchn: use rb_entry() xen/setup: Don't relocate p2m over existing one
2017-01-03xen: events: Replace BUG() with BUG_ON()Shyam Saini1-2/+1
Replace BUG() with BUG_ON() using coccinelle Signed-off-by: Shyam Saini <mayhs11saini@gmail.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2016-12-25cpu/hotplug: Cleanup state namesThomas Gleixner1-1/+1
When the state names got added a script was used to add the extra argument to the calls. The script basically converted the state constant to a string, but the cleanup to convert these strings into meaningful ones did not happen. Replace all the useless strings with 'subsys/xxx/yyy:state' strings which are used in all the other places already. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sebastian Siewior <bigeasy@linutronix.de> Link: http://lkml.kernel.org/r/20161221192112.085444152@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-09-30xen/events: Convert to hotplug state machineSebastian Andrzej Siewior1-22/+12
Install the callbacks via the state machine. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2016-07-25xen/events: fifo: use xen_vcpu_id mappingVitaly Kuznetsov1-1/+1
EVTCHNOP_init_control has vCPU id as a parameter and Xen's idea of vCPU id should be used. Use the newly introduced xen_vcpu_id mapping to convert it from Linux's id. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2016-03-21xen: audit usages of module.h ; remove unnecessary instancesPaul Gortmaker1-1/+0
Code that uses no modular facilities whatsoever should not be sourcing module.h at all, since that header drags in a bunch of other headers with it. Similarly, code that is not explicitly using modular facilities like module_init() but only is declaring module_param setup variables should be using moduleparam.h and not the larger module.h file for that. In making this change, we also uncover an implicit use of BUG() in inline fcns within arch/arm/include/asm/xen/hypercall.h so we explicitly source <linux/bug.h> for that file now. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2016-01-12xen/events: use virt_xxx barriersMichael S. Tsirkin1-1/+2
drivers/xen/events/events_fifo.c uses rmb() to communicate with the other side. For guests compiled with CONFIG_SMP, smp_rmb would be sufficient, so rmb() here is only needed if a non-SMP guest runs on an SMP host. Switch to the virt_rmb barrier which serves this exact purpose. Pull in asm/barrier.h here to make sure the file is self-contained. Suggested-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: David Vrabel <david.vrabel@citrix.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2015-12-02xen/events/fifo: Consume unprocessed events when a CPU diesRoss Lagerwall1-5/+18
When a CPU is offlined, there may be unprocessed events on a port for that CPU. If the port is subsequently reused on a different CPU, it could be in an unexpected state with the link bit set, resulting in interrupts being missed. Fix this by consuming any unprocessed events for a particular CPU when that CPU dies. Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com> Cc: <stable@vger.kernel.org> # 3.14+ Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-10-23xen/events: fifo: Make it running on 64KB granularityJulien Grall1-1/+1
Only use the first 4KB of the page to store the events channel info. It means that we will waste 60KB every time we allocate page for: * control block: a page is allocating per CPU * event array: a page is allocating everytime we need to expand it I think we can reduce the memory waste for the 2 areas by: * control block: sharing between multiple vCPUs. Although it will require some bookkeeping in order to not free the page when the CPU goes offline and the other CPUs sharing the page still there * event array: always extend the array event by 64K (i.e 16 4K chunk). That would require more care when we fail to expand the event channel. Signed-off-by: Julien Grall <julien.grall@citrix.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Stefano Stabellini <stefano.stabellini@citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-09-08xen: Use correctly the Xen memory terminologiesJulien Grall1-2/+2
Based on include/xen/mm.h [1], Linux is mistakenly using MFN when GFN is meant, I suspect this is because the first support for Xen was for PV. This resulted in some misimplementation of helpers on ARM and confused developers about the expected behavior. For instance, with pfn_to_mfn, we expect to get an MFN based on the name. Although, if we look at the implementation on x86, it's returning a GFN. For clarity and avoid new confusion, replace any reference to mfn with gfn in any helpers used by PV drivers. The x86 code will still keep some reference of pfn_to_mfn which may be used by all kind of guests No changes as been made in the hypercall field, even though they may be invalid, in order to keep the same as the defintion in xen repo. Note that page_to_mfn has been renamed to xen_page_to_gfn to avoid a name to close to the KVM function gfn_to_page. Take also the opportunity to simplify simple construction such as pfn_to_mfn(page_to_pfn(page)) into xen_page_to_gfn. More complex clean up will come in follow-up patches. [1] http://xenbits.xen.org/gitweb/?p=xen.git;a=commitdiff;h=e758ed14f390342513405dd766e874934573e6cb Signed-off-by: Julien Grall <julien.grall@citrix.com> Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Acked-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-08-11Revert "xen/events/fifo: Handle linked events when closing a port"David Vrabel1-40/+5
This reverts commit fcdf31a7c162de0c93a2bee51df4688ab0a348f8. This was causing a WARNING whenever a PIRQ was closed since shutdown_pirq() is called with irqs disabled. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Cc: <stable@vger.kernel.org>
2015-08-04xen/events/fifo: Handle linked events when closing a portRoss Lagerwall1-5/+40
An event channel bound to a CPU that was offlined may still be linked on that CPU's queue. If this event channel is closed and reused, subsequent events will be lost because the event channel is never unlinked and thus cannot be linked onto the correct queue. When a channel is closed and the event is still linked into a queue, ensure that it is unlinked before completing. If the CPU to which the event channel bound is online, spin until the event is handled by that CPU. If that CPU is offline, it can't handle the event, so clear the event queue during the close, dropping the events. This fixes the missing interrupts (and subsequent disk stalls etc.) when offlining a CPU. Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com> Cc: <stable@vger.kernel.org> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-06-17xen: Include xen/page.h rather than asm/xen/page.hJulien Grall1-1/+1
Using xen/page.h will be necessary later for using common xen page helpers. As xen/page.h already include asm/xen/page.h, always use the later. Signed-off-by: Julien Grall <julien.grall@citrix.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com> Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: netdev@vger.kernel.org Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2014-07-31xen/events/fifo: remove a unecessary use of BM()Frediano Ziglio1-1/+1
Since 05a812ac474d0d6aef6d54b66bb08b81abde79c6 (xen/events/fifo: correctly align bitops), ready is an unsigned long instead of uint32_t and the BM() macro is no longer required. Signed-off-by: Frediano Ziglio <frediano.ziglio@citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2014-07-31xen/events/fifo: ensure all bitops are properly aligned even on x86David Vrabel1-3/+2
When using the FIFO-based ABI on x86_64, if the last port is at the end of an event array page then sync_test_bit() on this port's event word will read beyond the end of the page and in certain circumstances this may fault. The fault requires the following page in the kernel's direct mapping to be not present, which would mean: a) the array page is the last page of RAM; or b) the following page is ballooned out /and/ it has been used for a foreign mapping by a kernel driver (such as netback or blkback) /and/ the grant has been unmapped. Use the infrastructure added for arm64 to ensure that all bitops operating on event words are unsigned long aligned. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: stable@vger.kernel.org
2014-07-31xen/events/fifo: reset control block and local HEADs on resumeDavid Vrabel1-20/+28
When using the FIFO-based event channel ABI, if the control block or the local HEADs are not reset after resuming the guest may see stale HEAD values and will fail to traverse the FIFO correctly. This may prevent one or more VCPUs from receiving any events following a resume. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: stable@vger.kernel.org
2014-04-28xen/events/fifo: correctly align bitopsVladimir Murzin1-11/+30
FIFO event channels require bitops on 32-bit aligned values (the event words). Linux's bitops require unsigned long alignment which may be 64-bits. On arm64 an incorrectly unaligned access will fault. Fix this by aligning the bitops along with an adjustment for bit position and using an unsigned long for the local copy of the ready word. Cc: stable@vger.kernel.org Signed-off-by: Vladimir Murzin <murzin.v@gmail.com> Tested-by: Pranavkumar Sawargaonkar <pranavkumar@linaro.org> Reviewed-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2014-03-04xen: Use the proper irq functionsThomas Gleixner1-6/+2
generic_handler_irq() already tests for !desc so use this instead of generic_handle_irq_desc(). Use irq_get_irq_data() instead of desc->irq_data. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: David Vrabel <david.vrabel@citrix.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Xen <xen-devel@lists.xenproject.org> Link: http://lkml.kernel.org/r/20140223212738.222412125@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-01-10xen: delete new instances of __cpuinit usagePaul Gortmaker1-3/+3
Commit 1fe565517b57676884349dccfd6ce853ec338636 ("xen/events: use the FIFO-based ABI if available") added new instances of __cpuinit macro usage. We removed this a couple versions ago; we now want to remove the compat no-op stubs. Introducing new users is not what we want to see at this point in time, as it will break once the stubs are gone. Cc: David Vrabel <david.vrabel@citrix.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2014-01-07xen/evtchn_fifo: fix error return code in evtchn_fifo_setup()Wei Yongjun1-2/+4
Fix to return -ENOMEM from the error handling case instead of 0 (overwrited to 0 by the HYPERVISOR_event_channel_op call), otherwise the error condition cann't be reflected from the return value. Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com>
2014-01-06xen/events: use the FIFO-based ABI if availableDavid Vrabel1-0/+426
Implement all the event channel port ops for the FIFO-based ABI. If the hypervisor supports the FIFO-based ABI, enable it by initializing the control block for the boot VCPU and subsequent VCPUs as they are brought up and on resume. The event array is expanded as required when event ports are setup. The 'xen.fifo_events=0' command line option may be used to disable use of the FIFO-based ABI. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>