summaryrefslogtreecommitdiff
path: root/virt
AgeCommit message (Collapse)AuthorFilesLines
2016-03-15Merge branch 'sched-core-for-linus' of ↵Linus Torvalds2-11/+10
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: "The main changes in this cycle are: - Make schedstats a runtime tunable (disabled by default) and optimize it via static keys. As most distributions enable CONFIG_SCHEDSTATS=y due to its instrumentation value, this is a nice performance enhancement. (Mel Gorman) - Implement 'simple waitqueues' (swait): these are just pure waitqueues without any of the more complex features of full-blown waitqueues (callbacks, wake flags, wake keys, etc.). Simple waitqueues have less memory overhead and are faster. Use simple waitqueues in the RCU code (in 4 different places) and for handling KVM vCPU wakeups. (Peter Zijlstra, Daniel Wagner, Thomas Gleixner, Paul Gortmaker, Marcelo Tosatti) - sched/numa enhancements (Rik van Riel) - NOHZ performance enhancements (Rik van Riel) - Various sched/deadline enhancements (Steven Rostedt) - Various fixes (Peter Zijlstra) - ... and a number of other fixes, cleanups and smaller enhancements" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (29 commits) sched/cputime: Fix steal_account_process_tick() to always return jiffies sched/deadline: Remove dl_new from struct sched_dl_entity Revert "kbuild: Add option to turn incompatible pointer check into error" sched/deadline: Remove superfluous call to switched_to_dl() sched/debug: Fix preempt_disable_ip recording for preempt_disable() sched, time: Switch VIRT_CPU_ACCOUNTING_GEN to jiffy granularity time, acct: Drop irq save & restore from __acct_update_integrals() acct, time: Change indentation in __acct_update_integrals() sched, time: Remove non-power-of-two divides from __acct_update_integrals() sched/rt: Kick RT bandwidth timer immediately on start up sched/debug: Add deadline scheduler bandwidth ratio to /proc/sched_debug sched/debug: Move sched_domain_sysctl to debug.c sched/debug: Move the /sys/kernel/debug/sched_features file setup into debug.c sched/rt: Fix PI handling vs. sched_setscheduler() sched/core: Remove duplicated sched_group_set_shares() prototype sched/fair: Consolidate nohz CPU load update code sched/fair: Avoid using decay_load_missed() with a negative value sched/deadline: Always calculate end of period on sched_yield() sched/cgroup: Fix cgroup entity load tracking tear-down rcu: Use simple wait queues where possible in rcutree ...
2016-03-09kvm: cap halt polling at exactly halt_poll_nsDavid Matlack1-0/+3
When growing halt-polling, there is no check that the poll time exceeds the limit. It's possible for vcpu->halt_poll_ns grow once past halt_poll_ns, and stay there until a halt which takes longer than vcpu->halt_poll_ns. For example, booting a Linux guest with halt_poll_ns=11000: ... kvm:kvm_halt_poll_ns: vcpu 0: halt_poll_ns 0 (shrink 10000) ... kvm:kvm_halt_poll_ns: vcpu 0: halt_poll_ns 10000 (grow 0) ... kvm:kvm_halt_poll_ns: vcpu 0: halt_poll_ns 20000 (grow 10000) Signed-off-by: David Matlack <dmatlack@google.com> Fixes: aca6ff29c4063a8d467cdee241e6b3bf7dc4a171 Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-29Merge branch 'sched/urgent' into sched/core, to pick up fixes before ↵Ingo Molnar3-6/+9
applying new changes Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-25KVM: Use simple waitqueue for vcpu->wqMarcelo Tosatti2-11/+10
The problem: On -rt, an emulated LAPIC timer instances has the following path: 1) hard interrupt 2) ksoftirqd is scheduled 3) ksoftirqd wakes up vcpu thread 4) vcpu thread is scheduled This extra context switch introduces unnecessary latency in the LAPIC path for a KVM guest. The solution: Allow waking up vcpu thread from hardirq context, thus avoiding the need for ksoftirqd to be scheduled. Normal waitqueues make use of spinlocks, which on -RT are sleepable locks. Therefore, waking up a waitqueue waiter involves locking a sleeping lock, which is not allowed from hard interrupt context. cyclictest command line: This patch reduces the average latency in my tests from 14us to 11us. Daniel writes: Paolo asked for numbers from kvm-unit-tests/tscdeadline_latency benchmark on mainline. The test was run 1000 times on tip/sched/core 4.4.0-rc8-01134-g0905f04: ./x86-run x86/tscdeadline_latency.flat -cpu host with idle=poll. The test seems not to deliver really stable numbers though most of them are smaller. Paolo write: "Anything above ~10000 cycles means that the host went to C1 or lower---the number means more or less nothing in that case. The mean shows an improvement indeed." Before: min max mean std count 1000.000000 1000.000000 1000.000000 1000.000000 mean 5162.596000 2019270.084000 5824.491541 20681.645558 std 75.431231 622607.723969 89.575700 6492.272062 min 4466.000000 23928.000000 5537.926500 585.864966 25% 5163.000000 1613252.750000 5790.132275 16683.745433 50% 5175.000000 2281919.000000 5834.654000 23151.990026 75% 5190.000000 2382865.750000 5861.412950 24148.206168 max 5228.000000 4175158.000000 6254.827300 46481.048691 After min max mean std count 1000.000000 1000.00000 1000.000000 1000.000000 mean 5143.511000 2076886.10300 5813.312474 21207.357565 std 77.668322 610413.09583 86.541500 6331.915127 min 4427.000000 25103.00000 5529.756600 559.187707 25% 5148.000000 1691272.75000 5784.889825 17473.518244 50% 5160.000000 2308328.50000 5832.025000 23464.837068 75% 5172.000000 2393037.75000 5853.177675 24223.969976 max 5222.000000 3922458.00000 6186.720500 42520.379830 [Patch was originaly based on the swait implementation found in the -rt tree. Daniel ported it to mainline's version and gathered the benchmark numbers for tscdeadline_latency test.] Signed-off-by: Daniel Wagner <daniel.wagner@bmw-carit.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: linux-rt-users@vger.kernel.org Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/1455871601-27484-4-git-send-email-wagi@monom.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-02-25Merge tag 'kvm-arm-for-4.5-rc6' of ↵Paolo Bonzini1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-master KVM/ARM fixes for 4.5-rc6 - Fix per-vcpu vgic bitmap allocation - Do not give copy random memory on MMIO read - Fix GICv3 APR register restore order
2016-02-24KVM: async_pf: do not warn on page allocation failuresChristian Borntraeger1-1/+1
In async_pf we try to allocate with NOWAIT to get an element quickly or fail. This code also handle failures gracefully. Lets silence potential page allocation failures under load. qemu-system-s39: page allocation failure: order:0,mode:0x2200000 [...] Call Trace: ([<00000000001146b8>] show_trace+0xf8/0x148) [<000000000011476a>] show_stack+0x62/0xe8 [<00000000004a36b8>] dump_stack+0x70/0x98 [<0000000000272c3a>] warn_alloc_failed+0xd2/0x148 [<000000000027709e>] __alloc_pages_nodemask+0x94e/0xb38 [<00000000002cd36a>] new_slab+0x382/0x400 [<00000000002cf7ac>] ___slab_alloc.constprop.30+0x2dc/0x378 [<00000000002d03d0>] kmem_cache_alloc+0x160/0x1d0 [<0000000000133db4>] kvm_setup_async_pf+0x6c/0x198 [<000000000013dee8>] kvm_arch_vcpu_ioctl_run+0xd48/0xd58 [<000000000012fcaa>] kvm_vcpu_ioctl+0x372/0x690 [<00000000002f66f6>] do_vfs_ioctl+0x3be/0x510 [<00000000002f68ec>] SyS_ioctl+0xa4/0xb8 [<0000000000781c5e>] system_call+0xd6/0x264 [<000003ffa24fa06a>] 0x3ffa24fa06a Cc: stable@vger.kernel.org Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-23KVM: arm/arm64: vgic: Ensure bitmaps are long enoughMark Rutland1-2/+2
When we allocate bitmaps in vgic_vcpu_init_maps, we divide the number of bits we need by 8 to figure out how many bytes to allocate. However, bitmap elements are always accessed as unsigned longs, and if we didn't happen to allocate a size such that size % sizeof(unsigned long) == 0, bitmap accesses may go past the end of the allocation. When using KASAN (which does byte-granular access checks), this results in a continuous stream of BUGs whenever these bitmaps are accessed: ============================================================================= BUG kmalloc-128 (Tainted: G B ): kasan: bad access detected ----------------------------------------------------------------------------- INFO: Allocated in vgic_init.part.25+0x55c/0x990 age=7493 cpu=3 pid=1730 INFO: Slab 0xffffffbde6d5da40 objects=16 used=15 fp=0xffffffc935769700 flags=0x4000000000000080 INFO: Object 0xffffffc935769500 @offset=1280 fp=0x (null) Bytes b4 ffffffc9357694f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Object ffffffc935769500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Object ffffffc935769510: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Object ffffffc935769520: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Object ffffffc935769530: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Object ffffffc935769540: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Object ffffffc935769550: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Object ffffffc935769560: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Object ffffffc935769570: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Padding ffffffc9357695b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Padding ffffffc9357695c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Padding ffffffc9357695d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Padding ffffffc9357695e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Padding ffffffc9357695f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ CPU: 3 PID: 1740 Comm: kvm-vcpu-0 Tainted: G B 4.4.0+ #17 Hardware name: ARM Juno development board (r1) (DT) Call trace: [<ffffffc00008e770>] dump_backtrace+0x0/0x280 [<ffffffc00008ea04>] show_stack+0x14/0x20 [<ffffffc000726360>] dump_stack+0x100/0x188 [<ffffffc00030d324>] print_trailer+0xfc/0x168 [<ffffffc000312294>] object_err+0x3c/0x50 [<ffffffc0003140fc>] kasan_report_error+0x244/0x558 [<ffffffc000314548>] __asan_report_load8_noabort+0x48/0x50 [<ffffffc000745688>] __bitmap_or+0xc0/0xc8 [<ffffffc0000d9e44>] kvm_vgic_flush_hwstate+0x1bc/0x650 [<ffffffc0000c514c>] kvm_arch_vcpu_ioctl_run+0x2ec/0xa60 [<ffffffc0000b9a6c>] kvm_vcpu_ioctl+0x474/0xa68 [<ffffffc00036b7b0>] do_vfs_ioctl+0x5b8/0xcb0 [<ffffffc00036bf34>] SyS_ioctl+0x8c/0xa0 [<ffffffc000086cb0>] el0_svc_naked+0x24/0x28 Memory state around the buggy address: ffffffc935769400: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffffffc935769480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffffffc935769500: 04 fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffffffc935769580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffffffc935769600: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== Fix the issue by always allocating a multiple of sizeof(unsigned long), as we do elsewhere in the vgic code. Fixes: c1bfb577a ("arm/arm64: KVM: vgic: switch to dynamic allocation") Cc: stable@vger.kernel.org Acked-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-08KVM: arm/arm64: Fix reference to uninitialised VGICAndre Przywara1-3/+6
Commit 4b4b4512da2a ("arm/arm64: KVM: Rework the arch timer to use level-triggered semantics") brought the virtual architected timer closer to the VGIC. There is one occasion were we don't properly check for the VGIC actually having been initialized before, but instead go on to check the active state of some IRQ number. If userland hasn't instantiated a virtual GIC, we end up with a kernel NULL pointer dereference: ========= Unable to handle kernel NULL pointer dereference at virtual address 00000000 pgd = ffffffc9745c5000 [00000000] *pgd=00000009f631e003, *pud=00000009f631e003, *pmd=0000000000000000 Internal error: Oops: 96000006 [#2] PREEMPT SMP Modules linked in: CPU: 0 PID: 2144 Comm: kvm_simplest-ar Tainted: G D 4.5.0-rc2+ #1300 Hardware name: ARM Juno development board (r1) (DT) task: ffffffc976da8000 ti: ffffffc976e28000 task.ti: ffffffc976e28000 PC is at vgic_bitmap_get_irq_val+0x78/0x90 LR is at kvm_vgic_map_is_active+0xac/0xc8 pc : [<ffffffc0000b7e28>] lr : [<ffffffc0000b972c>] pstate: 20000145 .... ========= Fix this by bailing out early of kvm_timer_flush_hwstate() if we don't have a VGIC at all. Reported-by: Cosmin Gorgovan <cosmin@linux-geek.org> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Cc: <stable@vger.kernel.org> # 4.4.x
2016-01-16kvm: rename pfn_t to kvm_pfn_tDan Williams1-23/+24
To date, we have implemented two I/O usage models for persistent memory, PMEM (a persistent "ram disk") and DAX (mmap persistent memory into userspace). This series adds a third, DAX-GUP, that allows DAX mappings to be the target of direct-i/o. It allows userspace to coordinate DMA/RDMA from/to persistent memory. The implementation leverages the ZONE_DEVICE mm-zone that went into 4.3-rc1 (also discussed at kernel summit) to flag pages that are owned and dynamically mapped by a device driver. The pmem driver, after mapping a persistent memory range into the system memmap via devm_memremap_pages(), arranges for DAX to distinguish pfn-only versus page-backed pmem-pfns via flags in the new pfn_t type. The DAX code, upon seeing a PFN_DEV+PFN_MAP flagged pfn, flags the resulting pte(s) inserted into the process page tables with a new _PAGE_DEVMAP flag. Later, when get_user_pages() is walking ptes it keys off _PAGE_DEVMAP to pin the device hosting the page range active. Finally, get_page() and put_page() are modified to take references against the device driver established page mapping. Finally, this need for "struct page" for persistent memory requires memory capacity to store the memmap array. Given the memmap array for a large pool of persistent may exhaust available DRAM introduce a mechanism to allocate the memmap from persistent memory. The new "struct vmem_altmap *" parameter to devm_memremap_pages() enables arch_add_memory() to use reserved pmem capacity rather than the page allocator. This patch (of 18): The core has developed a need for a "pfn_t" type [1]. Move the existing pfn_t in KVM to kvm_pfn_t [2]. [1]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002199.html [2]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002218.html Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-13Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds5-46/+23
Pull KVM updates from Paolo Bonzini: "PPC changes will come next week. - s390: Support for runtime instrumentation within guests, support of 248 VCPUs. - ARM: rewrite of the arm64 world switch in C, support for 16-bit VM identifiers. Performance counter virtualization missed the boat. - x86: Support for more Hyper-V features (synthetic interrupt controller), MMU cleanups" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (115 commits) kvm: x86: Fix vmwrite to SECONDARY_VM_EXEC_CONTROL kvm/x86: Hyper-V SynIC timers tracepoints kvm/x86: Hyper-V SynIC tracepoints kvm/x86: Update SynIC timers on guest entry only kvm/x86: Skip SynIC vector check for QEMU side kvm/x86: Hyper-V fix SynIC timer disabling condition kvm/x86: Reorg stimer_expiration() to better control timer restart kvm/x86: Hyper-V unify stimer_start() and stimer_restart() kvm/x86: Drop stimer_stop() function kvm/x86: Hyper-V timers fix incorrect logical operation KVM: move architecture-dependent requests to arch/ KVM: renumber vcpu->request bits KVM: document which architecture uses each request bit KVM: Remove unused KVM_REQ_KICK to save a bit in vcpu->requests kvm: x86: Check kvm_write_guest return value in kvm_write_wall_clock KVM: s390: implement the RI support of guest kvm/s390: drop unpaired smp_mb kvm: x86: fix comment about {mmu,nested_mmu}.gva_to_gpa KVM: x86: MMU: Use clear_page() instead of init_shadow_page_table() arm/arm64: KVM: Detect vGIC presence at runtime ...
2016-01-08KVM: move architecture-dependent requests to arch/Paolo Bonzini1-10/+0
Since the numbers now overlap, it makes sense to enumerate them in asm/kvm_host.h rather than linux/kvm_host.h. Functions that refer to architecture-specific requests are also moved to arch/. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-01-07Merge tag 'kvm-arm-for-4.5-1' of ↵Paolo Bonzini2-9/+4
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-next KVM/ARM changes for Linux v4.5 - Complete rewrite of the arm64 world switch in C, hopefully paving the way for more sharing with the 32bit code, better maintainability and easier integration of new features. Also smaller and slightly faster in some cases... - Support for 16bit VM identifiers - Various cleanups
2015-12-14arm64: KVM: Turn system register numbers to an enumMarc Zyngier1-0/+1
Having the system register numbers as #defines has been a pain since day one, as the ordering is pretty fragile, and moving things around leads to renumbering and epic conflict resolutions. Now that we're mostly acessing the sysreg file in C, an enum is a much better type to use, and we can clean things up a bit. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-12-14KVM: arm/arm64: vgic-v3: Make the LR indexing macro publicMarc Zyngier1-8/+2
We store GICv3 LRs in reverse order so that the CPU can save/restore them in rever order as well (don't ask why, the design is crazy), and yet generate memory traffic that doesn't completely suck. We need this macro to be available to the C version of save/restore. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-12-14KVM: arm/arm64: vgic: make vgic_io_ops staticJisheng Zhang1-1/+1
vgic_io_ops is only referenced within vgic.c, so it can be declared static. Signed-off-by: Jisheng Zhang <jszhang@marvell.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-12-11KVM: arm/arm64: vgic: Fix kvm_vgic_map_is_active's dist checkChristoffer Dall1-1/+1
External inputs to the vgic from time to time need to poke into the state of a virtual interrupt, the prime example is the architected timer code. Since the IRQ's active state can be represented in two places; the LR or the distributor, we first loop over the LRs but if not active in the LRs we just return if *any* IRQ is active on the VCPU in question. This is of course bogus, as we should check if the specific IRQ in quesiton is active on the distributor instead. Reported-by: Eric Auger <eric.auger@linaro.org> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-11-30KVM: Remove unnecessary debugfs dentry referencesJanosch Frank1-14/+4
KVM creates debugfs files to export VM statistics to userland. To be able to remove them on kvm exit it tracks the files' dentries. Since their parent directory is also tracked and since each parent direntry knows its children we can easily remove them by using debugfs_remove_recursive(kvm_debugfs_dir). Therefore we don't need the extra tracking in the kvm_stats_debugfs_item anymore. Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com> Reviewed-By: Sascha Silbe <silbe@linux.vnet.ibm.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-11-30KVM: Use common function for VCPU lookup by idDavid Hildenbrand1-7/+5
Let's reuse the new common function for VPCU lookup by id. Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> [split out the new function into a separate patch]
2015-11-25KVM: kvm_is_visible_gfn can be booleanYaowei Bai1-3/+3
This patch makes kvm_is_visible_gfn return bool due to this particular function only using either one or zero as its return value. No functional change. Signed-off-by: Yaowei Bai <baiyaowei@cmss.chinamobile.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-11-25KVM-async_pf: Delete an unnecessary check before the function call ↵Markus Elfring1-2/+1
"kmem_cache_destroy" The kmem_cache_destroy() function tests whether its argument is NULL and then returns immediately. Thus the test around the call is not needed. This issue was detected by using the Coccinelle software. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-11-25kvm/irqchip: kvm_arch_irq_routing_update renaming splitAndrey Smetanin1-1/+6
Actually kvm_arch_irq_routing_update() should be kvm_arch_post_irq_routing_update() as it's called at the end of irq routing update. This renaming frees kvm_arch_irq_routing_update function name. kvm_arch_irq_routing_update() weak function which will be used to update mappings for arch-specific irq routing entries (in particular, the upcoming Hyper-V synthetic interrupts). Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com> Reviewed-by: Roman Kagan <rkagan@virtuozzo.com> Signed-off-by: Denis V. Lunev <den@openvz.org> CC: Gleb Natapov <gleb@kernel.org> CC: Paolo Bonzini <pbonzini@redhat.com> CC: Roman Kagan <rkagan@virtuozzo.com> CC: Denis V. Lunev <den@openvz.org> CC: qemu-devel@nongnu.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-11-24KVM: arm/arm64: vgic: Trust the LR state for HW IRQsChristoffer Dall1-14/+2
We were probing the physial distributor state for the active state of a HW virtual IRQ, because we had seen evidence that the LR state was not cleared when the guest deactivated a virtual interrupted. However, this issue turned out to be a software bug in the GIC, which was solved by: 84aab5e68c2a5e1e18d81ae8308c3ce25d501b29 (KVM: arm/arm64: arch_timer: Preserve physical dist. active state on LR.active, 2015-11-24) Therefore, get rid of the complexities and just look at the LR. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-11-24KVM: arm/arm64: arch_timer: Preserve physical dist. active state on LR.activeChristoffer Dall2-23/+39
We were incorrectly removing the active state from the physical distributor on the timer interrupt when the timer output level was deasserted. We shouldn't be doing this without considering the virtual interrupt's active state, because the architecture requires that when an LR has the HW bit set and the pending or active bits set, then the physical interrupt must also have the corresponding bits set. This addresses an issue where we have been observing an inconsistency between the LR state and the physical distributor state where the LR state was active and the physical distributor was not active, which shouldn't happen. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-11-06Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds14-364/+681
Pull KVM updates from Paolo Bonzini: "First batch of KVM changes for 4.4. s390: A bunch of fixes and optimizations for interrupt and time handling. PPC: Mostly bug fixes. ARM: No big features, but many small fixes and prerequisites including: - a number of fixes for the arch-timer - introducing proper level-triggered semantics for the arch-timers - a series of patches to synchronously halt a guest (prerequisite for IRQ forwarding) - some tracepoint improvements - a tweak for the EL2 panic handlers - some more VGIC cleanups getting rid of redundant state x86: Quite a few changes: - support for VT-d posted interrupts (i.e. PCI devices can inject interrupts directly into vCPUs). This introduces a new component (in virt/lib/) that connects VFIO and KVM together. The same infrastructure will be used for ARM interrupt forwarding as well. - more Hyper-V features, though the main one Hyper-V synthetic interrupt controller will have to wait for 4.5. These will let KVM expose Hyper-V devices. - nested virtualization now supports VPID (same as PCID but for vCPUs) which makes it quite a bit faster - for future hardware that supports NVDIMM, there is support for clflushopt, clwb, pcommit - support for "split irqchip", i.e. LAPIC in kernel + IOAPIC/PIC/PIT in userspace, which reduces the attack surface of the hypervisor - obligatory smattering of SMM fixes - on the guest side, stable scheduler clock support was rewritten to not require help from the hypervisor" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (123 commits) KVM: VMX: Fix commit which broke PML KVM: x86: obey KVM_X86_QUIRK_CD_NW_CLEARED in kvm_set_cr0() KVM: x86: allow RSM from 64-bit mode KVM: VMX: fix SMEP and SMAP without EPT KVM: x86: move kvm_set_irq_inatomic to legacy device assignment KVM: device assignment: remove pointless #ifdefs KVM: x86: merge kvm_arch_set_irq with kvm_set_msi_inatomic KVM: x86: zero apic_arb_prio on reset drivers/hv: share Hyper-V SynIC constants with userspace KVM: x86: handle SMBASE as physical address in RSM KVM: x86: add read_phys to x86_emulate_ops KVM: x86: removing unused variable KVM: don't pointlessly leave KVM_COMPAT=y in non-KVM configs KVM: arm/arm64: Merge vgic_set_lr() and vgic_sync_lr_elrsr() KVM: arm/arm64: Clean up vgic_retire_lr() and surroundings KVM: arm/arm64: Optimize away redundant LR tracking KVM: s390: use simple switch statement as multiplexer KVM: s390: drop useless newline in debugging data KVM: s390: SCA must not cross page boundaries KVM: arm: Do not indent the arguments of DECLARE_BITMAP ...
2015-11-04KVM: x86: merge kvm_arch_set_irq with kvm_set_msi_inatomicPaolo Bonzini1-7/+4
We do not want to do too much work in atomic context, in particular not walking all the VCPUs of the virtual machine. So we want to distinguish the architecture-specific injection function for irqfd from kvm_set_msi. Since it's still empty, reuse the newly added kvm_arch_set_irq and rename it to kvm_arch_set_irq_inatomic. Reviewed-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-11-04KVM: don't pointlessly leave KVM_COMPAT=y in non-KVM configsJan Beulich1-1/+1
The symbol was missing a KVM dependency. Signed-off-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-11-04Merge tag 'kvm-arm-for-4.4' of ↵Paolo Bonzini6-248/+331
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/ARM Changes for v4.4-rc1 Includes a number of fixes for the arch-timer, introducing proper level-triggered semantics for the arch-timers, a series of patches to synchronously halt a guest (prerequisite for IRQ forwarding), some tracepoint improvements, a tweak for the EL2 panic handlers, some more VGIC cleanups getting rid of redundant state, and finally a stylistic change that gets rid of some ctags warnings. Conflicts: arch/x86/include/asm/kvm_host.h
2015-11-04KVM: arm/arm64: Merge vgic_set_lr() and vgic_sync_lr_elrsr()Pavel Fedin3-22/+2
Now we see that vgic_set_lr() and vgic_sync_lr_elrsr() are always used together. Merge them into one function, saving from second vgic_ops dereferencing every time. Signed-off-by: Pavel Fedin <p.fedin@samsung.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-11-04KVM: arm/arm64: Clean up vgic_retire_lr() and surroundingsPavel Fedin1-27/+10
1. Remove unnecessary 'irq' argument, because irq number can be retrieved from the LR. 2. Since cff9211eb1a1f58ce7f5a2d596b617928fd4be0e ("arm/arm64: KVM: Fix arch timer behavior for disabled interrupts ") LR_STATE_PENDING is queued back by vgic_retire_lr() itself. Also, it clears vlr.state itself. Therefore, we remove the same, now duplicated, check with all accompanying bit manipulations from vgic_unqueue_irqs(). 3. vgic_retire_lr() is always accompanied by vgic_irq_clear_queued(). Since it already does more than just clearing the LR, move vgic_irq_clear_queued() inside of it. Signed-off-by: Pavel Fedin <p.fedin@samsung.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-11-04KVM: arm/arm64: Optimize away redundant LR trackingPavel Fedin3-38/+17
Currently we use vgic_irq_lr_map in order to track which LRs hold which IRQs, and lr_used bitmap in order to track which LRs are used or free. vgic_irq_lr_map is actually used only for piggy-back optimization, and can be easily replaced by iteration over lr_used. This is good because in future, when LPI support is introduced, number of IRQs will grow up to at least 16384, while numbers from 1024 to 8192 are never going to be used. This would be a huge memory waste. In its turn, lr_used is also completely redundant since ae705930fca6322600690df9dc1c7d0516145a93 ("arm/arm64: KVM: Keep elrsr/aisr in sync with software model"), because together with lr_used we also update elrsr. This allows to easily replace lr_used with elrsr, inverting all conditions (because in elrsr '1' means 'free'). Signed-off-by: Pavel Fedin <p.fedin@samsung.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-11-04Merge branch 'irq-core-for-linus' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq updates from Thomas Gleixner: "The irq departement delivers: - Rework the irqdomain core infrastructure to accomodate ACPI based systems. This is required to support ARM64 without creating artificial device tree nodes. - Sanitize the ACPI based ARM GIC initialization by making use of the new firmware independent irqdomain core - Further improvements to the generic MSI management - Generalize the irq migration on CPU hotplug - Improvements to the threaded interrupt infrastructure - Allow the migration of "chained" low level interrupt handlers - Allow optional force masking of interrupts in disable_irq[_nosysnc] - Support for two new interrupt chips - Sigh! - A larger set of errata fixes for ARM gicv3 - The usual pile of fixes, updates, improvements and cleanups all over the place" * 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (71 commits) Document that IRQ_NONE should be returned when IRQ not actually handled PCI/MSI: Allow the MSI domain to be device-specific PCI: Add per-device MSI domain hook of/irq: Use the msi-map property to provide device-specific MSI domain of/irq: Split of_msi_map_rid to reuse msi-map lookup irqchip/gic-v3-its: Parse new version of msi-parent property PCI/MSI: Use of_msi_get_domain instead of open-coded "msi-parent" parsing of/irq: Use of_msi_get_domain instead of open-coded "msi-parent" parsing of/irq: Add support code for multi-parent version of "msi-parent" irqchip/gic-v3-its: Add handling of PCI requester id. PCI/MSI: Add helper function pci_msi_domain_get_msi_rid(). of/irq: Add new function of_msi_map_rid() Docs: dt: Add PCI MSI map bindings irqchip/gic-v2m: Add support for multiple MSI frames irqchip/gic-v3: Fix translation of LPIs after conversion to irq_fwspec irqchip/mxs: Add Alphascale ASM9260 support irqchip/mxs: Prepare driver for hardware with different offsets irqchip/mxs: Panic if ioremap or domain creation fails irqdomain: Documentation updates irqdomain/msi: Use fwnode instead of of_node ...
2015-10-23arm/arm64: KVM: Add tracepoints for vgic and timerChristoffer Dall3-0/+72
The VGIC and timer code for KVM arm/arm64 doesn't have any tracepoints or tracepoint infrastructure defined. Rewriting some of the timer code handling showed me how much we need this, so let's add these simple trace points once and for all and we can easily expand with additional trace points in these files as we go along. Cc: Wei Huang <wei@redhat.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-10-23arm/arm64: KVM: Support edge-triggered forwarded interruptsChristoffer Dall1-18/+22
We mark edge-triggered interrupts with the HW bit set as queued to prevent the VGIC code from injecting LRs with both the Active and Pending bits set at the same time while also setting the HW bit, because the hardware does not support this. However, this means that we must also clear the queued flag when we sync back a LR where the state on the physical distributor went from active to inactive because the guest deactivated the interrupt. At this point we must also check if the interrupt is pending on the distributor, and tell the VGIC to queue it again if it is. Since these actions on the sync path are extremely close to those for level-triggered interrupts, rename process_level_irq to process_queued_irq, allowing it to cater for both cases. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-10-23arm/arm64: KVM: Rework the arch timer to use level-triggered semanticsChristoffer Dall2-101/+82
The arch timer currently uses edge-triggered semantics in the sense that the line is never sampled by the vgic and lowering the line from the timer to the vgic doesn't have any effect on the pending state of virtual interrupts in the vgic. This means that we do not support a guest with the otherwise valid behavior of (1) disable interrupts (2) enable the timer (3) disable the timer (4) enable interrupts. Such a guest would validly not expect to see any interrupts on real hardware, but will see interrupts on KVM. This patch fixes this shortcoming through the following series of changes. First, we change the flow of the timer/vgic sync/flush operations. Now the timer is always flushed/synced before the vgic, because the vgic samples the state of the timer output. This has the implication that we move the timer operations in to non-preempible sections, but that is fine after the previous commit getting rid of hrtimer schedules on every entry/exit. Second, we change the internal behavior of the timer, letting the timer keep track of its previous output state, and only lower/raise the line to the vgic when the state changes. Note that in theory this could have been accomplished more simply by signalling the vgic every time the state *potentially* changed, but we don't want to be hitting the vgic more often than necessary. Third, we get rid of the use of the map->active field in the vgic and instead simply set the interrupt as active on the physical distributor whenever the input to the GIC is asserted and conversely clear the physical active state when the input to the GIC is deasserted. Fourth, and finally, we now initialize the timer PPIs (and all the other unused PPIs for now), to be level-triggered, and modify the sync code to sample the line state on HW sync and re-inject a new interrupt if it is still pending at that time. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-10-23arm/arm64: KVM: Use appropriate define in VGIC reset codeChristoffer Dall1-2/+6
We currently initialize the SGIs to be enabled in the VGIC code, but we use the VGIC_NR_PPIS define for this purpose, instead of the the more natural VGIC_NR_SGIS. Change this slightly confusing use of the defines. Note: This should have no functional change, as both names are defined to the number 16. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-10-23arm/arm64: KVM: Implement GICD_ICFGR as RO for PPIsChristoffer Dall1-3/+2
The GICD_ICFGR allows the bits for the SGIs and PPIs to be read only. We currently simulate this behavior by writing a hardcoded value to the register for the SGIs and PPIs on every write of these bits to the register (ignoring what the guest actually wrote), and by writing the same value as the reset value to the register. This is a bit counter-intuitive, as the register is RO for these bits, and we can just implement it that way, allowing us to control the value of the bits purely in the reset code. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-10-23arm/arm64: KVM: vgic: Factor out level irq processing on guest exitChristoffer Dall1-38/+56
Currently vgic_process_maintenance() processes dealing with a completed level-triggered interrupt directly, but we are soon going to reuse this logic for level-triggered mapped interrupts with the HW bit set, so move this logic into a separate static function. Probably the most scary part of this commit is convincing yourself that the current flow is safe compared to the old one. In the following I try to list the changes and why they are harmless: Move vgic_irq_clear_queued after kvm_notify_acked_irq: Harmless because the only potential effect of clearing the queued flag wrt. kvm_set_irq is that vgic_update_irq_pending does not set the pending bit on the emulated CPU interface or in the pending_on_cpu bitmask if the function is called with level=1. However, the point of kvm_notify_acked_irq is to call kvm_set_irq with level=0, and we set the queued flag again in __kvm_vgic_sync_hwstate later on if the level is stil high. Move vgic_set_lr before kvm_notify_acked_irq: Also, harmless because the LR are cpu-local operations and kvm_notify_acked only affects the dist Move vgic_dist_irq_clear_soft_pend after kvm_notify_acked_irq: Also harmless, because now we check the level state in the clear_soft_pend function and lower the pending bits if the level is low. Reviewed-by: Eric Auger <eric.auger@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-10-23arm/arm64: KVM: arch_timer: Only schedule soft timer on vcpu_blockChristoffer Dall1-34/+60
We currently schedule a soft timer every time we exit the guest if the timer did not expire while running the guest. This is really not necessary, because the only work we do in the timer work function is to kick the vcpu. Kicking the vcpu does two things: (1) If the vpcu thread is on a waitqueue, make it runnable and remove it from the waitqueue. (2) If the vcpu is running on a different physical CPU from the one doing the kick, it sends a reschedule IPI. The second case cannot happen, because the soft timer is only ever scheduled when the vcpu is not running. The first case is only relevant when the vcpu thread is on a waitqueue, which is only the case when the vcpu thread has called kvm_vcpu_block(). Therefore, we only need to make sure a timer is scheduled for kvm_vcpu_block(), which we do by encapsulating all calls to kvm_vcpu_block() with kvm_timer_{un}schedule calls. Additionally, we only schedule a soft timer if the timer is enabled and unmasked, since it is useless otherwise. Note that theoretically userspace can use the SET_ONE_REG interface to change registers that should cause the timer to fire, even if the vcpu is blocked without a scheduled timer, but this case was not supported before this patch and we leave it for future work for now. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-10-23KVM: Add kvm_arch_vcpu_{un}blocking callbacksChristoffer Dall1-0/+3
Some times it is useful for architecture implementations of KVM to know when the VCPU thread is about to block or when it comes back from blocking (arm/arm64 needs to know this to properly implement timers, for example). Therefore provide a generic architecture callback function in line with what we do elsewhere for KVM generic-arch interactions. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-10-20arm/arm64: KVM: Fix disabled distributor operationChristoffer Dall1-5/+6
We currently do a single update of the vgic state when the distributor enable/disable control register is accessed and then bypass updating the state for as long as the distributor remains disabled. This is incorrect, because updating the state does not consider the distributor enable bit, and this you can end up in a situation where an interrupt is marked as pending on the CPU interface, but not pending on the distributor, which is an impossible state to be in, and triggers a warning. Consider for example the following sequence of events: 1. An interrupt is marked as pending on the distributor - the interrupt is also forwarded to the CPU interface 2. The guest turns off the distributor (it's about to do a reboot) - we stop updating the CPU interface state from now on 3. The guest disables the pending interrupt - we remove the pending state from the distributor, but don't touch the CPU interface, see point 2. Since the distributor disable bit really means that no interrupts should be forwarded to the CPU interface, we modify the code to keep updating the internal VGIC state, but always set the CPU interface pending bits to zero when the distributor is disabled. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-10-20arm/arm64: KVM: Clear map->active on pend/active clearChristoffer Dall1-1/+31
When a guest reboots or offlines/onlines CPUs, it is not uncommon for it to clear the pending and active states of an interrupt through the emulated VGIC distributor. However, since the architected timers are defined by the architecture to be level triggered and the guest rightfully expects them to be that, but we emulate them as edge-triggered, we have to mimic level-triggered behavior for an edge-triggered virtual implementation. We currently do not signal the VGIC when the map->active field is true, because it indicates that the guest has already been signalled of the interrupt as required. Normally this field is set to false when the guest deactivates the virtual interrupt through the sync path. We also need to catch the case where the guest deactivates the interrupt through the emulated distributor, again allowing guests to boot even if the original virtual timer signal hit before the guest's GIC initialization sequence is run. Reviewed-by: Eric Auger <eric.auger@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-10-20arm/arm64: KVM: Fix arch timer behavior for disabled interruptsChristoffer Dall2-32/+30
We have an interesting issue when the guest disables the timer interrupt on the VGIC, which happens when turning VCPUs off using PSCI, for example. The problem is that because the guest disables the virtual interrupt at the VGIC level, we never inject interrupts to the guest and therefore never mark the interrupt as active on the physical distributor. The host also never takes the timer interrupt (we only use the timer device to trigger a guest exit and everything else is done in software), so the interrupt does not become active through normal means. The result is that we keep entering the guest with a programmed timer that will always fire as soon as we context switch the hardware timer state and run the guest, preventing forward progress for the VCPU. Since the active state on the physical distributor is really part of the timer logic, it is the job of our virtual arch timer driver to manage this state. The timer->map->active boolean field indicates whether we have signalled this interrupt to the vgic and if that interrupt is still pending or active. As long as that is the case, the hardware doesn't have to generate physical interrupts and therefore we mark the interrupt as active on the physical distributor. We also have to restore the pending state of an interrupt that was queued to an LR but was retired from the LR for some reason, while remaining pending in the LR. Cc: Marc Zyngier <marc.zyngier@arm.com> Reported-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-10-20KVM: arm/arm64: Do not inject spurious interruptsPavel Fedin1-2/+7
When lowering a level-triggered line from userspace, we forgot to lower the pending bit on the emulated CPU interface and we also did not re-compute the pending_on_cpu bitmap for the CPU affected by the change. Update vgic_update_irq_pending() to fix the two issues above and also raise a warning in vgic_quue_irq_to_lr if we encounter an interrupt pending on a CPU which is neither marked active nor pending. [ Commit text reworked completely - Christoffer ] Signed-off-by: Pavel Fedin <p.fedin@samsung.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-10-16kvm/irqchip: allow only multiple irqchip routes per GSIAndrey Smetanin1-3/+3
Any other irq routing types (MSI, S390_ADAPTER, upcoming Hyper-V SynIC) map one-to-one to GSI. Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com> Reviewed-by: Roman Kagan <rkagan@virtuozzo.com> Signed-off-by: Denis V. Lunev <den@openvz.org> CC: Vitaly Kuznetsov <vkuznets@redhat.com> CC: "K. Y. Srinivasan" <kys@microsoft.com> CC: Gleb Natapov <gleb@kernel.org> CC: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-16kvm/eventfd: add arch-specific set_irqAndrey Smetanin1-1/+12
Allow for arch-specific interrupt types to be set. For that, add kvm_arch_set_irq() which takes interrupt type-specific action if it recognizes the interrupt type given, and -EWOULDBLOCK otherwise. The default implementation always returns -EWOULDBLOCK. Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com> Reviewed-by: Roman Kagan <rkagan@virtuozzo.com> Signed-off-by: Denis V. Lunev <den@openvz.org> CC: Vitaly Kuznetsov <vkuznets@redhat.com> CC: "K. Y. Srinivasan" <kys@microsoft.com> CC: Gleb Natapov <gleb@kernel.org> CC: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-16kvm/eventfd: factor out kvm_notify_acked_gsi()Andrey Smetanin1-5/+11
Factor out kvm_notify_acked_gsi() helper to iterate over EOI listeners and notify those matching the given gsi. It will be reused in the upcoming Hyper-V SynIC implementation. Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com> Reviewed-by: Roman Kagan <rkagan@virtuozzo.com> Signed-off-by: Denis V. Lunev <den@openvz.org> CC: Vitaly Kuznetsov <vkuznets@redhat.com> CC: "K. Y. Srinivasan" <kys@microsoft.com> CC: Gleb Natapov <gleb@kernel.org> CC: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-16kvm/eventfd: avoid loop inside irqfd_update()Andrey Smetanin1-8/+5
The loop(for) inside irqfd_update() is unnecessary because any other value for irq_entry.type will just trigger schedule_work(&irqfd->inject) in irqfd_wakeup. Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com> Reviewed-by: Roman Kagan <rkagan@virtuozzo.com> Signed-off-by: Denis V. Lunev <den@openvz.org> CC: Vitaly Kuznetsov <vkuznets@redhat.com> CC: "K. Y. Srinivasan" <kys@microsoft.com> CC: Gleb Natapov <gleb@kernel.org> CC: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-14kvm: fix waitqueue_active without memory barrier in virt/kvm/async_pf.cKosuke Tatsukawa1-0/+4
async_pf_execute() seems to be missing a memory barrier which might cause the waker to not notice the waiter and miss sending a wake_up as in the following figure. async_pf_execute kvm_vcpu_block ------------------------------------------------------------------------ spin_lock(&vcpu->async_pf.lock); if (waitqueue_active(&vcpu->wq)) /* The CPU might reorder the test for the waitqueue up here, before prior writes complete */ prepare_to_wait(&vcpu->wq, &wait, TASK_INTERRUPTIBLE); /*if (kvm_vcpu_check_block(vcpu) < 0) */ /*if (kvm_arch_vcpu_runnable(vcpu)) { */ ... return (vcpu->arch.mp_state == KVM_MP_STATE_RUNNABLE && !vcpu->arch.apf.halted) || !list_empty_careful(&vcpu->async_pf.done) ... return 0; list_add_tail(&apf->link, &vcpu->async_pf.done); spin_unlock(&vcpu->async_pf.lock); waited = true; schedule(); ------------------------------------------------------------------------ The attached patch adds the missing memory barrier. I found this issue when I was looking through the linux source code for places calling waitqueue_active() before wake_up*(), but without preceding memory barriers, after sending a patch to fix a similar issue in drivers/tty/n_tty.c (Details about the original issue can be found here: https://lkml.org/lkml/2015/9/28/849). Signed-off-by: Kosuke Tatsukawa <tatsu@ab.jp.nec.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-10arm/arm64: KVM: Only allow 64bit hosts to build VGICv3Jean-Philippe Brucker1-2/+2
Hardware virtualisation of GICv3 is only supported by 64bit hosts for the moment. Some VGICv3 bits are missing from the 32bit side, and this patch allows to still be able to build 32bit hosts when CONFIG_ARM_GIC_V3 is selected. To this end, we introduce a new option, CONFIG_KVM_ARM_VGIC_V3, that is only enabled on the 64bit side. The selection is done unconditionally because CONFIG_ARM_GIC_V3 is always enabled on arm64. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-10-01KVM: Update Posted-Interrupts Descriptor when vCPU is blockedFeng Wu1-0/+3
This patch updates the Posted-Interrupts Descriptor when vCPU is blocked. pre-block: - Add the vCPU to the blocked per-CPU list - Set 'NV' to POSTED_INTR_WAKEUP_VECTOR post-block: - Remove the vCPU from the per-CPU list Signed-off-by: Feng Wu <feng.wu@intel.com> [Concentrate invocation of pre/post-block hooks to vcpu_block. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-30 12:48:43 +0300