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* kvm: x86: Add memcg accounting to KVM allocationsBen Gardon2019-02-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are many KVM kernel memory allocations which are tied to the life of the VM process and should be charged to the VM process's cgroup. If the allocations aren't tied to the process, the OOM killer will not know that killing the process will free the associated kernel memory. Add __GFP_ACCOUNT flags to many of the allocations which are not yet being charged to the VM process's cgroup. Tested: Ran all kvm-unit-tests on a 64 bit Haswell machine, the patch introduced no new failures. Ran a kernel memory accounting test which creates a VM to touch memory and then checks that the kernel memory allocated for the process is within certain bounds. With this patch we account for much more of the vmalloc and slab memory allocated for the VM. There remain a few allocations which should be charged to the VM's cgroup but are not. In x86, they include: vcpu->arch.pio_data There allocations are unaccounted in this patch because they are mapped to userspace, and accounting them to a cgroup causes problems. This should be addressed in a future patch. Signed-off-by: Ben Gardon <bgardon@google.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* KVM: x86: take slots_lock in kvm_free_pitRadim Krčmář2017-07-121-0/+2
| | | | | | | | | | | | | | | | | | | | | | | kvm_vm_release() did not have slots_lock when calling kvm_io_bus_unregister_dev() and this went unnoticed until 4a12f9517728 ("KVM: mark kvm->busses as rcu protected") added dynamic checks. Luckily, there should be no race at that point: ============================= WARNING: suspicious RCU usage 4.12.0.kvm+ #0 Not tainted ----------------------------- ./include/linux/kvm_host.h:479 suspicious rcu_dereference_check() usage! lockdep_rcu_suspicious+0xc5/0x100 kvm_io_bus_unregister_dev+0x173/0x190 [kvm] kvm_free_pit+0x28/0x80 [kvm] kvm_arch_sync_events+0x2d/0x30 [kvm] kvm_put_kvm+0xa7/0x2a0 [kvm] kvm_vm_release+0x21/0x30 [kvm] Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
* KVM: x86: Handle the kthread worker using the new APIPetr Mladek2016-12-081-9/+6Star
| | | | | | | | | | | | | | | | | | | | | | | | Use the new API to create and destroy the "kvm-pit" kthread worker. The API hides some implementation details. In particular, kthread_create_worker() allocates and initializes struct kthread_worker. It runs the kthread the right way and stores task_struct into the worker structure. kthread_destroy_worker() flushes all pending works, stops the kthread and frees the structure. This patch does not change the existing behavior except for dynamically allocating struct kthread_worker and storing only the pointer of this structure. It is compile tested only because I did not find an easy way how to run the code. Well, it should be pretty safe given the nature of the change. Signed-off-by: Petr Mladek <pmladek@suse.com> Message-Id: <1476877847-11217-1-git-send-email-pmladek@suse.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* kthread: kthread worker API cleanupPetr Mladek2016-10-121-7/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A good practice is to prefix the names of functions by the name of the subsystem. The kthread worker API is a mix of classic kthreads and workqueues. Each worker has a dedicated kthread. It runs a generic function that process queued works. It is implemented as part of the kthread subsystem. This patch renames the existing kthread worker API to use the corresponding name from the workqueues API prefixed by kthread_: __init_kthread_worker() -> __kthread_init_worker() init_kthread_worker() -> kthread_init_worker() init_kthread_work() -> kthread_init_work() insert_kthread_work() -> kthread_insert_work() queue_kthread_work() -> kthread_queue_work() flush_kthread_work() -> kthread_flush_work() flush_kthread_worker() -> kthread_flush_worker() Note that the names of DEFINE_KTHREAD_WORK*() macros stay as they are. It is common that the "DEFINE_" prefix has precedence over the subsystem names. Note that INIT() macros and init() functions use different naming scheme. There is no good solution. There are several reasons for this solution: + "init" in the function names stands for the verb "initialize" aka "initialize worker". While "INIT" in the macro names stands for the noun "INITIALIZER" aka "worker initializer". + INIT() macros are used only in DEFINE() macros + init() functions are used close to the other kthread() functions. It looks much better if all the functions use the same scheme. + There will be also kthread_destroy_worker() that will be used close to kthread_cancel_work(). It is related to the init() function. Again it looks better if all functions use the same naming scheme. + there are several precedents for such init() function names, e.g. amd_iommu_init_device(), free_area_init_node(), jump_label_init_type(), regmap_init_mmio_clk(), + It is not an argument but it was inconsistent even before. [arnd@arndb.de: fix linux-next merge conflict] Link: http://lkml.kernel.org/r/20160908135724.1311726-1-arnd@arndb.de Link: http://lkml.kernel.org/r/1470754545-17632-3-git-send-email-pmladek@suse.com Suggested-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Petr Mladek <pmladek@suse.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Tejun Heo <tj@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Borislav Petkov <bp@suse.de> Cc: Michal Hocko <mhocko@suse.cz> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* KVM: x86: protect KVM_CREATE_PIT/KVM_CREATE_PIT2 with kvm->lockPaolo Bonzini2016-06-031-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The syzkaller folks reported a NULL pointer dereference that seems to be cause by a race between KVM_CREATE_IRQCHIP and KVM_CREATE_PIT2. The former takes kvm->lock (except when registering the devices, which needs kvm->slots_lock); the latter takes kvm->slots_lock only. Change KVM_CREATE_PIT2 to follow the same model as KVM_CREATE_IRQCHIP. Testcase: #include <pthread.h> #include <linux/kvm.h> #include <fcntl.h> #include <sys/ioctl.h> #include <stdint.h> #include <string.h> #include <stdlib.h> #include <sys/syscall.h> #include <unistd.h> long r[23]; void* thr1(void* arg) { struct kvm_pit_config pitcfg = { .flags = 4 }; switch ((long)arg) { case 0: r[2] = open("/dev/kvm", O_RDONLY|O_ASYNC); break; case 1: r[3] = ioctl(r[2], KVM_CREATE_VM, 0); break; case 2: r[4] = ioctl(r[3], KVM_CREATE_IRQCHIP, 0); break; case 3: r[22] = ioctl(r[3], KVM_CREATE_PIT2, &pitcfg); break; } return 0; } int main(int argc, char **argv) { long i; pthread_t th[4]; memset(r, -1, sizeof(r)); for (i = 0; i < 4; i++) { pthread_create(&th[i], 0, thr, (void*)i); if (argc > 1 && rand()%2) usleep(rand()%1000); } usleep(20000); return 0; } Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
* KVM: i8254: drop local copy of mul_u64_u32_divPaolo Bonzini2016-03-041-23/+3Star
| | | | | | | | | A function that does the same as i8254.c's muldiv64 has been added (for KVM's own use, in fact!) in include/linux/math64.h. Use it instead of muldiv64. Reviewed-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* KVM: i8254: turn kvm_kpit_state.reinject into atomic_tRadim Krčmář2016-03-041-4/+4
| | | | | | | | | Document possible races between readers and concurrent update to the ioctl. Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* KVM: i8254: move PIT timer function initializationRadim Krčmář2016-03-041-2/+1Star
| | | | | | | | We can do it just once. Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* KVM: i8254: remove pointless dereference of PITRadim Krčmář2016-03-041-2/+2
| | | | | | | | PIT is known at that point. Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* KVM: i8254: remove pit and kvm from kvm_kpit_stateRadim Krčmář2016-03-041-5/+9
| | | | | | | | | kvm isn't ever used and pit can be accessed with container_of. If you *really* need kvm, pit_state_to_pit(ps)->kvm. Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* KVM: i8254: refactor kvm_free_pitRadim Krčmář2016-03-041-13/+11Star
| | | | | | | | Could be easier to read, but git history will become deeper. Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* KVM: i8254: refactor kvm_create_pitRadim Krčmář2016-03-041-15/+12Star
| | | | | | | | | Locks are gone, so we don't need to duplicate error paths. Use goto everywhere. Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* KVM: i8254: remove notifiers from PIT discard policyRadim Krčmář2016-03-041-11/+27
| | | | | | | | | | Discard policy doesn't rely on information from notifiers, so we don't need to register notifiers unconditionally. We kept correct counts in case userspace switched between policies during runtime, but that can be avoided by reseting the state. Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* KVM: i8254: remove unnecessary uses of PIT state lockRadim Krčmář2016-03-041-8/+1Star
| | | | | | | | | | | | | | | | | | - kvm_create_pit had to lock only because it exposed kvm->arch.vpit very early, but initialization doesn't use kvm->arch.vpit since the last patch, so we can drop locking. - kvm_free_pit is only run after there are no users of KVM and therefore is the sole actor. - Locking in kvm_vm_ioctl_reinject doesn't do anything, because reinject is only protected at that place. - kvm_pit_reset isn't used anywhere and its locking can be dropped if we hide it. Removing useless locking allows to see what actually is being protected by PIT state lock (values accessible from the guest). Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* KVM: i8254: pass struct kvm_pit instead of kvm in PITRadim Krčmář2016-03-041-60/+52Star
| | | | | | | | | | This patch passes struct kvm_pit into internal PIT functions. Those functions used to get PIT through kvm->arch.vpit, even though most of them never used *kvm for other purposes. Another benefit is that we don't need to set kvm->arch.vpit during initialization. Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* KVM: i8254: tone down WARN_ON pit.state_lockRadim Krčmář2016-03-041-14/+3Star
| | | | | | | | | If the guest could hit this, it would hang the host kernel, bacause of sheer number of those reports. Internal callers have to be sensible anyway, so we now only check for it in an API function. Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* KVM: i8254: use atomic_t instead of pit.inject_lockRadim Krčmář2016-03-041-33/+23Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The lock was an overkill, the same can be done with atomics. A mb() was added in kvm_pit_ack_irq, to pair with implicit barrier between pit_timer_fn and pit_do_work. The mb() prevents a race that could happen if pending == 0 and irq_ack == 0: kvm_pit_ack_irq: | pit_timer_fn: p = atomic_read(&ps->pending); | | atomic_inc(&ps->pending); | queue_work(pit_do_work); | pit_do_work: | atomic_xchg(&ps->irq_ack, 0); | return; atomic_set(&ps->irq_ack, 1); | if (p == 0) return; | where the interrupt would not be delivered in this tick of pit_timer_fn. PIT would have eventually delivered the interrupt, but we sacrifice perofmance to make sure that interrupts are not needlessly delayed. sfence isn't enough: atomic_dec_if_positive does atomic_read first and x86 can reorder loads before stores. lfence isn't enough: store can pass lfence, turning it into a nop. A compiler barrier would be more than enough as CPU needs to stall for unbelievably long to use fences. This patch doesn't do anything in kvm_pit_reset_reinject, because any order of resets can race, but the result differs by at most one interrupt, which is ok, because it's the same result as if the reset happened at a slightly different time. (Original code didn't protect the reset path with a proper lock, so users have to be robust.) Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* KVM: i8254: add kvm_pit_reset_reinjectRadim Krčmář2016-03-041-8/+10
| | | | | | | | pit_state.pending and pit_state.irq_ack are always reset at the same time. Create a function for them. Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* KVM: i8254: simplify atomics in kvm_pit_ack_irqRadim Krčmář2016-03-041-11/+1Star
| | | | | | | We already have a helper that does the same thing. Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* KVM: i8254: change PIT discard tick policyRadim Krčmář2016-03-041-5/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | Discard policy uses ack_notifiers to prevent injection of PIT interrupts before EOI from the last one. This patch changes the policy to always try to deliver the interrupt, which makes a difference when its vector is in ISR. Old implementation would drop the interrupt, but proposed one injects to IRR, like real hardware would. The old policy breaks legacy NMI watchdogs, where PIT is used through virtual wire (LVT0): PIT never sends an interrupt before receiving EOI, thus a guest deadlock with disabled interrupts will stop NMIs. Note that NMI doesn't do EOI, so PIT also had to send a normal interrupt through IOAPIC. (KVM's PIT is deeply rotten and luckily not used much in modern systems.) Even though there is a chance of regressions, I think we can fix the LVT0 NMI bug without introducing a new tick policy. Cc: <stable@vger.kernel.org> Reported-by: Yuki Shibuya <shibuya.yk@ncos.nec.co.jp> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* kvm: x86: only channel 0 of the i8254 is linked to the HPETPaolo Bonzini2016-01-071-0/+1
| | | | | | | | | | | | While setting the KVM PIT counters in 'kvm_pit_load_count', if 'hpet_legacy_start' is set, the function disables the timer on channel[0], instead of the respective index 'channel'. This is because channels 1-3 are not linked to the HPET. Fix the caller to only activate the special HPET processing for channel 0. Reported-by: P J P <pjp@fedoraproject.org> Fixes: 0185604c2d82c560dab2f2933a18f797e74ab5a8 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* KVM: x86: Split the APIC from the rest of IRQCHIP.Steve Rutherford2015-10-011-1/+3
| | | | | | | | | | | | | | | | First patch in a series which enables the relocation of the PIC/IOAPIC to userspace. Adds capability KVM_CAP_SPLIT_IRQCHIP; KVM_CAP_SPLIT_IRQCHIP enables the construction of LAPICs without the rest of the irqchip. Compile tested for x86. Signed-off-by: Steve Rutherford <srutherford@google.com> Suggested-by: Andrew Honig <ahonig@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* KVM: x86: make vapics_in_nmi_mode atomicRadim Krčmář2015-07-031-1/+1
| | | | | | | | | | | Writes were a bit racy, but hard to turn into a bug at the same time. (Particularly because modern Linux doesn't use this feature anymore.) Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> [Actually the next patch makes it much, much easier to trigger the race so I'm including this one for stable@ as well. - Paolo] Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* KVM: Redesign kvm_io_bus_ API to pass VCPU structure to the callbacks.Nikolay Nikolaev2015-03-261-5/+9
| | | | | | | | | | | | This is needed in e.g. ARM vGIC emulation, where the MMIO handling depends on the VCPU that does the access. Signed-off-by: Nikolay Nikolaev <n.nikolaev@virtualopensystems.com> Signed-off-by: Andre Przywara <andre.przywara@arm.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
* KVM: x86: Improve thread safety in pitAndy Honig2014-10-241-0/+2
| | | | | | | | | | | | | There's a race condition in the PIT emulation code in KVM. In __kvm_migrate_pit_timer the pit_timer object is accessed without synchronization. If the race condition occurs at the wrong time this can crash the host kernel. This fixes CVE-2014-3611. Cc: stable@vger.kernel.org Signed-off-by: Andrew Honig <ahonig@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* KVM: x86: limit PIT timer frequencyMarcelo Tosatti2014-01-151-0/+18
| | | | | | | | | | Limit PIT timer frequency similarly to the limit applied by LAPIC timer. Cc: stable@kernel.org Reviewed-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* KVM: Let ioapic know the irq line statusYang Zhang2013-04-161-2/+2
| | | | | | | | | Userspace may deliver RTC interrupt without query the status. So we want to track RTC EOI for this case. Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com> Reviewed-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* kvm: fix i8254 counter 0 wraparoundNickolai Zeldovich2012-12-181-1/+0Star
| | | | | | | | | | | | | | | | | | | | | | | | The kvm i8254 emulation for counter 0 (but not for counters 1 and 2) has at least two bugs in mode 0: 1. The OUT bit, computed by pit_get_out(), is never set high. 2. The counter value, computed by pit_get_count(), wraps back around to the initial counter value, rather than wrapping back to 0xFFFF (which is the behavior described in the comment in __kpit_elapsed, the behavior implemented by qemu, and the behavior observed on AMD hardware). The bug stems from __kpit_elapsed computing the elapsed time mod the initial counter value (stored as nanoseconds in ps->period). This is both unnecessary (none of the callers of kpit_elapsed expect the value to be at most the initial counter value) and incorrect (it causes pit_get_count to appear to wrap around to the initial counter value rather than 0xFFFF). Removing this mod from __kpit_elapsed fixes both of the above bugs. Signed-off-by: Nickolai Zeldovich <nickolai@csail.mit.edu> Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
* KVM: fold kvm_pit_timer into kvm_kpit_stateAvi Kivity2012-08-011-27/+25Star
| | | | | | | One structure nests inside the other, providing no value at all. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: Simplify kvm_pit_timerAvi Kivity2012-08-011-13/+1Star
| | | | | | | | | | | | 'timer_mode_mask' is unused 'tscdeadline' is unused 't_ops' only adds needless indirection 'vcpu' is unused Remove. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: Remove internal timer abstractionAvi Kivity2012-08-011-4/+4
| | | | | | | | | | | kvm_timer_fn(), the sole inhabitant of timer.c, is only used by lapic.c. Move it there to make it easier to hack on it. struct kvm_timer is a thin wrapper around hrtimer, and only adds obfuscation. Move near its two users (with different names) to prepare for simplification. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: x86: Run PIT work in own kthreadJan Kiszka2012-04-281-12/+19
| | | | | | | | | | | | | | | | | We can't run PIT IRQ injection work in the interrupt context of the host timer. This would allow the user to influence the handler complexity by asking for a broadcast to a large number of VCPUs. Therefore, this work was pushed into workqueue context in 9d244caf2e. However, this prevents prioritizing the PIT injection over other task as workqueues share kernel threads. This replaces the workqueue with a kthread worker and gives that thread a name in the format "kvm-pit/<owner-process-pid>". That allows to identify and adjust the kthread priority according to the VM process parameters. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: x86: Consolidate PIT legacy testJan Kiszka2011-12-271-7/+3Star
| | | | | | | | Move the test for KVM_PIT_FLAGS_HPET_LEGACY into create_pit_timer instead of replicating it on the caller site. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: x86: Prevent starting PIT timers in the absence of irqchip supportJan Kiszka2011-12-251-3/+7
| | | | | | | | | | | | | | | | | | | | | | User space may create the PIT and forgets about setting up the irqchips. In that case, firing PIT IRQs will crash the host: BUG: unable to handle kernel NULL pointer dereference at 0000000000000128 IP: [<ffffffffa10f6280>] kvm_set_irq+0x30/0x170 [kvm] ... Call Trace: [<ffffffffa11228c1>] pit_do_work+0x51/0xd0 [kvm] [<ffffffff81071431>] process_one_work+0x111/0x4d0 [<ffffffff81071bb2>] worker_thread+0x152/0x340 [<ffffffff81075c8e>] kthread+0x7e/0x90 [<ffffffff815a4474>] kernel_thread_helper+0x4/0x10 Prevent this by checking the irqchip mode before starting a timer. We can't deny creating the PIT if the irqchips aren't set up yet as current user land expects this order to work. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: Intelligent device lookup on I/O busSasha Levin2011-09-251-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | Currently the method of dealing with an IO operation on a bus (PIO/MMIO) is to call the read or write callback for each device registered on the bus until we find a device which handles it. Since the number of devices on a bus can be significant due to ioeventfds and coalesced MMIO zones, this leads to a lot of overhead on each IO operation. Instead of registering devices, we now register ranges which points to a device. Lookup is done using an efficient bsearch instead of a linear search. Performance test was conducted by comparing exit count per second with 200 ioeventfds created on one byte and the guest is trying to access a different byte continuously (triggering usermode exits). Before the patch the guest has achieved 259k exits per second, after the patch the guest does 274k exits per second. Cc: Avi Kivity <avi@redhat.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Sasha Levin <levinsasha928@gmail.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: fix typo in copyright noticeNicolas Kaiser2010-10-241-1/+1
| | | | | | | Fix typo in copyright notice. Signed-off-by: Nicolas Kaiser <nikai@nikai.net> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: pit: Do not check pending pit timer in vcpu threadJason Wang2010-10-241-9/+0Star
| | | | | | | | | Pit interrupt injection was done by workqueue, so no need to check pending pit timer in vcpu thread which could lead unnecessary unblocking of vcpu. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: PIT: free irq source id in handling error pathXiao Guangrong2010-08-171-0/+1
| | | | | | | Free irq source id if create pit workqueue fail Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: destroy workqueue on kvm_create_pit() failuresXiaotian Feng2010-08-151-1/+1
| | | | | | | | | | | | | | | | kernel needs to destroy workqueue if kvm_create_pit() fails, otherwise after pit is freed, the workqueue is leaked. Signed-off-by: Xiaotian Feng <dfeng@redhat.com> Cc: Avi Kivity <avi@redhat.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Gleb Natapov <gleb@redhat.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Gregory Haskins <ghaskins@novell.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: PIT: stop vpit before freeing irq_routingXiao Guangrong2010-08-021-0/+3
| | | | | | | | | | | | | | | | | | | Fix: general protection fault: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC ...... Call Trace: [<ffffffffa0159bd1>] ? kvm_set_irq+0xdd/0x24b [kvm] [<ffffffff8106ea8b>] ? trace_hardirqs_off_caller+0x1f/0x10e [<ffffffff813ad17f>] ? sub_preempt_count+0xe/0xb6 [<ffffffff8106d273>] ? put_lock_stats+0xe/0x27 ... RIP [<ffffffffa0159c72>] kvm_set_irq+0x17e/0x24b [kvm] This bug is triggered when guest is shutdown, is because we freed irq_routing before pit thread stopped Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: fix lock imbalance in kvm_create_pit()Jiri Slaby2010-08-021-0/+1
| | | | | | | | | | | | | | | | | | Stanse found that there is an omitted unlock in kvm_create_pit in one fail path. Add proper unlock there. Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Cc: Avi Kivity <avi@redhat.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: x86@kernel.org Cc: Gleb Natapov <gleb@redhat.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Gregory Haskins <ghaskins@novell.com> Cc: kvm@vger.kernel.org Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: x86: Introduce a workqueue to deliver PIT timer interruptsChris Lalancette2010-08-011-56/+85
| | | | | | | | | | We really want to "kvm_set_irq" during the hrtimer callback, but that is risky because that is during interrupt context. Instead, offload the work to a workqueue, which is a bit safer and should provide most of the same functionality. Signed-off-by: Chris Lalancette <clalance@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: Update Red Hat copyrightsAvi Kivity2010-08-011-0/+1
| | | | Signed-off-by: Avi Kivity <avi@redhat.com>
* include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo2010-03-301-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
* KVM: Convert i8254/i8259 locks to raw_spinlocksThomas Gleixner2010-03-011-5/+5
| | | | | | | | The i8254/i8259 locks need to be real spinlocks on preempt-rt. Convert them to raw_spinlock. No change for !RT kernels. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: PIT: unregister kvm irq notifier if fail to create pitWei Yongjun2010-03-011-2/+3
| | | | | | | | | If fail to create pit, we should unregister kvm irq notifier which register in kvm_create_pit(). Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com> Acked-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: convert slots_lock to a mutexMarcelo Tosatti2010-03-011-1/+1
| | | | Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: convert io_bus to SRCUMarcelo Tosatti2010-03-011-3/+3
| | | | Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: PIT: control word is write-onlyMarcelo Tosatti2010-02-091-0/+3
| | | | | | | PIT control word (address 0x43) is write-only, reads are undefined. Cc: stable@kernel.org Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* x86: i8254.c: Add pr_fmt(fmt)Joe Perches2009-12-101-5/+7
| | | | | | | | | - Add pr_fmt(fmt) "pit: " fmt - Strip pit: prefixes from pr_debug Signed-off-by: Joe Perches <joe@perches.com> LKML-Reference: <bbd4de532f18bb7c11f64ba20d224c08291cb126.1260383912.git.joe@perches.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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