From: Junaid Shahid Date: Fri, 4 Jan 2019 01:14:28 +0000 (-0800) Subject: kvm: Convert kvm_lock to a mutex X-Git-Tag: v4.19.84~10 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=30d8d8d6cd928b5bc8547aca6d8eb30b334d5451;p=platform%2Fkernel%2Flinux-rpi.git kvm: Convert kvm_lock to a mutex commit 0d9ce162cf46c99628cc5da9510b959c7976735b upstream. It doesn't seem as if there is any particular need for kvm_lock to be a spinlock, so convert the lock to a mutex so that sleepable functions (in particular cond_resched()) can be called while holding it. Signed-off-by: Junaid Shahid Signed-off-by: Paolo Bonzini Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman --- diff --git a/Documentation/virtual/kvm/locking.txt b/Documentation/virtual/kvm/locking.txt index 1bb8bca..635cd6e 100644 --- a/Documentation/virtual/kvm/locking.txt +++ b/Documentation/virtual/kvm/locking.txt @@ -15,8 +15,6 @@ The acquisition orders for mutexes are as follows: On x86, vcpu->mutex is taken outside kvm->arch.hyperv.hv_lock. -For spinlocks, kvm_lock is taken outside kvm->mmu_lock. - Everything else is a leaf: no other lock is taken inside the critical sections. @@ -169,7 +167,7 @@ which time it will be set using the Dirty tracking mechanism described above. ------------ Name: kvm_lock -Type: spinlock_t +Type: mutex Arch: any Protects: - vm_list diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index fac1d4e..3c317bc 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -2110,13 +2110,13 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) kvm->arch.sca = (struct bsca_block *) get_zeroed_page(alloc_flags); if (!kvm->arch.sca) goto out_err; - spin_lock(&kvm_lock); + mutex_lock(&kvm_lock); sca_offset += 16; if (sca_offset + sizeof(struct bsca_block) > PAGE_SIZE) sca_offset = 0; kvm->arch.sca = (struct bsca_block *) ((char *) kvm->arch.sca + sca_offset); - spin_unlock(&kvm_lock); + mutex_unlock(&kvm_lock); sprintf(debug_name, "kvm-%u", current->pid); diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 8894026..c9d4e02 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -5819,7 +5819,7 @@ mmu_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) int nr_to_scan = sc->nr_to_scan; unsigned long freed = 0; - spin_lock(&kvm_lock); + mutex_lock(&kvm_lock); list_for_each_entry(kvm, &vm_list, vm_list) { int idx; @@ -5869,7 +5869,7 @@ unlock: break; } - spin_unlock(&kvm_lock); + mutex_unlock(&kvm_lock); return freed; } diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 5de2c4a..2f8589d 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -6529,7 +6529,7 @@ static void kvm_hyperv_tsc_notifier(void) struct kvm_vcpu *vcpu; int cpu; - spin_lock(&kvm_lock); + mutex_lock(&kvm_lock); list_for_each_entry(kvm, &vm_list, vm_list) kvm_make_mclock_inprogress_request(kvm); @@ -6555,7 +6555,7 @@ static void kvm_hyperv_tsc_notifier(void) spin_unlock(&ka->pvclock_gtod_sync_lock); } - spin_unlock(&kvm_lock); + mutex_unlock(&kvm_lock); } #endif @@ -6613,17 +6613,17 @@ static int kvmclock_cpufreq_notifier(struct notifier_block *nb, unsigned long va smp_call_function_single(freq->cpu, tsc_khz_changed, freq, 1); - spin_lock(&kvm_lock); + mutex_lock(&kvm_lock); list_for_each_entry(kvm, &vm_list, vm_list) { kvm_for_each_vcpu(i, vcpu, kvm) { if (vcpu->cpu != freq->cpu) continue; kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu); - if (vcpu->cpu != smp_processor_id()) + if (vcpu->cpu != raw_smp_processor_id()) send_ipi = 1; } } - spin_unlock(&kvm_lock); + mutex_unlock(&kvm_lock); if (freq->old < freq->new && send_ipi) { /* @@ -6749,12 +6749,12 @@ static void pvclock_gtod_update_fn(struct work_struct *work) struct kvm_vcpu *vcpu; int i; - spin_lock(&kvm_lock); + mutex_lock(&kvm_lock); list_for_each_entry(kvm, &vm_list, vm_list) kvm_for_each_vcpu(i, vcpu, kvm) kvm_make_request(KVM_REQ_MASTERCLOCK_UPDATE, vcpu); atomic_set(&kvm_guest_has_master_clock, 0); - spin_unlock(&kvm_lock); + mutex_unlock(&kvm_lock); } static DECLARE_WORK(pvclock_gtod_work, pvclock_gtod_update_fn); diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 3d0a6194..553a311 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -141,7 +141,7 @@ static inline bool is_error_page(struct page *page) extern struct kmem_cache *kvm_vcpu_cache; -extern spinlock_t kvm_lock; +extern struct mutex kvm_lock; extern struct list_head vm_list; struct kvm_io_range { diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 0c578a1..5482949 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -92,7 +92,7 @@ EXPORT_SYMBOL_GPL(halt_poll_ns_shrink); * kvm->lock --> kvm->slots_lock --> kvm->irq_lock */ -DEFINE_SPINLOCK(kvm_lock); +DEFINE_MUTEX(kvm_lock); static DEFINE_RAW_SPINLOCK(kvm_count_lock); LIST_HEAD(vm_list); @@ -685,9 +685,9 @@ static struct kvm *kvm_create_vm(unsigned long type) if (r) goto out_err; - spin_lock(&kvm_lock); + mutex_lock(&kvm_lock); list_add(&kvm->vm_list, &vm_list); - spin_unlock(&kvm_lock); + mutex_unlock(&kvm_lock); preempt_notifier_inc(); @@ -733,9 +733,9 @@ static void kvm_destroy_vm(struct kvm *kvm) kvm_uevent_notify_change(KVM_EVENT_DESTROY_VM, kvm); kvm_destroy_vm_debugfs(kvm); kvm_arch_sync_events(kvm); - spin_lock(&kvm_lock); + mutex_lock(&kvm_lock); list_del(&kvm->vm_list); - spin_unlock(&kvm_lock); + mutex_unlock(&kvm_lock); kvm_free_irq_routing(kvm); for (i = 0; i < KVM_NR_BUSES; i++) { struct kvm_io_bus *bus = kvm_get_bus(kvm, i); @@ -3831,13 +3831,13 @@ static int vm_stat_get(void *_offset, u64 *val) u64 tmp_val; *val = 0; - spin_lock(&kvm_lock); + mutex_lock(&kvm_lock); list_for_each_entry(kvm, &vm_list, vm_list) { stat_tmp.kvm = kvm; vm_stat_get_per_vm((void *)&stat_tmp, &tmp_val); *val += tmp_val; } - spin_unlock(&kvm_lock); + mutex_unlock(&kvm_lock); return 0; } @@ -3850,12 +3850,12 @@ static int vm_stat_clear(void *_offset, u64 val) if (val) return -EINVAL; - spin_lock(&kvm_lock); + mutex_lock(&kvm_lock); list_for_each_entry(kvm, &vm_list, vm_list) { stat_tmp.kvm = kvm; vm_stat_clear_per_vm((void *)&stat_tmp, 0); } - spin_unlock(&kvm_lock); + mutex_unlock(&kvm_lock); return 0; } @@ -3870,13 +3870,13 @@ static int vcpu_stat_get(void *_offset, u64 *val) u64 tmp_val; *val = 0; - spin_lock(&kvm_lock); + mutex_lock(&kvm_lock); list_for_each_entry(kvm, &vm_list, vm_list) { stat_tmp.kvm = kvm; vcpu_stat_get_per_vm((void *)&stat_tmp, &tmp_val); *val += tmp_val; } - spin_unlock(&kvm_lock); + mutex_unlock(&kvm_lock); return 0; } @@ -3889,12 +3889,12 @@ static int vcpu_stat_clear(void *_offset, u64 val) if (val) return -EINVAL; - spin_lock(&kvm_lock); + mutex_lock(&kvm_lock); list_for_each_entry(kvm, &vm_list, vm_list) { stat_tmp.kvm = kvm; vcpu_stat_clear_per_vm((void *)&stat_tmp, 0); } - spin_unlock(&kvm_lock); + mutex_unlock(&kvm_lock); return 0; } @@ -3915,7 +3915,7 @@ static void kvm_uevent_notify_change(unsigned int type, struct kvm *kvm) if (!kvm_dev.this_device || !kvm) return; - spin_lock(&kvm_lock); + mutex_lock(&kvm_lock); if (type == KVM_EVENT_CREATE_VM) { kvm_createvm_count++; kvm_active_vms++; @@ -3924,7 +3924,7 @@ static void kvm_uevent_notify_change(unsigned int type, struct kvm *kvm) } created = kvm_createvm_count; active = kvm_active_vms; - spin_unlock(&kvm_lock); + mutex_unlock(&kvm_lock); env = kzalloc(sizeof(*env), GFP_KERNEL); if (!env)