From ce35ef27d4b751706f76c48d32a7b0d27f2d2d19 Mon Sep 17 00:00:00 2001 From: Suraj Jitindar Singh Date: Wed, 19 Oct 2016 13:49:47 +1100 Subject: kvm/stats: Update kvm stats to clear on write to their debugfs entry MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Various kvm vm and vcpu stats are provided via debugfs entries. Currently there is no way to reset these stats back to zero. Add the ability to clear (reset back to zero) these stats on a per stat basis by writing to the debugfs files. Only a write value of 0 is accepted. Signed-off-by: Suraj Jitindar Singh Signed-off-by: Radim Krčmář --- virt/kvm/kvm_main.c | 78 ++++++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 72 insertions(+), 6 deletions(-) (limited to 'virt') diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index d92c3d5b0fbe..b44edd85011a 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -595,7 +595,7 @@ static int kvm_create_vm_debugfs(struct kvm *kvm, int fd) stat_data->kvm = kvm; stat_data->offset = p->offset; kvm->debugfs_stat_data[p - debugfs_entries] = stat_data; - if (!debugfs_create_file(p->name, 0444, + if (!debugfs_create_file(p->name, 0644, kvm->debugfs_dentry, stat_data, stat_fops_per_vm[p->kind])) @@ -3663,11 +3663,23 @@ static int vm_stat_get_per_vm(void *data, u64 *val) return 0; } +static int vm_stat_clear_per_vm(void *data, u64 val) +{ + struct kvm_stat_data *stat_data = (struct kvm_stat_data *)data; + + if (val) + return -EINVAL; + + *(ulong *)((void *)stat_data->kvm + stat_data->offset) = 0; + + return 0; +} + static int vm_stat_get_per_vm_open(struct inode *inode, struct file *file) { __simple_attr_check_format("%llu\n", 0ull); return kvm_debugfs_open(inode, file, vm_stat_get_per_vm, - NULL, "%llu\n"); + vm_stat_clear_per_vm, "%llu\n"); } static const struct file_operations vm_stat_get_per_vm_fops = { @@ -3693,11 +3705,26 @@ static int vcpu_stat_get_per_vm(void *data, u64 *val) return 0; } +static int vcpu_stat_clear_per_vm(void *data, u64 val) +{ + int i; + struct kvm_stat_data *stat_data = (struct kvm_stat_data *)data; + struct kvm_vcpu *vcpu; + + if (val) + return -EINVAL; + + kvm_for_each_vcpu(i, vcpu, stat_data->kvm) + *(u64 *)((void *)vcpu + stat_data->offset) = 0; + + return 0; +} + static int vcpu_stat_get_per_vm_open(struct inode *inode, struct file *file) { __simple_attr_check_format("%llu\n", 0ull); return kvm_debugfs_open(inode, file, vcpu_stat_get_per_vm, - NULL, "%llu\n"); + vcpu_stat_clear_per_vm, "%llu\n"); } static const struct file_operations vcpu_stat_get_per_vm_fops = { @@ -3732,7 +3759,26 @@ static int vm_stat_get(void *_offset, u64 *val) return 0; } -DEFINE_SIMPLE_ATTRIBUTE(vm_stat_fops, vm_stat_get, NULL, "%llu\n"); +static int vm_stat_clear(void *_offset, u64 val) +{ + unsigned offset = (long)_offset; + struct kvm *kvm; + struct kvm_stat_data stat_tmp = {.offset = offset}; + + if (val) + return -EINVAL; + + spin_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); + + return 0; +} + +DEFINE_SIMPLE_ATTRIBUTE(vm_stat_fops, vm_stat_get, vm_stat_clear, "%llu\n"); static int vcpu_stat_get(void *_offset, u64 *val) { @@ -3752,7 +3798,27 @@ static int vcpu_stat_get(void *_offset, u64 *val) return 0; } -DEFINE_SIMPLE_ATTRIBUTE(vcpu_stat_fops, vcpu_stat_get, NULL, "%llu\n"); +static int vcpu_stat_clear(void *_offset, u64 val) +{ + unsigned offset = (long)_offset; + struct kvm *kvm; + struct kvm_stat_data stat_tmp = {.offset = offset}; + + if (val) + return -EINVAL; + + spin_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); + + return 0; +} + +DEFINE_SIMPLE_ATTRIBUTE(vcpu_stat_fops, vcpu_stat_get, vcpu_stat_clear, + "%llu\n"); static const struct file_operations *stat_fops[] = { [KVM_STAT_VCPU] = &vcpu_stat_fops, @@ -3770,7 +3836,7 @@ static int kvm_init_debug(void) kvm_debugfs_num_entries = 0; for (p = debugfs_entries; p->name; ++p, kvm_debugfs_num_entries++) { - if (!debugfs_create_file(p->name, 0444, kvm_debugfs_dir, + if (!debugfs_create_file(p->name, 0644, kvm_debugfs_dir, (void *)(long)p->offset, stat_fops[p->kind])) goto out_dir; -- cgit v1.2.3-59-g8ed1b