KVM: debugfs: Reuse binary stats descriptors

To remove code duplication, use the binary stats descriptors in the
implementation of the debugfs interface for statistics. This unifies
the definition of statistics for the binary and debugfs interfaces.

Signed-off-by: Jing Zhang <jingzhangos@google.com>
Message-Id: <20210618222709.1858088-8-jingzhangos@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 76 insertions, 28 deletions

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index c8d0028df4ac..3dcc2abbfc60 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -115,7 +115,6 @@ static DEFINE_PER_CPU(struct kvm_vcpu *, kvm_running_vcpu);
 struct dentry *kvm_debugfs_dir;
 EXPORT_SYMBOL_GPL(kvm_debugfs_dir);
 
-static int kvm_debugfs_num_entries;
 static const struct file_operations stat_fops_per_vm;
 
 static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl,
@@ -860,9 +859,24 @@ static void kvm_free_memslots(struct kvm *kvm, struct kvm_memslots *slots)
 	kvfree(slots);
 }
 
+static umode_t kvm_stats_debugfs_mode(const struct _kvm_stats_desc *pdesc)
+{
+	switch (pdesc->desc.flags & KVM_STATS_TYPE_MASK) {
+	case KVM_STATS_TYPE_INSTANT:
+		return 0444;
+	case KVM_STATS_TYPE_CUMULATIVE:
+	case KVM_STATS_TYPE_PEAK:
+	default:
+		return 0644;
+	}
+}
+
+
 static void kvm_destroy_vm_debugfs(struct kvm *kvm)
 {
 	int i;
+	int kvm_debugfs_num_entries = kvm_vm_stats_header.num_desc +
+				      kvm_vcpu_stats_header.num_desc;
 
 	if (!kvm->debugfs_dentry)
 		return;
@@ -880,7 +894,10 @@ static int kvm_create_vm_debugfs(struct kvm *kvm, int fd)
 {
 	char dir_name[ITOA_MAX_LEN * 2];
 	struct kvm_stat_data *stat_data;
-	struct kvm_stats_debugfs_item *p;
+	const struct _kvm_stats_desc *pdesc;
+	int i;
+	int kvm_debugfs_num_entries = kvm_vm_stats_header.num_desc +
+				      kvm_vcpu_stats_header.num_desc;
 
 	if (!debugfs_initialized())
 		return 0;
@@ -894,15 +911,32 @@ static int kvm_create_vm_debugfs(struct kvm *kvm, int fd)
 	if (!kvm->debugfs_stat_data)
 		return -ENOMEM;
 
-	for (p = debugfs_entries; p->name; p++) {
+	for (i = 0; i < kvm_vm_stats_header.num_desc; ++i) {
+		pdesc = &kvm_vm_stats_desc[i];
 		stat_data = kzalloc(sizeof(*stat_data), GFP_KERNEL_ACCOUNT);
 		if (!stat_data)
 			return -ENOMEM;
 
 		stat_data->kvm = kvm;
-		stat_data->dbgfs_item = p;
-		kvm->debugfs_stat_data[p - debugfs_entries] = stat_data;
-		debugfs_create_file(p->name, KVM_DBGFS_GET_MODE(p),
+		stat_data->desc = pdesc;
+		stat_data->kind = KVM_STAT_VM;
+		kvm->debugfs_stat_data[i] = stat_data;
+		debugfs_create_file(pdesc->name, kvm_stats_debugfs_mode(pdesc),
+				    kvm->debugfs_dentry, stat_data,
+				    &stat_fops_per_vm);
+	}
+
+	for (i = 0; i < kvm_vcpu_stats_header.num_desc; ++i) {
+		pdesc = &kvm_vcpu_stats_desc[i];
+		stat_data = kzalloc(sizeof(*stat_data), GFP_KERNEL_ACCOUNT);
+		if (!stat_data)
+			return -ENOMEM;
+
+		stat_data->kvm = kvm;
+		stat_data->desc = pdesc;
+		stat_data->kind = KVM_STAT_VCPU;
+		kvm->debugfs_stat_data[i] = stat_data;
+		debugfs_create_file(pdesc->name, kvm_stats_debugfs_mode(pdesc),
 				    kvm->debugfs_dentry, stat_data,
 				    &stat_fops_per_vm);
 	}
@@ -4900,7 +4934,7 @@ static int kvm_debugfs_open(struct inode *inode, struct file *file,
 		return -ENOENT;
 
 	if (simple_attr_open(inode, file, get,
-		    KVM_DBGFS_GET_MODE(stat_data->dbgfs_item) & 0222
+		    kvm_stats_debugfs_mode(stat_data->desc) & 0222
 		    ? set : NULL,
 		    fmt)) {
 		kvm_put_kvm(stat_data->kvm);
@@ -4923,14 +4957,14 @@ static int kvm_debugfs_release(struct inode *inode, struct file *file)
 
 static int kvm_get_stat_per_vm(struct kvm *kvm, size_t offset, u64 *val)
 {
-	*val = *(u64 *)((void *)kvm + offset);
+	*val = *(u64 *)((void *)(&kvm->stat) + offset);
 
 	return 0;
 }
 
 static int kvm_clear_stat_per_vm(struct kvm *kvm, size_t offset)
 {
-	*(u64 *)((void *)kvm + offset) = 0;
+	*(u64 *)((void *)(&kvm->stat) + offset) = 0;
 
 	return 0;
 }
@@ -4943,7 +4977,7 @@ static int kvm_get_stat_per_vcpu(struct kvm *kvm, size_t offset, u64 *val)
 	*val = 0;
 
 	kvm_for_each_vcpu(i, vcpu, kvm)
-		*val += *(u64 *)((void *)vcpu + offset);
+		*val += *(u64 *)((void *)(&vcpu->stat) + offset);
 
 	return 0;
 }
@@ -4954,7 +4988,7 @@ static int kvm_clear_stat_per_vcpu(struct kvm *kvm, size_t offset)
 	struct kvm_vcpu *vcpu;
 
 	kvm_for_each_vcpu(i, vcpu, kvm)
-		*(u64 *)((void *)vcpu + offset) = 0;
+		*(u64 *)((void *)(&vcpu->stat) + offset) = 0;
 
 	return 0;
 }
@@ -4964,14 +4998,14 @@ static int kvm_stat_data_get(void *data, u64 *val)
 	int r = -EFAULT;
 	struct kvm_stat_data *stat_data = (struct kvm_stat_data *)data;
 
-	switch (stat_data->dbgfs_item->kind) {
+	switch (stat_data->kind) {
 	case KVM_STAT_VM:
 		r = kvm_get_stat_per_vm(stat_data->kvm,
-					stat_data->dbgfs_item->offset, val);
+					stat_data->desc->desc.offset, val);
 		break;
 	case KVM_STAT_VCPU:
 		r = kvm_get_stat_per_vcpu(stat_data->kvm,
-					  stat_data->dbgfs_item->offset, val);
+					  stat_data->desc->desc.offset, val);
 		break;
 	}
 
@@ -4986,14 +5020,14 @@ static int kvm_stat_data_clear(void *data, u64 val)
 	if (val)
 		return -EINVAL;
 
-	switch (stat_data->dbgfs_item->kind) {
+	switch (stat_data->kind) {
 	case KVM_STAT_VM:
 		r = kvm_clear_stat_per_vm(stat_data->kvm,
-					  stat_data->dbgfs_item->offset);
+					  stat_data->desc->desc.offset);
 		break;
 	case KVM_STAT_VCPU:
 		r = kvm_clear_stat_per_vcpu(stat_data->kvm,
-					    stat_data->dbgfs_item->offset);
+					    stat_data->desc->desc.offset);
 		break;
 	}
 
@@ -5050,6 +5084,7 @@ static int vm_stat_clear(void *_offset, u64 val)
 }
 
 DEFINE_SIMPLE_ATTRIBUTE(vm_stat_fops, vm_stat_get, vm_stat_clear, "%llu\n");
+DEFINE_SIMPLE_ATTRIBUTE(vm_stat_readonly_fops, vm_stat_get, NULL, "%llu\n");
 
 static int vcpu_stat_get(void *_offset, u64 *val)
 {
@@ -5086,11 +5121,7 @@ static int vcpu_stat_clear(void *_offset, u64 val)
 
 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,
-	[KVM_STAT_VM]   = &vm_stat_fops,
-};
+DEFINE_SIMPLE_ATTRIBUTE(vcpu_stat_readonly_fops, vcpu_stat_get, NULL, "%llu\n");
 
 static void kvm_uevent_notify_change(unsigned int type, struct kvm *kvm)
 {
@@ -5144,15 +5175,32 @@ static void kvm_uevent_notify_change(unsigned int type, struct kvm *kvm)
 
 static void kvm_init_debug(void)
 {
-	struct kvm_stats_debugfs_item *p;
+	const struct file_operations *fops;
+	const struct _kvm_stats_desc *pdesc;
+	int i;
 
 	kvm_debugfs_dir = debugfs_create_dir("kvm", NULL);
 
-	kvm_debugfs_num_entries = 0;
-	for (p = debugfs_entries; p->name; ++p, kvm_debugfs_num_entries++) {
-		debugfs_create_file(p->name, KVM_DBGFS_GET_MODE(p),
-				    kvm_debugfs_dir, (void *)(long)p->offset,
-				    stat_fops[p->kind]);
+	for (i = 0; i < kvm_vm_stats_header.num_desc; ++i) {
+		pdesc = &kvm_vm_stats_desc[i];
+		if (kvm_stats_debugfs_mode(pdesc) & 0222)
+			fops = &vm_stat_fops;
+		else
+			fops = &vm_stat_readonly_fops;
+		debugfs_create_file(pdesc->name, kvm_stats_debugfs_mode(pdesc),
+				kvm_debugfs_dir,
+				(void *)(long)pdesc->desc.offset, fops);
+	}
+
+	for (i = 0; i < kvm_vcpu_stats_header.num_desc; ++i) {
+		pdesc = &kvm_vcpu_stats_desc[i];
+		if (kvm_stats_debugfs_mode(pdesc) & 0222)
+			fops = &vcpu_stat_fops;
+		else
+			fops = &vcpu_stat_readonly_fops;
+		debugfs_create_file(pdesc->name, kvm_stats_debugfs_mode(pdesc),
+				kvm_debugfs_dir,
+				(void *)(long)pdesc->desc.offset, fops);
 	}
 }