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kvm: Refactor handling of VM debugfs files
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We can store reference to kvm_stats_debugfs_item instead of copying
its values to kvm_stat_data.
This allows us to remove duplicated code and usage of temporary
kvm_stat_data inside vm_stat_get et al.

Signed-off-by: Milan Pandurov <milanpa@amazon.de>
Reviewed-by: Alexander Graf <graf@amazon.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Milan Pandurov authored and Paolo Bonzini committed Jan 21, 2020
1 parent e30a7d6 commit 09cbcef
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Showing 2 changed files with 76 additions and 73 deletions.
7 changes: 5 additions & 2 deletions include/linux/kvm_host.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1108,9 +1108,8 @@ enum kvm_stat_kind {
};

struct kvm_stat_data {
int offset;
int mode;
struct kvm *kvm;
struct kvm_stats_debugfs_item *dbgfs_item;
};

struct kvm_stats_debugfs_item {
Expand All @@ -1119,6 +1118,10 @@ struct kvm_stats_debugfs_item {
enum kvm_stat_kind kind;
int mode;
};

#define KVM_DBGFS_GET_MODE(dbgfs_item) \
((dbgfs_item)->mode ? (dbgfs_item)->mode : 0644)

extern struct kvm_stats_debugfs_item debugfs_entries[];
extern struct dentry *kvm_debugfs_dir;

Expand Down
142 changes: 71 additions & 71 deletions virt/kvm/kvm_main.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -113,7 +113,7 @@ 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 const struct file_operations stat_fops_per_vm;

static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl,
unsigned long arg);
Expand Down Expand Up @@ -650,11 +650,11 @@ static int kvm_create_vm_debugfs(struct kvm *kvm, int fd)
return -ENOMEM;

stat_data->kvm = kvm;
stat_data->offset = p->offset;
stat_data->mode = p->mode ? p->mode : 0644;
stat_data->dbgfs_item = p;
kvm->debugfs_stat_data[p - debugfs_entries] = stat_data;
debugfs_create_file(p->name, stat_data->mode, kvm->debugfs_dentry,
stat_data, stat_fops_per_vm[p->kind]);
debugfs_create_file(p->name, KVM_DBGFS_GET_MODE(p),
kvm->debugfs_dentry, stat_data,
&stat_fops_per_vm);
}
return 0;
}
Expand Down Expand Up @@ -4010,8 +4010,9 @@ static int kvm_debugfs_open(struct inode *inode, struct file *file,
return -ENOENT;

if (simple_attr_open(inode, file, get,
stat_data->mode & S_IWUGO ? set : NULL,
fmt)) {
KVM_DBGFS_GET_MODE(stat_data->dbgfs_item) & 0222
? set : NULL,
fmt)) {
kvm_put_kvm(stat_data->kvm);
return -ENOMEM;
}
Expand All @@ -4030,105 +4031,111 @@ static int kvm_debugfs_release(struct inode *inode, struct file *file)
return 0;
}

static int vm_stat_get_per_vm(void *data, u64 *val)
static int kvm_get_stat_per_vm(struct kvm *kvm, size_t offset, u64 *val)
{
struct kvm_stat_data *stat_data = (struct kvm_stat_data *)data;
*val = *(ulong *)((void *)kvm + offset);

*val = *(ulong *)((void *)stat_data->kvm + stat_data->offset);
return 0;
}

static int kvm_clear_stat_per_vm(struct kvm *kvm, size_t offset)
{
*(ulong *)((void *)kvm + offset) = 0;

return 0;
}

static int vm_stat_clear_per_vm(void *data, u64 val)
static int kvm_get_stat_per_vcpu(struct kvm *kvm, size_t offset, u64 *val)
{
struct kvm_stat_data *stat_data = (struct kvm_stat_data *)data;
int i;
struct kvm_vcpu *vcpu;

if (val)
return -EINVAL;
*val = 0;

*(ulong *)((void *)stat_data->kvm + stat_data->offset) = 0;
kvm_for_each_vcpu(i, vcpu, kvm)
*val += *(u64 *)((void *)vcpu + offset);

return 0;
}

static int vm_stat_get_per_vm_open(struct inode *inode, struct file *file)
static int kvm_clear_stat_per_vcpu(struct kvm *kvm, size_t offset)
{
__simple_attr_check_format("%llu\n", 0ull);
return kvm_debugfs_open(inode, file, vm_stat_get_per_vm,
vm_stat_clear_per_vm, "%llu\n");
}
int i;
struct kvm_vcpu *vcpu;

static const struct file_operations vm_stat_get_per_vm_fops = {
.owner = THIS_MODULE,
.open = vm_stat_get_per_vm_open,
.release = kvm_debugfs_release,
.read = simple_attr_read,
.write = simple_attr_write,
.llseek = no_llseek,
};
kvm_for_each_vcpu(i, vcpu, kvm)
*(u64 *)((void *)vcpu + offset) = 0;

return 0;
}

static int vcpu_stat_get_per_vm(void *data, u64 *val)
static int kvm_stat_data_get(void *data, u64 *val)
{
int i;
int r = -EFAULT;
struct kvm_stat_data *stat_data = (struct kvm_stat_data *)data;
struct kvm_vcpu *vcpu;

*val = 0;

kvm_for_each_vcpu(i, vcpu, stat_data->kvm)
*val += *(u64 *)((void *)vcpu + stat_data->offset);
switch (stat_data->dbgfs_item->kind) {
case KVM_STAT_VM:
r = kvm_get_stat_per_vm(stat_data->kvm,
stat_data->dbgfs_item->offset, val);
break;
case KVM_STAT_VCPU:
r = kvm_get_stat_per_vcpu(stat_data->kvm,
stat_data->dbgfs_item->offset, val);
break;
}

return 0;
return r;
}

static int vcpu_stat_clear_per_vm(void *data, u64 val)
static int kvm_stat_data_clear(void *data, u64 val)
{
int i;
int r = -EFAULT;
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;
switch (stat_data->dbgfs_item->kind) {
case KVM_STAT_VM:
r = kvm_clear_stat_per_vm(stat_data->kvm,
stat_data->dbgfs_item->offset);
break;
case KVM_STAT_VCPU:
r = kvm_clear_stat_per_vcpu(stat_data->kvm,
stat_data->dbgfs_item->offset);
break;
}

return 0;
return r;
}

static int vcpu_stat_get_per_vm_open(struct inode *inode, struct file *file)
static int kvm_stat_data_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,
vcpu_stat_clear_per_vm, "%llu\n");
return kvm_debugfs_open(inode, file, kvm_stat_data_get,
kvm_stat_data_clear, "%llu\n");
}

static const struct file_operations vcpu_stat_get_per_vm_fops = {
.owner = THIS_MODULE,
.open = vcpu_stat_get_per_vm_open,
static const struct file_operations stat_fops_per_vm = {
.owner = THIS_MODULE,
.open = kvm_stat_data_open,
.release = kvm_debugfs_release,
.read = simple_attr_read,
.write = simple_attr_write,
.llseek = no_llseek,
};

static const struct file_operations *stat_fops_per_vm[] = {
[KVM_STAT_VCPU] = &vcpu_stat_get_per_vm_fops,
[KVM_STAT_VM] = &vm_stat_get_per_vm_fops,
.read = simple_attr_read,
.write = simple_attr_write,
.llseek = no_llseek,
};

static int vm_stat_get(void *_offset, u64 *val)
{
unsigned offset = (long)_offset;
struct kvm *kvm;
struct kvm_stat_data stat_tmp = {.offset = offset};
u64 tmp_val;

*val = 0;
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);
kvm_get_stat_per_vm(kvm, offset, &tmp_val);
*val += tmp_val;
}
mutex_unlock(&kvm_lock);
Expand All @@ -4139,15 +4146,13 @@ 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;

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);
kvm_clear_stat_per_vm(kvm, offset);
}
mutex_unlock(&kvm_lock);

Expand All @@ -4160,14 +4165,12 @@ static int vcpu_stat_get(void *_offset, u64 *val)
{
unsigned offset = (long)_offset;
struct kvm *kvm;
struct kvm_stat_data stat_tmp = {.offset = offset};
u64 tmp_val;

*val = 0;
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);
kvm_get_stat_per_vcpu(kvm, offset, &tmp_val);
*val += tmp_val;
}
mutex_unlock(&kvm_lock);
Expand All @@ -4178,15 +4181,13 @@ 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;

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);
kvm_clear_stat_per_vcpu(kvm, offset);
}
mutex_unlock(&kvm_lock);

Expand Down Expand Up @@ -4259,9 +4260,8 @@ static void kvm_init_debug(void)

kvm_debugfs_num_entries = 0;
for (p = debugfs_entries; p->name; ++p, kvm_debugfs_num_entries++) {
int mode = p->mode ? p->mode : 0644;
debugfs_create_file(p->name, mode, kvm_debugfs_dir,
(void *)(long)p->offset,
debugfs_create_file(p->name, KVM_DBGFS_GET_MODE(p),
kvm_debugfs_dir, (void *)(long)p->offset,
stat_fops[p->kind]);
}
}
Expand Down

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