KVM: Create debugfs dir and stat files for each VM

This patch adds a kvm debugfs subdirectory for each VM, which is named
after its pid and file descriptor. The directories contain the same
kind of files that are already in the kvm debugfs directory, but the
data exported through them is now VM specific.

This makes the debugfs kvm data a convenient alternative to the
tracepoints which already have per VM data. The debugfs data is easy
to read and low overhead.

CC: Dan Carpenter <dan.carpenter@oracle.com> [includes fixes by Dan Carpenter]
Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index b1fa8f1..1c9c973 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -412,6 +412,8 @@ struct kvm {
 #endif
 	long tlbs_dirty;
 	struct list_head devices;
+	struct dentry *debugfs_dentry;
+	struct kvm_stat_data **debugfs_stat_data;
 };
 
 #define kvm_err(fmt, ...) \
@@ -991,6 +993,11 @@ enum kvm_stat_kind {
 	KVM_STAT_VCPU,
 };
 
+struct kvm_stat_data {
+	int offset;
+	struct kvm *kvm;
+};
+
 struct kvm_stats_debugfs_item {
 	const char *name;
 	int offset;