KVM: Add internal filesystem for generating inodes
The kvmfs inodes will represent virtual machines and vcpus, as necessary,
reducing cacheline bouncing due to inodes and filps being shared.
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index 0df0eeb..c01252e 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -36,6 +36,8 @@
#include <asm/desc.h>
#include <linux/sysdev.h>
#include <linux/cpu.h>
+#include <linux/fs.h>
+#include <linux/mount.h>
#include "x86_emulate.h"
#include "segment_descriptor.h"
@@ -72,6 +74,9 @@
static struct dentry *debugfs_dir;
+#define KVMFS_MAGIC 0x19700426
+struct vfsmount *kvmfs_mnt;
+
#define MAX_IO_MSRS 256
#define CR0_RESEVED_BITS 0xffffffff1ffaffc0ULL
@@ -2252,6 +2257,18 @@
hpa_t bad_page_address;
+static int kvmfs_get_sb(struct file_system_type *fs_type, int flags,
+ const char *dev_name, void *data, struct vfsmount *mnt)
+{
+ return get_sb_pseudo(fs_type, "kvm:", NULL, KVMFS_MAGIC, mnt);
+}
+
+static struct file_system_type kvm_fs_type = {
+ .name = "kvmfs",
+ .get_sb = kvmfs_get_sb,
+ .kill_sb = kill_anon_super,
+};
+
int kvm_init_arch(struct kvm_arch_ops *ops, struct module *module)
{
int r;
@@ -2328,8 +2345,16 @@
static __init int kvm_init(void)
{
static struct page *bad_page;
- int r = 0;
+ int r;
+ r = register_filesystem(&kvm_fs_type);
+ if (r)
+ goto out3;
+
+ kvmfs_mnt = kern_mount(&kvm_fs_type);
+ r = PTR_ERR(kvmfs_mnt);
+ if (IS_ERR(kvmfs_mnt))
+ goto out2;
kvm_init_debug();
kvm_init_msr_list();
@@ -2346,6 +2371,10 @@
out:
kvm_exit_debug();
+ mntput(kvmfs_mnt);
+out2:
+ unregister_filesystem(&kvm_fs_type);
+out3:
return r;
}
@@ -2353,6 +2382,8 @@
{
kvm_exit_debug();
__free_page(pfn_to_page(bad_page_address >> PAGE_SHIFT));
+ mntput(kvmfs_mnt);
+ unregister_filesystem(&kvm_fs_type);
}
module_init(kvm_init)