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authorJing Zhang <jingzhangos@google.com>2021-06-18 22:27:05 +0000
committerPaolo Bonzini <pbonzini@redhat.com>2021-06-24 18:00:10 -0400
commitfcfe1baeddbf1c7c448b44c82586d0cbc8abc9f5 (patch)
tree1d7b6b70c649bbfbb2ada937a4dcec2b8558625c /virt
parentcb082bfab59a224a49ae803fed52cd03e8d6b5e0 (diff)
downloadlinux-fcfe1baeddbf1c7c448b44c82586d0cbc8abc9f5.tar.bz2
KVM: stats: Support binary stats retrieval for a VM
Add a VM ioctl to get a statistics file descriptor by which a read functionality is provided for userspace to read out VM stats header, descriptors and data. Define VM statistics descriptors and header for all architectures. Reviewed-by: David Matlack <dmatlack@google.com> Reviewed-by: Ricardo Koller <ricarkol@google.com> Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Reviewed-by: Fuad Tabba <tabba@google.com> Tested-by: Fuad Tabba <tabba@google.com> #arm64 Signed-off-by: Jing Zhang <jingzhangos@google.com> Message-Id: <20210618222709.1858088-4-jingzhangos@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'virt')
-rw-r--r--virt/kvm/kvm_main.c42
1 files changed, 42 insertions, 0 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index cec986487b30..33ec43a87d0f 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -4055,6 +4055,42 @@ static int kvm_vm_ioctl_enable_cap_generic(struct kvm *kvm,
}
}
+static ssize_t kvm_vm_stats_read(struct file *file, char __user *user_buffer,
+ size_t size, loff_t *offset)
+{
+ struct kvm *kvm = file->private_data;
+
+ return kvm_stats_read(kvm->stats_id, &kvm_vm_stats_header,
+ &kvm_vm_stats_desc[0], &kvm->stat,
+ sizeof(kvm->stat), user_buffer, size, offset);
+}
+
+static const struct file_operations kvm_vm_stats_fops = {
+ .read = kvm_vm_stats_read,
+ .llseek = noop_llseek,
+};
+
+static int kvm_vm_ioctl_get_stats_fd(struct kvm *kvm)
+{
+ int fd;
+ struct file *file;
+
+ fd = get_unused_fd_flags(O_CLOEXEC);
+ if (fd < 0)
+ return fd;
+
+ file = anon_inode_getfile("kvm-vm-stats",
+ &kvm_vm_stats_fops, kvm, O_RDONLY);
+ if (IS_ERR(file)) {
+ put_unused_fd(fd);
+ return PTR_ERR(file);
+ }
+ file->f_mode |= FMODE_PREAD;
+ fd_install(fd, file);
+
+ return fd;
+}
+
static long kvm_vm_ioctl(struct file *filp,
unsigned int ioctl, unsigned long arg)
{
@@ -4237,6 +4273,9 @@ static long kvm_vm_ioctl(struct file *filp,
case KVM_RESET_DIRTY_RINGS:
r = kvm_vm_ioctl_reset_dirty_pages(kvm);
break;
+ case KVM_GET_STATS_FD:
+ r = kvm_vm_ioctl_get_stats_fd(kvm);
+ break;
default:
r = kvm_arch_vm_ioctl(filp, ioctl, arg);
}
@@ -4316,6 +4355,9 @@ static int kvm_dev_ioctl_create_vm(unsigned long type)
if (r < 0)
goto put_kvm;
+ snprintf(kvm->stats_id, sizeof(kvm->stats_id),
+ "kvm-%d", task_pid_nr(current));
+
file = anon_inode_getfile("kvm-vm", &kvm_vm_fops, kvm, O_RDWR);
if (IS_ERR(file)) {
put_unused_fd(r);