KVM: Get an fd before creating the VM

Allocate a VM's fd at the very beginning of kvm_dev_ioctl_create_vm() so
that KVM can use the fd value to generate strigns, e.g. for debugfs,
when creating and initializing the VM.

Signed-off-by: Oliver Upton <oupton@google.com>
Message-Id: <20220720092259.3491733-4-oliver.upton@linux.dev>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Oliver Upton 2022-07-20 09:22:49 +00:00 committed by Paolo Bonzini
parent 58fc116645
commit 20020f4cf2

View file

@ -4889,25 +4889,27 @@ EXPORT_SYMBOL_GPL(file_is_kvm);
static int kvm_dev_ioctl_create_vm(unsigned long type)
{
int r;
int r, fd;
struct kvm *kvm;
struct file *file;
fd = get_unused_fd_flags(O_CLOEXEC);
if (fd < 0)
return fd;
kvm = kvm_create_vm(type);
if (IS_ERR(kvm))
return PTR_ERR(kvm);
if (IS_ERR(kvm)) {
r = PTR_ERR(kvm);
goto put_fd;
}
#ifdef CONFIG_KVM_MMIO
r = kvm_coalesced_mmio_init(kvm);
if (r < 0)
goto put_kvm;
#endif
r = get_unused_fd_flags(O_CLOEXEC);
if (r < 0)
goto put_kvm;
file = anon_inode_getfile("kvm-vm", &kvm_vm_fops, kvm, O_RDWR);
if (IS_ERR(file)) {
put_unused_fd(r);
r = PTR_ERR(file);
goto put_kvm;
}
@ -4918,18 +4920,20 @@ static int kvm_dev_ioctl_create_vm(unsigned long type)
* cases it will be called by the final fput(file) and will take
* care of doing kvm_put_kvm(kvm).
*/
if (kvm_create_vm_debugfs(kvm, r) < 0) {
put_unused_fd(r);
if (kvm_create_vm_debugfs(kvm, fd) < 0) {
fput(file);
return -ENOMEM;
r = -ENOMEM;
goto put_fd;
}
kvm_uevent_notify_change(KVM_EVENT_CREATE_VM, kvm);
fd_install(r, file);
return r;
fd_install(fd, file);
return fd;
put_kvm:
kvm_put_kvm(kvm);
put_fd:
put_unused_fd(fd);
return r;
}