From 20020f4cf2f92115c34b7bbaea02fcc810709a7e Mon Sep 17 00:00:00 2001 From: Oliver Upton Date: Wed, 20 Jul 2022 09:22:49 +0000 Subject: [PATCH] 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 Message-Id: <20220720092259.3491733-4-oliver.upton@linux.dev> Signed-off-by: Paolo Bonzini --- virt/kvm/kvm_main.c | 30 +++++++++++++++++------------- 1 file changed, 17 insertions(+), 13 deletions(-) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index f601428e0cc8..eeb084a9cb70 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -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; }