On Mon, Jun 10, 2024 at 11:53 PM Sean Christopherson <seanjc@xxxxxxxxxx> wrote:
>
> On Mon, Jun 10, 2024, Alexey Dobriyan wrote:
> > Some allocations done by KVM are temporary, they are created as result
> > of program actions, but can't exists for arbitrary long times.
> >
> > They should have been GFP_TEMPORARY (rip!).
>
> Wouldn't GFP_USER be more appropriate for all of these? E.g. KVM_SET_REGS uses
> memdup_user() and thus GFP_USER.
The only difference between GFP_KERNEL and GFP_USER (worst name
ever...) is that the latter strictly respects the cpuset policy, see
cpuset_node_allowed(). It's not needed for allocations such as these
ones, which are bounded in both size and lifetime.
Paolo
>
> > OTOH, kvm-nx-lpage-recovery and kvm-pit kernel threads exist for as long
> > as VM exists but their task_struct memory is not accounted.
> > This is story for another day.
> >
> > Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx>
> > ---
> >
> > virt/kvm/kvm_main.c | 11 +++++------
> > 1 file changed, 5 insertions(+), 6 deletions(-)
> >
> > --- a/virt/kvm/kvm_main.c
> > +++ b/virt/kvm/kvm_main.c
> > @@ -4427,7 +4427,7 @@ static long kvm_vcpu_ioctl(struct file *filp,
> > struct kvm_regs *kvm_regs;
> >
> > r = -ENOMEM;
> > - kvm_regs = kzalloc(sizeof(struct kvm_regs), GFP_KERNEL_ACCOUNT);
> > + kvm_regs = kzalloc(sizeof(struct kvm_regs), GFP_KERNEL);
> > if (!kvm_regs)
> > goto out;
> > r = kvm_arch_vcpu_ioctl_get_regs(vcpu, kvm_regs);
> > @@ -4454,8 +4454,7 @@ static long kvm_vcpu_ioctl(struct file *filp,
> > break;
> > }
> > case KVM_GET_SREGS: {
> > - kvm_sregs = kzalloc(sizeof(struct kvm_sregs),
> > - GFP_KERNEL_ACCOUNT);
> > + kvm_sregs = kzalloc(sizeof(struct kvm_sregs), GFP_KERNEL);
> > r = -ENOMEM;
> > if (!kvm_sregs)
> > goto out;
> > @@ -4547,7 +4546,7 @@ static long kvm_vcpu_ioctl(struct file *filp,
> > break;
> > }
> > case KVM_GET_FPU: {
> > - fpu = kzalloc(sizeof(struct kvm_fpu), GFP_KERNEL_ACCOUNT);
> > + fpu = kzalloc(sizeof(struct kvm_fpu), GFP_KERNEL);
> > r = -ENOMEM;
> > if (!fpu)
> > goto out;
> > @@ -6210,7 +6209,7 @@ static void kvm_uevent_notify_change(unsigned int type, struct kvm *kvm)
> > active = kvm_active_vms;
> > mutex_unlock(&kvm_lock);
> >
> > - env = kzalloc(sizeof(*env), GFP_KERNEL_ACCOUNT);
> > + env = kzalloc(sizeof(*env), GFP_KERNEL);
> > if (!env)
> > return;
> >
> > @@ -6226,7 +6225,7 @@ static void kvm_uevent_notify_change(unsigned int type, struct kvm *kvm)
> > add_uevent_var(env, "PID=%d", kvm->userspace_pid);
> >
> > if (!IS_ERR(kvm->debugfs_dentry)) {
> > - char *tmp, *p = kmalloc(PATH_MAX, GFP_KERNEL_ACCOUNT);
> > + char *tmp, *p = kmalloc(PATH_MAX, GFP_KERNEL);
> >
> > if (p) {
> > tmp = dentry_path_raw(kvm->debugfs_dentry, p, PATH_MAX);
>
