On Mon, 10 Jul 2017 11:40:55 +0200
David Hildenbrand <david@xxxxxxxxxx> wrote:
> On 10.07.2017 11:20, Claudio Imbrenda wrote:
>
> Minor minor nit:
>
> The subject should state "creating or destroying a VM"
I'll fix it
[...]
> > +static void kvm_uevent_notify_change(unsigned int type, struct kvm
> > *kvm) +{
> > + char cbuf[32], abuf[32], pidbuf[32], evbuf[16];
>
> do we really need that much space for a pid?
unfortunately yes. we don't have access to the pid when destroying the
VM, so I take it from the debugfs entry, and that has the format
"%d-%d", with pid and file descriptor, both can be 10 bytes long.
> > + const char pathvar[11] = "STATS_PATH=";
> > + char *ptr[6] = {cbuf, abuf, pidbuf, NULL, NULL, NULL};
> > + char *tmp, *pathbuf;
> > + unsigned long long created, active;
> > + int idx = 3;
> > +
> > + if (!kvm_dev.this_device || !kvm || !kvm->debugfs_dentry)
> > + return;
> > +
> > + spin_lock(&kvm_lock);
> > + if (type == KVM_EVENT_CREATE_VM) {
> > + kvm_createvm_count++;
> > + kvm_active_vms++;
> > + } else if (type == KVM_EVENT_DESTROY_VM) {
> > + kvm_active_vms--;
> > + }
> > + created = kvm_createvm_count;
> > + active = kvm_active_vms;
> > + spin_unlock(&kvm_lock);
> > +
> > + pathbuf = kmalloc(PATH_MAX, GFP_KERNEL);
> > + if (pathbuf) {
> > + tmp = dentry_path_raw(kvm->debugfs_dentry,
> > + pathbuf + sizeof(pathvar),
> > + PATH_MAX - sizeof(pathvar));
> > + if (!IS_ERR(tmp)) {
> > + memcpy(tmp - sizeof(pathvar), pathvar,
> > sizeof(pathvar));
> > + ptr[idx++] = tmp - sizeof(pathvar);
> > + }
> > + }
> > + snprintf(cbuf, sizeof(cbuf), "CREATED=%llu", created);
>
> Did you think about using struct kobj_uevent_env / add_uevent_var()?
for what I could see, that only works with a more invasive patch. I'll
see what I can do.
> But most probably the problem here is special handling for
> dentry_path_raw().
