On Sat, 2022-10-29 at 23:22 -0700, isaku.yamahata@xxxxxxxxx wrote: > From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx> > > TDX private host key id is assigned to guest TD. The memory controller > encrypts guest TD memory with the assigned TDX private host key id (HIKD). ^ HKID. And since you already mentioned in the first sentence, you can put (HKID) part there. And I think you can just use HKID in the rest places to save some typing as this is the purpose of using (HKID) I suppose. [...] > > +/* TDX KeyID pool */ > +static DEFINE_IDA(tdx_keyid_pool); > + > +int tdx_keyid_alloc(void) > +{ > + if (WARN_ON_ONCE(!tdx_keyid_start || !tdx_keyid_num)) > + return -EINVAL; > + > + /* The first keyID is reserved for the global key. */ > + return ida_alloc_range(&tdx_keyid_pool, tdx_keyid_start + 1, > + tdx_keyid_start + tdx_keyid_num - 1, > + GFP_KERNEL); > +} > +EXPORT_SYMBOL_GPL(tdx_keyid_alloc); > + > +void tdx_keyid_free(int keyid) > +{ > + /* keyid = 0 is reserved. */ > + if (!keyid || keyid <= 0) > + return; Double check of keyid == 0. I think you can just use: if (keyid <= tdx_keyid_start) return; And/or add a WARN() as it's a bug if above happens. > + > + ida_free(&tdx_keyid_pool, keyid); > +} > +EXPORT_SYMBOL_GPL(tdx_keyid_free); > + > static void __init tdx_memory_destroy(void) > { > while (!list_empty(&tdx_memlist)) {