From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Kirill A. Shutemov" Date: Fri, 07 Dec 2018 11:47:09 +0000 Subject: Re: [RFC v2 12/13] keys/mktme: Save MKTME data if kernel cmdline parameter allows Message-Id: <20181207114709.kmrbghihyrht2l65@kshutemo-mobl1> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit List-Id: References: <1544148839.28511.28.camel@intel.com> In-Reply-To: <1544148839.28511.28.camel@intel.com> To: "Huang, Kai" Cc: "tglx@linutronix.de" , "Schofield, Alison" , "dhowells@redhat.com" , "kirill.shutemov@linux.intel.com" , "peterz@infradead.org" , "jmorris@namei.org" , "keyrings@vger.kernel.org" , "linux-mm@kvack.org" , "linux-security-module@vger.kernel.org" , "Williams, Dan J" , "x86@kernel.org" , "hpa@zytor.com" , "mingo@redhat.com" , "luto@kernel.org" , "Sakkinen, Jarkko" , "bp@alien8.de" , "Hansen, Dave" , "Nakajima, Jun" On Fri, Dec 07, 2018 at 02:14:03AM +0000, Huang, Kai wrote: > Alternatively, we can choose to use per-socket keyID, but not to program > keyID globally across all sockets, so you don't have to save key while > still supporting CPU hotplug. Per-socket KeyID approach would make things more complex. For instance KeyID on its own will not be enough to refer a key. You will need a node too. It will also require a way to track whether theirs an KeyID on other node for the key. It also makes memory management less flexible: runtime migration of the memory between nodes will be limited and it can hurt memory availablity for non-encrypted tasks too. In general, I don't see per-socket KeyID handling very attractive. It creates more problems than solves. -- Kirill A. Shutemov