On Tue, Dec 03, 2024 at 12:20:15PM +0100, Borislav Petkov wrote: > On Mon, Dec 02, 2024 at 03:35:21PM -0800, Pawan Gupta wrote: > > It is in this doc: > > > > https://www.intel.com/content/www/us/en/developer/articles/technical/software-security-guidance/technical-documentation/indirect-branch-restricted-speculation.html > > > > I hope those URLs remain more stable than past experience shows. > > > "Processors with enhanced IBRS still support the usage model where IBRS is > > set only in the OS/VMM for OSes that enable SMEP. To do this, such > > processors will ensure that guest behavior cannot control the RSB after a > > VM exit once IBRS is set, even if IBRS was not set at the time of the VM > > exit." > > ACK, thanks. > > Now, can we pls add those excerpts to Documentation/ and point to them from > the code so that it is crystal clear why it is ok? Ok, I'll try to write up a document. I'm thinking it should go in its own return-based-attacks.rst file rather than spectre.rst, which is more of an outdated historical document at this point. And we want this document to actually be read (and kept up to date) by developers instead of mostly ignored like the others. -- Josh
