On Mon, Jun 04, 2018 at 09:54:40AM +0100, Daniel P. Berrangé wrote: > On Fri, Jun 01, 2018 at 11:38:08AM -0400, Konrad Rzeszutek Wilk wrote: > > AMD future CPUs expose _two_ ways to utilize the Intel equivalant > > of the Speculative Store Bypass Disable. The first is via > > the virtualized VIRT_SPEC CTRL MSR (0xC001_011f) and the second > > is via the SPEC_CTRL MSR (0x48). The document titled: > > 124441_AMD64_SpeculativeStoreBypassDisable_Whitepaper_final.pdf > > > > gives priority of SPEC CTRL MSR over the VIRT SPEC CTRL MSR. > > > > A copy of this document is available at > > https://bugzilla.kernel.org/show_bug.cgi?id=199889 > > > > Anyhow, this means that on future AMD CPUs there will be _two_ ways to > > deal with SSBD. > > Oh what fun ;-) > > Unless I'm mistaken the current Linux kernel doesn't know about these > new amd-ssbd / amd-no-ssb flags either. Will you also be sending patches > for that half of the problem ? I sent them as well. But forgot to CC qemu-devel :-(
