On 20/07/18 10:58, Olaf Hering wrote: > Am Fri, 20 Jul 2018 10:38:30 +0100 > schrieb Andrew Cooper <andrew.coop...@citrix.com>: > >> On 20/07/18 10:21, Olaf Hering wrote: >>> Is the loss of cpuflags intentional? >> Yes, but they've got nothing to do with Spectre. > Thank you, Andrew. After a few more reboots I figured that booting without > any cmdline option makes no difference. > > From the original report that I got, these additional flags disappeared: > > cqm_llc > cqm_occup_llc > pln > pts > > I assume a domU can not make use of them either? They are not listed in CPUID > in wikipedia, perhaps just not with those names.
CQM is the quality-of-service measurement infrastructure on newer Intel hardware. They are behind the `psr` command line option, and can be used with `xl psr-*` but only by the privileged domain, as they monitor system-wide shared resources. PLN is Power Limit Notification (apparently) which surely means that to be used, we'd need a Xen driver. PTS is Package Thermal Status and is presumably the same. Neither are things which even dom0 could use. Having looked over the code, we actually hide all of the Thermal leaf even from dom0. It was the monitor leaf we conditionally leak back in. For the gory details, read xen/arch/x86/cpuid.c:guest_cpuid() ~Andrew _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
