Messages in this thread | | | Date | Thu, 31 May 2012 08:39:15 +0100 | From | "Jan Beulich" <> | Subject | Re: [Xen-devel] [PATCH] x86/amd: fix crash as Xen Dom0 on AMD Trinity systems |
| |
>>> On 30.05.12 at 20:17, Borislav Petkov <bp@alien8.de> wrote: > On Wed, May 30, 2012 at 11:00:23AM -0700, H. Peter Anvin wrote: > The other place where we use the amd_safe variants is an obscure K8, > revC and earlier fix for _some_ BIOSen and this hasn't bitten us yet > so I'm assuming people haven't run xen on such boxes yet. Does it need > fixing? Probably, if we really really have to.
This again is something that shouldn't even be attempted under Xen. The hypervisor, unless really old, does this (and wouldn't allow the write by any domain - privileged or not - anyway).
There's one more user though - the code triggered by the "show_msr=" command line option. This one indeed requires rdmsr_safe_regs to be functional (albeit under Xen, once again, this won't work currently anyway for those MRS on old CPUs where the special key in %edi is required, which the emulation code in Xen doesn't support).
Jan
| |