Messages in this thread | | | From | Tony Luck <> | Date | Wed, 9 Jan 2019 10:41:47 -0800 | Subject | Re: [PATCH] x86/intel_rdt: use rdmsr_safe() to workaround AWS host issue |
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On Wed, Jan 9, 2019 at 5:00 AM Borislav Petkov <bp@alien8.de> wrote: > > On Wed, Jan 09, 2019 at 01:09:31PM +0100, Vitaly Kuznetsov wrote: > > Hm, why is that? In theory, hypervisors can pass through or emulate the > > required MSRs... > > ...and when the theory becomes reality we'll remove the check.
In practice that may be a long time coming. We don't have many CLOSIDs, or bits in a cache mask, at the h/w level. If you start trying to subdivide those resources to pass a subset to a guest, then you'll quickly find that you have no flexibility in the guest to do anything useful. It would only work if you limited to two, or perhaps three guests.
-Tony
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