Re: [Xen-devel] [PATCH 8/9] x86/CPUID: drop INVPCID dependency on PCID

2019-09-12 Thread Roger Pau Monné
On Wed, Sep 11, 2019 at 05:26:12PM +0200, Jan Beulich wrote: > PCID validly depends on LM, as it can be enabled in Long Mode only. > INVPCID, otoh, can be used not only without PCID enabled, but also > outside of Long Mode altogether. In both cases its functionality is > simply restricted to PCID 0

[Xen-devel] [PATCH 8/9] x86/CPUID: drop INVPCID dependency on PCID

2019-09-11 Thread Jan Beulich
PCID validly depends on LM, as it can be enabled in Long Mode only. INVPCID, otoh, can be used not only without PCID enabled, but also outside of Long Mode altogether. In both cases its functionality is simply restricted to PCID 0, which is sort of expected as no other PCID can be activated there.

[Xen-devel] [PATCH 8/9] x86/CPUID: drop INVPCID dependency on PCID

2019-05-02 Thread Jan Beulich
PCID validly depends on LM, as it can be enabled in Long Mode only. INVPCID, otoh, can be used not only without PCID enabled, but also outside of Long Mode altogether. In both cases its functionality is simply restricted to PCID 0, which is sort of expected as no other PCID can be activated there.