On 2/26/25 11:46, Rik van Riel wrote: > On Wed, 2025-02-26 at 11:36 -0600, Tom Lendacky wrote: >> >> Right, but the ASID valid bit is not set, so the flushing may match >> more >> than just host/hypervisor TLB entries. >> > Good point, when using SVM these flushes could result > in flushing more TLB entries than we really want. > > On the flip side, when SVM is not initialized, the > invlpgb instruction will fail with a general protection > fault if we have anything at all in the ASID field. > > I don't know whether setting the ASID valid bit in > rAX will cause a system to crash when SVM is not > enabled or initialized. As long as you keep the ASID value in EDX[15:0] as 0, then you won't #GP. ASID 0 is the host/hypervisor. An ASID > 0 belongs to a guest. Thanks, Tom >
