Nakajima, Jun wrote:
And actually you don't need the write to CR3 to flush TLB because the one to CR4 does it. Or does kvm_flush_tlb_kernel assume that CR3 is updated at the same time? Jun
It should not be necessary, but I believe this was added as a workaround to a PII erratum. I can't find the erratum, however, and the history of using G bits in Linux is complicated (several bugs introduced and many intermediate versions of this code). Since this is not performance critical, I think it is probably best to leave the CR3 reload.
However, being unnecessary on modern processors, I already submitted a patch to eliminate it on 64-bit (or maybe just told Andi about it, I can't recall).
Zach _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/virtualization
