On 19/03/2018 16:29, Tim Shearer wrote: > From: Tim Shearer <tshearer@xxxxxxxxxxxxxxx> > > This reverts commit 8eb73e2d410f00d383023fe41c0c25c6195b7389. This > reverts commit d59d51f088014f25c2562de59b9abff4f42a7468. > Reintroducing the I/O port 0x80 bypass, the removal of which incurred > a significant performance penalty for NFV guests due to excessive and > time-consuming VMEXITs. This obviously reintroduces the same issue noted in the second of these commits: "If the guest floods this port with writes it generates exceptions and instability in the host kernel, leading to a crash". So this patch is not acceptable. What is exactly the use case where a VM is doing a lot of 0x80 accesses at run-time? Paolo
