On Fri, Dec 18, 2015 at 06:19:25PM +0300, Pavel Fedin wrote: > I dislike implementing architecture-dependent exit code where we could implement an architecture-independent one. > > As far as i understand this code, KVM_EXIT_HYPERV is called when one of three MSRs are accessed. But, shouldn't we have implemented > instead something more generic, like KVM_EXIT_REG_IO, which would work similar to KVM_EXIT_PIO or KVM_EXIT_MMIO, but carry register > code and value? > > This would allow us to solve the same task which we have done here, but this solution would be reusable for other devices and other > archirectures. What if in future we have more system registers to emulate in userspace? > > I write this because at one point i suggested similar thing for ARM64 (but i never actually wrote it), to emulate physical CP15 > timer. And it would require exactly the same capability - process some trapped system register accesses in userspace. Note that, as Paolo pointed out, in case of HyperV the value of the register is of interest not only to the userspace but to the KVM, too. Otherwise I don't see off hand why a generic infrastructure wouldn't fit in our usecase. Roman. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
