On 06/02/2017 11:46, James Hogan wrote: > Documentation/virtual/kvm/api.txt seems to suggest that > KVM_EXIT_HYPERCALL is obsolete. When it suggests using KVM_EXIT_MMIO, > does it simply mean the guest should use MMIO to some virtio device of > some sort rather than using hypercalls, or that the hypercall should > somehow be munged into the mmio exit information? The former. But there are cases when using hypercalls is unavoidable. In that case the trend is to use other exit reasons than KVM_EXIT_HYPERCALL, such as KVM_EXIT_PAPR_HCALL in PowerPC. Feel free to add KVM_EXIT_MIPS_CONOUT or something like that. How would you find the character device to write to in QEMU? Paolo
