KVM: MIPS: GVA/GPA page tables, dirty logging, SYNC_MMU etc
Numerous MIPS KVM fixes, improvements, and features for 4.11, many of
which continue to pave the way for VZ support, the most interesting of
which are:
- Add GVA->HPA page tables for T&E, to cache GVA mappings.
- Generate fast-path TLB refill exception handler which loads host TLB
entries from GVA page table, avoiding repeated guest memory
translation and guest TLB lookups.
- Use uaccess macros when T&E needs to access guest memory, which with
GVA page tables and the Linux TLB refill handler improves robustness
against TLB faults and fixes EVA hosts.
- Use BadInstr/BadInstrP registers when available to obtain instruction
encodings after a synchronous trap.
- Add GPA->HPA page tables to replace the inflexible linear array,
allowing for multiple sparsely arranged memory regions.
- Properly implement dirty page logging.
- Add KVM_CAP_SYNC_MMU support so that changes in GPA mappings become
effective in guests even if they are already running, allowing for
copy-on-write, KSM, idle page tracking, swapping, and guest memory
ballooning.
- Add KVM_CAP_READONLY_MEM support, so writes to specified memory
regions are treated as MMIO.
- Implement proper CP0_EBase support in T&E.
- Expose a few more missing CP0 registers to userland.
- Add KVM_CAP_NR_VCPUS and KVM_CAP_MAX_VCPUS support, and allow up to 8
VCPUs to be created in a VM.
- Various cleanups and dropping of dead and duplicated code.