KVM: x86: SMM support

Thanks to the thorough review, I'm removing the RFC tag.  The only
major remaining point of contention is the code duplication between
virt/kvm/kvm_main.c and arch/x86/kvm/smram.c.

As before, I have only tested these patches with Q35's high SMRAM
and with open SMRAM.  Still, the TODO list has gotten smaller.

I still haven't tried using #define for offsets.  The main obstacle
is doing math to compute offsets.

Reviewed-by tags for individual patches are appreciated (especially
patches 1 and 2 which I'd like to push separately).

Paolo

RFC->v1:
- two patches (Radim's kvm_write_guest_page optimization + my fix
  for CR4.SMEP=1/CR0.WP=0) have already graduated to kvm/next
- one new patch ("kvm: x86: introduce num_emulated_msrs")
- fix pasto in do_get_msr
- introduced kvm_set_hflags
- replaced printk with tracepoints
- added smi.pending and smi.rsm_unmasks_nmi fields to kvm_vcpu_events,
  to fix NMIs and add support for latching an SMI
- SMBASE is not guest-readable
- rebased on top of kvm/next so that SMBASE is not reset on INIT
- fix access rights (shift left by 8) in 32-bit SMM state save format
- disable if !unrestricted_guest && !emulate_invalid_guest_state

TODO:
- test on AMD
- test with true SMRAM support in QEMU (only affects patch 10)

Paolo Bonzini (12):
  KVM: export __gfn_to_pfn_memslot, drop gfn_to_pfn_async
  KVM: x86: introduce num_emulated_msrs
  KVM: remove unnecessary arg from mark_page_dirty_in_slot, export it
  KVM: x86: pass host_initiated to functions that read MSRs
  KVM: x86: pass the whole hflags field to emulator and back
  KVM: x86: API changes for SMM support
  KVM: x86: stubs for SMM support
  KVM: x86: save/load state on SMM switch
  KVM: x86: add vcpu-specific functions to read/write/translate GFNs
  KVM: x86: add SMM to the MMU role
  KVM: x86: add KVM_MEM_X86_SMRAM memory slot flag
  KVM: x86: advertise KVM_CAP_X86_SMM

 Documentation/virtual/kvm/api.txt  |  58 +++-
 arch/x86/include/asm/kvm_emulate.h |   9 +-
 arch/x86/include/asm/kvm_host.h    |  42 ++-
 arch/x86/include/asm/vmx.h         |   1 +
 arch/x86/include/uapi/asm/kvm.h    |  14 +-
 arch/x86/kvm/Makefile              |   2 +-
 arch/x86/kvm/cpuid.h               |   8 +
 arch/x86/kvm/emulate.c             | 262 +++++++++++++++++-
 arch/x86/kvm/kvm_cache_regs.h      |   5 +
 arch/x86/kvm/lapic.c               |  26 +-
 arch/x86/kvm/mmu.c                 |  20 +-
 arch/x86/kvm/paging_tmpl.h         |   8 +-
 arch/x86/kvm/smram.c               | 229 ++++++++++++++++
 arch/x86/kvm/svm.c                 |  69 +++--
 arch/x86/kvm/trace.h               |  22 ++
 arch/x86/kvm/vmx.c                 |  80 +++---
 arch/x86/kvm/x86.c                 | 543 +++++++++++++++++++++++++++++++------
 include/linux/kvm_host.h           |  20 +-
 include/uapi/linux/kvm.h           |   5 +-
 virt/kvm/kvm_main.c                |  44 ++-
 20 files changed, 1223 insertions(+), 244 deletions(-)
 create mode 100644 arch/x86/kvm/smram.c

-- 
1.8.3.1