Merge remote-tracking branch 'remotes/bonzini/tags/for-upstream-sev' into staging

Merge remote-tracking branch 'remotes/bonzini/tags/for-upstream-sev' into staging

* Migrate MSR_SMI_COUNT (Liran)
* Update kernel headers (Gerd, myself)
* SEV support (Brijesh)

I have not tested non-x86 compilation, but I reordered the SEV patches
so that all non-x86-specific changes go first to catch any possible
issues (which weren't there anyway :)).

# gpg: Signature made Tue 13 Mar 2018 16:37:06 GMT
# gpg:                using RSA key BFFBD25F78C7AE83
# gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>"
# gpg:                 aka "Paolo Bonzini <pbonzini@redhat.com>"
# Primary key fingerprint: 46F5 9FBD 57D6 12E7 BFD4  E2F7 7E15 100C CD36 69B1
#      Subkey fingerprint: F133 3857 4B66 2389 866C  7682 BFFB D25F 78C7 AE83

* remotes/bonzini/tags/for-upstream-sev: (22 commits)
  sev/i386: add sev_get_capabilities()
  sev/i386: qmp: add query-sev-capabilities command
  sev/i386: qmp: add query-sev-launch-measure command
  sev/i386: hmp: add 'info sev' command
  cpu/i386: populate CPUID 0x8000_001F when SEV is active
  sev/i386: add migration blocker
  sev/i386: finalize the SEV guest launch flow
  sev/i386: add support to LAUNCH_MEASURE command
  target/i386: encrypt bios rom
  sev/i386: add command to encrypt guest memory region
  sev/i386: add command to create launch memory encryption context
  sev/i386: register the guest memory range which may contain encrypted data
  sev/i386: add command to initialize the memory encryption context
  include: add psp-sev.h header file
  sev/i386: qmp: add query-sev command
  target/i386: add Secure Encrypted Virtualization (SEV) object
  kvm: introduce memory encryption APIs
  kvm: add memory encryption context
  docs: add AMD Secure Encrypted Virtualization (SEV)
  machine: add memory-encryption option
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>