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

Bugfixes for 5.0-rc2.

# gpg: Signature made Thu 02 Apr 2020 19:57:47 BST
# gpg:                using RSA key F13338574B662389866C7682BFFBD25F78C7AE83
# gpg:                issuer "pbonzini@redhat.com"
# gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>" [full]
# gpg:                 aka "Paolo Bonzini <pbonzini@redhat.com>" [full]
# 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:
  xen: fixup RAM memory region initialization
  object-add: don't create return value if failed
  qmp: fix leak on callbacks that return both value and error
  migration: fix cleanup_bh leak on resume
  target/i386: do not set unsupported VMX secondary execution controls
  serial: Fix double migration data
  i386: hvf: Reset IRQ inhibition after moving RIP
  vl: fix broken IPA range for ARM -M virt with KVM enabled
  util/bufferiszero: improve avx2 accelerator
  util/bufferiszero: assign length_to_accel value for each accelerator case
  MAINTAINERS: Add an entry for the HVF accelerator
  softmmu: fix crash with invalid -M memory-backend=
  virtio-iommu: depend on PCI
  hw/isa/superio: Correct the license text
  hw/scsi/vmw_pvscsi: Remove assertion for kick after reset

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