KVM_SYNC_GPRS, KVM_SYNC_ACRS, KVM_SYNC_CRS and KVM_SYNC_PREFIX are
available since kernel 3.10. Since we already require at least kernel
3.15 in the s390x KVM code, we can also assume that the KVM_CAP_SYNC_REGS
sync code is always possible for these registers, and remove the
related checks and fallbacks via KVM_SET_REGS and KVM_GET_REGS.

v2:
- Split the patch from v1 into two patches
- Use a #define KVM_SYNC_REQUIRED_BITS for the required sync bits
- Use memcpy() instead of for-loops for copying the registers

Thomas Huth (2):
  target/s390x/kvm: Turn KVM_CAP_SYNC_REGS into a hard requirement
  target/s390x/kvm: Simplify the GPRs, ACRs, CRs and prefix
    synchronization code

 target/s390x/kvm/kvm.c | 120 ++++++++++++-----------------------------
 1 file changed, 33 insertions(+), 87 deletions(-)

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2.41.0