KVM: x86: Fixes for debug registers, IA32_APIC_BASE, and nVMX

This is on top of next after merging in the two patches of mine that are only present in master ATM.

Highlights:
- reworked fix of DR6 reading on SVM
- full check for invalid writes to IA32_APIC_BASE
- fixed support for halting in L2 (nVMX)
- fully emulated preemption timer (nVMX)
- tracing of nested vmexits (nVMX)

The patch "KVM: nVMX: Leave VMX mode on clearing of feature control MSR" is included again, unchanged from previous posting.

Most fixes are backed by KVM unit tests, to be posted soon as well.

Jan Kiszka (12):
KVM: x86: Sync DR7 on KVM_SET_DEBUGREGS
KVM: SVM: Fix reading of DR6
KVM: VMX: Fix DR6 update on #DB exception
KVM: x86: Validate guest writes to MSR_IA32_APICBASE
KVM: nVMX: Leave VMX mode on clearing of feature control MSR
KVM: nVMX: Pass vmexit parameters to nested_vmx_vmexit
KVM: nVMX: Add tracepoints for nested_vmexit and nested_vmexit_inject
KVM: nVMX: Clean up handling of VMX-related MSRs
KVM: nVMX: Fix nested_run_pending on activity state HLT
KVM: nVMX: Update guest activity state field on L2 exits
KVM: nVMX: Rework interception of IRQs and NMIs
KVM: nVMX: Fully emulate preemption timer

 arch/x86/include/asm/kvm_host.h       |   4 +
 arch/x86/include/uapi/asm/msr-index.h |   1 +
 arch/x86/kvm/cpuid.h                  |   8 +
 arch/x86/kvm/lapic.h                  |   2 +-
 arch/x86/kvm/svm.c                    |  15 ++
 arch/x86/kvm/vmx.c                    | 399 ++++++++++++++++++++--------------
 arch/x86/kvm/x86.c                    |  67 +++++-
 7 files changed, 318 insertions(+), 178 deletions(-)

1.8.1.1.298.ge7eed54