Merge tag 'kvm-x86-apic-6.20' of https://github.com/kvm-x86/linux into HEAD

Merge tag 'kvm-x86-apic-6.20' of https://github.com/kvm-x86/linux into HEAD

KVM x86 APIC-ish changes for 6.20

 - Fix a benign bug where KVM could use the wrong memslots (ignored SMM) when
   creating a vCPU-specific mapping of guest memory.

 - Clean up KVM's handling of marking mapped vCPU pages dirty.

 - Drop a pile of *ancient* sanity checks hidden behind in KVM's unused
   ASSERT() macro, most of which could be trivially triggered by the guest
   and/or user, and all of which were useless.

 - Fold "struct dest_map" into its sole user, "struct rtc_status", to make it
   more obvious what the weird parameter is used for, and to allow burying the
   RTC shenanigans behind CONFIG_KVM_IOAPIC=y.

 - Bury all of ioapic.h and KVM_IRQCHIP_KERNEL behind CONFIG_KVM_IOAPIC=y.

 - Add a regression test for recent APICv update fixes.

 - Rework KVM's handling of VMCS updates while L2 is active to temporarily
   switch to vmcs01 instead of deferring the update until the next nested
   VM-Exit.  The deferred updates approach directly contributed to several
   bugs, was proving to be a maintenance burden due to the difficulty in
   auditing the correctness of deferred updates, and was polluting
   "struct nested_vmx" with a growing pile of booleans.

 - Handle "hardware APIC ISR", a.k.a. SVI, updates in kvm_apic_update_apicv()
   to consolidate the updates, and to co-locate SVI updates with the updates
   for KVM's own cache of ISR information.

 - Drop a dead function declaration.