MFC: r346714: Add accessor function for vm->maxcpus

Replace most VM_MAXCPU constant useses with an accessor function to
vm->maxcpus which for now is initialized and kept at the value of
VM_MAXCPUS.

This is a rework of Fabian Freyer (fabian.freyer_physik.tu-berlin.de)
work from D10070 to adjust it for the cpu topology changes that
occured in r332298

Approved by: re (kib)

Revert r330897:

This was intended to be a non-functional change. It wasn't. The commit
message was thus wrong. In addition it broke arm, and merged crypto
related code.

Revert with prejudice.

This revert skips files touched in r316370 since that commit was since
MFCed. This revert also skips files that require $FreeBSD$ property
changes.

Thank you to those who helped me get out of this mess including but not
limited to gonzo, kevans, rgrimes.

Requested by: gjb (re)

Partial merge of the SPDX changes

These changes are incomplete but are making it difficult
to determine what other changes can/should be merged.

No objections from: pfg

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

vmm(4): Small spelling fixes.

Reviewed by: grehan

Fix non-deterministic delays when accessing a vcpu that was in "running" or
"sleeping" state. This is done by forcing the vcpu to transition to "idle"
by returning to userspace with an exit code of VM_EXITCODE_REQIDLE.

MFC after: 2 weeks

Don't require <sys/cpuset.h> to be always included before <machine/vmm.h>.

Only a subset of source files that include <machine/vmm.h> need to use the
APIs that require the inclusion of <sys/cpuset.h>.

MFC after: 1 week

Expose the amount of resident and wired memory from the guest's vmspace.

This is different than the amount shown for the process e.g. by
/usr/bin/top - that is the mappings faulted in by the mmap'd region
of guest memory.

The values can be fetched with bhyvectl

# bhyvectl --get-stats --vm=myvm
...
Resident memory 413749248
Wired memory 0
...

vmm_stat.[ch] -
Modify the counter code in bhyve to allow direct setting of a counter
as opposed to incrementing, and providing a callback to fetch a
counter's value.

Reviewed by: neel

Add ioctl(VM_REINIT) to reinitialize the virtual machine state maintained
by vmm.ko. This allows the virtual machine to be restarted without having
to destroy it first.

Reviewed by: grehan

Add a counter to differentiate between VM-exits due to nested paging faults
and instruction emulation faults.

Handle a VM-exit due to a NMI properly by vectoring to the host's NMI handler
via a software interrupt.

This is safe to do because the logical processor is already cognizant of the
NMI and further NMIs are blocked until the host's NMI handler executes "iret".

Add an API to rendezvous all active vcpus in a virtual machine. The rendezvous
can be initiated in the context of a vcpu thread or from the bhyve(8) control
process.

The first use of this functionality is to update the vlapic trigger-mode
register when the IOAPIC pin configuration is changed.

Prior to this change we would update the TMR in the virtual-APIC page at
the time of interrupt delivery. But this doesn't work with Posted Interrupts
because there is no way to program the EOI_exit_bitmap[] in the VMCS of
the target at the time of interrupt delivery.

Discussed with: grehan@

Support array-type of stats in bhyve.

An array-type stat in vmm.ko is defined as follows:
VMM_STAT_ARRAY(IPIS_SENT, VM_MAXCPU, "ipis sent to vcpu");

It is incremented as follows:
vmm_stat_array_incr(vm, vcpuid, IPIS_SENT, array_index, 1);

And output of 'bhyvectl --get-stats' looks like:
ipis sent to vcpu[0] 3114
ipis sent to vcpu[1] 0

Reviewed by: grehan
Obtained from: NetApp

Add some more stats to keep track of all the reasons that a vcpu is exiting.

Allow vmm stats to be specific to the underlying hardware assist technology.
This can be done by using the new macros VMM_STAT_INTEL() and VMM_STAT_AMD().
Statistic counters that are common across the two are defined using VMM_STAT().

Suggested by: Anish Gupta
Discussed with: grehan
Obtained from: NetApp

Add svn properties to the recently merged bhyve source files.

The pre-commit hook will not allow any commits without the svn:keywords
property in head.

Merge projects/bhyve to head.

'bhyve' was developed by grehan@ and myself at NetApp (thanks!).

Special thanks to Peter Snyder, Joe Caradonna and Michael Dexter for their
support and encouragement.

Obtained from: NetApp

IFC @ r222830

First cut at porting the kernel portions of 221828 and 221905 from the
BHyVe reference branch to HEAD.

Import of bhyve hypervisor and utilities, part 1.
vmm.ko - kernel module for VT-x, VT-d and hypervisor control
bhyve - user-space sequencer and i/o emulation
vmmctl - dump of hypervisor register state
libvmm - front-end to vmm.ko chardev interface

bhyve was designed and implemented by Neel Natu.

Thanks to the following folk from NetApp who helped to make this available:
Joe CaraDonna
Peter Snyder
Jeff Heller
Sandeep Mann
Steve Miller
Brian Pawlowski