port-arm/58194: Resurrect vmt(4) from bitrot

On this architecture vmt(4) used to search for a node "/hypervisor" in the
FDT and probed the VMware hypervisor call only when the node was
found. However, things appear to have changed and VMware no longer provides
the FDT node.

Since vmt(4) doesn't actually need to read anything from FDT, and the
hypervisor call logically resides in virtual CPUs themselves, it would be
better to attach it directly to cpu, just like how it's probed on x86.

fix llvm build

Process all queued messages without delay immediately. From OpenBSD.

Apply the remaining part of OpenBSD sys/dev/vmt.c rev. 1.22.

> The VM host might send multiple messages at once but vmt(4) only
> processed one of time per second. Change the code to process all
> queued messages without delay immediately. This fixes two things: a)
> the vmt time sensor is available on boot when ntpd -s is loaded and b)
> the random seeding on resume (OS_Resume message) is executed almost
> immediately and not delayed by about 20 seconds.

Apply OpenBSD sys/dev/pv/vmt.c rev. 1.4.

> Merge two return branches in vmt_tclo_tick(). No functional changes.

On error, give time to recover and wait a second.

Part of OpenBSD sys/dev/vmt.c rev. 1.22.

Use a table like OpenBSD vmt.c rev. 1.27. No functional change.

Add new vmt_tclo_rpc[] table and use it. In this change, all of
vmt_tclo_xxx()'s functionality are not changed from previous.

Now we can understand what's the difference between OpenBSD's
sys/dev/pv/vmt.c and NetBSD's sys/dev/vmt/vmt_subr.c.

Move a prototype definition. No functional change.

KNF. No functional change.

Removed little endian dependencies.
Now vmt(4) works on aarch64eb on vmware ESXIonARM.

branches: 1.2.2;
use aprint_verbose_dev()

branches: 1.1.2;
move vmt(4) from MD to MI, and add support vmt on aarch64. tested on ESXi-Arm Fling

- move from sys/arch/x86/x86/{vmt.c,vmtreg.h,vmtvar.h} to sys/dev/vmt/{vmt_subr.c,vmtreg.h,vmtvar.h},
and split the attach part of the cpufeaturebus and fdt
- add aarch64 vmware backdoor op
- add include guard to vmt{reg,var}.h
- Yet there is still some little-endian dependency. it needs to be fixed in order to work properly on aarch64eb

fix llvm build

Process all queued messages without delay immediately. From OpenBSD.

Apply the remaining part of OpenBSD sys/dev/vmt.c rev. 1.22.

> The VM host might send multiple messages at once but vmt(4) only
> processed one of time per second. Change the code to process all
> queued messages without delay immediately. This fixes two things: a)
> the vmt time sensor is available on boot when ntpd -s is loaded and b)
> the random seeding on resume (OS_Resume message) is executed almost
> immediately and not delayed by about 20 seconds.

Apply OpenBSD sys/dev/pv/vmt.c rev. 1.4.

> Merge two return branches in vmt_tclo_tick(). No functional changes.

On error, give time to recover and wait a second.

Part of OpenBSD sys/dev/vmt.c rev. 1.22.

Use a table like OpenBSD vmt.c rev. 1.27. No functional change.

Add new vmt_tclo_rpc[] table and use it. In this change, all of
vmt_tclo_xxx()'s functionality are not changed from previous.

Now we can understand what's the difference between OpenBSD's
sys/dev/pv/vmt.c and NetBSD's sys/dev/vmt/vmt_subr.c.

Move a prototype definition. No functional change.

KNF. No functional change.

Removed little endian dependencies.
Now vmt(4) works on aarch64eb on vmware ESXIonARM.

branches: 1.2.2;
use aprint_verbose_dev()

branches: 1.1.2;
move vmt(4) from MD to MI, and add support vmt on aarch64. tested on ESXi-Arm Fling

- move from sys/arch/x86/x86/{vmt.c,vmtreg.h,vmtvar.h} to sys/dev/vmt/{vmt_subr.c,vmtreg.h,vmtvar.h},
and split the attach part of the cpufeaturebus and fdt
- add aarch64 vmware backdoor op
- add include guard to vmt{reg,var}.h
- Yet there is still some little-endian dependency. it needs to be fixed in order to work properly on aarch64eb

Process all queued messages without delay immediately. From OpenBSD.

Apply the remaining part of OpenBSD sys/dev/vmt.c rev. 1.22.

> The VM host might send multiple messages at once but vmt(4) only
> processed one of time per second. Change the code to process all
> queued messages without delay immediately. This fixes two things: a)
> the vmt time sensor is available on boot when ntpd -s is loaded and b)
> the random seeding on resume (OS_Resume message) is executed almost
> immediately and not delayed by about 20 seconds.

Apply OpenBSD sys/dev/pv/vmt.c rev. 1.4.

> Merge two return branches in vmt_tclo_tick(). No functional changes.

On error, give time to recover and wait a second.

Part of OpenBSD sys/dev/vmt.c rev. 1.22.

Use a table like OpenBSD vmt.c rev. 1.27. No functional change.

Add new vmt_tclo_rpc[] table and use it. In this change, all of
vmt_tclo_xxx()'s functionality are not changed from previous.

Now we can understand what's the difference between OpenBSD's
sys/dev/pv/vmt.c and NetBSD's sys/dev/vmt/vmt_subr.c.

Move a prototype definition. No functional change.

KNF. No functional change.

Removed little endian dependencies.
Now vmt(4) works on aarch64eb on vmware ESXIonARM.

branches: 1.2.2;
use aprint_verbose_dev()

branches: 1.1.2;
move vmt(4) from MD to MI, and add support vmt on aarch64. tested on ESXi-Arm Fling

- move from sys/arch/x86/x86/{vmt.c,vmtreg.h,vmtvar.h} to sys/dev/vmt/{vmt_subr.c,vmtreg.h,vmtvar.h},
and split the attach part of the cpufeaturebus and fdt
- add aarch64 vmware backdoor op
- add include guard to vmt{reg,var}.h
- Yet there is still some little-endian dependency. it needs to be fixed in order to work properly on aarch64eb

Removed little endian dependencies.
Now vmt(4) works on aarch64eb on vmware ESXIonARM.

use aprint_verbose_dev()

branches: 1.1.2;
move vmt(4) from MD to MI, and add support vmt on aarch64. tested on ESXi-Arm Fling

- move from sys/arch/x86/x86/{vmt.c,vmtreg.h,vmtvar.h} to sys/dev/vmt/{vmt_subr.c,vmtreg.h,vmtvar.h},
and split the attach part of the cpufeaturebus and fdt
- add aarch64 vmware backdoor op
- add include guard to vmt{reg,var}.h
- Yet there is still some little-endian dependency. it needs to be fixed in order to work properly on aarch64eb

use aprint_verbose_dev()

move vmt(4) from MD to MI, and add support vmt on aarch64. tested on ESXi-Arm Fling

- move from sys/arch/x86/x86/{vmt.c,vmtreg.h,vmtvar.h} to sys/dev/vmt/{vmt_subr.c,vmtreg.h,vmtvar.h},
and split the attach part of the cpufeaturebus and fdt
- add aarch64 vmware backdoor op
- add include guard to vmt{reg,var}.h
- Yet there is still some little-endian dependency. it needs to be fixed in order to work properly on aarch64eb

move vmt(4) from MD to MI, and add support vmt on aarch64. tested on ESXi-Arm Fling

- move from sys/arch/x86/x86/{vmt.c,vmtreg.h,vmtvar.h} to sys/dev/vmt/{vmt_subr.c,vmtreg.h,vmtvar.h},
and split the attach part of the cpufeaturebus and fdt
- add aarch64 vmware backdoor op
- add include guard to vmt{reg,var}.h
- Yet there is still some little-endian dependency. it needs to be fixed in order to work properly on aarch64eb