Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

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

MFC r266933
Activate vcpus from bhyve(8) using the ioctl VM_ACTIVATE_CPU instead of doing
it implicitly in vmm.ko.

MFC 266125:
Implement a PCI interrupt router to route PCI legacy INTx interrupts to
the legacy 8259A PICs.

MFC 262884,263236,265407:
Various uart fixes:
- Open the uart emulation's backing tty in non-blocking mode.
- Support 16-bit register access.
- Disable the 'uart_drain()' callback when the emulated receive FIFO
is full.

MFC 259942,262274,263035,263054,263211,263744,264179,264324,264468,264631,
264648,264650,264651,266572,267558:
Flesh out the AT PIC and 8254 PIT emulations and move them into the kernel.

MFC 261904,261905,262143,262184,264921,265211,267169,267292,267294:
Various PCI fixes:
- Allow PCI devices to be configured on all valid bus numbers from 0 to 255.
- Tweak the handling of PCI capabilities in emulated devices to remove
the non-standard zero capability list terminator.
- Add a check to validate that memory BARs of passthru devices are 4KB
aligned.
- Respect and track the enable bit in the PCI configuration address word.
- Handle quad-word access to 32-bit register pairs.

MFC 260206:
Rework the DSDT generation code a bit to generate more accurate info about
LPC devices. Among other things, the LPC serial ports now appear as
ACPI devices.

MFC 257422,257661,258075,258476,258494,258579,258609,258699:
Several enhancements to the I/O APIC support in bhyve including:
- Move the I/O APIC device model from userspace into vmm.ko and add
ioctls to assert and deassert I/O APIC pins.
- Add HPET device emulation including a single timer block with 8 timers.
- Remove the 'vdev' abstraction.

Approved by: neel

MFC r257293.

Add support for PCI-to-ISA LPC bridge emulation. If the LPC bus is attached
to a virtual machine then we implicitly create COM1 and COM2 ISA devices.

Prior to this change the only way of attaching a COM port to the virtual
machine was by presenting it as a PCI device that is mapped at the legacy
I/O address 0x3F8 or 0x2F8.

There were some issues with the original approach:
- It did not work at all with UEFI because UEFI will reprogram the PCI device
BARs and remap the COM1/COM2 ports at non-legacy addresses.
- OpenBSD GENERIC kernel does not create a /dev/console because it expects
the uart device at the legacy 0x3F8/0x2F8 address to be an ISA device.
- It was functional with a FreeBSD guest but caused the console to appear
on /dev/ttyu2 which was not intuitive.

The uart emulation is now independent of the bus on which it resides. Thus it
is possible to have uart devices on the PCI bus in addition to the legacy
COM1/COM2 devices behind the LPC bus.

The command line option to attach ISA COM1/COM2 ports to a virtual machine is
"-s <bus>,lpc -l com1,stdio".

The command line option to create a PCI-attached uart device is:
"-s <bus>,uart[,stdio]"

The command line option to create PCI-attached COM1/COM2 device is:
"-S <bus>,uart[,stdio]". This style of creating COM ports is deprecated.

Approved by: re (glebius)

Add support for PCI-to-ISA LPC bridge emulation. If the LPC bus is attached
to a virtual machine then we implicitly create COM1 and COM2 ISA devices.

Prior to this change the only way of attaching a COM port to the virtual
machine was by presenting it as a PCI device that is mapped at the legacy
I/O address 0x3F8 or 0x2F8.

There were some issues with the original approach:
- It did not work at all with UEFI because UEFI will reprogram the PCI device
BARs and remap the COM1/COM2 ports at non-legacy addresses.
- OpenBSD GENERIC kernel does not create a /dev/console because it expects
the uart device at the legacy 0x3F8/0x2F8 address to be an ISA device.
- It was functional with a FreeBSD guest but caused the console to appear
on /dev/ttyu2 which was not intuitive.

The uart emulation is now independent of the bus on which it resides. Thus it
is possible to have uart devices on the PCI bus in addition to the legacy
COM1/COM2 devices behind the LPC bus.

The command line option to attach ISA COM1/COM2 ports to a virtual machine is
"-s <bus>,lpc -l com1,stdio".

The command line option to create a PCI-attached uart device is:
"-s <bus>,uart[,stdio]"

The command line option to create PCI-attached COM1/COM2 device is:
"-S <bus>,uart[,stdio]". This style of creating COM ports is deprecated.

Discussed with: grehan
Reviewed by: grehan
Submitted by: Tycho Nightingale (tycho.nightingale@pluribusnetworks.com)

M share/examples/bhyve/vmrun.sh
AM usr.sbin/bhyve/legacy_irq.c
AM usr.sbin/bhyve/legacy_irq.h
M usr.sbin/bhyve/Makefile
AM usr.sbin/bhyve/uart_emul.c
M usr.sbin/bhyve/bhyverun.c
AM usr.sbin/bhyve/uart_emul.h
M usr.sbin/bhyve/pci_uart.c
M usr.sbin/bhyve/pci_emul.c
M usr.sbin/bhyve/inout.c
M usr.sbin/bhyve/pci_emul.h
M usr.sbin/bhyve/inout.h
AM usr.sbin/bhyve/pci_lpc.c
AM usr.sbin/bhyve/pci_lpc.h