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)

1 files changed, 41 insertions, 0 deletions

diff --git a/usr.sbin/bhyve/legacy_irq.h b/usr.sbin/bhyve/legacy_irq.h
new file mode 100644
index 0000000..3531e11
--- /dev/null
+++ b/usr.sbin/bhyve/legacy_irq.h
@@ -0,0 +1,41 @@
+/*-
+ * Copyright (c) 2013 Neel Natu <neel@freebsd.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL NETAPP, INC OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef _LEGACY_IRQ_H_
+#define	_LEGACY_IRQ_H_
+
+/*
+ * Allocate a legacy irq. The argument 'irq' can be set to -1 to allocate any
+ * available irq.
+ *
+ * Returns -1 on failure or the allocated irq number on success.
+ */
+int	legacy_irq_alloc(int irq);
+void	legacy_irq_init(void);
+
+#endif