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freebsd/usr.sbin/bhyve/ioapic.c
John Baldwin 3cbf3585cb Enhance the support for PCI legacy INTx interrupts and enable them in
the virtio backends.
- Add a new ioctl to export the count of pins on the I/O APIC from vmm
  to the hypervisor.
- Use pins on the I/O APIC >= 16 for PCI interrupts leaving 0-15 for
  ISA interrupts.
- Populate the MP Table with I/O interrupt entries for any PCI INTx
  interrupts.
- Create a _PRT table under the PCI root bridge in ACPI to route any
  PCI INTx interrupts appropriately.
- Track which INTx interrupts are in use per-slot so that functions
  that share a slot attempt to distribute their INTx interrupts across
  the four available pins.
- Implicitly mask INTx interrupts if either MSI or MSI-X is enabled
  and when the INTx DIS bit is set in a function's PCI command register.
  Either assert or deassert the associated I/O APIC pin when the
  state of one of those conditions changes.
- Add INTx support to the virtio backends.
- Always advertise the MSI capability in the virtio backends.

Submitted by:	neel (7)
Reviewed by:	neel
MFC after:	2 weeks
2014-01-29 14:56:48 +00:00

75 lines
2.2 KiB
C

/*-
* Copyright (c) 2014 Advanced Computing Technologies LLC
* Written by: John H. Baldwin <jhb@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 THE AUTHOR AND CONTRIBUTORS ``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 THE AUTHOR 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <machine/vmm.h>
#include <vmmapi.h>
#include "ioapic.h"
/*
* Assign PCI INTx interrupts to I/O APIC pins in a round-robin
* fashion. Note that we have no idea what the HPET is using, but the
* HPET is also programmable whereas this is intended for hardwired
* PCI interrupts.
*
* This assumes a single I/O APIC where pins >= 16 are permitted for
* PCI devices.
*/
static int pci_pins;
void
ioapic_init(struct vmctx *ctx)
{
if (vm_ioapic_pincount(ctx, &pci_pins) < 0) {
pci_pins = 0;
return;
}
/* Ignore the first 16 pins. */
if (pci_pins <= 16) {
pci_pins = 0;
return;
}
pci_pins -= 16;
}
int
ioapic_pci_alloc_irq(void)
{
static int last_pin;
if (pci_pins == 0)
return (-1);
return (16 + (last_pin++ % pci_pins));
}