2 * Copyright (c) 2011 NetApp, Inc.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL NETAPP, INC OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
32 #include <sys/param.h>
33 #include <sys/systm.h>
37 #include <machine/intr_machdep.h>
38 #include <machine/apicvar.h>
39 #include <machine/segments.h>
40 #include <machine/md_var.h>
42 #include <machine/vmm.h>
45 extern inthand_t IDTVEC(rsvd), IDTVEC(justreturn);
47 CTASSERT(APIC_SPURIOUS_INT == 255);
54 struct gate_descriptor *ip;
57 * Search backwards from the highest IDT vector available for use
58 * as our IPI vector. We install the 'justreturn' handler at that
59 * vector and use it to interrupt the vcpus.
61 * We do this because the IPI_AST is heavyweight and saves all
62 * registers in the trapframe. This is overkill for our use case
63 * which is simply to EOI the interrupt and return.
65 idx = APIC_SPURIOUS_INT;
66 while (--idx >= APIC_IPI_INTS) {
68 func = ((long)ip->gd_hioffset << 16 | ip->gd_looffset);
69 if (func == (uintptr_t)&IDTVEC(rsvd)) {
70 setidt(idx , IDTVEC(justreturn), SDT_SYSIGT,
79 vmm_ipi_free(int ipinum)
82 struct gate_descriptor *ip;
84 KASSERT(ipinum >= APIC_IPI_INTS && ipinum < APIC_SPURIOUS_INT,
85 ("invalid ipi %d", ipinum));
88 func = ((long)ip->gd_hioffset << 16 | ip->gd_looffset);
89 KASSERT(func == (uintptr_t)&IDTVEC(justreturn),
90 ("invalid ipi %d", ipinum));
92 setidt(ipinum, IDTVEC(rsvd), SDT_SYSIGT, SEL_KPL, 0);