freebsd-skq/usr.sbin/bhyve/spinup_ap.c
neel 01173b0b4a The "unrestricted guest" capability is a feature of Intel VT-x that allows
the guest to execute real or unpaged protected mode code - bhyve relies on
this feature to execute the AP bootstrap code.

Get rid of the hack that allowed bhyve to support SMP guests on processors
that do not have the "unrestricted guest" capability. This hack was entirely
FreeBSD-specific and would not work with any other guest OS.

Instead, limit the number of vcpus to 1 when executing on processors without
"unrestricted guest" capability.

Suggested by:	grehan
Obtained from:	NetApp
2013-01-04 02:04:41 +00:00

120 lines
3.3 KiB
C

/*-
* Copyright (c) 2012 NetApp, Inc.
* 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.
*
* $FreeBSD$
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/types.h>
#include <machine/vmm.h>
#include <vmmapi.h>
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include "bhyverun.h"
#include "spinup_ap.h"
static void
spinup_ap_realmode(struct vmctx *ctx, int newcpu, uint64_t *rip)
{
int vector, error;
uint16_t cs;
uint64_t desc_base;
uint32_t desc_limit, desc_access;
vector = *rip >> PAGE_SHIFT;
*rip = 0;
/*
* Update the %cs and %rip of the guest so that it starts
* executing real mode code at at 'vector << 12'.
*/
error = vm_set_register(ctx, newcpu, VM_REG_GUEST_RIP, *rip);
assert(error == 0);
error = vm_get_desc(ctx, newcpu, VM_REG_GUEST_CS, &desc_base,
&desc_limit, &desc_access);
assert(error == 0);
desc_base = vector << PAGE_SHIFT;
error = vm_set_desc(ctx, newcpu, VM_REG_GUEST_CS,
desc_base, desc_limit, desc_access);
assert(error == 0);
cs = (vector << PAGE_SHIFT) >> 4;
error = vm_set_register(ctx, newcpu, VM_REG_GUEST_CS, cs);
assert(error == 0);
}
int
spinup_ap(struct vmctx *ctx, int vcpu, int newcpu, uint64_t rip)
{
int error;
assert(newcpu != 0);
assert(newcpu < guest_ncpus);
error = vcpu_reset(ctx, newcpu);
assert(error == 0);
/* Set up capabilities */
if (fbsdrun_vmexit_on_hlt()) {
error = vm_set_capability(ctx, newcpu, VM_CAP_HALT_EXIT, 1);
assert(error == 0);
}
if (fbsdrun_vmexit_on_pause()) {
error = vm_set_capability(ctx, newcpu, VM_CAP_PAUSE_EXIT, 1);
assert(error == 0);
}
if (fbsdrun_disable_x2apic())
error = vm_set_x2apic_state(ctx, newcpu, X2APIC_DISABLED);
else
error = vm_set_x2apic_state(ctx, newcpu, X2APIC_ENABLED);
assert(error == 0);
/*
* Enable the 'unrestricted guest' mode for 'newcpu'.
*
* Set up the processor state in power-on 16-bit mode, with the CS:IP
* init'd to the specified low-mem 4K page.
*/
error = vm_set_capability(ctx, newcpu, VM_CAP_UNRESTRICTED_GUEST, 1);
assert(error == 0);
spinup_ap_realmode(ctx, newcpu, &rip);
fbsdrun_addcpu(ctx, newcpu, rip);
return (newcpu);
}