freebsd-dev/usr.sbin/bhyve/mem.c
Marcelo Araujo f2b5dc3aec While I was investigating CID 1194192 related with a resource leak on mrp memory
allocation, I could identify that actually we use this pointer on pci_emul.c as
well as on vga.c source file.

I have reworked the logic here to make it more readable and also add a warn to
explicit show the function where the memory allocation error could happen,
also sort headers.

Also CID 1194192 was marked as "Intentional".

Obtained from:	TrueOS
MFC after:	4 weeks.
Sponsored by:	iXsystems Inc.
2018-06-13 11:49:34 +00:00

362 lines
8.5 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* 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.
*
* $FreeBSD$
*/
/*
* Memory ranges are represented with an RB tree. On insertion, the range
* is checked for overlaps. On lookup, the key has the same base and limit
* so it can be searched within the range.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <sys/errno.h>
#include <sys/tree.h>
#include <machine/vmm.h>
#include <machine/vmm_instruction_emul.h>
#include <assert.h>
#include <err.h>
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include "mem.h"
struct mmio_rb_range {
RB_ENTRY(mmio_rb_range) mr_link; /* RB tree links */
struct mem_range mr_param;
uint64_t mr_base;
uint64_t mr_end;
};
struct mmio_rb_tree;
RB_PROTOTYPE(mmio_rb_tree, mmio_rb_range, mr_link, mmio_rb_range_compare);
RB_HEAD(mmio_rb_tree, mmio_rb_range) mmio_rb_root, mmio_rb_fallback;
/*
* Per-vCPU cache. Since most accesses from a vCPU will be to
* consecutive addresses in a range, it makes sense to cache the
* result of a lookup.
*/
static struct mmio_rb_range *mmio_hint[VM_MAXCPU];
static pthread_rwlock_t mmio_rwlock;
static int
mmio_rb_range_compare(struct mmio_rb_range *a, struct mmio_rb_range *b)
{
if (a->mr_end < b->mr_base)
return (-1);
else if (a->mr_base > b->mr_end)
return (1);
return (0);
}
static int
mmio_rb_lookup(struct mmio_rb_tree *rbt, uint64_t addr,
struct mmio_rb_range **entry)
{
struct mmio_rb_range find, *res;
find.mr_base = find.mr_end = addr;
res = RB_FIND(mmio_rb_tree, rbt, &find);
if (res != NULL) {
*entry = res;
return (0);
}
return (ENOENT);
}
static int
mmio_rb_add(struct mmio_rb_tree *rbt, struct mmio_rb_range *new)
{
struct mmio_rb_range *overlap;
overlap = RB_INSERT(mmio_rb_tree, rbt, new);
if (overlap != NULL) {
#ifdef RB_DEBUG
printf("overlap detected: new %lx:%lx, tree %lx:%lx\n",
new->mr_base, new->mr_end,
overlap->mr_base, overlap->mr_end);
#endif
return (EEXIST);
}
return (0);
}
#if 0
static void
mmio_rb_dump(struct mmio_rb_tree *rbt)
{
int perror;
struct mmio_rb_range *np;
pthread_rwlock_rdlock(&mmio_rwlock);
RB_FOREACH(np, mmio_rb_tree, rbt) {
printf(" %lx:%lx, %s\n", np->mr_base, np->mr_end,
np->mr_param.name);
}
perror = pthread_rwlock_unlock(&mmio_rwlock);
assert(perror == 0);
}
#endif
RB_GENERATE(mmio_rb_tree, mmio_rb_range, mr_link, mmio_rb_range_compare);
typedef int (mem_cb_t)(struct vmctx *ctx, int vcpu, uint64_t gpa,
struct mem_range *mr, void *arg);
static int
mem_read(void *ctx, int vcpu, uint64_t gpa, uint64_t *rval, int size, void *arg)
{
int error;
struct mem_range *mr = arg;
error = (*mr->handler)(ctx, vcpu, MEM_F_READ, gpa, size,
rval, mr->arg1, mr->arg2);
return (error);
}
static int
mem_write(void *ctx, int vcpu, uint64_t gpa, uint64_t wval, int size, void *arg)
{
int error;
struct mem_range *mr = arg;
error = (*mr->handler)(ctx, vcpu, MEM_F_WRITE, gpa, size,
&wval, mr->arg1, mr->arg2);
return (error);
}
static int
access_memory(struct vmctx *ctx, int vcpu, uint64_t paddr, mem_cb_t *cb,
void *arg)
{
struct mmio_rb_range *entry;
int err, perror, immutable;
pthread_rwlock_rdlock(&mmio_rwlock);
/*
* First check the per-vCPU cache
*/
if (mmio_hint[vcpu] &&
paddr >= mmio_hint[vcpu]->mr_base &&
paddr <= mmio_hint[vcpu]->mr_end) {
entry = mmio_hint[vcpu];
} else
entry = NULL;
if (entry == NULL) {
if (mmio_rb_lookup(&mmio_rb_root, paddr, &entry) == 0) {
/* Update the per-vCPU cache */
mmio_hint[vcpu] = entry;
} else if (mmio_rb_lookup(&mmio_rb_fallback, paddr, &entry)) {
perror = pthread_rwlock_unlock(&mmio_rwlock);
assert(perror == 0);
return (ESRCH);
}
}
assert(entry != NULL);
/*
* An 'immutable' memory range is guaranteed to be never removed
* so there is no need to hold 'mmio_rwlock' while calling the
* handler.
*
* XXX writes to the PCIR_COMMAND register can cause register_mem()
* to be called. If the guest is using PCI extended config space
* to modify the PCIR_COMMAND register then register_mem() can
* deadlock on 'mmio_rwlock'. However by registering the extended
* config space window as 'immutable' the deadlock can be avoided.
*/
immutable = (entry->mr_param.flags & MEM_F_IMMUTABLE);
if (immutable) {
perror = pthread_rwlock_unlock(&mmio_rwlock);
assert(perror == 0);
}
err = cb(ctx, vcpu, paddr, &entry->mr_param, arg);
if (!immutable) {
perror = pthread_rwlock_unlock(&mmio_rwlock);
assert(perror == 0);
}
return (err);
}
struct emulate_mem_args {
struct vie *vie;
struct vm_guest_paging *paging;
};
static int
emulate_mem_cb(struct vmctx *ctx, int vcpu, uint64_t paddr, struct mem_range *mr,
void *arg)
{
struct emulate_mem_args *ema;
ema = arg;
return (vmm_emulate_instruction(ctx, vcpu, paddr, ema->vie, ema->paging,
mem_read, mem_write, mr));
}
int
emulate_mem(struct vmctx *ctx, int vcpu, uint64_t paddr, struct vie *vie,
struct vm_guest_paging *paging)
{
struct emulate_mem_args ema;
ema.vie = vie;
ema.paging = paging;
return (access_memory(ctx, vcpu, paddr, emulate_mem_cb, &ema));
}
struct read_mem_args {
uint64_t *rval;
int size;
};
static int
read_mem_cb(struct vmctx *ctx, int vcpu, uint64_t paddr, struct mem_range *mr,
void *arg)
{
struct read_mem_args *rma;
rma = arg;
return (mr->handler(ctx, vcpu, MEM_F_READ, paddr, rma->size,
rma->rval, mr->arg1, mr->arg2));
}
int
read_mem(struct vmctx *ctx, int vcpu, uint64_t gpa, uint64_t *rval, int size)
{
struct read_mem_args rma;
rma.rval = rval;
rma.size = size;
return (access_memory(ctx, vcpu, gpa, read_mem_cb, &rma));
}
static int
register_mem_int(struct mmio_rb_tree *rbt, struct mem_range *memp)
{
struct mmio_rb_range *entry, *mrp;
int err, perror;
err = 0;
mrp = malloc(sizeof(struct mmio_rb_range));
if (mrp == NULL) {
warn("%s: couldn't allocate memory for mrp\n",
__func__);
err = ENOMEM;
} else {
mrp->mr_param = *memp;
mrp->mr_base = memp->base;
mrp->mr_end = memp->base + memp->size - 1;
pthread_rwlock_wrlock(&mmio_rwlock);
if (mmio_rb_lookup(rbt, memp->base, &entry) != 0)
err = mmio_rb_add(rbt, mrp);
perror = pthread_rwlock_unlock(&mmio_rwlock);
assert(perror == 0);
if (err)
free(mrp);
}
return (err);
}
int
register_mem(struct mem_range *memp)
{
return (register_mem_int(&mmio_rb_root, memp));
}
int
register_mem_fallback(struct mem_range *memp)
{
return (register_mem_int(&mmio_rb_fallback, memp));
}
int
unregister_mem(struct mem_range *memp)
{
struct mem_range *mr;
struct mmio_rb_range *entry = NULL;
int err, perror, i;
pthread_rwlock_wrlock(&mmio_rwlock);
err = mmio_rb_lookup(&mmio_rb_root, memp->base, &entry);
if (err == 0) {
mr = &entry->mr_param;
assert(mr->name == memp->name);
assert(mr->base == memp->base && mr->size == memp->size);
assert((mr->flags & MEM_F_IMMUTABLE) == 0);
RB_REMOVE(mmio_rb_tree, &mmio_rb_root, entry);
/* flush Per-vCPU cache */
for (i=0; i < VM_MAXCPU; i++) {
if (mmio_hint[i] == entry)
mmio_hint[i] = NULL;
}
}
perror = pthread_rwlock_unlock(&mmio_rwlock);
assert(perror == 0);
if (entry)
free(entry);
return (err);
}
void
init_mem(void)
{
RB_INIT(&mmio_rb_root);
RB_INIT(&mmio_rb_fallback);
pthread_rwlock_init(&mmio_rwlock, NULL);
}