qemu/kvm-all.c
aliguori 62d60e8cc4 Make KVM slot management more robust
KVM keeps track of physical memory based on slots in the kernel.  The current
code that translates QEMU memory mappings to slots work but is not robust
in the fact of reregistering partial regions of memory.

This patch does the right thing for reregistering partial regions of memory.  It
also prevents QEMU from using KVM private slots.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5734 c046a42c-6fe2-441c-8c8c-71466251a162
2008-11-18 15:41:18 +00:00

436 lines
10 KiB
C

/*
* QEMU KVM support
*
* Copyright IBM, Corp. 2008
*
* Authors:
* Anthony Liguori <aliguori@us.ibm.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
*/
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <stdarg.h>
#include <linux/kvm.h>
#include "qemu-common.h"
#include "sysemu.h"
#include "kvm.h"
//#define DEBUG_KVM
#ifdef DEBUG_KVM
#define dprintf(fmt, ...) \
do { fprintf(stderr, fmt, ## __VA_ARGS__); } while (0)
#else
#define dprintf(fmt, ...) \
do { } while (0)
#endif
typedef struct kvm_userspace_memory_region KVMSlot;
int kvm_allowed = 0;
struct KVMState
{
KVMSlot slots[32];
int fd;
int vmfd;
};
static KVMState *kvm_state;
static KVMSlot *kvm_alloc_slot(KVMState *s)
{
int i;
for (i = 0; i < ARRAY_SIZE(s->slots); i++) {
/* KVM private memory slots */
if (i >= 8 && i < 12)
continue;
if (s->slots[i].memory_size == 0)
return &s->slots[i];
}
return NULL;
}
static KVMSlot *kvm_lookup_slot(KVMState *s, target_phys_addr_t start_addr)
{
int i;
for (i = 0; i < ARRAY_SIZE(s->slots); i++) {
KVMSlot *mem = &s->slots[i];
if (start_addr >= mem->guest_phys_addr &&
start_addr < (mem->guest_phys_addr + mem->memory_size))
return mem;
}
return NULL;
}
int kvm_init_vcpu(CPUState *env)
{
KVMState *s = kvm_state;
long mmap_size;
int ret;
dprintf("kvm_init_vcpu\n");
ret = kvm_vm_ioctl(s, KVM_CREATE_VCPU, env->cpu_index);
if (ret < 0) {
dprintf("kvm_create_vcpu failed\n");
goto err;
}
env->kvm_fd = ret;
env->kvm_state = s;
mmap_size = kvm_ioctl(s, KVM_GET_VCPU_MMAP_SIZE, 0);
if (mmap_size < 0) {
dprintf("KVM_GET_VCPU_MMAP_SIZE failed\n");
goto err;
}
env->kvm_run = mmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_SHARED,
env->kvm_fd, 0);
if (env->kvm_run == MAP_FAILED) {
ret = -errno;
dprintf("mmap'ing vcpu state failed\n");
goto err;
}
ret = kvm_arch_init_vcpu(env);
err:
return ret;
}
int kvm_init(int smp_cpus)
{
KVMState *s;
int ret;
int i;
if (smp_cpus > 1)
return -EINVAL;
s = qemu_mallocz(sizeof(KVMState));
if (s == NULL)
return -ENOMEM;
for (i = 0; i < ARRAY_SIZE(s->slots); i++)
s->slots[i].slot = i;
s->vmfd = -1;
s->fd = open("/dev/kvm", O_RDWR);
if (s->fd == -1) {
fprintf(stderr, "Could not access KVM kernel module: %m\n");
ret = -errno;
goto err;
}
ret = kvm_ioctl(s, KVM_GET_API_VERSION, 0);
if (ret < KVM_API_VERSION) {
if (ret > 0)
ret = -EINVAL;
fprintf(stderr, "kvm version too old\n");
goto err;
}
if (ret > KVM_API_VERSION) {
ret = -EINVAL;
fprintf(stderr, "kvm version not supported\n");
goto err;
}
s->vmfd = kvm_ioctl(s, KVM_CREATE_VM, 0);
if (s->vmfd < 0)
goto err;
/* initially, KVM allocated its own memory and we had to jump through
* hooks to make phys_ram_base point to this. Modern versions of KVM
* just use a user allocated buffer so we can use phys_ram_base
* unmodified. Make sure we have a sufficiently modern version of KVM.
*/
ret = kvm_ioctl(s, KVM_CHECK_EXTENSION, KVM_CAP_USER_MEMORY);
if (ret <= 0) {
if (ret == 0)
ret = -EINVAL;
fprintf(stderr, "kvm does not support KVM_CAP_USER_MEMORY\n");
goto err;
}
ret = kvm_arch_init(s, smp_cpus);
if (ret < 0)
goto err;
kvm_state = s;
return 0;
err:
if (s) {
if (s->vmfd != -1)
close(s->vmfd);
if (s->fd != -1)
close(s->fd);
}
qemu_free(s);
return ret;
}
static int kvm_handle_io(CPUState *env, uint16_t port, void *data,
int direction, int size, uint32_t count)
{
int i;
uint8_t *ptr = data;
for (i = 0; i < count; i++) {
if (direction == KVM_EXIT_IO_IN) {
switch (size) {
case 1:
stb_p(ptr, cpu_inb(env, port));
break;
case 2:
stw_p(ptr, cpu_inw(env, port));
break;
case 4:
stl_p(ptr, cpu_inl(env, port));
break;
}
} else {
switch (size) {
case 1:
cpu_outb(env, port, ldub_p(ptr));
break;
case 2:
cpu_outw(env, port, lduw_p(ptr));
break;
case 4:
cpu_outl(env, port, ldl_p(ptr));
break;
}
}
ptr += size;
}
return 1;
}
int kvm_cpu_exec(CPUState *env)
{
struct kvm_run *run = env->kvm_run;
int ret;
dprintf("kvm_cpu_exec()\n");
do {
kvm_arch_pre_run(env, run);
if ((env->interrupt_request & CPU_INTERRUPT_EXIT)) {
dprintf("interrupt exit requested\n");
ret = 0;
break;
}
ret = kvm_vcpu_ioctl(env, KVM_RUN, 0);
kvm_arch_post_run(env, run);
if (ret == -EINTR || ret == -EAGAIN) {
dprintf("io window exit\n");
ret = 0;
break;
}
if (ret < 0) {
dprintf("kvm run failed %s\n", strerror(-ret));
abort();
}
ret = 0; /* exit loop */
switch (run->exit_reason) {
case KVM_EXIT_IO:
dprintf("handle_io\n");
ret = kvm_handle_io(env, run->io.port,
(uint8_t *)run + run->io.data_offset,
run->io.direction,
run->io.size,
run->io.count);
break;
case KVM_EXIT_MMIO:
dprintf("handle_mmio\n");
cpu_physical_memory_rw(run->mmio.phys_addr,
run->mmio.data,
run->mmio.len,
run->mmio.is_write);
ret = 1;
break;
case KVM_EXIT_IRQ_WINDOW_OPEN:
dprintf("irq_window_open\n");
break;
case KVM_EXIT_SHUTDOWN:
dprintf("shutdown\n");
qemu_system_reset_request();
ret = 1;
break;
case KVM_EXIT_UNKNOWN:
dprintf("kvm_exit_unknown\n");
break;
case KVM_EXIT_FAIL_ENTRY:
dprintf("kvm_exit_fail_entry\n");
break;
case KVM_EXIT_EXCEPTION:
dprintf("kvm_exit_exception\n");
break;
case KVM_EXIT_DEBUG:
dprintf("kvm_exit_debug\n");
break;
default:
dprintf("kvm_arch_handle_exit\n");
ret = kvm_arch_handle_exit(env, run);
break;
}
} while (ret > 0);
if ((env->interrupt_request & CPU_INTERRUPT_EXIT)) {
env->interrupt_request &= ~CPU_INTERRUPT_EXIT;
env->exception_index = EXCP_INTERRUPT;
}
return ret;
}
void kvm_set_phys_mem(target_phys_addr_t start_addr,
ram_addr_t size,
ram_addr_t phys_offset)
{
KVMState *s = kvm_state;
ram_addr_t flags = phys_offset & ~TARGET_PAGE_MASK;
KVMSlot *mem;
/* KVM does not support read-only slots */
phys_offset &= ~IO_MEM_ROM;
mem = kvm_lookup_slot(s, start_addr);
if (mem) {
if (flags == IO_MEM_UNASSIGNED) {
mem->memory_size = 0;
mem->guest_phys_addr = start_addr;
mem->userspace_addr = 0;
mem->flags = 0;
kvm_vm_ioctl(s, KVM_SET_USER_MEMORY_REGION, mem);
} else if (start_addr >= mem->guest_phys_addr &&
(start_addr + size) <= (mem->guest_phys_addr +
mem->memory_size)) {
KVMSlot slot;
target_phys_addr_t mem_start;
ram_addr_t mem_size, mem_offset;
/* Not splitting */
if ((phys_offset - (start_addr - mem->guest_phys_addr)) ==
((uint8_t *)mem->userspace_addr - phys_ram_base))
return;
/* unregister whole slot */
memcpy(&slot, mem, sizeof(slot));
mem->memory_size = 0;
kvm_vm_ioctl(s, KVM_SET_USER_MEMORY_REGION, mem);
/* register prefix slot */
mem_start = slot.guest_phys_addr;
mem_size = start_addr - slot.guest_phys_addr;
mem_offset = (uint8_t *)slot.userspace_addr - phys_ram_base;
if (mem_size)
kvm_set_phys_mem(mem_start, mem_size, mem_offset);
/* register new slot */
kvm_set_phys_mem(start_addr, size, phys_offset);
/* register suffix slot */
mem_start = start_addr + size;
mem_offset += mem_size + size;
mem_size = slot.memory_size - mem_size - size;
if (mem_size)
kvm_set_phys_mem(mem_start, mem_size, mem_offset);
return;
} else {
printf("Registering overlapping slot\n");
abort();
}
}
/* KVM does not need to know about this memory */
if (flags >= IO_MEM_UNASSIGNED)
return;
mem = kvm_alloc_slot(s);
mem->memory_size = size;
mem->guest_phys_addr = start_addr;
mem->userspace_addr = (unsigned long)(phys_ram_base + phys_offset);
mem->flags = 0;
kvm_vm_ioctl(s, KVM_SET_USER_MEMORY_REGION, mem);
/* FIXME deal with errors */
}
int kvm_ioctl(KVMState *s, int type, ...)
{
int ret;
void *arg;
va_list ap;
va_start(ap, type);
arg = va_arg(ap, void *);
va_end(ap);
ret = ioctl(s->fd, type, arg);
if (ret == -1)
ret = -errno;
return ret;
}
int kvm_vm_ioctl(KVMState *s, int type, ...)
{
int ret;
void *arg;
va_list ap;
va_start(ap, type);
arg = va_arg(ap, void *);
va_end(ap);
ret = ioctl(s->vmfd, type, arg);
if (ret == -1)
ret = -errno;
return ret;
}
int kvm_vcpu_ioctl(CPUState *env, int type, ...)
{
int ret;
void *arg;
va_list ap;
va_start(ap, type);
arg = va_arg(ap, void *);
va_end(ap);
ret = ioctl(env->kvm_fd, type, arg);
if (ret == -1)
ret = -errno;
return ret;
}