qemu/kvm-all.c

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/*
* QEMU KVM support
*
* Copyright IBM, Corp. 2008
* Red Hat, Inc. 2008
*
* Authors:
* Anthony Liguori <aliguori@us.ibm.com>
* Glauber Costa <gcosta@redhat.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 "gdbstub.h"
#include "kvm.h"
/* KVM uses PAGE_SIZE in it's definition of COALESCED_MMIO_MAX */
#define PAGE_SIZE TARGET_PAGE_SIZE
//#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 KVMSlot
{
target_phys_addr_t start_addr;
ram_addr_t memory_size;
ram_addr_t phys_offset;
int slot;
int flags;
} KVMSlot;
typedef struct kvm_dirty_log KVMDirtyLog;
int kvm_allowed = 0;
struct KVMState
{
KVMSlot slots[32];
int fd;
int vmfd;
int coalesced_mmio;
#ifdef KVM_CAP_SET_GUEST_DEBUG
struct kvm_sw_breakpoint_head kvm_sw_breakpoints;
#endif
};
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->start_addr &&
start_addr < (mem->start_addr + mem->memory_size))
return mem;
}
return NULL;
}
static int kvm_set_user_memory_region(KVMState *s, KVMSlot *slot)
{
struct kvm_userspace_memory_region mem;
mem.slot = slot->slot;
mem.guest_phys_addr = slot->start_addr;
mem.memory_size = slot->memory_size;
mem.userspace_addr = (unsigned long)phys_ram_base + slot->phys_offset;
mem.flags = slot->flags;
return kvm_vm_ioctl(s, KVM_SET_USER_MEMORY_REGION, &mem);
}
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_sync_vcpus(void)
{
CPUState *env;
for (env = first_cpu; env != NULL; env = env->next_cpu) {
int ret;
ret = kvm_arch_put_registers(env);
if (ret)
return ret;
}
return 0;
}
/*
* dirty pages logging control
*/
static int kvm_dirty_pages_log_change(target_phys_addr_t phys_addr, target_phys_addr_t end_addr,
unsigned flags,
unsigned mask)
{
KVMState *s = kvm_state;
KVMSlot *mem = kvm_lookup_slot(s, phys_addr);
if (mem == NULL) {
dprintf("invalid parameters %llx-%llx\n", phys_addr, end_addr);
return -EINVAL;
}
flags = (mem->flags & ~mask) | flags;
/* Nothing changed, no need to issue ioctl */
if (flags == mem->flags)
return 0;
mem->flags = flags;
return kvm_set_user_memory_region(s, mem);
}
int kvm_log_start(target_phys_addr_t phys_addr, target_phys_addr_t end_addr)
{
return kvm_dirty_pages_log_change(phys_addr, end_addr,
KVM_MEM_LOG_DIRTY_PAGES,
KVM_MEM_LOG_DIRTY_PAGES);
}
int kvm_log_stop(target_phys_addr_t phys_addr, target_phys_addr_t end_addr)
{
return kvm_dirty_pages_log_change(phys_addr, end_addr,
0,
KVM_MEM_LOG_DIRTY_PAGES);
}
/**
* kvm_physical_sync_dirty_bitmap - Grab dirty bitmap from kernel space
* This function updates qemu's dirty bitmap using cpu_physical_memory_set_dirty().
* This means all bits are set to dirty.
*
* @start_add: start of logged region. This is what we use to search the memslot
* @end_addr: end of logged region.
*/
void kvm_physical_sync_dirty_bitmap(target_phys_addr_t start_addr, target_phys_addr_t end_addr)
{
KVMState *s = kvm_state;
KVMDirtyLog d;
KVMSlot *mem = kvm_lookup_slot(s, start_addr);
unsigned long alloc_size;
ram_addr_t addr;
target_phys_addr_t phys_addr = start_addr;
dprintf("sync addr: %llx into %lx\n", start_addr, mem->phys_offset);
if (mem == NULL) {
fprintf(stderr, "BUG: %s: invalid parameters\n", __func__);
return;
}
alloc_size = mem->memory_size >> TARGET_PAGE_BITS / sizeof(d.dirty_bitmap);
d.dirty_bitmap = qemu_mallocz(alloc_size);
d.slot = mem->slot;
dprintf("slot %d, phys_addr %llx, uaddr: %llx\n",
d.slot, mem->start_addr, mem->phys_offset);
if (kvm_vm_ioctl(s, KVM_GET_DIRTY_LOG, &d) == -1) {
dprintf("ioctl failed %d\n", errno);
goto out;
}
phys_addr = start_addr;
for (addr = mem->phys_offset; phys_addr < end_addr; phys_addr+= TARGET_PAGE_SIZE, addr += TARGET_PAGE_SIZE) {
unsigned long *bitmap = (unsigned long *)d.dirty_bitmap;
unsigned nr = (phys_addr - start_addr) >> TARGET_PAGE_BITS;
unsigned word = nr / (sizeof(*bitmap) * 8);
unsigned bit = nr % (sizeof(*bitmap) * 8);
if ((bitmap[word] >> bit) & 1)
cpu_physical_memory_set_dirty(addr);
}
out:
qemu_free(d.dirty_bitmap);
}
int kvm_coalesce_mmio_region(target_phys_addr_t start, ram_addr_t size)
{
int ret = -ENOSYS;
#ifdef KVM_CAP_COALESCED_MMIO
KVMState *s = kvm_state;
if (s->coalesced_mmio) {
struct kvm_coalesced_mmio_zone zone;
zone.addr = start;
zone.size = size;
ret = kvm_vm_ioctl(s, KVM_REGISTER_COALESCED_MMIO, &zone);
}
#endif
return ret;
}
int kvm_uncoalesce_mmio_region(target_phys_addr_t start, ram_addr_t size)
{
int ret = -ENOSYS;
#ifdef KVM_CAP_COALESCED_MMIO
KVMState *s = kvm_state;
if (s->coalesced_mmio) {
struct kvm_coalesced_mmio_zone zone;
zone.addr = start;
zone.size = size;
ret = kvm_vm_ioctl(s, KVM_UNREGISTER_COALESCED_MMIO, &zone);
}
#endif
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));
#ifdef KVM_CAP_SET_GUEST_DEBUG
TAILQ_INIT(&s->kvm_sw_breakpoints);
#endif
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;
}
/* There was a nasty bug in < kvm-80 that prevents memory slots from being
* destroyed properly. Since we rely on this capability, refuse to work
* with any kernel without this capability. */
ret = kvm_ioctl(s, KVM_CHECK_EXTENSION,
KVM_CAP_DESTROY_MEMORY_REGION_WORKS);
if (ret <= 0) {
if (ret == 0)
ret = -EINVAL;
fprintf(stderr,
"KVM kernel module broken (DESTROY_MEMORY_REGION)\n"
"Please upgrade to at least kvm-81.\n");
goto err;
}
s->coalesced_mmio = 0;
#ifdef KVM_CAP_COALESCED_MMIO
ret = kvm_ioctl(s, KVM_CHECK_EXTENSION, KVM_CAP_COALESCED_MMIO);
if (ret > 0)
s->coalesced_mmio = ret;
#endif
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;
}
static void kvm_run_coalesced_mmio(CPUState *env, struct kvm_run *run)
{
#ifdef KVM_CAP_COALESCED_MMIO
KVMState *s = kvm_state;
if (s->coalesced_mmio) {
struct kvm_coalesced_mmio_ring *ring;
ring = (void *)run + (s->coalesced_mmio * TARGET_PAGE_SIZE);
while (ring->first != ring->last) {
struct kvm_coalesced_mmio *ent;
ent = &ring->coalesced_mmio[ring->first];
cpu_physical_memory_write(ent->phys_addr, ent->data, ent->len);
/* FIXME smp_wmb() */
ring->first = (ring->first + 1) % KVM_COALESCED_MMIO_MAX;
}
}
#endif
}
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->exit_request) {
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();
}
kvm_run_coalesced_mmio(env, run);
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");
#ifdef KVM_CAP_SET_GUEST_DEBUG
if (kvm_arch_debug(&run->debug.arch)) {
gdb_set_stop_cpu(env);
vm_stop(EXCP_DEBUG);
env->exception_index = EXCP_DEBUG;
return 0;
}
/* re-enter, this exception was guest-internal */
ret = 1;
#endif /* KVM_CAP_SET_GUEST_DEBUG */
break;
default:
dprintf("kvm_arch_handle_exit\n");
ret = kvm_arch_handle_exit(env, run);
break;
}
} while (ret > 0);
if (env->exit_request) {
env->exit_request = 0;
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) || (flags >= TLB_MMIO)) {
mem->memory_size = 0;
mem->start_addr = start_addr;
mem->phys_offset = 0;
mem->flags = 0;
kvm_set_user_memory_region(s, mem);
} else if (start_addr >= mem->start_addr &&
(start_addr + size) <= (mem->start_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->start_addr)) ==
mem->phys_offset)
return;
/* unregister whole slot */
memcpy(&slot, mem, sizeof(slot));
mem->memory_size = 0;
kvm_set_user_memory_region(s, mem);
/* register prefix slot */
mem_start = slot.start_addr;
mem_size = start_addr - slot.start_addr;
mem_offset = slot.phys_offset;
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->start_addr = start_addr;
mem->phys_offset = phys_offset;
mem->flags = 0;
kvm_set_user_memory_region(s, 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;
}
int kvm_has_sync_mmu(void)
{
#ifdef KVM_CAP_SYNC_MMU
KVMState *s = kvm_state;
if (kvm_ioctl(s, KVM_CHECK_EXTENSION, KVM_CAP_SYNC_MMU) > 0)
return 1;
#endif
return 0;
}
#ifdef KVM_CAP_SET_GUEST_DEBUG
struct kvm_sw_breakpoint *kvm_find_sw_breakpoint(CPUState *env,
target_ulong pc)
{
struct kvm_sw_breakpoint *bp;
TAILQ_FOREACH(bp, &env->kvm_state->kvm_sw_breakpoints, entry) {
if (bp->pc == pc)
return bp;
}
return NULL;
}
int kvm_sw_breakpoints_active(CPUState *env)
{
return !TAILQ_EMPTY(&env->kvm_state->kvm_sw_breakpoints);
}
int kvm_update_guest_debug(CPUState *env, unsigned long reinject_trap)
{
struct kvm_guest_debug dbg;
dbg.control = 0;
if (env->singlestep_enabled)
dbg.control = KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_SINGLESTEP;
kvm_arch_update_guest_debug(env, &dbg);
dbg.control |= reinject_trap;
return kvm_vcpu_ioctl(env, KVM_SET_GUEST_DEBUG, &dbg);
}
int kvm_insert_breakpoint(CPUState *current_env, target_ulong addr,
target_ulong len, int type)
{
struct kvm_sw_breakpoint *bp;
CPUState *env;
int err;
if (type == GDB_BREAKPOINT_SW) {
bp = kvm_find_sw_breakpoint(current_env, addr);
if (bp) {
bp->use_count++;
return 0;
}
bp = qemu_malloc(sizeof(struct kvm_sw_breakpoint));
if (!bp)
return -ENOMEM;
bp->pc = addr;
bp->use_count = 1;
err = kvm_arch_insert_sw_breakpoint(current_env, bp);
if (err) {
free(bp);
return err;
}
TAILQ_INSERT_HEAD(&current_env->kvm_state->kvm_sw_breakpoints,
bp, entry);
} else {
err = kvm_arch_insert_hw_breakpoint(addr, len, type);
if (err)
return err;
}
for (env = first_cpu; env != NULL; env = env->next_cpu) {
err = kvm_update_guest_debug(env, 0);
if (err)
return err;
}
return 0;
}
int kvm_remove_breakpoint(CPUState *current_env, target_ulong addr,
target_ulong len, int type)
{
struct kvm_sw_breakpoint *bp;
CPUState *env;
int err;
if (type == GDB_BREAKPOINT_SW) {
bp = kvm_find_sw_breakpoint(current_env, addr);
if (!bp)
return -ENOENT;
if (bp->use_count > 1) {
bp->use_count--;
return 0;
}
err = kvm_arch_remove_sw_breakpoint(current_env, bp);
if (err)
return err;
TAILQ_REMOVE(&current_env->kvm_state->kvm_sw_breakpoints, bp, entry);
qemu_free(bp);
} else {
err = kvm_arch_remove_hw_breakpoint(addr, len, type);
if (err)
return err;
}
for (env = first_cpu; env != NULL; env = env->next_cpu) {
err = kvm_update_guest_debug(env, 0);
if (err)
return err;
}
return 0;
}
void kvm_remove_all_breakpoints(CPUState *current_env)
{
struct kvm_sw_breakpoint *bp, *next;
KVMState *s = current_env->kvm_state;
CPUState *env;
TAILQ_FOREACH_SAFE(bp, &s->kvm_sw_breakpoints, entry, next) {
if (kvm_arch_remove_sw_breakpoint(current_env, bp) != 0) {
/* Try harder to find a CPU that currently sees the breakpoint. */
for (env = first_cpu; env != NULL; env = env->next_cpu) {
if (kvm_arch_remove_sw_breakpoint(env, bp) == 0)
break;
}
}
}
kvm_arch_remove_all_hw_breakpoints();
for (env = first_cpu; env != NULL; env = env->next_cpu)
kvm_update_guest_debug(env, 0);
}
#else /* !KVM_CAP_SET_GUEST_DEBUG */
int kvm_update_guest_debug(CPUState *env, unsigned long reinject_trap)
{
return -EINVAL;
}
int kvm_insert_breakpoint(CPUState *current_env, target_ulong addr,
target_ulong len, int type)
{
return -EINVAL;
}
int kvm_remove_breakpoint(CPUState *current_env, target_ulong addr,
target_ulong len, int type)
{
return -EINVAL;
}
void kvm_remove_all_breakpoints(CPUState *current_env)
{
}
#endif /* !KVM_CAP_SET_GUEST_DEBUG */