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 "qemu-barrier.h"
#include "sysemu.h"
#include "hw/hw.h"
#include "gdbstub.h"
#include "kvm.h"
#include "bswap.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;
struct KVMState
{
KVMSlot slots[32];
int fd;
int vmfd;
int coalesced_mmio;
#ifdef KVM_CAP_COALESCED_MMIO
struct kvm_coalesced_mmio_ring *coalesced_mmio_ring;
#endif
int broken_set_mem_region;
int migration_log;
int vcpu_events;
int robust_singlestep;
int debugregs;
#ifdef KVM_CAP_SET_GUEST_DEBUG
struct kvm_sw_breakpoint_head kvm_sw_breakpoints;
#endif
int irqchip_in_kernel;
int pit_in_kernel;
int xsave, xcrs;
};
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];
}
fprintf(stderr, "%s: no free slot available\n", __func__);
abort();
}
static KVMSlot *kvm_lookup_matching_slot(KVMState *s,
target_phys_addr_t start_addr,
target_phys_addr_t end_addr)
{
int i;
for (i = 0; i < ARRAY_SIZE(s->slots); i++) {
KVMSlot *mem = &s->slots[i];
if (start_addr == mem->start_addr &&
end_addr == mem->start_addr + mem->memory_size) {
return mem;
}
}
return NULL;
}
/*
* Find overlapping slot with lowest start address
*/
static KVMSlot *kvm_lookup_overlapping_slot(KVMState *s,
target_phys_addr_t start_addr,
target_phys_addr_t end_addr)
{
KVMSlot *found = NULL;
int i;
for (i = 0; i < ARRAY_SIZE(s->slots); i++) {
KVMSlot *mem = &s->slots[i];
if (mem->memory_size == 0 ||
(found && found->start_addr < mem->start_addr)) {
continue;
}
if (end_addr > mem->start_addr &&
start_addr < mem->start_addr + mem->memory_size) {
found = mem;
}
}
return found;
}
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)qemu_get_ram_ptr(slot->phys_offset);
mem.flags = slot->flags;
if (s->migration_log) {
mem.flags |= KVM_MEM_LOG_DIRTY_PAGES;
}
return kvm_vm_ioctl(s, KVM_SET_USER_MEMORY_REGION, &mem);
}
static void kvm_reset_vcpu(void *opaque)
{
CPUState *env = opaque;
kvm_arch_reset_vcpu(env);
}
int kvm_irqchip_in_kernel(void)
{
return kvm_state->irqchip_in_kernel;
}
int kvm_pit_in_kernel(void)
{
return kvm_state->pit_in_kernel;
}
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;
}
#ifdef KVM_CAP_COALESCED_MMIO
if (s->coalesced_mmio && !s->coalesced_mmio_ring)
s->coalesced_mmio_ring = (void *) env->kvm_run +
s->coalesced_mmio * PAGE_SIZE;
#endif
ret = kvm_arch_init_vcpu(env);
if (ret == 0) {
qemu_register_reset(kvm_reset_vcpu, env);
kvm_arch_reset_vcpu(env);
}
err:
return ret;
}
/*
* dirty pages logging control
*/
static int kvm_dirty_pages_log_change(target_phys_addr_t phys_addr,
ram_addr_t size, int flags, int mask)
{
KVMState *s = kvm_state;
KVMSlot *mem = kvm_lookup_matching_slot(s, phys_addr, phys_addr + size);
int old_flags;
if (mem == NULL) {
fprintf(stderr, "BUG: %s: invalid parameters " TARGET_FMT_plx "-"
TARGET_FMT_plx "\n", __func__, phys_addr,
(target_phys_addr_t)(phys_addr + size - 1));
return -EINVAL;
}
old_flags = mem->flags;
flags = (mem->flags & ~mask) | flags;
mem->flags = flags;
/* If nothing changed effectively, no need to issue ioctl */
if (s->migration_log) {
flags |= KVM_MEM_LOG_DIRTY_PAGES;
}
if (flags == old_flags) {
return 0;
}
return kvm_set_user_memory_region(s, mem);
}
int kvm_log_start(target_phys_addr_t phys_addr, ram_addr_t size)
{
return kvm_dirty_pages_log_change(phys_addr, size,
KVM_MEM_LOG_DIRTY_PAGES,
KVM_MEM_LOG_DIRTY_PAGES);
}
int kvm_log_stop(target_phys_addr_t phys_addr, ram_addr_t size)
{
return kvm_dirty_pages_log_change(phys_addr, size,
0,
KVM_MEM_LOG_DIRTY_PAGES);
}
static int kvm_set_migration_log(int enable)
{
KVMState *s = kvm_state;
KVMSlot *mem;
int i, err;
s->migration_log = enable;
for (i = 0; i < ARRAY_SIZE(s->slots); i++) {
mem = &s->slots[i];
if (!!(mem->flags & KVM_MEM_LOG_DIRTY_PAGES) == enable) {
continue;
}
err = kvm_set_user_memory_region(s, mem);
if (err) {
return err;
}
}
return 0;
}
/* get kvm's dirty pages bitmap and update qemu's */
static int kvm_get_dirty_pages_log_range(unsigned long start_addr,
unsigned long *bitmap,
unsigned long offset,
unsigned long mem_size)
{
unsigned int i, j;
unsigned long page_number, addr, addr1, c;
ram_addr_t ram_addr;
unsigned int len = ((mem_size / TARGET_PAGE_SIZE) + HOST_LONG_BITS - 1) /
HOST_LONG_BITS;
/*
* bitmap-traveling is faster than memory-traveling (for addr...)
* especially when most of the memory is not dirty.
*/
for (i = 0; i < len; i++) {
if (bitmap[i] != 0) {
c = leul_to_cpu(bitmap[i]);
do {
j = ffsl(c) - 1;
c &= ~(1ul << j);
page_number = i * HOST_LONG_BITS + j;
addr1 = page_number * TARGET_PAGE_SIZE;
addr = offset + addr1;
ram_addr = cpu_get_physical_page_desc(addr);
cpu_physical_memory_set_dirty(ram_addr);
} while (c != 0);
}
}
return 0;
}
#define ALIGN(x, y) (((x)+(y)-1) & ~((y)-1))
/**
* 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.
* @end_addr: end of logged region.
*/
static int kvm_physical_sync_dirty_bitmap(target_phys_addr_t start_addr,
target_phys_addr_t end_addr)
{
KVMState *s = kvm_state;
unsigned long size, allocated_size = 0;
KVMDirtyLog d;
KVMSlot *mem;
int ret = 0;
d.dirty_bitmap = NULL;
while (start_addr < end_addr) {
mem = kvm_lookup_overlapping_slot(s, start_addr, end_addr);
if (mem == NULL) {
break;
}
size = ALIGN(((mem->memory_size) >> TARGET_PAGE_BITS), HOST_LONG_BITS) / 8;
if (!d.dirty_bitmap) {
d.dirty_bitmap = qemu_malloc(size);
} else if (size > allocated_size) {
d.dirty_bitmap = qemu_realloc(d.dirty_bitmap, size);
}
allocated_size = size;
memset(d.dirty_bitmap, 0, allocated_size);
d.slot = mem->slot;
if (kvm_vm_ioctl(s, KVM_GET_DIRTY_LOG, &d) == -1) {
DPRINTF("ioctl failed %d\n", errno);
ret = -1;
break;
}
kvm_get_dirty_pages_log_range(mem->start_addr, d.dirty_bitmap,
mem->start_addr, mem->memory_size);
start_addr = mem->start_addr + mem->memory_size;
}
qemu_free(d.dirty_bitmap);
return ret;
}
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_check_extension(KVMState *s, unsigned int extension)
{
int ret;
ret = kvm_ioctl(s, KVM_CHECK_EXTENSION, extension);
if (ret < 0) {
ret = 0;
}
return ret;
}
static 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, old;
int err;
if (start_addr & ~TARGET_PAGE_MASK) {
if (flags >= IO_MEM_UNASSIGNED) {
if (!kvm_lookup_overlapping_slot(s, start_addr,
start_addr + size)) {
return;
}
fprintf(stderr, "Unaligned split of a KVM memory slot\n");
} else {
fprintf(stderr, "Only page-aligned memory slots supported\n");
}
abort();
}
/* KVM does not support read-only slots */
phys_offset &= ~IO_MEM_ROM;
while (1) {
mem = kvm_lookup_overlapping_slot(s, start_addr, start_addr + size);
if (!mem) {
break;
}
if (flags < IO_MEM_UNASSIGNED && start_addr >= mem->start_addr &&
(start_addr + size <= mem->start_addr + mem->memory_size) &&
(phys_offset - start_addr == mem->phys_offset - mem->start_addr)) {
/* The new slot fits into the existing one and comes with
* identical parameters - nothing to be done. */
return;
}
old = *mem;
/* unregister the overlapping slot */
mem->memory_size = 0;
err = kvm_set_user_memory_region(s, mem);
if (err) {
fprintf(stderr, "%s: error unregistering overlapping slot: %s\n",
__func__, strerror(-err));
abort();
}
/* Workaround for older KVM versions: we can't join slots, even not by
* unregistering the previous ones and then registering the larger
* slot. We have to maintain the existing fragmentation. Sigh.
*
* This workaround assumes that the new slot starts at the same
* address as the first existing one. If not or if some overlapping
* slot comes around later, we will fail (not seen in practice so far)
* - and actually require a recent KVM version. */
if (s->broken_set_mem_region &&
old.start_addr == start_addr && old.memory_size < size &&
flags < IO_MEM_UNASSIGNED) {
mem = kvm_alloc_slot(s);
mem->memory_size = old.memory_size;
mem->start_addr = old.start_addr;
mem->phys_offset = old.phys_offset;
mem->flags = 0;
err = kvm_set_user_memory_region(s, mem);
if (err) {
fprintf(stderr, "%s: error updating slot: %s\n", __func__,
strerror(-err));
abort();
}
start_addr += old.memory_size;
phys_offset += old.memory_size;
size -= old.memory_size;
continue;
}
/* register prefix slot */
if (old.start_addr < start_addr) {
mem = kvm_alloc_slot(s);
mem->memory_size = start_addr - old.start_addr;
mem->start_addr = old.start_addr;
mem->phys_offset = old.phys_offset;
mem->flags = 0;
err = kvm_set_user_memory_region(s, mem);
if (err) {
fprintf(stderr, "%s: error registering prefix slot: %s\n",
__func__, strerror(-err));
abort();
}
}
/* register suffix slot */
if (old.start_addr + old.memory_size > start_addr + size) {
ram_addr_t size_delta;
mem = kvm_alloc_slot(s);
mem->start_addr = start_addr + size;
size_delta = mem->start_addr - old.start_addr;
mem->memory_size = old.memory_size - size_delta;
mem->phys_offset = old.phys_offset + size_delta;
mem->flags = 0;
err = kvm_set_user_memory_region(s, mem);
if (err) {
fprintf(stderr, "%s: error registering suffix slot: %s\n",
__func__, strerror(-err));
abort();
}
}
}
/* in case the KVM bug workaround already "consumed" the new slot */
if (!size)
return;
/* 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;
err = kvm_set_user_memory_region(s, mem);
if (err) {
fprintf(stderr, "%s: error registering slot: %s\n", __func__,
strerror(-err));
abort();
}
}
static void kvm_client_set_memory(struct CPUPhysMemoryClient *client,
target_phys_addr_t start_addr,
ram_addr_t size,
ram_addr_t phys_offset)
{
kvm_set_phys_mem(start_addr, size, phys_offset);
}
static int kvm_client_sync_dirty_bitmap(struct CPUPhysMemoryClient *client,
target_phys_addr_t start_addr,
target_phys_addr_t end_addr)
{
return kvm_physical_sync_dirty_bitmap(start_addr, end_addr);
}
static int kvm_client_migration_log(struct CPUPhysMemoryClient *client,
int enable)
{
return kvm_set_migration_log(enable);
}
static CPUPhysMemoryClient kvm_cpu_phys_memory_client = {
.set_memory = kvm_client_set_memory,
.sync_dirty_bitmap = kvm_client_sync_dirty_bitmap,
.migration_log = kvm_client_migration_log,
};
int kvm_init(int smp_cpus)
{
static const char upgrade_note[] =
"Please upgrade to at least kernel 2.6.29 or recent kvm-kmod\n"
"(see http://sourceforge.net/projects/kvm).\n";
KVMState *s;
int ret;
int i;
s = qemu_mallocz(sizeof(KVMState));
#ifdef KVM_CAP_SET_GUEST_DEBUG
QTAILQ_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 = qemu_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) {
#ifdef TARGET_S390X
fprintf(stderr, "Please add the 'switch_amode' kernel parameter to "
"your host kernel command line\n");
#endif
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 regular pages
* unmodified. Make sure we have a sufficiently modern version of KVM.
*/
if (!kvm_check_extension(s, KVM_CAP_USER_MEMORY)) {
ret = -EINVAL;
fprintf(stderr, "kvm does not support KVM_CAP_USER_MEMORY\n%s",
upgrade_note);
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. */
if (!kvm_check_extension(s, KVM_CAP_DESTROY_MEMORY_REGION_WORKS)) {
ret = -EINVAL;
fprintf(stderr,
"KVM kernel module broken (DESTROY_MEMORY_REGION).\n%s",
upgrade_note);
goto err;
}
s->coalesced_mmio = 0;
#ifdef KVM_CAP_COALESCED_MMIO
s->coalesced_mmio = kvm_check_extension(s, KVM_CAP_COALESCED_MMIO);
s->coalesced_mmio_ring = NULL;
#endif
s->broken_set_mem_region = 1;
#ifdef KVM_CAP_JOIN_MEMORY_REGIONS_WORKS
ret = kvm_ioctl(s, KVM_CHECK_EXTENSION, KVM_CAP_JOIN_MEMORY_REGIONS_WORKS);
if (ret > 0) {
s->broken_set_mem_region = 0;
}
#endif
s->vcpu_events = 0;
#ifdef KVM_CAP_VCPU_EVENTS
s->vcpu_events = kvm_check_extension(s, KVM_CAP_VCPU_EVENTS);
#endif
s->robust_singlestep = 0;
#ifdef KVM_CAP_X86_ROBUST_SINGLESTEP
s->robust_singlestep =
kvm_check_extension(s, KVM_CAP_X86_ROBUST_SINGLESTEP);
#endif
s->debugregs = 0;
#ifdef KVM_CAP_DEBUGREGS
s->debugregs = kvm_check_extension(s, KVM_CAP_DEBUGREGS);
#endif
s->xsave = 0;
#ifdef KVM_CAP_XSAVE
s->xsave = kvm_check_extension(s, KVM_CAP_XSAVE);
#endif
s->xcrs = 0;
#ifdef KVM_CAP_XCRS
s->xcrs = kvm_check_extension(s, KVM_CAP_XCRS);
#endif
ret = kvm_arch_init(s, smp_cpus);
if (ret < 0)
goto err;
kvm_state = s;
cpu_register_phys_memory_client(&kvm_cpu_phys_memory_client);
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(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(port));
break;
case 2:
stw_p(ptr, cpu_inw(port));
break;
case 4:
stl_p(ptr, cpu_inl(port));
break;
}
} else {
switch (size) {
case 1:
cpu_outb(port, ldub_p(ptr));
break;
case 2:
cpu_outw(port, lduw_p(ptr));
break;
case 4:
cpu_outl(port, ldl_p(ptr));
break;
}
}
ptr += size;
}
return 1;
}
#ifdef KVM_CAP_INTERNAL_ERROR_DATA
static void kvm_handle_internal_error(CPUState *env, struct kvm_run *run)
{
if (kvm_check_extension(kvm_state, KVM_CAP_INTERNAL_ERROR_DATA)) {
int i;
fprintf(stderr, "KVM internal error. Suberror: %d\n",
run->internal.suberror);
for (i = 0; i < run->internal.ndata; ++i) {
fprintf(stderr, "extra data[%d]: %"PRIx64"\n",
i, (uint64_t)run->internal.data[i]);
}
}
cpu_dump_state(env, stderr, fprintf, 0);
if (run->internal.suberror == KVM_INTERNAL_ERROR_EMULATION) {
fprintf(stderr, "emulation failure\n");
if (!kvm_arch_stop_on_emulation_error(env))
return;
}
/* FIXME: Should trigger a qmp message to let management know
* something went wrong.
*/
vm_stop(0);
}
#endif
void kvm_flush_coalesced_mmio_buffer(void)
{
#ifdef KVM_CAP_COALESCED_MMIO
KVMState *s = kvm_state;
if (s->coalesced_mmio_ring) {
struct kvm_coalesced_mmio_ring *ring = s->coalesced_mmio_ring;
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);
smp_wmb();
ring->first = (ring->first + 1) % KVM_COALESCED_MMIO_MAX;
}
}
#endif
}
static void do_kvm_cpu_synchronize_state(void *_env)
{
CPUState *env = _env;
if (!env->kvm_vcpu_dirty) {
kvm_arch_get_registers(env);
env->kvm_vcpu_dirty = 1;
}
}
void kvm_cpu_synchronize_state(CPUState *env)
{
if (!env->kvm_vcpu_dirty)
run_on_cpu(env, do_kvm_cpu_synchronize_state, env);
}
KVM: Rework VCPU state writeback API This grand cleanup drops all reset and vmsave/load related synchronization points in favor of four(!) generic hooks: - cpu_synchronize_all_states in qemu_savevm_state_complete (initial sync from kernel before vmsave) - cpu_synchronize_all_post_init in qemu_loadvm_state (writeback after vmload) - cpu_synchronize_all_post_init in main after machine init - cpu_synchronize_all_post_reset in qemu_system_reset (writeback after system reset) These writeback points + the existing one of VCPU exec after cpu_synchronize_state map on three levels of writeback: - KVM_PUT_RUNTIME_STATE (during runtime, other VCPUs continue to run) - KVM_PUT_RESET_STATE (on synchronous system reset, all VCPUs stopped) - KVM_PUT_FULL_STATE (on init or vmload, all VCPUs stopped as well) This level is passed to the arch-specific VCPU state writing function that will decide which concrete substates need to be written. That way, no writer of load, save or reset functions that interact with in-kernel KVM states will ever have to worry about synchronization again. That also means that a lot of reasons for races, segfaults and deadlocks are eliminated. cpu_synchronize_state remains untouched, just as Anthony suggested. We continue to need it before reading or writing of VCPU states that are also tracked by in-kernel KVM subsystems. Consequently, this patch removes many cpu_synchronize_state calls that are now redundant, just like remaining explicit register syncs. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-03-01 21:10:30 +03:00
void kvm_cpu_synchronize_post_reset(CPUState *env)
{
kvm_arch_put_registers(env, KVM_PUT_RESET_STATE);
env->kvm_vcpu_dirty = 0;
}
void kvm_cpu_synchronize_post_init(CPUState *env)
{
kvm_arch_put_registers(env, KVM_PUT_FULL_STATE);
env->kvm_vcpu_dirty = 0;
}
int kvm_cpu_exec(CPUState *env)
{
struct kvm_run *run = env->kvm_run;
int ret;
DPRINTF("kvm_cpu_exec()\n");
do {
#ifndef CONFIG_IOTHREAD
if (env->exit_request) {
DPRINTF("interrupt exit requested\n");
ret = 0;
break;
}
#endif
if (kvm_arch_process_irqchip_events(env)) {
ret = 0;
break;
}
if (env->kvm_vcpu_dirty) {
KVM: Rework VCPU state writeback API This grand cleanup drops all reset and vmsave/load related synchronization points in favor of four(!) generic hooks: - cpu_synchronize_all_states in qemu_savevm_state_complete (initial sync from kernel before vmsave) - cpu_synchronize_all_post_init in qemu_loadvm_state (writeback after vmload) - cpu_synchronize_all_post_init in main after machine init - cpu_synchronize_all_post_reset in qemu_system_reset (writeback after system reset) These writeback points + the existing one of VCPU exec after cpu_synchronize_state map on three levels of writeback: - KVM_PUT_RUNTIME_STATE (during runtime, other VCPUs continue to run) - KVM_PUT_RESET_STATE (on synchronous system reset, all VCPUs stopped) - KVM_PUT_FULL_STATE (on init or vmload, all VCPUs stopped as well) This level is passed to the arch-specific VCPU state writing function that will decide which concrete substates need to be written. That way, no writer of load, save or reset functions that interact with in-kernel KVM states will ever have to worry about synchronization again. That also means that a lot of reasons for races, segfaults and deadlocks are eliminated. cpu_synchronize_state remains untouched, just as Anthony suggested. We continue to need it before reading or writing of VCPU states that are also tracked by in-kernel KVM subsystems. Consequently, this patch removes many cpu_synchronize_state calls that are now redundant, just like remaining explicit register syncs. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-03-01 21:10:30 +03:00
kvm_arch_put_registers(env, KVM_PUT_RUNTIME_STATE);
env->kvm_vcpu_dirty = 0;
}
kvm_arch_pre_run(env, run);
cpu_single_env = NULL;
qemu_mutex_unlock_iothread();
ret = kvm_vcpu_ioctl(env, KVM_RUN, 0);
qemu_mutex_lock_iothread();
cpu_single_env = env;
kvm_arch_post_run(env, run);
if (ret == -EINTR || ret == -EAGAIN) {
cpu_exit(env);
DPRINTF("io window exit\n");
ret = 0;
break;
}
if (ret < 0) {
DPRINTF("kvm run failed %s\n", strerror(-ret));
abort();
}
kvm_flush_coalesced_mmio_buffer();
ret = 0; /* exit loop */
switch (run->exit_reason) {
case KVM_EXIT_IO:
DPRINTF("handle_io\n");
ret = kvm_handle_io(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;
#ifdef KVM_CAP_INTERNAL_ERROR_DATA
case KVM_EXIT_INTERNAL_ERROR:
kvm_handle_internal_error(env, run);
break;
#endif
case KVM_EXIT_DEBUG:
DPRINTF("kvm_exit_debug\n");
#ifdef KVM_CAP_SET_GUEST_DEBUG
if (kvm_arch_debug(&run->debug.arch)) {
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;
}
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;
return kvm_check_extension(s, KVM_CAP_SYNC_MMU);
#else
return 0;
#endif
}
int kvm_has_vcpu_events(void)
{
return kvm_state->vcpu_events;
}
int kvm_has_robust_singlestep(void)
{
return kvm_state->robust_singlestep;
}
int kvm_has_debugregs(void)
{
return kvm_state->debugregs;
}
int kvm_has_xsave(void)
{
return kvm_state->xsave;
}
int kvm_has_xcrs(void)
{
return kvm_state->xcrs;
}
void kvm_setup_guest_memory(void *start, size_t size)
{
if (!kvm_has_sync_mmu()) {
#ifdef MADV_DONTFORK
int ret = madvise(start, size, MADV_DONTFORK);
if (ret) {
perror("madvice");
exit(1);
}
#else
fprintf(stderr,
"Need MADV_DONTFORK in absence of synchronous KVM MMU\n");
exit(1);
#endif
}
}
#ifdef KVM_CAP_SET_GUEST_DEBUG
struct kvm_sw_breakpoint *kvm_find_sw_breakpoint(CPUState *env,
target_ulong pc)
{
struct kvm_sw_breakpoint *bp;
QTAILQ_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 !QTAILQ_EMPTY(&env->kvm_state->kvm_sw_breakpoints);
}
struct kvm_set_guest_debug_data {
struct kvm_guest_debug dbg;
CPUState *env;
int err;
};
static void kvm_invoke_set_guest_debug(void *data)
{
struct kvm_set_guest_debug_data *dbg_data = data;
CPUState *env = dbg_data->env;
dbg_data->err = kvm_vcpu_ioctl(env, KVM_SET_GUEST_DEBUG, &dbg_data->dbg);
}
int kvm_update_guest_debug(CPUState *env, unsigned long reinject_trap)
{
struct kvm_set_guest_debug_data data;
data.dbg.control = reinject_trap;
if (env->singlestep_enabled) {
data.dbg.control |= KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_SINGLESTEP;
}
kvm_arch_update_guest_debug(env, &data.dbg);
data.env = env;
run_on_cpu(env, kvm_invoke_set_guest_debug, &data);
return data.err;
}
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;
}
QTAILQ_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;
QTAILQ_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;
QTAILQ_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 */
int kvm_set_signal_mask(CPUState *env, const sigset_t *sigset)
{
struct kvm_signal_mask *sigmask;
int r;
if (!sigset)
return kvm_vcpu_ioctl(env, KVM_SET_SIGNAL_MASK, NULL);
sigmask = qemu_malloc(sizeof(*sigmask) + sizeof(*sigset));
sigmask->len = 8;
memcpy(sigmask->sigset, sigset, sizeof(*sigset));
r = kvm_vcpu_ioctl(env, KVM_SET_SIGNAL_MASK, sigmask);
free(sigmask);
return r;
}
int kvm_set_ioeventfd_mmio_long(int fd, uint32_t addr, uint32_t val, bool assign)
{
#ifdef KVM_IOEVENTFD
int ret;
struct kvm_ioeventfd iofd;
iofd.datamatch = val;
iofd.addr = addr;
iofd.len = 4;
iofd.flags = KVM_IOEVENTFD_FLAG_DATAMATCH;
iofd.fd = fd;
if (!kvm_enabled()) {
return -ENOSYS;
}
if (!assign) {
iofd.flags |= KVM_IOEVENTFD_FLAG_DEASSIGN;
}
ret = kvm_vm_ioctl(kvm_state, KVM_IOEVENTFD, &iofd);
if (ret < 0) {
return -errno;
}
return 0;
#else
return -ENOSYS;
#endif
}
int kvm_set_ioeventfd_pio_word(int fd, uint16_t addr, uint16_t val, bool assign)
{
#ifdef KVM_IOEVENTFD
struct kvm_ioeventfd kick = {
.datamatch = val,
.addr = addr,
.len = 2,
.flags = KVM_IOEVENTFD_FLAG_DATAMATCH | KVM_IOEVENTFD_FLAG_PIO,
.fd = fd,
};
int r;
if (!kvm_enabled())
return -ENOSYS;
if (!assign)
kick.flags |= KVM_IOEVENTFD_FLAG_DEASSIGN;
r = kvm_vm_ioctl(kvm_state, KVM_IOEVENTFD, &kick);
if (r < 0)
return r;
return 0;
#else
return -ENOSYS;
#endif
}