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"
/* This check must be after config-host.h is included */
#ifdef CONFIG_EVENTFD
#include <sys/eventfd.h>
#endif
/* 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;
struct kvm_coalesced_mmio_ring *coalesced_mmio_ring;
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;
int many_ioeventfds;
};
KVMState *kvm_state;
static const KVMCapabilityInfo kvm_required_capabilites[] = {
KVM_CAP_INFO(USER_MEMORY),
KVM_CAP_INFO(DESTROY_MEMORY_REGION_WORKS),
KVM_CAP_LAST_INFO
};
static KVMSlot *kvm_alloc_slot(KVMState *s)
{
int i;
for (i = 0; i < ARRAY_SIZE(s->slots); i++) {
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;
}
int kvm_physical_memory_addr_from_ram(KVMState *s, ram_addr_t ram_addr,
target_phys_addr_t *phys_addr)
{
int i;
for (i = 0; i < ARRAY_SIZE(s->slots); i++) {
KVMSlot *mem = &s->slots[i];
if (ram_addr >= mem->phys_offset &&
ram_addr < mem->phys_offset + mem->memory_size) {
*phys_addr = mem->start_addr + (ram_addr - mem->phys_offset);
return 1;
}
}
return 0;
}
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_safe_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;
env->kvm_vcpu_dirty = 1;
mmap_size = kvm_ioctl(s, KVM_GET_VCPU_MMAP_SIZE, 0);
if (mmap_size < 0) {
ret = mmap_size;
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;
}
if (s->coalesced_mmio && !s->coalesced_mmio_ring) {
s->coalesced_mmio_ring =
(void *)env->kvm_run + s->coalesced_mmio * PAGE_SIZE;
}
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_mem_flags(KVMState *s, bool log_dirty)
{
return log_dirty ? KVM_MEM_LOG_DIRTY_PAGES : 0;
}
static int kvm_slot_dirty_pages_log_change(KVMSlot *mem, bool log_dirty)
{
KVMState *s = kvm_state;
int flags, mask = KVM_MEM_LOG_DIRTY_PAGES;
int old_flags;
old_flags = mem->flags;
flags = (mem->flags & ~mask) | kvm_mem_flags(s, log_dirty);
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);
}
static int kvm_dirty_pages_log_change(target_phys_addr_t phys_addr,
ram_addr_t size, bool log_dirty)
{
KVMState *s = kvm_state;
KVMSlot *mem = kvm_lookup_matching_slot(s, phys_addr, phys_addr + size);
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;
}
return kvm_slot_dirty_pages_log_change(mem, log_dirty);
}
static int kvm_log_start(CPUPhysMemoryClient *client,
target_phys_addr_t phys_addr, ram_addr_t size)
{
return kvm_dirty_pages_log_change(phys_addr, size, true);
}
static int kvm_log_stop(CPUPhysMemoryClient *client,
target_phys_addr_t phys_addr, ram_addr_t size)
{
return kvm_dirty_pages_log_change(phys_addr, size, false);
}
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->memory_size) {
continue;
}
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;
}
fix crash in migration, 32-bit userspace on 64-bit host This change fixes a long-standing immediate crash (memory corruption and abort in glibc malloc code) in migration on 32bits. The bug is present since this commit: commit 692d9aca97b865b0f7903565274a52606910f129 Author: Bruce Rogers <brogers@novell.com> Date: Wed Sep 23 16:13:18 2009 -0600 qemu-kvm: allocate correct size for dirty bitmap The dirty bitmap copied out to userspace is stored in a long array, and gets copied out to userspace accordingly. This patch accounts for that correctly. Currently I'm seeing kvm crashing due to writing beyond the end of the alloc'd dirty bitmap memory, because the buffer has the wrong size. Signed-off-by: Bruce Rogers Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> --- a/qemu-kvm.c +++ b/qemu-kvm.c @@ int kvm_get_dirty_pages_range(kvm_context_t kvm, unsigned long phys_addr, - buf = qemu_malloc((slots[i].len / 4096 + 7) / 8 + 2); + buf = qemu_malloc(BITMAP_SIZE(slots[i].len)); r = kvm_get_map(kvm, KVM_GET_DIRTY_LOG, i, buf); BITMAP_SIZE is now open-coded in that function, like this: size = ALIGN(((mem->memory_size) >> TARGET_PAGE_BITS), HOST_LONG_BITS) / 8; The problem is that HOST_LONG_BITS in 32bit userspace is 32 but it's 64 in 64bit kernel. So userspace aligns this to 32, and kernel to 64, but since no length is passed from userspace to kernel on ioctl, kernel uses its size calculation and copies 4 extra bytes to userspace, corrupting memory. Here's how it looks like during migrate execution: our=20, kern=24 our=4, kern=8 ... our=4, kern=8 our=4064, kern=4064 our=512, kern=512 our=4, kern=8 our=20, kern=24 our=4, kern=8 ... our=4, kern=8 our=4064, kern=4064 *** glibc detected *** ./x86_64-softmmu/qemu-system-x86_64: realloc(): invalid next size: 0x08f20528 *** (our is userspace size above, kern is the size as calculated by the kernel). Fix this by always aligning to 64 in a hope that no platform will have sizeof(long)>8 any time soon, and add a comment describing it all. It's a small price to pay for bad kernel design. Alternatively it's possible to fix that in the kernel by using different size calculation depending on the current process. But this becomes quite ugly. Special thanks goes to Stefan Hajnoczi for spotting the fundamental cause of the issue, and to Alexander Graf for his support in #qemu. Signed-off-by: Michael Tokarev <mjt@tls.msk.ru> CC: Bruce Rogers <brogers@novell.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-04-26 20:13:49 +04:00
/* XXX bad kernel interface alert
* For dirty bitmap, kernel allocates array of size aligned to
* bits-per-long. But for case when the kernel is 64bits and
* the userspace is 32bits, userspace can't align to the same
* bits-per-long, since sizeof(long) is different between kernel
* and user space. This way, userspace will provide buffer which
* may be 4 bytes less than the kernel will use, resulting in
* userspace memory corruption (which is not detectable by valgrind
* too, in most cases).
* So for now, let's align to 64 instead of HOST_LONG_BITS here, in
* a hope that sizeof(long) wont become >8 any time soon.
*/
size = ALIGN(((mem->memory_size) >> TARGET_PAGE_BITS),
/*HOST_LONG_BITS*/ 64) / 8;
if (!d.dirty_bitmap) {
d.dirty_bitmap = g_malloc(size);
} else if (size > allocated_size) {
d.dirty_bitmap = g_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;
}
g_free(d.dirty_bitmap);
return ret;
}
int kvm_coalesce_mmio_region(target_phys_addr_t start, ram_addr_t size)
{
int ret = -ENOSYS;
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);
}
return ret;
}
int kvm_uncoalesce_mmio_region(target_phys_addr_t start, ram_addr_t size)
{
int ret = -ENOSYS;
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);
}
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 int kvm_check_many_ioeventfds(void)
{
/* Userspace can use ioeventfd for io notification. This requires a host
* that supports eventfd(2) and an I/O thread; since eventfd does not
* support SIGIO it cannot interrupt the vcpu.
*
* Older kernels have a 6 device limit on the KVM io bus. Find out so we
* can avoid creating too many ioeventfds.
*/
#if defined(CONFIG_EVENTFD)
int ioeventfds[7];
int i, ret = 0;
for (i = 0; i < ARRAY_SIZE(ioeventfds); i++) {
ioeventfds[i] = eventfd(0, EFD_CLOEXEC);
if (ioeventfds[i] < 0) {
break;
}
ret = kvm_set_ioeventfd_pio_word(ioeventfds[i], 0, i, true);
if (ret < 0) {
close(ioeventfds[i]);
break;
}
}
/* Decide whether many devices are supported or not */
ret = i == ARRAY_SIZE(ioeventfds);
while (i-- > 0) {
kvm_set_ioeventfd_pio_word(ioeventfds[i], 0, i, false);
close(ioeventfds[i]);
}
return ret;
#else
return 0;
#endif
}
static const KVMCapabilityInfo *
kvm_check_extension_list(KVMState *s, const KVMCapabilityInfo *list)
{
while (list->name) {
if (!kvm_check_extension(s, list->value)) {
return list;
}
list++;
}
return NULL;
}
static void kvm_set_phys_mem(target_phys_addr_t start_addr, ram_addr_t size,
ram_addr_t phys_offset, bool log_dirty)
{
KVMState *s = kvm_state;
ram_addr_t flags = phys_offset & ~TARGET_PAGE_MASK;
KVMSlot *mem, old;
int err;
/* kvm works in page size chunks, but the function may be called
with sub-page size and unaligned start address. */
size = TARGET_PAGE_ALIGN(size);
start_addr = TARGET_PAGE_ALIGN(start_addr);
/* 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 - update flags and done. */
kvm_slot_dirty_pages_log_change(mem, log_dirty);
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 = kvm_mem_flags(s, log_dirty);
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 = kvm_mem_flags(s, log_dirty);
err = kvm_set_user_memory_region(s, mem);
if (err) {
fprintf(stderr, "%s: error registering prefix slot: %s\n",
__func__, strerror(-err));
#ifdef TARGET_PPC
fprintf(stderr, "%s: This is probably because your kernel's " \
"PAGE_SIZE is too big. Please try to use 4k " \
"PAGE_SIZE!\n", __func__);
#endif
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 = kvm_mem_flags(s, log_dirty);
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 = kvm_mem_flags(s, log_dirty);
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,
bool log_dirty)
{
kvm_set_phys_mem(start_addr, size, phys_offset, log_dirty);
}
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,
.log_start = kvm_log_start,
.log_stop = kvm_log_stop,
};
static void kvm_handle_interrupt(CPUState *env, int mask)
{
env->interrupt_request |= mask;
if (!qemu_cpu_is_self(env)) {
qemu_cpu_kick(env);
}
}
int kvm_init(void)
{
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;
const KVMCapabilityInfo *missing_cap;
int ret;
int i;
s = g_malloc0(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;
}
missing_cap = kvm_check_extension_list(s, kvm_required_capabilites);
if (!missing_cap) {
missing_cap =
kvm_check_extension_list(s, kvm_arch_required_capabilities);
}
if (missing_cap) {
ret = -EINVAL;
fprintf(stderr, "kvm does not support %s\n%s",
missing_cap->name, upgrade_note);
goto err;
}
s->coalesced_mmio = kvm_check_extension(s, KVM_CAP_COALESCED_MMIO);
s->broken_set_mem_region = 1;
ret = kvm_check_extension(s, KVM_CAP_JOIN_MEMORY_REGIONS_WORKS);
if (ret > 0) {
s->broken_set_mem_region = 0;
}
#ifdef KVM_CAP_VCPU_EVENTS
s->vcpu_events = kvm_check_extension(s, KVM_CAP_VCPU_EVENTS);
#endif
s->robust_singlestep =
kvm_check_extension(s, KVM_CAP_X86_ROBUST_SINGLESTEP);
#ifdef KVM_CAP_DEBUGREGS
s->debugregs = kvm_check_extension(s, KVM_CAP_DEBUGREGS);
#endif
#ifdef KVM_CAP_XSAVE
s->xsave = kvm_check_extension(s, KVM_CAP_XSAVE);
#endif
#ifdef KVM_CAP_XCRS
s->xcrs = kvm_check_extension(s, KVM_CAP_XCRS);
#endif
ret = kvm_arch_init(s);
if (ret < 0) {
goto err;
}
kvm_state = s;
cpu_register_phys_memory_client(&kvm_cpu_phys_memory_client);
s->many_ioeventfds = kvm_check_many_ioeventfds();
cpu_interrupt_handler = kvm_handle_interrupt;
return 0;
err:
if (s) {
if (s->vmfd != -1) {
close(s->vmfd);
}
if (s->fd != -1) {
close(s->fd);
}
}
g_free(s);
return ret;
}
static void 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;
}
}
static int kvm_handle_internal_error(CPUState *env, struct kvm_run *run)
{
fprintf(stderr, "KVM internal error.");
if (kvm_check_extension(kvm_state, KVM_CAP_INTERNAL_ERROR_DATA)) {
int i;
fprintf(stderr, " 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]);
}
} else {
fprintf(stderr, "\n");
}
if (run->internal.suberror == KVM_INTERNAL_ERROR_EMULATION) {
fprintf(stderr, "emulation failure\n");
if (!kvm_arch_stop_on_emulation_error(env)) {
cpu_dump_state(env, stderr, fprintf, CPU_DUMP_CODE);
return EXCP_INTERRUPT;
}
}
/* FIXME: Should trigger a qmp message to let management know
* something went wrong.
*/
return -1;
}
void kvm_flush_coalesced_mmio_buffer(void)
{
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;
}
}
}
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, run_ret;
DPRINTF("kvm_cpu_exec()\n");
if (kvm_arch_process_async_events(env)) {
env->exit_request = 0;
return EXCP_HLT;
}
cpu_single_env = env;
do {
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);
if (env->exit_request) {
DPRINTF("interrupt exit requested\n");
/*
* KVM requires us to reenter the kernel after IO exits to complete
* instruction emulation. This self-signal will ensure that we
* leave ASAP again.
*/
qemu_cpu_kick_self();
}
cpu_single_env = NULL;
qemu_mutex_unlock_iothread();
run_ret = kvm_vcpu_ioctl(env, KVM_RUN, 0);
qemu_mutex_lock_iothread();
cpu_single_env = env;
kvm_arch_post_run(env, run);
kvm_flush_coalesced_mmio_buffer();
if (run_ret < 0) {
if (run_ret == -EINTR || run_ret == -EAGAIN) {
DPRINTF("io window exit\n");
ret = EXCP_INTERRUPT;
break;
}
DPRINTF("kvm run failed %s\n", strerror(-run_ret));
abort();
}
switch (run->exit_reason) {
case KVM_EXIT_IO:
DPRINTF("handle_io\n");
kvm_handle_io(run->io.port,
(uint8_t *)run + run->io.data_offset,
run->io.direction,
run->io.size,
run->io.count);
ret = 0;
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 = 0;
break;
case KVM_EXIT_IRQ_WINDOW_OPEN:
DPRINTF("irq_window_open\n");
ret = EXCP_INTERRUPT;
break;
case KVM_EXIT_SHUTDOWN:
DPRINTF("shutdown\n");
qemu_system_reset_request();
ret = EXCP_INTERRUPT;
break;
case KVM_EXIT_UNKNOWN:
fprintf(stderr, "KVM: unknown exit, hardware reason %" PRIx64 "\n",
(uint64_t)run->hw.hardware_exit_reason);
ret = -1;
break;
case KVM_EXIT_INTERNAL_ERROR:
ret = kvm_handle_internal_error(env, run);
break;
default:
DPRINTF("kvm_arch_handle_exit\n");
ret = kvm_arch_handle_exit(env, run);
break;
}
} while (ret == 0);
if (ret < 0) {
cpu_dump_state(env, stderr, fprintf, CPU_DUMP_CODE);
vm_stop(RUN_STATE_INTERNAL_ERROR);
}
env->exit_request = 0;
cpu_single_env = NULL;
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)
{
return kvm_check_extension(kvm_state, KVM_CAP_SYNC_MMU);
}
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;
}
int kvm_has_many_ioeventfds(void)
{
if (!kvm_enabled()) {
return 0;
}
return kvm_state->many_ioeventfds;
}
void kvm_setup_guest_memory(void *start, size_t size)
{
if (!kvm_has_sync_mmu()) {
Introduce qemu_madvise() vl.c has a Sun-specific hack to supply a prototype for madvise(), but the call site has apparently moved to arch_init.c. Haiku doesn't implement madvise() in favor of posix_madvise(). OpenBSD and Solaris 10 don't implement posix_madvise() but madvise(). MinGW implements neither. Check for madvise() and posix_madvise() in configure and supply qemu_madvise() as wrapper. Prefer madvise() over posix_madvise() due to flag availability. Convert all callers to use qemu_madvise() and QEMU_MADV_*. Note that on Solaris the warning is fixed by moving the madvise() prototype, not by qemu_madvise() itself. It helps with porting though, and it simplifies most call sites. v7 -> v8: * Some versions of MinGW have no sys/mman.h header. Reported by Blue Swirl. v6 -> v7: * Adopt madvise() rather than posix_madvise() semantics for returning errors. * Use EINVAL in place of ENOTSUP. v5 -> v6: * Replace two leftover instances of POSIX_MADV_NORMAL with QEMU_MADV_INVALID. Spotted by Blue Swirl. v4 -> v5: * Introduce QEMU_MADV_INVALID, suggested by Alexander Graf. Note that this relies on -1 not being a valid advice value. v3 -> v4: * Eliminate #ifdefs at qemu_advise() call sites. Requested by Blue Swirl. This will currently break the check in kvm-all.c by calling madvise() with a supported flag, which will not fail. Ideas/patches welcome. v2 -> v3: * Reuse the *_MADV_* defines for QEMU_MADV_*. Suggested by Alexander Graf. * Add configure check for madvise(), too. Add defines to Makefile, not QEMU_CFLAGS. Convert all callers, untested. Suggested by Blue Swirl. * Keep Solaris' madvise() prototype around. Pointed out by Alexander Graf. * Display configure check results. v1 -> v2: * Don't rely on posix_madvise() availability, add qemu_madvise(). Suggested by Blue Swirl. Signed-off-by: Andreas Färber <afaerber@opensolaris.org> Cc: Blue Swirl <blauwirbel@gmail.com> Cc: Alexander Graf <agraf@suse.de> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2010-09-25 15:26:05 +04:00
int ret = qemu_madvise(start, size, QEMU_MADV_DONTFORK);
if (ret) {
Introduce qemu_madvise() vl.c has a Sun-specific hack to supply a prototype for madvise(), but the call site has apparently moved to arch_init.c. Haiku doesn't implement madvise() in favor of posix_madvise(). OpenBSD and Solaris 10 don't implement posix_madvise() but madvise(). MinGW implements neither. Check for madvise() and posix_madvise() in configure and supply qemu_madvise() as wrapper. Prefer madvise() over posix_madvise() due to flag availability. Convert all callers to use qemu_madvise() and QEMU_MADV_*. Note that on Solaris the warning is fixed by moving the madvise() prototype, not by qemu_madvise() itself. It helps with porting though, and it simplifies most call sites. v7 -> v8: * Some versions of MinGW have no sys/mman.h header. Reported by Blue Swirl. v6 -> v7: * Adopt madvise() rather than posix_madvise() semantics for returning errors. * Use EINVAL in place of ENOTSUP. v5 -> v6: * Replace two leftover instances of POSIX_MADV_NORMAL with QEMU_MADV_INVALID. Spotted by Blue Swirl. v4 -> v5: * Introduce QEMU_MADV_INVALID, suggested by Alexander Graf. Note that this relies on -1 not being a valid advice value. v3 -> v4: * Eliminate #ifdefs at qemu_advise() call sites. Requested by Blue Swirl. This will currently break the check in kvm-all.c by calling madvise() with a supported flag, which will not fail. Ideas/patches welcome. v2 -> v3: * Reuse the *_MADV_* defines for QEMU_MADV_*. Suggested by Alexander Graf. * Add configure check for madvise(), too. Add defines to Makefile, not QEMU_CFLAGS. Convert all callers, untested. Suggested by Blue Swirl. * Keep Solaris' madvise() prototype around. Pointed out by Alexander Graf. * Display configure check results. v1 -> v2: * Don't rely on posix_madvise() availability, add qemu_madvise(). Suggested by Blue Swirl. Signed-off-by: Andreas Färber <afaerber@opensolaris.org> Cc: Blue Swirl <blauwirbel@gmail.com> Cc: Alexander Graf <agraf@suse.de> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2010-09-25 15:26:05 +04:00
perror("qemu_madvise");
fprintf(stderr,
"Need MADV_DONTFORK in absence of synchronous KVM MMU\n");
exit(1);
}
}
}
#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 = g_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) {
g_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);
g_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 = g_malloc(sizeof(*sigmask) + sizeof(*sigset));
sigmask->len = 8;
memcpy(sigmask->sigset, sigset, sizeof(*sigset));
r = kvm_vcpu_ioctl(env, KVM_SET_SIGNAL_MASK, sigmask);
g_free(sigmask);
return r;
}
int kvm_set_ioeventfd_mmio_long(int fd, uint32_t addr, uint32_t val, bool assign)
{
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;
}
int kvm_set_ioeventfd_pio_word(int fd, uint16_t addr, uint16_t val, bool assign)
{
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;
}
int kvm_on_sigbus_vcpu(CPUState *env, int code, void *addr)
{
return kvm_arch_on_sigbus_vcpu(env, code, addr);
}
int kvm_on_sigbus(int code, void *addr)
{
return kvm_arch_on_sigbus(code, addr);
}