qemu/target-arm/kvm.c
Christoffer Dall 4b7a6bf402 target-arm: kvm: Differentiate registers based on write-back levels
Some registers like the CNTVCT register should only be written to the
kernel as part of machine initialization or on vmload operations, but
never during runtime, as this can potentially make time go backwards or
create inconsistent time observations between VCPUs.

Introduce a list of registers that should not be written back at runtime
and check this list on syncing the register state to the KVM state.

Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Message-id: 1437046488-10773-1-git-send-email-christoffer.dall@linaro.org
[PMM: tweaked a few comments, added the new argument to the stub
 write_list_to_kvmstate() in target-arm/kvm-stub.c]
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2015-07-21 11:18:45 +01:00

612 lines
15 KiB
C

/*
* ARM implementation of KVM hooks
*
* Copyright Christoffer Dall 2009-2010
*
* 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 <stdio.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <linux/kvm.h>
#include "qemu-common.h"
#include "qemu/timer.h"
#include "sysemu/sysemu.h"
#include "sysemu/kvm.h"
#include "kvm_arm.h"
#include "cpu.h"
#include "internals.h"
#include "hw/arm/arm.h"
#include "exec/memattrs.h"
const KVMCapabilityInfo kvm_arch_required_capabilities[] = {
KVM_CAP_LAST_INFO
};
static bool cap_has_mp_state;
int kvm_arm_vcpu_init(CPUState *cs)
{
ARMCPU *cpu = ARM_CPU(cs);
struct kvm_vcpu_init init;
init.target = cpu->kvm_target;
memcpy(init.features, cpu->kvm_init_features, sizeof(init.features));
return kvm_vcpu_ioctl(cs, KVM_ARM_VCPU_INIT, &init);
}
bool kvm_arm_create_scratch_host_vcpu(const uint32_t *cpus_to_try,
int *fdarray,
struct kvm_vcpu_init *init)
{
int ret, kvmfd = -1, vmfd = -1, cpufd = -1;
kvmfd = qemu_open("/dev/kvm", O_RDWR);
if (kvmfd < 0) {
goto err;
}
vmfd = ioctl(kvmfd, KVM_CREATE_VM, 0);
if (vmfd < 0) {
goto err;
}
cpufd = ioctl(vmfd, KVM_CREATE_VCPU, 0);
if (cpufd < 0) {
goto err;
}
ret = ioctl(vmfd, KVM_ARM_PREFERRED_TARGET, init);
if (ret >= 0) {
ret = ioctl(cpufd, KVM_ARM_VCPU_INIT, init);
if (ret < 0) {
goto err;
}
} else {
/* Old kernel which doesn't know about the
* PREFERRED_TARGET ioctl: we know it will only support
* creating one kind of guest CPU which is its preferred
* CPU type.
*/
while (*cpus_to_try != QEMU_KVM_ARM_TARGET_NONE) {
init->target = *cpus_to_try++;
memset(init->features, 0, sizeof(init->features));
ret = ioctl(cpufd, KVM_ARM_VCPU_INIT, init);
if (ret >= 0) {
break;
}
}
if (ret < 0) {
goto err;
}
}
fdarray[0] = kvmfd;
fdarray[1] = vmfd;
fdarray[2] = cpufd;
return true;
err:
if (cpufd >= 0) {
close(cpufd);
}
if (vmfd >= 0) {
close(vmfd);
}
if (kvmfd >= 0) {
close(kvmfd);
}
return false;
}
void kvm_arm_destroy_scratch_host_vcpu(int *fdarray)
{
int i;
for (i = 2; i >= 0; i--) {
close(fdarray[i]);
}
}
static void kvm_arm_host_cpu_class_init(ObjectClass *oc, void *data)
{
ARMHostCPUClass *ahcc = ARM_HOST_CPU_CLASS(oc);
/* All we really need to set up for the 'host' CPU
* is the feature bits -- we rely on the fact that the
* various ID register values in ARMCPU are only used for
* TCG CPUs.
*/
if (!kvm_arm_get_host_cpu_features(ahcc)) {
fprintf(stderr, "Failed to retrieve host CPU features!\n");
abort();
}
}
static void kvm_arm_host_cpu_initfn(Object *obj)
{
ARMHostCPUClass *ahcc = ARM_HOST_CPU_GET_CLASS(obj);
ARMCPU *cpu = ARM_CPU(obj);
CPUARMState *env = &cpu->env;
cpu->kvm_target = ahcc->target;
cpu->dtb_compatible = ahcc->dtb_compatible;
env->features = ahcc->features;
}
static const TypeInfo host_arm_cpu_type_info = {
.name = TYPE_ARM_HOST_CPU,
#ifdef TARGET_AARCH64
.parent = TYPE_AARCH64_CPU,
#else
.parent = TYPE_ARM_CPU,
#endif
.instance_init = kvm_arm_host_cpu_initfn,
.class_init = kvm_arm_host_cpu_class_init,
.class_size = sizeof(ARMHostCPUClass),
};
int kvm_arch_init(MachineState *ms, KVMState *s)
{
/* For ARM interrupt delivery is always asynchronous,
* whether we are using an in-kernel VGIC or not.
*/
kvm_async_interrupts_allowed = true;
cap_has_mp_state = kvm_check_extension(s, KVM_CAP_MP_STATE);
type_register_static(&host_arm_cpu_type_info);
return 0;
}
unsigned long kvm_arch_vcpu_id(CPUState *cpu)
{
return cpu->cpu_index;
}
/* We track all the KVM devices which need their memory addresses
* passing to the kernel in a list of these structures.
* When board init is complete we run through the list and
* tell the kernel the base addresses of the memory regions.
* We use a MemoryListener to track mapping and unmapping of
* the regions during board creation, so the board models don't
* need to do anything special for the KVM case.
*/
typedef struct KVMDevice {
struct kvm_arm_device_addr kda;
struct kvm_device_attr kdattr;
MemoryRegion *mr;
QSLIST_ENTRY(KVMDevice) entries;
int dev_fd;
} KVMDevice;
static QSLIST_HEAD(kvm_devices_head, KVMDevice) kvm_devices_head;
static void kvm_arm_devlistener_add(MemoryListener *listener,
MemoryRegionSection *section)
{
KVMDevice *kd;
QSLIST_FOREACH(kd, &kvm_devices_head, entries) {
if (section->mr == kd->mr) {
kd->kda.addr = section->offset_within_address_space;
}
}
}
static void kvm_arm_devlistener_del(MemoryListener *listener,
MemoryRegionSection *section)
{
KVMDevice *kd;
QSLIST_FOREACH(kd, &kvm_devices_head, entries) {
if (section->mr == kd->mr) {
kd->kda.addr = -1;
}
}
}
static MemoryListener devlistener = {
.region_add = kvm_arm_devlistener_add,
.region_del = kvm_arm_devlistener_del,
};
static void kvm_arm_set_device_addr(KVMDevice *kd)
{
struct kvm_device_attr *attr = &kd->kdattr;
int ret;
/* If the device control API is available and we have a device fd on the
* KVMDevice struct, let's use the newer API
*/
if (kd->dev_fd >= 0) {
uint64_t addr = kd->kda.addr;
attr->addr = (uintptr_t)&addr;
ret = kvm_device_ioctl(kd->dev_fd, KVM_SET_DEVICE_ATTR, attr);
} else {
ret = kvm_vm_ioctl(kvm_state, KVM_ARM_SET_DEVICE_ADDR, &kd->kda);
}
if (ret < 0) {
fprintf(stderr, "Failed to set device address: %s\n",
strerror(-ret));
abort();
}
}
static void kvm_arm_machine_init_done(Notifier *notifier, void *data)
{
KVMDevice *kd, *tkd;
memory_listener_unregister(&devlistener);
QSLIST_FOREACH_SAFE(kd, &kvm_devices_head, entries, tkd) {
if (kd->kda.addr != -1) {
kvm_arm_set_device_addr(kd);
}
memory_region_unref(kd->mr);
g_free(kd);
}
}
static Notifier notify = {
.notify = kvm_arm_machine_init_done,
};
void kvm_arm_register_device(MemoryRegion *mr, uint64_t devid, uint64_t group,
uint64_t attr, int dev_fd)
{
KVMDevice *kd;
if (!kvm_irqchip_in_kernel()) {
return;
}
if (QSLIST_EMPTY(&kvm_devices_head)) {
memory_listener_register(&devlistener, NULL);
qemu_add_machine_init_done_notifier(&notify);
}
kd = g_new0(KVMDevice, 1);
kd->mr = mr;
kd->kda.id = devid;
kd->kda.addr = -1;
kd->kdattr.flags = 0;
kd->kdattr.group = group;
kd->kdattr.attr = attr;
kd->dev_fd = dev_fd;
QSLIST_INSERT_HEAD(&kvm_devices_head, kd, entries);
memory_region_ref(kd->mr);
}
static int compare_u64(const void *a, const void *b)
{
if (*(uint64_t *)a > *(uint64_t *)b) {
return 1;
}
if (*(uint64_t *)a < *(uint64_t *)b) {
return -1;
}
return 0;
}
/* Initialize the CPUState's cpreg list according to the kernel's
* definition of what CPU registers it knows about (and throw away
* the previous TCG-created cpreg list).
*/
int kvm_arm_init_cpreg_list(ARMCPU *cpu)
{
struct kvm_reg_list rl;
struct kvm_reg_list *rlp;
int i, ret, arraylen;
CPUState *cs = CPU(cpu);
rl.n = 0;
ret = kvm_vcpu_ioctl(cs, KVM_GET_REG_LIST, &rl);
if (ret != -E2BIG) {
return ret;
}
rlp = g_malloc(sizeof(struct kvm_reg_list) + rl.n * sizeof(uint64_t));
rlp->n = rl.n;
ret = kvm_vcpu_ioctl(cs, KVM_GET_REG_LIST, rlp);
if (ret) {
goto out;
}
/* Sort the list we get back from the kernel, since cpreg_tuples
* must be in strictly ascending order.
*/
qsort(&rlp->reg, rlp->n, sizeof(rlp->reg[0]), compare_u64);
for (i = 0, arraylen = 0; i < rlp->n; i++) {
if (!kvm_arm_reg_syncs_via_cpreg_list(rlp->reg[i])) {
continue;
}
switch (rlp->reg[i] & KVM_REG_SIZE_MASK) {
case KVM_REG_SIZE_U32:
case KVM_REG_SIZE_U64:
break;
default:
fprintf(stderr, "Can't handle size of register in kernel list\n");
ret = -EINVAL;
goto out;
}
arraylen++;
}
cpu->cpreg_indexes = g_renew(uint64_t, cpu->cpreg_indexes, arraylen);
cpu->cpreg_values = g_renew(uint64_t, cpu->cpreg_values, arraylen);
cpu->cpreg_vmstate_indexes = g_renew(uint64_t, cpu->cpreg_vmstate_indexes,
arraylen);
cpu->cpreg_vmstate_values = g_renew(uint64_t, cpu->cpreg_vmstate_values,
arraylen);
cpu->cpreg_array_len = arraylen;
cpu->cpreg_vmstate_array_len = arraylen;
for (i = 0, arraylen = 0; i < rlp->n; i++) {
uint64_t regidx = rlp->reg[i];
if (!kvm_arm_reg_syncs_via_cpreg_list(regidx)) {
continue;
}
cpu->cpreg_indexes[arraylen] = regidx;
arraylen++;
}
assert(cpu->cpreg_array_len == arraylen);
if (!write_kvmstate_to_list(cpu)) {
/* Shouldn't happen unless kernel is inconsistent about
* what registers exist.
*/
fprintf(stderr, "Initial read of kernel register state failed\n");
ret = -EINVAL;
goto out;
}
out:
g_free(rlp);
return ret;
}
bool write_kvmstate_to_list(ARMCPU *cpu)
{
CPUState *cs = CPU(cpu);
int i;
bool ok = true;
for (i = 0; i < cpu->cpreg_array_len; i++) {
struct kvm_one_reg r;
uint64_t regidx = cpu->cpreg_indexes[i];
uint32_t v32;
int ret;
r.id = regidx;
switch (regidx & KVM_REG_SIZE_MASK) {
case KVM_REG_SIZE_U32:
r.addr = (uintptr_t)&v32;
ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &r);
if (!ret) {
cpu->cpreg_values[i] = v32;
}
break;
case KVM_REG_SIZE_U64:
r.addr = (uintptr_t)(cpu->cpreg_values + i);
ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &r);
break;
default:
abort();
}
if (ret) {
ok = false;
}
}
return ok;
}
bool write_list_to_kvmstate(ARMCPU *cpu, int level)
{
CPUState *cs = CPU(cpu);
int i;
bool ok = true;
for (i = 0; i < cpu->cpreg_array_len; i++) {
struct kvm_one_reg r;
uint64_t regidx = cpu->cpreg_indexes[i];
uint32_t v32;
int ret;
if (kvm_arm_cpreg_level(regidx) > level) {
continue;
}
r.id = regidx;
switch (regidx & KVM_REG_SIZE_MASK) {
case KVM_REG_SIZE_U32:
v32 = cpu->cpreg_values[i];
r.addr = (uintptr_t)&v32;
break;
case KVM_REG_SIZE_U64:
r.addr = (uintptr_t)(cpu->cpreg_values + i);
break;
default:
abort();
}
ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, &r);
if (ret) {
/* We might fail for "unknown register" and also for
* "you tried to set a register which is constant with
* a different value from what it actually contains".
*/
ok = false;
}
}
return ok;
}
void kvm_arm_reset_vcpu(ARMCPU *cpu)
{
int ret;
/* Re-init VCPU so that all registers are set to
* their respective reset values.
*/
ret = kvm_arm_vcpu_init(CPU(cpu));
if (ret < 0) {
fprintf(stderr, "kvm_arm_vcpu_init failed: %s\n", strerror(-ret));
abort();
}
if (!write_kvmstate_to_list(cpu)) {
fprintf(stderr, "write_kvmstate_to_list failed\n");
abort();
}
}
/*
* Update KVM's MP_STATE based on what QEMU thinks it is
*/
int kvm_arm_sync_mpstate_to_kvm(ARMCPU *cpu)
{
if (cap_has_mp_state) {
struct kvm_mp_state mp_state = {
.mp_state =
cpu->powered_off ? KVM_MP_STATE_STOPPED : KVM_MP_STATE_RUNNABLE
};
int ret = kvm_vcpu_ioctl(CPU(cpu), KVM_SET_MP_STATE, &mp_state);
if (ret) {
fprintf(stderr, "%s: failed to set MP_STATE %d/%s\n",
__func__, ret, strerror(-ret));
return -1;
}
}
return 0;
}
/*
* Sync the KVM MP_STATE into QEMU
*/
int kvm_arm_sync_mpstate_to_qemu(ARMCPU *cpu)
{
if (cap_has_mp_state) {
struct kvm_mp_state mp_state;
int ret = kvm_vcpu_ioctl(CPU(cpu), KVM_GET_MP_STATE, &mp_state);
if (ret) {
fprintf(stderr, "%s: failed to get MP_STATE %d/%s\n",
__func__, ret, strerror(-ret));
abort();
}
cpu->powered_off = (mp_state.mp_state == KVM_MP_STATE_STOPPED);
}
return 0;
}
void kvm_arch_pre_run(CPUState *cs, struct kvm_run *run)
{
}
MemTxAttrs kvm_arch_post_run(CPUState *cs, struct kvm_run *run)
{
return MEMTXATTRS_UNSPECIFIED;
}
int kvm_arch_handle_exit(CPUState *cs, struct kvm_run *run)
{
return 0;
}
bool kvm_arch_stop_on_emulation_error(CPUState *cs)
{
return true;
}
int kvm_arch_process_async_events(CPUState *cs)
{
return 0;
}
int kvm_arch_on_sigbus_vcpu(CPUState *cs, int code, void *addr)
{
return 1;
}
int kvm_arch_on_sigbus(int code, void *addr)
{
return 1;
}
void kvm_arch_update_guest_debug(CPUState *cs, struct kvm_guest_debug *dbg)
{
qemu_log_mask(LOG_UNIMP, "%s: not implemented\n", __func__);
}
int kvm_arch_insert_sw_breakpoint(CPUState *cs,
struct kvm_sw_breakpoint *bp)
{
qemu_log_mask(LOG_UNIMP, "%s: not implemented\n", __func__);
return -EINVAL;
}
int kvm_arch_insert_hw_breakpoint(target_ulong addr,
target_ulong len, int type)
{
qemu_log_mask(LOG_UNIMP, "%s: not implemented\n", __func__);
return -EINVAL;
}
int kvm_arch_remove_hw_breakpoint(target_ulong addr,
target_ulong len, int type)
{
qemu_log_mask(LOG_UNIMP, "%s: not implemented\n", __func__);
return -EINVAL;
}
int kvm_arch_remove_sw_breakpoint(CPUState *cs,
struct kvm_sw_breakpoint *bp)
{
qemu_log_mask(LOG_UNIMP, "%s: not implemented\n", __func__);
return -EINVAL;
}
void kvm_arch_remove_all_hw_breakpoints(void)
{
qemu_log_mask(LOG_UNIMP, "%s: not implemented\n", __func__);
}
void kvm_arch_init_irq_routing(KVMState *s)
{
}
int kvm_arch_irqchip_create(KVMState *s)
{
int ret;
/* If we can create the VGIC using the newer device control API, we
* let the device do this when it initializes itself, otherwise we
* fall back to the old API */
ret = kvm_create_device(s, KVM_DEV_TYPE_ARM_VGIC_V2, true);
if (ret == 0) {
return 1;
}
return 0;
}
int kvm_arch_fixup_msi_route(struct kvm_irq_routing_entry *route,
uint64_t address, uint32_t data)
{
return 0;
}
int kvm_arch_msi_data_to_gsi(uint32_t data)
{
return (data - 32) & 0xffff;
}