qemu-patch-raspberry4/target-arm/machine.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

331 lines
9.4 KiB
C

#include "hw/hw.h"
#include "hw/boards.h"
#include "sysemu/kvm.h"
#include "kvm_arm.h"
#include "internals.h"
static bool vfp_needed(void *opaque)
{
ARMCPU *cpu = opaque;
CPUARMState *env = &cpu->env;
return arm_feature(env, ARM_FEATURE_VFP);
}
static int get_fpscr(QEMUFile *f, void *opaque, size_t size)
{
ARMCPU *cpu = opaque;
CPUARMState *env = &cpu->env;
uint32_t val = qemu_get_be32(f);
vfp_set_fpscr(env, val);
return 0;
}
static void put_fpscr(QEMUFile *f, void *opaque, size_t size)
{
ARMCPU *cpu = opaque;
CPUARMState *env = &cpu->env;
qemu_put_be32(f, vfp_get_fpscr(env));
}
static const VMStateInfo vmstate_fpscr = {
.name = "fpscr",
.get = get_fpscr,
.put = put_fpscr,
};
static const VMStateDescription vmstate_vfp = {
.name = "cpu/vfp",
.version_id = 3,
.minimum_version_id = 3,
.needed = vfp_needed,
.fields = (VMStateField[]) {
VMSTATE_FLOAT64_ARRAY(env.vfp.regs, ARMCPU, 64),
/* The xregs array is a little awkward because element 1 (FPSCR)
* requires a specific accessor, so we have to split it up in
* the vmstate:
*/
VMSTATE_UINT32(env.vfp.xregs[0], ARMCPU),
VMSTATE_UINT32_SUB_ARRAY(env.vfp.xregs, ARMCPU, 2, 14),
{
.name = "fpscr",
.version_id = 0,
.size = sizeof(uint32_t),
.info = &vmstate_fpscr,
.flags = VMS_SINGLE,
.offset = 0,
},
VMSTATE_END_OF_LIST()
}
};
static bool iwmmxt_needed(void *opaque)
{
ARMCPU *cpu = opaque;
CPUARMState *env = &cpu->env;
return arm_feature(env, ARM_FEATURE_IWMMXT);
}
static const VMStateDescription vmstate_iwmmxt = {
.name = "cpu/iwmmxt",
.version_id = 1,
.minimum_version_id = 1,
.needed = iwmmxt_needed,
.fields = (VMStateField[]) {
VMSTATE_UINT64_ARRAY(env.iwmmxt.regs, ARMCPU, 16),
VMSTATE_UINT32_ARRAY(env.iwmmxt.cregs, ARMCPU, 16),
VMSTATE_END_OF_LIST()
}
};
static bool m_needed(void *opaque)
{
ARMCPU *cpu = opaque;
CPUARMState *env = &cpu->env;
return arm_feature(env, ARM_FEATURE_M);
}
static const VMStateDescription vmstate_m = {
.name = "cpu/m",
.version_id = 1,
.minimum_version_id = 1,
.needed = m_needed,
.fields = (VMStateField[]) {
VMSTATE_UINT32(env.v7m.other_sp, ARMCPU),
VMSTATE_UINT32(env.v7m.vecbase, ARMCPU),
VMSTATE_UINT32(env.v7m.basepri, ARMCPU),
VMSTATE_UINT32(env.v7m.control, ARMCPU),
VMSTATE_INT32(env.v7m.current_sp, ARMCPU),
VMSTATE_INT32(env.v7m.exception, ARMCPU),
VMSTATE_END_OF_LIST()
}
};
static bool thumb2ee_needed(void *opaque)
{
ARMCPU *cpu = opaque;
CPUARMState *env = &cpu->env;
return arm_feature(env, ARM_FEATURE_THUMB2EE);
}
static const VMStateDescription vmstate_thumb2ee = {
.name = "cpu/thumb2ee",
.version_id = 1,
.minimum_version_id = 1,
.needed = thumb2ee_needed,
.fields = (VMStateField[]) {
VMSTATE_UINT32(env.teecr, ARMCPU),
VMSTATE_UINT32(env.teehbr, ARMCPU),
VMSTATE_END_OF_LIST()
}
};
static bool pmsav7_needed(void *opaque)
{
ARMCPU *cpu = opaque;
CPUARMState *env = &cpu->env;
return arm_feature(env, ARM_FEATURE_MPU) &&
arm_feature(env, ARM_FEATURE_V7);
}
static bool pmsav7_rgnr_vmstate_validate(void *opaque, int version_id)
{
ARMCPU *cpu = opaque;
return cpu->env.cp15.c6_rgnr < cpu->pmsav7_dregion;
}
static const VMStateDescription vmstate_pmsav7 = {
.name = "cpu/pmsav7",
.version_id = 1,
.minimum_version_id = 1,
.needed = pmsav7_needed,
.fields = (VMStateField[]) {
VMSTATE_VARRAY_UINT32(env.pmsav7.drbar, ARMCPU, pmsav7_dregion, 0,
vmstate_info_uint32, uint32_t),
VMSTATE_VARRAY_UINT32(env.pmsav7.drsr, ARMCPU, pmsav7_dregion, 0,
vmstate_info_uint32, uint32_t),
VMSTATE_VARRAY_UINT32(env.pmsav7.dracr, ARMCPU, pmsav7_dregion, 0,
vmstate_info_uint32, uint32_t),
VMSTATE_VALIDATE("rgnr is valid", pmsav7_rgnr_vmstate_validate),
VMSTATE_END_OF_LIST()
}
};
static int get_cpsr(QEMUFile *f, void *opaque, size_t size)
{
ARMCPU *cpu = opaque;
CPUARMState *env = &cpu->env;
uint32_t val = qemu_get_be32(f);
env->aarch64 = ((val & PSTATE_nRW) == 0);
if (is_a64(env)) {
pstate_write(env, val);
return 0;
}
/* Avoid mode switch when restoring CPSR */
env->uncached_cpsr = val & CPSR_M;
cpsr_write(env, val, 0xffffffff);
return 0;
}
static void put_cpsr(QEMUFile *f, void *opaque, size_t size)
{
ARMCPU *cpu = opaque;
CPUARMState *env = &cpu->env;
uint32_t val;
if (is_a64(env)) {
val = pstate_read(env);
} else {
val = cpsr_read(env);
}
qemu_put_be32(f, val);
}
static const VMStateInfo vmstate_cpsr = {
.name = "cpsr",
.get = get_cpsr,
.put = put_cpsr,
};
static void cpu_pre_save(void *opaque)
{
ARMCPU *cpu = opaque;
if (kvm_enabled()) {
if (!write_kvmstate_to_list(cpu)) {
/* This should never fail */
abort();
}
} else {
if (!write_cpustate_to_list(cpu)) {
/* This should never fail. */
abort();
}
}
cpu->cpreg_vmstate_array_len = cpu->cpreg_array_len;
memcpy(cpu->cpreg_vmstate_indexes, cpu->cpreg_indexes,
cpu->cpreg_array_len * sizeof(uint64_t));
memcpy(cpu->cpreg_vmstate_values, cpu->cpreg_values,
cpu->cpreg_array_len * sizeof(uint64_t));
}
static int cpu_post_load(void *opaque, int version_id)
{
ARMCPU *cpu = opaque;
int i, v;
/* Update the values list from the incoming migration data.
* Anything in the incoming data which we don't know about is
* a migration failure; anything we know about but the incoming
* data doesn't specify retains its current (reset) value.
* The indexes list remains untouched -- we only inspect the
* incoming migration index list so we can match the values array
* entries with the right slots in our own values array.
*/
for (i = 0, v = 0; i < cpu->cpreg_array_len
&& v < cpu->cpreg_vmstate_array_len; i++) {
if (cpu->cpreg_vmstate_indexes[v] > cpu->cpreg_indexes[i]) {
/* register in our list but not incoming : skip it */
continue;
}
if (cpu->cpreg_vmstate_indexes[v] < cpu->cpreg_indexes[i]) {
/* register in their list but not ours: fail migration */
return -1;
}
/* matching register, copy the value over */
cpu->cpreg_values[i] = cpu->cpreg_vmstate_values[v];
v++;
}
if (kvm_enabled()) {
if (!write_list_to_kvmstate(cpu, KVM_PUT_FULL_STATE)) {
return -1;
}
/* Note that it's OK for the TCG side not to know about
* every register in the list; KVM is authoritative if
* we're using it.
*/
write_list_to_cpustate(cpu);
} else {
if (!write_list_to_cpustate(cpu)) {
return -1;
}
}
hw_breakpoint_update_all(cpu);
hw_watchpoint_update_all(cpu);
return 0;
}
const VMStateDescription vmstate_arm_cpu = {
.name = "cpu",
.version_id = 22,
.minimum_version_id = 22,
.pre_save = cpu_pre_save,
.post_load = cpu_post_load,
.fields = (VMStateField[]) {
VMSTATE_UINT32_ARRAY(env.regs, ARMCPU, 16),
VMSTATE_UINT64_ARRAY(env.xregs, ARMCPU, 32),
VMSTATE_UINT64(env.pc, ARMCPU),
{
.name = "cpsr",
.version_id = 0,
.size = sizeof(uint32_t),
.info = &vmstate_cpsr,
.flags = VMS_SINGLE,
.offset = 0,
},
VMSTATE_UINT32(env.spsr, ARMCPU),
VMSTATE_UINT64_ARRAY(env.banked_spsr, ARMCPU, 8),
VMSTATE_UINT32_ARRAY(env.banked_r13, ARMCPU, 8),
VMSTATE_UINT32_ARRAY(env.banked_r14, ARMCPU, 8),
VMSTATE_UINT32_ARRAY(env.usr_regs, ARMCPU, 5),
VMSTATE_UINT32_ARRAY(env.fiq_regs, ARMCPU, 5),
VMSTATE_UINT64_ARRAY(env.elr_el, ARMCPU, 4),
VMSTATE_UINT64_ARRAY(env.sp_el, ARMCPU, 4),
/* The length-check must come before the arrays to avoid
* incoming data possibly overflowing the array.
*/
VMSTATE_INT32_POSITIVE_LE(cpreg_vmstate_array_len, ARMCPU),
VMSTATE_VARRAY_INT32(cpreg_vmstate_indexes, ARMCPU,
cpreg_vmstate_array_len,
0, vmstate_info_uint64, uint64_t),
VMSTATE_VARRAY_INT32(cpreg_vmstate_values, ARMCPU,
cpreg_vmstate_array_len,
0, vmstate_info_uint64, uint64_t),
VMSTATE_UINT64(env.exclusive_addr, ARMCPU),
VMSTATE_UINT64(env.exclusive_val, ARMCPU),
VMSTATE_UINT64(env.exclusive_high, ARMCPU),
VMSTATE_UINT64(env.features, ARMCPU),
VMSTATE_UINT32(env.exception.syndrome, ARMCPU),
VMSTATE_UINT32(env.exception.fsr, ARMCPU),
VMSTATE_UINT64(env.exception.vaddress, ARMCPU),
VMSTATE_TIMER_PTR(gt_timer[GTIMER_PHYS], ARMCPU),
VMSTATE_TIMER_PTR(gt_timer[GTIMER_VIRT], ARMCPU),
VMSTATE_BOOL(powered_off, ARMCPU),
VMSTATE_END_OF_LIST()
},
.subsections = (const VMStateDescription*[]) {
&vmstate_vfp,
&vmstate_iwmmxt,
&vmstate_m,
&vmstate_thumb2ee,
&vmstate_pmsav7,
NULL
}
};