xemu/target-arm/machine.c
Peter Maydell f8c88bbcda target-arm: Raw CPSR writes should skip checks and bank switching
Raw CPSR writes should skip the architectural checks for whether
we're allowed to set the A or F bits and should also not do
the switching of register banks if the mode changes. Handle
this inside cpsr_write(), which allows us to drop the "manually
set the mode bits to avoid the bank switch" code from all the
callsites which are using CPSRWriteRaw.

This fixes a bug in 32-bit KVM handling where we had forgotten
the "manually set the mode bits" part and could thus potentially
trash the register state if the mode from the last exit to userspace
differed from the mode on this exit.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Sergey Fedorov <serge.fdrv@gmail.com>
Message-id: 1455556977-3644-4-git-send-email-peter.maydell@linaro.org
2016-02-26 15:09:41 +00:00

348 lines
9.8 KiB
C

#include "qemu/osdep.h"
#include "hw/hw.h"
#include "hw/boards.h"
#include "qemu/error-report.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;
}
cpsr_write(env, val, 0xffffffff, CPSRWriteRaw);
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
}
};
const char *gicv3_class_name(void)
{
if (kvm_irqchip_in_kernel()) {
#ifdef TARGET_AARCH64
return "kvm-arm-gicv3";
#else
error_report("KVM GICv3 acceleration is not supported on this "
"platform");
#endif
} else {
/* TODO: Software emulation is not implemented yet */
error_report("KVM is currently required for GICv3 emulation");
}
exit(1);
}