/**
* kvm_handle_wfx - handle a WFI or WFE instructions trapped in guests
* @vcpu: the vcpu pointer
* @run: the kvm_run structure pointer
*
* WFE: Yield the CPU and come back to this vcpu when the scheduler
* decides to.
* WFI: Simply call kvm_vcpu_block(), which will halt execution of
* world-switches and schedule other host processes until there is an
* incoming IRQ or FIQ to the VM.
*/
static int kvm_handle_wfx(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
if (kvm_vcpu_get_hsr(vcpu) & HSR_WFI_IS_WFE) {
trace_kvm_wfx(*vcpu_pc(vcpu), true);
kvm_vcpu_on_spin(vcpu);
} else {
trace_kvm_wfx(*vcpu_pc(vcpu), false);
kvm_vcpu_block(vcpu);
}
kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
return 1;
}
/**
* kvm_handle_wfx - handle a wait-for-interrupts or wait-for-event
* instruction executed by a guest
*
* @vcpu: the vcpu pointer
*
* WFE: Yield the CPU and come back to this vcpu when the scheduler
* decides to.
* WFI: Simply call kvm_vcpu_block(), which will halt execution of
* world-switches and schedule other host processes until there is an
* incoming IRQ or FIQ to the VM.
*/
static int kvm_handle_wfx(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
if (kvm_vcpu_get_hsr(vcpu) & ESR_ELx_WFx_ISS_WFE) {
trace_kvm_wfx_arm64(*vcpu_pc(vcpu), true);
vcpu->stat.wfe_exit_stat++;
kvm_vcpu_on_spin(vcpu, vcpu_mode_priv(vcpu));
} else {
trace_kvm_wfx_arm64(*vcpu_pc(vcpu), false);
vcpu->stat.wfi_exit_stat++;
kvm_vcpu_block(vcpu);
kvm_clear_request(KVM_REQ_UNHALT, vcpu);
}
kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
return 1;
}
static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
{
struct kvm *kvm = source_vcpu->kvm;
struct kvm_vcpu *vcpu = NULL;
wait_queue_head_t *wq;
unsigned long cpu_id;
unsigned long context_id;
phys_addr_t target_pc;
cpu_id = *vcpu_reg(source_vcpu, 1) & MPIDR_HWID_BITMASK;
if (vcpu_mode_is_32bit(source_vcpu))
cpu_id &= ~((u32) 0);
vcpu = kvm_mpidr_to_vcpu(kvm, cpu_id);
/*
* Make sure the caller requested a valid CPU and that the CPU is
* turned off.
*/
if (!vcpu)
return PSCI_RET_INVALID_PARAMS;
if (!vcpu->arch.power_off) {
if (kvm_psci_version(source_vcpu) != KVM_ARM_PSCI_0_1)
return PSCI_RET_ALREADY_ON;
else
return PSCI_RET_INVALID_PARAMS;
}
target_pc = *vcpu_reg(source_vcpu, 2);
context_id = *vcpu_reg(source_vcpu, 3);
kvm_reset_vcpu(vcpu);
/* Gracefully handle Thumb2 entry point */
if (vcpu_mode_is_32bit(vcpu) && (target_pc & 1)) {
target_pc &= ~((phys_addr_t) 1);
vcpu_set_thumb(vcpu);
}
/* Propagate caller endianness */
if (kvm_vcpu_is_be(source_vcpu))
kvm_vcpu_set_be(vcpu);
*vcpu_pc(vcpu) = target_pc;
/*
* NOTE: We always update r0 (or x0) because for PSCI v0.1
* the general puspose registers are undefined upon CPU_ON.
*/
*vcpu_reg(vcpu, 0) = context_id;
vcpu->arch.power_off = false;
smp_mb(); /* Make sure the above is visible */
wq = kvm_arch_vcpu_wq(vcpu);
wake_up_interruptible(wq);
return PSCI_RET_SUCCESS;
}
/**
* kvm_handle_wfx - handle a WFI or WFE instructions trapped in guests
* @vcpu: the vcpu pointer
* @run: the kvm_run structure pointer
*
* WFE: Yield the CPU and come back to this vcpu when the scheduler
* decides to.
* WFI: Simply call kvm_vcpu_block(), which will halt execution of
* world-switches and schedule other host processes until there is an
* incoming IRQ or FIQ to the VM.
*/
static int kvm_handle_wfx(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
trace_kvm_wfi(*vcpu_pc(vcpu));
if (kvm_vcpu_get_hsr(vcpu) & HSR_WFI_IS_WFE)
kvm_vcpu_on_spin(vcpu);
else
kvm_vcpu_block(vcpu);
return 1;
}
/*
* Return > 0 to return to guest, < 0 on error, 0 (and set exit_reason) on
* proper exit to userspace.
*/
int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
int exception_index)
{
if (ARM_SERROR_PENDING(exception_index)) {
u8 hsr_ec = ESR_ELx_EC(kvm_vcpu_get_hsr(vcpu));
/*
* HVC/SMC already have an adjusted PC, which we need
* to correct in order to return to after having
* injected the SError.
*/
if (hsr_ec == ESR_ELx_EC_HVC32 || hsr_ec == ESR_ELx_EC_HVC64 ||
hsr_ec == ESR_ELx_EC_SMC32 || hsr_ec == ESR_ELx_EC_SMC64) {
u32 adj = kvm_vcpu_trap_il_is32bit(vcpu) ? 4 : 2;
*vcpu_pc(vcpu) -= adj;
}
return 1;
}
exception_index = ARM_EXCEPTION_CODE(exception_index);
switch (exception_index) {
case ARM_EXCEPTION_IRQ:
return 1;
case ARM_EXCEPTION_EL1_SERROR:
/* We may still need to return for single-step */
if (!(*vcpu_cpsr(vcpu) & DBG_SPSR_SS)
&& kvm_arm_handle_step_debug(vcpu, run))
return 0;
else
return 1;
case ARM_EXCEPTION_TRAP:
return handle_trap_exceptions(vcpu, run);
case ARM_EXCEPTION_HYP_GONE:
/*
* EL2 has been reset to the hyp-stub. This happens when a guest
* is pre-empted by kvm_reboot()'s shutdown call.
*/
run->exit_reason = KVM_EXIT_FAIL_ENTRY;
return 0;
case ARM_EXCEPTION_IL:
/*
* We attempted an illegal exception return. Guest state must
* have been corrupted somehow. Give up.
*/
run->exit_reason = KVM_EXIT_FAIL_ENTRY;
return -EINVAL;
default:
kvm_pr_unimpl("Unsupported exception type: %d",
exception_index);
run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
return 0;
}
}
static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
trace_kvm_hvc(*vcpu_pc(vcpu), *vcpu_reg(vcpu, 0),
kvm_vcpu_hvc_get_imm(vcpu));
if (kvm_psci_call(vcpu))
return 1;
kvm_inject_undefined(vcpu);
return 1;
}
/*
* Return > 0 to return to guest, < 0 on error, 0 (and set exit_reason) on
* proper exit to userspace.
*/
int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
int exception_index)
{
exit_handle_fn exit_handler;
if (ARM_ABORT_PENDING(exception_index)) {
u8 hsr_ec = kvm_vcpu_trap_get_class(vcpu);
/*
* HVC/SMC already have an adjusted PC, which we need
* to correct in order to return to after having
* injected the abort.
*/
if (hsr_ec == HSR_EC_HVC || hsr_ec == HSR_EC_SMC) {
u32 adj = kvm_vcpu_trap_il_is32bit(vcpu) ? 4 : 2;
*vcpu_pc(vcpu) -= adj;
}
kvm_inject_vabt(vcpu);
return 1;
}
exception_index = ARM_EXCEPTION_CODE(exception_index);
switch (exception_index) {
case ARM_EXCEPTION_IRQ:
return 1;
case ARM_EXCEPTION_HVC:
/*
* See ARM ARM B1.14.1: "Hyp traps on instructions
* that fail their condition code check"
*/
if (!kvm_condition_valid(vcpu)) {
kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
return 1;
}
exit_handler = kvm_get_exit_handler(vcpu);
return exit_handler(vcpu, run);
case ARM_EXCEPTION_DATA_ABORT:
kvm_inject_vabt(vcpu);
return 1;
default:
kvm_pr_unimpl("Unsupported exception type: %d",
exception_index);
run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
return 0;
}
}
static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
int ret;
trace_kvm_hvc_arm64(*vcpu_pc(vcpu), vcpu_get_reg(vcpu, 0),
kvm_vcpu_hvc_get_imm(vcpu));
ret = kvm_psci_call(vcpu);
if (ret < 0) {
kvm_inject_undefined(vcpu);
return 1;
}
return ret;
}
static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
int ret;
trace_kvm_hvc_arm64(*vcpu_pc(vcpu), vcpu_get_reg(vcpu, 0),
kvm_vcpu_hvc_get_imm(vcpu));
vcpu->stat.hvc_exit_stat++;
ret = kvm_hvc_call_handler(vcpu);
if (ret < 0) {
vcpu_set_reg(vcpu, 0, ~0UL);
return 1;
}
return ret;
}
static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
{
struct kvm *kvm = source_vcpu->kvm;
struct kvm_vcpu *vcpu;
wait_queue_head_t *wq;
unsigned long cpu_id;
phys_addr_t target_pc;
cpu_id = *vcpu_reg(source_vcpu, 1);
if (vcpu_mode_is_32bit(source_vcpu))
cpu_id &= ~((u32) 0);
if (cpu_id >= atomic_read(&kvm->online_vcpus))
return KVM_PSCI_RET_INVAL;
target_pc = *vcpu_reg(source_vcpu, 2);
vcpu = kvm_get_vcpu(kvm, cpu_id);
wq = kvm_arch_vcpu_wq(vcpu);
if (!waitqueue_active(wq))
return KVM_PSCI_RET_INVAL;
kvm_reset_vcpu(vcpu);
/* Gracefully handle Thumb2 entry point */
if (vcpu_mode_is_32bit(vcpu) && (target_pc & 1)) {
target_pc &= ~((phys_addr_t) 1);
vcpu_set_thumb(vcpu);
}
*vcpu_pc(vcpu) = target_pc;
vcpu->arch.pause = false;
smp_mb(); /* Make sure the above is visible */
wake_up_interruptible(wq);
return KVM_PSCI_RET_SUCCESS;
}
/**
* kvm_handle_guest_abort - handles all 2nd stage aborts
* @vcpu: the VCPU pointer
* @run: the kvm_run structure
*
* Any abort that gets to the host is almost guaranteed to be caused by a
* missing second stage translation table entry, which can mean that either the
* guest simply needs more memory and we must allocate an appropriate page or it
* can mean that the guest tried to access I/O memory, which is emulated by user
* space. The distinction is based on the IPA causing the fault and whether this
* memory region has been registered as standard RAM by user space.
*/
int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
unsigned long fault_status;
phys_addr_t fault_ipa;
struct kvm_memory_slot *memslot;
bool is_iabt;
gfn_t gfn;
int ret, idx;
is_iabt = kvm_vcpu_trap_is_iabt(vcpu);
fault_ipa = kvm_vcpu_get_fault_ipa(vcpu);
trace_kvm_guest_fault(*vcpu_pc(vcpu), kvm_vcpu_get_hsr(vcpu),
kvm_vcpu_get_hfar(vcpu), fault_ipa);
/* Check the stage-2 fault is trans. fault or write fault */
fault_status = kvm_vcpu_trap_get_fault(vcpu);
if (fault_status != FSC_FAULT && fault_status != FSC_PERM) {
kvm_err("Unsupported fault status: EC=%#x DFCS=%#lx\n",
kvm_vcpu_trap_get_class(vcpu), fault_status);
return -EFAULT;
}
idx = srcu_read_lock(&vcpu->kvm->srcu);
gfn = fault_ipa >> PAGE_SHIFT;
if (!kvm_is_visible_gfn(vcpu->kvm, gfn)) {
if (is_iabt) {
/* Prefetch Abort on I/O address */
kvm_inject_pabt(vcpu, kvm_vcpu_get_hfar(vcpu));
ret = 1;
goto out_unlock;
}
if (fault_status != FSC_FAULT) {
kvm_err("Unsupported fault status on io memory: %#lx\n",
fault_status);
ret = -EFAULT;
goto out_unlock;
}
/*
* The IPA is reported as [MAX:12], so we need to
* complement it with the bottom 12 bits from the
* faulting VA. This is always 12 bits, irrespective
* of the page size.
*/
fault_ipa |= kvm_vcpu_get_hfar(vcpu) & ((1 << 12) - 1);
ret = io_mem_abort(vcpu, run, fault_ipa);
goto out_unlock;
}
memslot = gfn_to_memslot(vcpu->kvm, gfn);
ret = user_mem_abort(vcpu, fault_ipa, gfn, memslot, fault_status);
if (ret == 0)
ret = 1;
out_unlock:
srcu_read_unlock(&vcpu->kvm->srcu, idx);
return ret;
}
/**
* kvm_handle_wfi - handle a wait-for-interrupts instruction executed by a guest
* @vcpu: the vcpu pointer
* @run: the kvm_run structure pointer
*
* Simply sets the wait_for_interrupts flag on the vcpu structure, which will
* halt execution of world-switches and schedule other host processes until
* there is an incoming IRQ or FIQ to the VM.
*/
static int kvm_handle_wfi(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
trace_kvm_wfi(*vcpu_pc(vcpu));
kvm_vcpu_block(vcpu);
return 1;
}