int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run *run,
phys_addr_t fault_ipa)
{
unsigned long data;
unsigned long rt;
int ret;
bool is_write;
int len;
u8 data_buf[8];
/*
* Prepare MMIO operation. First decode the syndrome data we get
* from the CPU. Then try if some in-kernel emulation feels
* responsible, otherwise let user space do its magic.
*/
if (kvm_vcpu_dabt_isvalid(vcpu)) {
ret = decode_hsr(vcpu, &is_write, &len);
if (ret)
return ret;
} else {
kvm_err("load/store instruction decoding not implemented\n");
return -ENOSYS;
}
rt = vcpu->arch.mmio_decode.rt;
if (is_write) {
data = vcpu_data_guest_to_host(vcpu, vcpu_get_reg(vcpu, rt),
len);
trace_kvm_mmio(KVM_TRACE_MMIO_WRITE, len, fault_ipa, data);
mmio_write_buf(data_buf, len, data);
ret = kvm_io_bus_write(vcpu, KVM_MMIO_BUS, fault_ipa, len,
data_buf);
} else {
trace_kvm_mmio(KVM_TRACE_MMIO_READ_UNSATISFIED, len,
fault_ipa, 0);
ret = kvm_io_bus_read(vcpu, KVM_MMIO_BUS, fault_ipa, len,
data_buf);
}
/* Now prepare kvm_run for the potential return to userland. */
run->mmio.is_write = is_write;
run->mmio.phys_addr = fault_ipa;
run->mmio.len = len;
memcpy(run->mmio.data, data_buf, len);
if (!ret) {
/* We handled the access successfully in the kernel. */
kvm_handle_mmio_return(vcpu, run);
return 1;
}
run->exit_reason = KVM_EXIT_MMIO;
return 0;
}
/**
* kvm_handle_mmio_return -- Handle MMIO loads after user space emulation
* @vcpu: The VCPU pointer
* @run: The VCPU run struct containing the mmio data
*
* This should only be called after returning from userspace for MMIO load
* emulation.
*/
int kvm_handle_mmio_return(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
unsigned long data;
unsigned int len;
int mask;
if (!run->mmio.is_write) {
len = run->mmio.len;
if (len > sizeof(unsigned long))
return -EINVAL;
data = mmio_read_buf(run->mmio.data, len);
if (vcpu->arch.mmio_decode.sign_extend &&
len < sizeof(unsigned long)) {
mask = 1U << ((len * 8) - 1);
data = (data ^ mask) - mask;
}
trace_kvm_mmio(KVM_TRACE_MMIO_READ, len, run->mmio.phys_addr,
data);
data = vcpu_data_host_to_guest(vcpu, data, len);
*vcpu_reg(vcpu, vcpu->arch.mmio_decode.rt) = data;
}
return 0;
}
int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run *run,
phys_addr_t fault_ipa)
{
struct kvm_exit_mmio mmio;
unsigned long data;
unsigned long rt;
int ret;
/*
* Prepare MMIO operation. First stash it in a private
* structure that we can use for in-kernel emulation. If the
* kernel can't handle it, copy it into run->mmio and let user
* space do its magic.
*/
if (kvm_vcpu_dabt_isvalid(vcpu)) {
ret = decode_hsr(vcpu, fault_ipa, &mmio);
if (ret)
return ret;
} else {
kvm_err("load/store instruction decoding not implemented\n");
return -ENOSYS;
}
rt = vcpu->arch.mmio_decode.rt;
data = vcpu_data_guest_to_host(vcpu, *vcpu_reg(vcpu, rt), mmio.len);
trace_kvm_mmio((mmio.is_write) ? KVM_TRACE_MMIO_WRITE :
KVM_TRACE_MMIO_READ_UNSATISFIED,
mmio.len, fault_ipa,
(mmio.is_write) ? data : 0);
if (mmio.is_write)
mmio_write_buf(mmio.data, mmio.len, data);
if (vgic_handle_mmio(vcpu, run, &mmio))
return 1;
kvm_prepare_mmio(run, &mmio);
return 0;
}
