static void kvm_set_status(struct virtio_device *vdev, u8 status)
{
BUG_ON(!status);
to_kvmdev(vdev)->desc->status = status;
kvm_hypercall1(KVM_S390_VIRTIO_SET_STATUS,
(unsigned long) to_kvmdev(vdev)->desc);
}
/*G:035
* Notice the lazy_hcall() above, rather than hcall(). This is our first real
* optimization trick!
*
* When lazy_mode is set, it means we're allowed to defer all hypercalls and do
* them as a batch when lazy_mode is eventually turned off. Because hypercalls
* are reasonably expensive, batching them up makes sense. For example, a
* large munmap might update dozens of page table entries: that code calls
* paravirt_enter_lazy_mmu(), does the dozen updates, then calls
* lguest_leave_lazy_mode().
*
* So, when we're in lazy mode, we call async_hcall() to store the call for
* future processing:
*/
static void lazy_hcall1(unsigned long call,
unsigned long arg1)
{
if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE)
kvm_hypercall1(call, arg1);
else
async_hcall(call, arg1, 0, 0, 0);
}
/* code for early console output with virtio_console */
static __init int early_put_chars(u32 vtermno, const char *buf, int count)
{
char scratch[17];
unsigned int len = count;
if (len > sizeof(scratch) - 1)
len = sizeof(scratch) - 1;
scratch[len] = '\0';
memcpy(scratch, buf, len);
kvm_hypercall1(KVM_S390_VIRTIO_NOTIFY, __pa(scratch));
return len;
}
/*
* We will eventually use the virtio console device to produce console output,
* but before that is set up we use LHCALL_NOTIFY on normal memory to produce
* console output.
*/
static __init int early_put_chars(u32 vtermno, const char *buf, int count)
{
char scratch[17];
unsigned int len = count;
/* We use a nul-terminated string, so we make a copy. Icky, huh? */
if (len > sizeof(scratch) - 1)
len = sizeof(scratch) - 1;
scratch[len] = '\0';
memcpy(scratch, buf, len);
kvm_hypercall1(LHCALL_NOTIFY, __pa(scratch));
/* This routine returns the number of bytes actually written. */
return len;
}
/*
* We also need a "struct clock_event_device": Linux asks us to set it to go
* off some time in the future. Actually, James Morris figured all this out, I
* just applied the patch.
*/
static int lguest_clockevent_set_next_event(unsigned long delta,
struct clock_event_device *evt)
{
/* FIXME: I don't think this can ever happen, but James tells me he had
* to put this code in. Maybe we should remove it now. Anyone? */
if (delta < LG_CLOCK_MIN_DELTA) {
if (printk_ratelimit())
printk(KERN_DEBUG "%s: small delta %lu ns\n",
__func__, delta);
return -ETIME;
}
/* Please wake us this far in the future. */
kvm_hypercall1(LHCALL_SET_CLOCKEVENT, delta);
return 0;
}
/*
* When the virtio_ring code wants to notify the Host, it calls us here and we
* make a hypercall. We hand the address of the virtqueue so the Host
* knows which virtqueue we're talking about.
*/
static void kvm_notify(struct virtqueue *vq)
{
struct kvm_vqconfig *config = vq->priv;
kvm_hypercall1(KVM_S390_VIRTIO_NOTIFY, config->address);
}
/*
* To reset the device, we use the KVM_VIRTIO_RESET hypercall, using the
* descriptor address. The Host will zero the status and all the
* features.
*/
static void kvm_reset(struct virtio_device *vdev)
{
kvm_hypercall1(KVM_S390_VIRTIO_RESET,
(unsigned long) to_kvmdev(vdev)->desc);
}
