Remove old lguest I/O infrrasructure.

This patch gets rid of the old lguest host I/O infrastructure and
replaces it with a single hypercall "LHCALL_NOTIFY" which takes an
address.

The main change is the removal of io.c: that mainly did inter-guest
I/O, which virtio doesn't yet support.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

1 files changed, 8 insertions, 18 deletions

diff --git a/drivers/lguest/hypercalls.c b/drivers/lguest/hypercalls.c
index 13b5f2f813de..3a53788ba450 100644
--- a/drivers/lguest/hypercalls.c
+++ b/drivers/lguest/hypercalls.c
@@ -60,22 +60,9 @@ static void do_hcall(struct lguest *lg, struct hcall_args *args)
                 else
                         guest_pagetable_flush_user(lg);
                 break;
-        case LHCALL_BIND_DMA:
-                /* BIND_DMA really wants four arguments, but it's the only call
-                 * which does.  So the Guest packs the number of buffers and
-                 * the interrupt number into the final argument, and we decode
-                 * it here.  This can legitimately fail, since we currently
-                 * place a limit on the number of DMA pools a Guest can have.
-                 * So we return true or false from this call. */
-                args->arg0 = bind_dma(lg, args->arg1, args->arg2,
-                                     args->arg3 >> 8, args->arg3 & 0xFF);
-                break;
 
         /* All these calls simply pass the arguments through to the right
          * routines. */
-        case LHCALL_SEND_DMA:
-                send_dma(lg, args->arg1, args->arg2);
-                break;
         case LHCALL_NEW_PGTABLE:
                 guest_new_pagetable(lg, args->arg1);
                 break;
@@ -99,6 +86,9 @@ static void do_hcall(struct lguest *lg, struct hcall_args *args)
                 /* Similarly, this sets the halted flag for run_guest(). */
                 lg->halted = 1;
                 break;
+        case LHCALL_NOTIFY:
+                lg->pending_notify = args->arg1;
+                break;
         default:
                 if (lguest_arch_do_hcall(lg, args))
                         kill_guest(lg, "Bad hypercall %li\n", args->arg0);
@@ -156,9 +146,9 @@ static void do_async_hcalls(struct lguest *lg)
                         break;
                 }
 
-                /* Stop doing hypercalls if we've just done a DMA to the
-                 * Launcher: it needs to service this first. */
-                if (lg->dma_is_pending)
+                /* Stop doing hypercalls if they want to notify the Launcher:
+                 * it needs to service this first. */
+                if (lg->pending_notify)
                         break;
         }
 }
@@ -220,9 +210,9 @@ void do_hypercalls(struct lguest *lg)
         do_async_hcalls(lg);
 
         /* If we stopped reading the hypercall ring because the Guest did a
-         * SEND_DMA to the Launcher, we want to return now.  Otherwise we do
+         * NOTIFY to the Launcher, we want to return now.  Otherwise we do
          * the hypercall. */
-        if (!lg->dma_is_pending) {
+        if (!lg->pending_notify) {
                 do_hcall(lg, lg->hcall);
                 /* Tricky point: we reset the hcall pointer to mark the
                  * hypercall as "done".  We use the hcall pointer rather than