[HVM] Replace shared-memory PIC state with a set-irq-level hypercall.

This simplifies the IRQ logic significantly and avoids the bogus
hvm_pic_assist() on domain resume path.

There is more work to be done here. At least:
 1. set-irq-level should really be set-interrupt-wire-level. Wire
    state needs to be distinguished from PIC (in particular, PIC IRR)
    state.
 2. Hypercalls can be batched in qemu and pushed down in one
    multicall.

Signed-off-by: Keir Fraser <keir@xensource.com>

1 files changed, 28 insertions, 0 deletions

diff --git a/tools/libxc/xc_misc.c b/tools/libxc/xc_misc.c
index 37c505e2bc..b1924611c3 100644
--- a/tools/libxc/xc_misc.c
+++ b/tools/libxc/xc_misc.c
@@ -5,6 +5,7 @@
  */
 
 #include "xc_private.h"
+#include <xen/hvm/hvm_op.h>
 
 int xc_readconsolering(int xc_handle,
                        char **pbuffer,
@@ -89,6 +90,33 @@ int xc_perfc_control(int xc_handle,
     return rc;
 }
 
+int xc_hvm_set_irq_level(int xc_handle, domid_t dom, int irq, int level)
+{
+    DECLARE_HYPERCALL;
+    struct xen_hvm_set_irq_level arg;
+    int rc;
+
+    hypercall.op     = __HYPERVISOR_hvm_op;
+    hypercall.arg[0] = HVMOP_set_irq_level;
+    hypercall.arg[1] = (unsigned long)&arg;
+
+    arg.domid = dom;
+    arg.irq   = irq;
+    arg.level = level;
+
+    if ( mlock(&arg, sizeof(arg)) != 0 )
+    {
+        PERROR("Could not lock memory");
+        return -1;
+    }
+
+    rc = do_xen_hypercall(xc_handle, &hypercall);
+
+    safe_munlock(&arg, sizeof(arg));
+
+    return rc;
+}
+
 /*
  * Local variables:
  * mode: C