vbox: disable ioapic support by default

and add xml configuration option to switch it on if required. Avoids trouble
on Windows 7 guest where IRQ injected by VMMDev PCI device is not delivered.

If ioapic is required and Windows guest addition "hangs", look in file
DevPCI.cpp, function pciSetIrqInternal, variable fIsApicEnabled. If

config[0xde] == 0xbe
config[0xad] == 0xef

it works. "Deadbeaf" seems to/should be set in ACPI file vbox.dsl. Happens for
unknown reason not on Genode/Nova.

Fixes #1188

repos/ports/ports/virtualbox.hash

@@ -1 +1 @@
-13aca05c49d35f7ce7a2cfd25d2751d9d6de9019
+8c27e2319a0ff50a02d4555148eccc829f77b4fc

repos/ports/run/virtualbox.run

@@ -90,6 +90,7 @@ append config {
 		<resource name="RAM" quantum="1G"/>
 		<config>
 			<image type="iso" file="test.iso" />
+<!--			<ioapic/> -->
 			<libc stdout="/dev/log" stderr="/dev/log">
 				<vfs>
 					<dir name="dev"> <log/> </dir>

repos/ports/src/virtualbox/hgcm_sync.patch

@@ -1,34 +0,0 @@
-+++ src/app/virtualbox/src/VBox/Devices/VMMDev/VMMDevHGCM.cpp
-@@ -39,6 +39,12 @@
- # define VBOXDD_HGCMCALL_COMPLETED_DONE(a,b,c,d)    do { } while (0)
- #endif
- 
-+#include <base/lock.h>
-+
-+
-+static Genode::Lock w4c(Genode::Lock::LOCKED);
-+
-+
- typedef enum _VBOXHGCMCMDTYPE
- {
-     VBOXHGCMCMDTYPE_LOADSTATE = 0,
-@@ -1147,6 +1153,9 @@ int vmmdevHGCMCall (VMMDevState *pVMMDevState, VMMDevHGCMCall *pHGCMCall, uint32
-         RTMemFree (pCmd);
-     }
- 
-+    /* wait for completion */
-+    w4c.lock();
-+
-     return rc;
- }
- 
-@@ -2382,6 +2391,9 @@ DECLCALLBACK(void) hgcmCompleted (PPDMIHGCMPORT pInterface, int32_t result, PVBO
-     int rc = VMR3ReqCallVoidNoWait(PDMDevHlpGetVM(pVMMDevState->pDevIns), VMCPUID_ANY,
-                                    (PFNRT)hgcmCompletedWorker, 3, pInterface, result, pCmd);
-     AssertRC(rc);
-+
-+    /* signal completion */
-+    w4c.unlock();
- }
- 
- /* @thread EMT */

repos/ports/src/virtualbox/main.cc

@@ -202,11 +202,16 @@ int main()
 	}
 
 	args.add(c_file);
-	args.add("-ioapic");
 
 	if (bOverlay)
 		args.add("-overlay");
 
+	/* ioapic support */
+	try {
+		Genode::Xml_node node = Genode::config()->xml_node().sub_node("ioapic");
+		args.add("-ioapic");
+	} catch (...) { }
+
 	/* shared folder setup */
 	unsigned shares = 0;
 	try {