[RFC PATCH v5 24/52] i386/xen: implement HYPERVISOR_event_channel_op

[David Woodhouse]

From: Joao Martins <joao.m.martins@oracle.com>

Additionally set XEN_INTERFACE_VERSION to most recent in order to
exercise the "new" event_channel_op.

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
[dwmw2: Ditch event_channel_op_compat which was never available to HVM guests]
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
---
 target/i386/kvm/xen-emu.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/target/i386/kvm/xen-emu.c b/target/i386/kvm/xen-emu.c
index 6521df0461..9cc939b41e 100644
--- a/target/i386/kvm/xen-emu.c
+++ b/target/i386/kvm/xen-emu.c
@@ -29,6 +29,7 @@
 #include "standard-headers/xen/memory.h"
 #include "standard-headers/xen/hvm/hvm_op.h"
 #include "standard-headers/xen/vcpu.h"
+#include "standard-headers/xen/event_channel.h"
 
 #include "xen-compat.h"
 
@@ -587,6 +588,24 @@ static bool kvm_xen_hcall_vcpu_op(struct kvm_xen_exit 
*exit, X86CPU *cpu,
     return true;
 }
 
+static bool kvm_xen_hcall_evtchn_op(struct kvm_xen_exit *exit,
+                                    int cmd, uint64_t arg)
+{
+    int err = -ENOSYS;
+
+    switch (cmd) {
+    case EVTCHNOP_init_control:
+        err = -ENOSYS;
+        break;
+
+    default:
+        return false;
+    }
+
+    exit->u.hcall.result = err;
+    return true;
+}
+
 static int kvm_xen_soft_reset(void)
 {
     CPUState *cpu;
@@ -686,6 +705,9 @@ static bool do_kvm_xen_handle_exit(X86CPU *cpu, struct 
kvm_xen_exit *exit)
     case __HYPERVISOR_sched_op:
         return kvm_xen_hcall_sched_op(exit, cpu, exit->u.hcall.params[0],
                                       exit->u.hcall.params[1]);
+    case __HYPERVISOR_event_channel_op:
+        return kvm_xen_hcall_evtchn_op(exit, exit->u.hcall.params[0],
+                                       exit->u.hcall.params[1]);
     case __HYPERVISOR_vcpu_op:
         return kvm_xen_hcall_vcpu_op(exit, cpu,
                                      exit->u.hcall.params[0],
-- 
2.35.3