[RFC PATCH v3 23/38] 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 | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/target/i386/kvm/xen-emu.c b/target/i386/kvm/xen-emu.c
index 09978c83ca..d6f3102d8e 100644
--- a/target/i386/kvm/xen-emu.c
+++ b/target/i386/kvm/xen-emu.c
@@ -27,6 +27,7 @@
 #include "standard-headers/xen/hvm/hvm_op.h"
 #include "standard-headers/xen/hvm/params.h"
 #include "standard-headers/xen/vcpu.h"
+#include "standard-headers/xen/event_channel.h"
 
 #include "xen-compat.h"
 
@@ -611,6 +612,23 @@ 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 bool do_kvm_xen_handle_exit(X86CPU *cpu, struct kvm_xen_exit *exit)
 {
     uint16_t code = exit->u.hcall.input;
@@ -621,6 +639,9 @@ static bool do_kvm_xen_handle_exit(X86CPU *cpu, struct 
kvm_xen_exit *exit)
     }
 
     switch (code) {
+    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