[RFC PATCH v2 21/22] 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 both event_channel_op and event_channel_op_compat.

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
---
 target/i386/xen.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/target/i386/xen.c b/target/i386/xen.c
index 1af336d9e5..f102c40f04 100644
--- a/target/i386/xen.c
+++ b/target/i386/xen.c
@@ -18,11 +18,14 @@
 #include "hw/i386/kvm/xen_overlay.h"
 #include "hw/i386/kvm/xen_evtchn.h"
 
+#define __XEN_INTERFACE_VERSION__ 0x00040400
+
 #include "standard-headers/xen/version.h"
 #include "standard-headers/xen/memory.h"
 #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"
 
 static bool kvm_gva_to_gpa(CPUState *cs, uint64_t gva, uint64_t *gpa,
                            size_t *len, bool is_write)
@@ -452,6 +455,42 @@ static bool kvm_xen_hcall_vcpu_op(struct kvm_xen_exit 
*exit, X86CPU *cpu,
     return true;
 }
 
+static bool kvm_xen_hcall_evtchn_op_compat(struct kvm_xen_exit *exit,
+                                          X86CPU *cpu, uint64_t arg)
+{
+    struct evtchn_op op;
+    int err = -EFAULT;
+
+    if (kvm_copy_from_gva(CPU(cpu), arg, &op, sizeof(op))) {
+        goto err;
+    }
+
+    switch (op.cmd) {
+    default:
+        return false;
+    }
+err:
+    exit->u.hcall.result = err;
+    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 __kvm_xen_handle_exit(X86CPU *cpu, struct kvm_xen_exit *exit)
 {
     uint16_t code = exit->u.hcall.input;
@@ -462,6 +501,12 @@ static bool __kvm_xen_handle_exit(X86CPU *cpu, struct 
kvm_xen_exit *exit)
     }
 
     switch (code) {
+    case __HYPERVISOR_event_channel_op_compat:
+        return kvm_xen_hcall_evtchn_op_compat(exit, cpu,
+                                              exit->u.hcall.params[0]);
+    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