[RFC PATCH v2 15/22] i386/xen: implement HYPERVISOR_vcpu_op

[David Woodhouse]

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

This is simply when guest tries to register a vcpu_info
and since vcpu_info placement is optional in the minimum ABI
therefore we can just fail with -ENOSYS

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
---
 target/i386/xen.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/target/i386/xen.c b/target/i386/xen.c
index 2847b4f864..9d1daadee1 100644
--- a/target/i386/xen.c
+++ b/target/i386/xen.c
@@ -19,6 +19,7 @@
 #include "standard-headers/xen/version.h"
 #include "standard-headers/xen/memory.h"
 #include "standard-headers/xen/hvm/hvm_op.h"
+#include "standard-headers/xen/vcpu.h"
 
 static int kvm_gva_rw(CPUState *cs, uint64_t gva, void *_buf, size_t sz,
                       bool is_write)
@@ -194,6 +195,25 @@ static bool kvm_xen_hcall_hvm_op(struct kvm_xen_exit *exit,
     }
 }
 
+static bool kvm_xen_hcall_vcpu_op(struct kvm_xen_exit *exit, X86CPU *cpu,
+                                  int cmd, int vcpu_id, uint64_t arg)
+{
+    int err;
+
+    switch (cmd) {
+    case VCPUOP_register_vcpu_info:
+        /* no vcpu info placement for now */
+        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;
@@ -204,6 +224,11 @@ static bool __kvm_xen_handle_exit(X86CPU *cpu, struct 
kvm_xen_exit *exit)
     }
 
     switch (code) {
+    case __HYPERVISOR_vcpu_op:
+        return kvm_xen_hcall_vcpu_op(exit, cpu,
+                                     exit->u.hcall.params[0],
+                                     exit->u.hcall.params[1],
+                                     exit->u.hcall.params[2]);
     case __HYPERVISOR_hvm_op:
         return kvm_xen_hcall_hvm_op(exit, exit->u.hcall.params[0],
                                     exit->u.hcall.params[1]);
-- 
2.35.3