[PATCH RFC 4/4] Implement XEN_DOMCTL_gethvmcontext part of arch_do_domctl

[Jaeyong Yoo <jaeyong.yoo@samsung.com>]

Signed-off-by: Jaeyong Yoo <jaeyong.yoo@samsung.com>
---
 xen/arch/arm/domctl.c |   58 ++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 57 insertions(+), 1 deletion(-)

diff --git a/xen/arch/arm/domctl.c b/xen/arch/arm/domctl.c
index 851ee40..a1ff570 100644
--- a/xen/arch/arm/domctl.c
+++ b/xen/arch/arm/domctl.c
@@ -9,12 +9,68 @@
 #include <xen/lib.h>
 #include <xen/errno.h>
 #include <xen/sched.h>
+#include <xen/hvm/save.h>
+#include <xen/guest_access.h>
 #include <public/domctl.h>
 
 long arch_do_domctl(struct xen_domctl *domctl, struct domain *d,
                     XEN_GUEST_HANDLE_PARAM(xen_domctl_t) u_domctl)
 {
-    return -ENOSYS;
+    long ret = 0;
+    bool_t copyback = 0;
+    switch ( domctl->cmd )
+    {
+    case XEN_DOMCTL_gethvmcontext:
+    {
+        struct hvm_domain_context c = { 0 };
+
+        ret = -EINVAL;
+        if ( !is_hvm_domain(d) ) {
+            printk("Domain is not hvm... Just go on...\n");
+        } 
+
+        c.size = hvm_save_size(d);
+
+        if ( guest_handle_is_null(domctl->u.hvmcontext.buffer) )
+        {
+            /* Client is querying for the correct buffer size */
+            domctl->u.hvmcontext.size = c.size;
+            ret = 0;
+            goto gethvmcontext_out;
+        }
+
+        /* Check that the client has a big enough buffer */
+        ret = -ENOSPC;
+        if ( domctl->u.hvmcontext.size < c.size )
+            goto gethvmcontext_out;
+
+        /* Allocate our own marshalling buffer */
+        ret = -ENOMEM;
+        if ( (c.data = xmalloc_bytes(c.size)) == NULL )
+            goto gethvmcontext_out;
+
+        domain_pause(d);
+        ret = hvm_save(d, &c);
+        domain_unpause(d);
+
+        domctl->u.hvmcontext.size = c.cur;
+        if ( copy_to_guest(domctl->u.hvmcontext.buffer, c.data, c.size) != 0 )
+            ret = -EFAULT;
+
+    gethvmcontext_out:
+        copyback = 1;
+
+        if ( c.data != NULL )
+            xfree(c.data);
+    }
+    break;
+    default:
+        return -EINVAL;
+    }
+    if ( copyback && __copy_to_guest(u_domctl, domctl, 1) )
+        ret = -EFAULT;
+
+    return ret;
 }
 
 void arch_get_info_guest(struct vcpu *v, vcpu_guest_context_u c)
-- 
1.7.9.5