libxc: osdep: add framework for abstracting access to dom0 OS hypervisor interfaces.

This patch introduces the basic infrastructure and uses it for open
and close operations on privcmd, evtchn and gnttab devices.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Ian Jackson <ian.jackson.citrix.com>

1 files changed, 63 insertions, 14 deletions

diff --git a/tools/libxc/xc_minios.c b/tools/libxc/xc_minios.c
index d5f93f59ee..d822cf3e47 100644
--- a/tools/libxc/xc_minios.c
+++ b/tools/libxc/xc_minios.c
@@ -49,14 +49,21 @@ extern void minios_evtchn_close_fd(int fd);
 
 extern struct wait_queue_head event_queue;
 
-int xc_interface_open_core(xc_interface *xch)
+static xc_osdep_handle minios_privcmd_open(xc_interface *xch)
 {
-    return alloc_fd(FTYPE_XC);
+    int fd = alloc_fd(FTYPE_XC);
+
+    if ( fd == -1)
+        return XC_OSDEP_OPEN_ERROR;
+
+    xch->fd = fd; /* Remove after transition to full xc_osdep_ops. */
+    return (xc_osdep_handle)fd;
 }
 
-int xc_interface_close_core(xc_interface *xch)
+static int minios_privcmd_close(xc_interface *xch, xc_osdep_handle h)
 {
-    return close(xch->fd);
+    int fd = (int)h;
+    return close(fd);
 }
 
 void minios_interface_close_fd(int fd)
@@ -172,20 +179,29 @@ int do_xen_hypercall(xc_interface *xch, privcmd_hypercall_t *hypercall)
     return call.result;
 }
 
-int xc_evtchn_open_core(xc_evtchn *xce)
+static struct xc_osdep_ops minios_privcmd_ops = {
+    .open = &minios_privcmd_open,
+    .close = &minios_privcmd_close,
+};
+
+static xc_osdep_handle minios_evtchn_open(xc_evtchn *xce)
 {
     int fd = alloc_fd(FTYPE_EVTCHN), i;
+    if ( fd == -1 )
+        return XC_OSDEP_OPEN_ERROR;
     for (i = 0; i < MAX_EVTCHN_PORTS; i++) {
 	files[fd].evtchn.ports[i].port = -1;
         files[fd].evtchn.ports[i].bound = 0;
     }
     printf("evtchn_open() -> %d\n", fd);
-    return fd;
+    xce->fd = fd; /* Remove after transition to full xc_osdep_ops. */
+    return (xc_osdep_handle)fd;
 }
 
-int xc_evtchn_close_core(xc_evtchn *xce)
+static int minios_evtchn_close(xc_evtchn *xce, xc_osdep_handle h)
 {
-    return close(xce->fd);
+    int fd = (int)h;
+    return close(fd);
 }
 
 void minios_evtchn_close_fd(int fd)
@@ -368,6 +384,11 @@ int xc_evtchn_unmask(xc_evtchn *xce, evtchn_port_t port)
     return 0;
 }
 
+static struct xc_osdep_ops minios_evtchn_ops = {
+    .open = &minios_evtchn_open,
+    .close = &minios_evtchn_close,
+};
+
 /* Optionally flush file to disk and discard page cache */
 void discard_file_cache(xc_interface *xch, int fd, int flush)
 {
@@ -375,17 +396,20 @@ void discard_file_cache(xc_interface *xch, int fd, int flush)
         fsync(fd);
 }
 
-int xc_gnttab_open_core(xc_gnttab *xcg)
+static xc_osdep_handle minios_gnttab_open(xc_gnttab *xcg)
 {
-    int fd;
-    fd = alloc_fd(FTYPE_GNTMAP);
+    int fd = alloc_fd(FTYPE_GNTMAP);
+    if ( fd == -1 )
+        return XC_OSDEP_OPEN_ERROR;
     gntmap_init(&files[fd].gntmap);
-    return fd;
+    xcg->fd = fd; /* Remove after transition to full xc_osdep_ops. */
+    return (xc_osdep_handle)fd;
 }
 
-int xc_gnttab_close_core(xc_gnttab *xcg)
+static int minios_gnttab_close(xc_gnttab *xcg, xc_osdep_handle h)
 {
-    return close(xcg->fd);
+    int fd = (int)h;
+    return close(fd);
 }
 
 void minios_gnttab_close_fd(int fd)
@@ -460,6 +484,31 @@ int xc_gnttab_set_max_grants(xc_gnttab *xcg,
     return ret;
 }
 
+static struct xc_osdep_ops minios_gnttab_ops = {
+    .open = &minios_gnttab_open,
+    .close = &minios_gnttab_close,
+};
+
+static struct xc_osdep_ops *minios_osdep_init(xc_interface *xch, enum xc_osdep_type type)
+{
+    switch ( type )
+    {
+    case XC_OSDEP_PRIVCMD:
+        return &minios_privcmd_ops;
+    case XC_OSDEP_EVTCHN:
+        return &minios_evtchn_ops;
+    case XC_OSDEP_GNTTAB:
+        return &minios_gnttab_ops;
+    default:
+        return NULL;
+    }
+}
+
+xc_osdep_info_t xc_osdep_info = {
+    .name = "Minios Native OS interface",
+    .init = &minios_osdep_init,
+};
+
 /*
  * Local variables:
  * mode: C