tools: extend xc_assign_device() to support rdm reservation policy

This patch passes rdm reservation policy to xc_assign_device() so the policy
is checked when assigning devices to a VM.

Note this also bring some fallout to python usage of xc_assign_device().

CC: Ian Jackson <ian.jackson@eu.citrix.com>
CC: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
CC: Ian Campbell <ian.campbell@citrix.com>
CC: Wei Liu <wei.liu2@citrix.com>
CC: David Scott <dave.scott@eu.citrix.com>
Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>

tools/libxc/include/xenctrl.h

@@ -2067,7 +2067,8 @@ int xc_hvm_destroy_ioreq_server(xc_interface *xch,
 /* HVM guest pass-through */
 int xc_assign_device(xc_interface *xch,
                      uint32_t domid,
-                     uint32_t machine_sbdf);
+                     uint32_t machine_sbdf,
+                     uint32_t flag);
 
 int xc_get_device_group(xc_interface *xch,
                      uint32_t domid,

tools/libxc/xc_domain.c

@@ -1697,7 +1697,8 @@ int xc_domain_setdebugging(xc_interface *xch,
 int xc_assign_device(
     xc_interface *xch,
     uint32_t domid,
-    uint32_t machine_sbdf)
+    uint32_t machine_sbdf,
+    uint32_t flag)
 {
     DECLARE_DOMCTL;
 
@@ -1705,6 +1706,7 @@ int xc_assign_device(
     domctl.domain = domid;
     domctl.u.assign_device.dev = XEN_DOMCTL_DEV_PCI;
     domctl.u.assign_device.u.pci.machine_sbdf = machine_sbdf;
+    domctl.u.assign_device.flag = flag;
 
     return do_domctl(xch, &domctl);
 }
@@ -1792,6 +1794,11 @@ int xc_assign_dt_device(
 
     domctl.u.assign_device.dev = XEN_DOMCTL_DEV_DT;
     domctl.u.assign_device.u.dt.size = size;
+    /*
+     * DT doesn't own any RDM so actually DT has nothing to do
+     * for any flag and here just fix that as 0.
+     */
+    domctl.u.assign_device.flag = 0;
     set_xen_guest_handle(domctl.u.assign_device.u.dt.path, path);
 
     rc = do_domctl(xch, &domctl);

tools/libxl/libxl_pci.c

@@ -894,6 +894,7 @@ static int do_pci_add(libxl__gc *gc, uint32_t domid, libxl_device_pci *pcidev, i
     FILE *f;
     unsigned long long start, end, flags, size;
     int irq, i, rc, hvm = 0;
+    uint32_t flag = XEN_DOMCTL_DEV_RDM_RELAXED;
 
     if (type == LIBXL_DOMAIN_TYPE_INVALID)
         return ERROR_FAIL;
@@ -987,7 +988,7 @@ static int do_pci_add(libxl__gc *gc, uint32_t domid, libxl_device_pci *pcidev, i
 
 out:
     if (!libxl_is_stubdom(ctx, domid, NULL)) {
-        rc = xc_assign_device(ctx->xch, domid, pcidev_encode_bdf(pcidev));
+        rc = xc_assign_device(ctx->xch, domid, pcidev_encode_bdf(pcidev), flag);
         if (rc < 0 && (hvm || errno != ENOSYS)) {
             LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "xc_assign_device failed");
             return ERROR_FAIL;

tools/ocaml/libs/xc/xenctrl_stubs.c

@@ -1172,12 +1172,17 @@ CAMLprim value stub_xc_domain_test_assign_device(value xch, value domid, value d
 	CAMLreturn(Val_bool(ret == 0));
 }
 
-CAMLprim value stub_xc_domain_assign_device(value xch, value domid, value desc)
+static int domain_assign_device_rdm_flag_table[] = {
+    XEN_DOMCTL_DEV_RDM_RELAXED,
+};
+
+CAMLprim value stub_xc_domain_assign_device(value xch, value domid, value desc,
+                                            value rflag)
 {
-	CAMLparam3(xch, domid, desc);
+	CAMLparam4(xch, domid, desc, rflag);
 	int ret;
 	int domain, bus, dev, func;
-	uint32_t sbdf;
+	uint32_t sbdf, flag;
 
 	domain = Int_val(Field(desc, 0));
 	bus = Int_val(Field(desc, 1));
@@ -1185,7 +1190,10 @@ CAMLprim value stub_xc_domain_assign_device(value xch, value domid, value desc)
 	func = Int_val(Field(desc, 3));
 	sbdf = encode_sbdf(domain, bus, dev, func);
 
-	ret = xc_assign_device(_H(xch), _D(domid), sbdf);
+	ret = Int_val(Field(rflag, 0));
+	flag = domain_assign_device_rdm_flag_table[ret];
+
+	ret = xc_assign_device(_H(xch), _D(domid), sbdf, flag);
 
 	if (ret < 0)
 		failwith_xc(_H(xch));

tools/python/xen/lowlevel/xc/xc.c

@@ -592,7 +592,8 @@ static int token_value(char *token)
     return strtol(token, NULL, 16);
 }
 
-static int next_bdf(char **str, int *seg, int *bus, int *dev, int *func)
+static int next_bdf(char **str, int *seg, int *bus, int *dev, int *func,
+                    int *flag)
 {
     char *token;
 
@@ -607,8 +608,17 @@ static int next_bdf(char **str, int *seg, int *bus, int *dev, int *func)
     *dev  = token_value(token);
     token = strchr(token, ',') + 1;
     *func  = token_value(token);
-    token = strchr(token, ',');
-    *str = token ? token + 1 : NULL;
+    token = strchr(token, ',') + 1;
+    if ( token ) {
+        *flag = token_value(token);
+        *str = token + 1;
+    }
+    else
+    {
+        /* O means we take "strict" as our default policy. */
+        *flag = 0;
+        *str = NULL;
+    }
 
     return 1;
 }
@@ -620,14 +630,14 @@ static PyObject *pyxc_test_assign_device(XcObject *self,
     uint32_t dom;
     char *pci_str;
     int32_t sbdf = 0;
-    int seg, bus, dev, func;
+    int seg, bus, dev, func, flag;
 
     static char *kwd_list[] = { "domid", "pci", NULL };
     if ( !PyArg_ParseTupleAndKeywords(args, kwds, "is", kwd_list,
                                       &dom, &pci_str) )
         return NULL;
 
-    while ( next_bdf(&pci_str, &seg, &bus, &dev, &func) )
+    while ( next_bdf(&pci_str, &seg, &bus, &dev, &func, &flag) )
     {
         sbdf = seg << 16;
         sbdf |= (bus & 0xff) << 8;
@@ -653,21 +663,21 @@ static PyObject *pyxc_assign_device(XcObject *self,
     uint32_t dom;
     char *pci_str;
     int32_t sbdf = 0;
-    int seg, bus, dev, func;
+    int seg, bus, dev, func, flag;
 
     static char *kwd_list[] = { "domid", "pci", NULL };
     if ( !PyArg_ParseTupleAndKeywords(args, kwds, "is", kwd_list,
                                       &dom, &pci_str) )
         return NULL;
 
-    while ( next_bdf(&pci_str, &seg, &bus, &dev, &func) )
+    while ( next_bdf(&pci_str, &seg, &bus, &dev, &func, &flag) )
     {
         sbdf = seg << 16;
         sbdf |= (bus & 0xff) << 8;
         sbdf |= (dev & 0x1f) << 3;
         sbdf |= (func & 0x7);
 
-        if ( xc_assign_device(self->xc_handle, dom, sbdf) != 0 )
+        if ( xc_assign_device(self->xc_handle, dom, sbdf, flag) != 0 )
         {
             if (errno == ENOSYS)
                 sbdf = -1;
@@ -686,14 +696,14 @@ static PyObject *pyxc_deassign_device(XcObject *self,
     uint32_t dom;
     char *pci_str;
     int32_t sbdf = 0;
-    int seg, bus, dev, func;
+    int seg, bus, dev, func, flag;
 
     static char *kwd_list[] = { "domid", "pci", NULL };
     if ( !PyArg_ParseTupleAndKeywords(args, kwds, "is", kwd_list,
                                       &dom, &pci_str) )
         return NULL;
 
-    while ( next_bdf(&pci_str, &seg, &bus, &dev, &func) )
+    while ( next_bdf(&pci_str, &seg, &bus, &dev, &func, &flag) )
     {
         sbdf = seg << 16;
         sbdf |= (bus & 0xff) << 8;