[Xen-devel] [PATCH v6 08/12] libxl: add libxl support for setting grant table resource limits

[Juergen Gross <jgross@xxxxxxxx>]

Add new domain config items for setting the limits for the maximum
numbers of grant table frames and maptrack frames of a domain.

Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
---
V6:
- made set_gnttab_limits hypercall mandatory, taking defaults from
  xl.conf

V4:
- rename configuration items to use max_ prefixes (Wei Liu)
---
 docs/man/xl.cfg.pod.5.in    | 16 ++++++++++++++++
 tools/libxl/libxl.h         |  6 ++++++
 tools/libxl/libxl_dm.c      |  3 +++
 tools/libxl/libxl_dom.c     |  6 ++++++
 tools/libxl/libxl_types.idl |  3 +++
 tools/xl/xl_parse.c         |  9 +++++++++
 tools/xl/xl_sxp.c           |  2 ++
 7 files changed, 45 insertions(+)

diff --git a/docs/man/xl.cfg.pod.5.in b/docs/man/xl.cfg.pod.5.in
index 79cb2eaea7..5b6d1f8e2f 100644
--- a/docs/man/xl.cfg.pod.5.in
+++ b/docs/man/xl.cfg.pod.5.in
@@ -444,6 +444,20 @@ unpausing the domain. With a properly constructed security 
policy (such
 as nomigrate_t in the example policy), this can be used to build a
 domain whose memory is not accessible to the toolstack domain.
 
+=item B<max_grant_frames=NUMBER>
+
+Specify the maximum number of grant frames the domain is allowed to have.
+This value controls how many pages the domain is able to grant access to for
+other domains, needed e.g. for the operation of paravirtualized devices.
+The default is settable via L<xl.conf(5)>.
+
+=item B<max_maptrack_frames=NUMBER>
+
+Specify the maximum number of grant maptrack frames the domain is allowed
+to have. This value controls how many pages of foreign domains can be accessed
+via the grant mechanism by this domain. The default value is settable via
+L<xl.conf(5)>.
+
 =item B<nomigrate=BOOLEAN>
 
 Disable migration of this domain.  This enables certain other features
@@ -2203,6 +2217,8 @@ No MCA capabilities in above list are enabled.
 
 =item L<xl(1)>
 
+=item L<xl.conf(5)>
+
 =item L<xlcpupool.cfg(5)>
 
 =item L<xl-disk-configuration(5)>
diff --git a/tools/libxl/libxl.h b/tools/libxl/libxl.h
index 9c455e59f9..29dfd54652 100644
--- a/tools/libxl/libxl.h
+++ b/tools/libxl/libxl.h
@@ -317,6 +317,12 @@
 #define LIBXL_HAVE_GET_MAX_HOST_MFN 1
 
 /*
+ * LIBXL_HAVE_BUILDINFO_GRANT_LIMITS indicates that libxl_domain_build_info
+ * has the max_grant_frames and max_maptrack_frames fields.
+ */
+#define LIBXL_HAVE_BUILDINFO_GRANT_LIMITS 1
+
+/*
  * libxl ABI compatibility
  *
  * The only guarantee which libxl makes regarding ABI compatibility
diff --git a/tools/libxl/libxl_dm.c b/tools/libxl/libxl_dm.c
index e0e6a99e67..0b769e44d1 100644
--- a/tools/libxl/libxl_dm.c
+++ b/tools/libxl/libxl_dm.c
@@ -1845,6 +1845,9 @@ void libxl__spawn_stub_dm(libxl__egc *egc, 
libxl__stub_dm_spawn_state *sdss)
         guest_config->b_info.video_memkb;
     dm_config->b_info.target_memkb = dm_config->b_info.max_memkb;
 
+    dm_config->b_info.max_grant_frames = guest_config->b_info.max_grant_frames;
+    dm_config->b_info.max_maptrack_frames = 0;
+
     dm_config->b_info.u.pv.features = "";
 
     dm_config->b_info.device_model_version =
diff --git a/tools/libxl/libxl_dom.c b/tools/libxl/libxl_dom.c
index f54fd49a73..b420738adf 100644
--- a/tools/libxl/libxl_dom.c
+++ b/tools/libxl/libxl_dom.c
@@ -322,6 +322,12 @@ int libxl__build_pre(libxl__gc *gc, uint32_t domid,
         return ERROR_FAIL;
     }
 
+    if (xc_domain_set_gnttab_limits(ctx->xch, domid, info->max_grant_frames,
+                                    info->max_maptrack_frames) != 0) {
+        LOG(ERROR, "Couldn't set grant table limits");
+        return ERROR_FAIL;
+    }
+
     /*
      * Check if the domain has any CPU or node affinity already. If not, try
      * to build up the latter via automatic NUMA placement. In fact, in case
diff --git a/tools/libxl/libxl_types.idl b/tools/libxl/libxl_types.idl
index 173d70acec..47487d69c5 100644
--- a/tools/libxl/libxl_types.idl
+++ b/tools/libxl/libxl_types.idl
@@ -472,6 +472,9 @@ libxl_domain_build_info = Struct("domain_build_info",[
     ("blkdev_start",    string),
 
     ("vnuma_nodes", Array(libxl_vnode_info, "num_vnuma_nodes")),
+
+    ("max_grant_frames",    uint32),
+    ("max_maptrack_frames", uint32),
     
     ("device_model_version", libxl_device_model_version),
     ("device_model_stubdomain", libxl_defbool),
diff --git a/tools/xl/xl_parse.c b/tools/xl/xl_parse.c
index 02ddd2e90d..6153c46bbf 100644
--- a/tools/xl/xl_parse.c
+++ b/tools/xl/xl_parse.c
@@ -943,6 +943,15 @@ void parse_config_data(const char *config_source,
         !xlu_cfg_get_string (config, "cpus_soft", &buf, 0))
         parse_vcpu_affinity(b_info, cpus, buf, num_cpus, false);
 
+    if (!xlu_cfg_get_long (config, "max_grant_frames", &l, 0))
+        b_info->max_grant_frames = l;
+    else
+        b_info->max_grant_frames = max_grant_frames;
+    if (!xlu_cfg_get_long (config, "max_maptrack_frames", &l, 0))
+        b_info->max_maptrack_frames = l;
+    else
+        b_info->max_maptrack_frames = max_maptrack_frames;
+
     libxl_defbool_set(&b_info->claim_mode, claim_mode);
 
     if (xlu_cfg_get_string (config, "on_poweroff", &buf, 0))
diff --git a/tools/xl/xl_sxp.c b/tools/xl/xl_sxp.c
index e738bf2465..e264cf2023 100644
--- a/tools/xl/xl_sxp.c
+++ b/tools/xl/xl_sxp.c
@@ -64,6 +64,8 @@ void printf_info_sexp(int domid, libxl_domain_config 
*d_config, FILE *fh)
 
     fprintf(fh, "\t(build_info)\n");
     fprintf(fh, "\t(max_vcpus %d)\n", b_info->max_vcpus);
+    fprintf(fh, "\t(max_grant_frames %d)\n", b_info->max_grant_frames);
+    fprintf(fh, "\t(max_maptrack_frames %d)\n", b_info->max_maptrack_frames);
     fprintf(fh, "\t(tsc_mode %s)\n", 
libxl_tsc_mode_to_string(b_info->tsc_mode));
     fprintf(fh, "\t(max_memkb %"PRId64")\n", b_info->max_memkb);
     fprintf(fh, "\t(target_memkb %"PRId64")\n", b_info->target_memkb);
-- 
2.12.3


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