[Xen-devel] [PATCH v9 7/7] xen/arm: export shared memory regions as reserved-memory on device tree

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

Shared memory regions need to be advertised to the guest. Fortunately, a
device tree binding for special memory regions already exist:
reserved-memory.

Add a reserved-memory node for each shared memory region, for both
owners and borrowers.

Signed-off-by: Stefano Stabellini <stefanos@xxxxxxxxxx>
---
Changes in v9:
- rename master to owner and slave to borrower
- always add offset because it is 0 for the owner
- use xen,id for id
- add xen,offset according to new bindings

Changes in v8:
- code style
- id is added to device tree

Changes in v7:
- change node name to xen-shmem
- add compatible property
- add id property
---
 tools/libxl/libxl_arch.h |  2 +-
 tools/libxl/libxl_arm.c  | 66 +++++++++++++++++++++++++++++++++++++++++++++---
 tools/libxl/libxl_dom.c  |  2 +-
 tools/libxl/libxl_x86.c  |  2 +-
 4 files changed, 66 insertions(+), 6 deletions(-)

diff --git a/tools/libxl/libxl_arch.h b/tools/libxl/libxl_arch.h
index 63c26cc..417e710 100644
--- a/tools/libxl/libxl_arch.h
+++ b/tools/libxl/libxl_arch.h
@@ -36,7 +36,7 @@ int libxl__arch_domain_create(libxl__gc *gc, 
libxl_domain_config *d_config,
 /* setup arch specific hardware description, i.e. DTB on ARM */
 _hidden
 int libxl__arch_domain_init_hw_description(libxl__gc *gc,
-                                           libxl_domain_build_info *info,
+                                           libxl_domain_config *d_config,
                                            libxl__domain_build_state *state,
                                            struct xc_dom_image *dom);
 /* finalize arch specific hardware description. */
diff --git a/tools/libxl/libxl_arm.c b/tools/libxl/libxl_arm.c
index 054ad58..aa1e07f 100644
--- a/tools/libxl/libxl_arm.c
+++ b/tools/libxl/libxl_arm.c
@@ -436,6 +436,63 @@ static int make_memory_nodes(libxl__gc *gc, void *fdt,
     return 0;
 }
 
+static int make_reserved_nodes(libxl__gc *gc, void *fdt,
+                               libxl_domain_config *d_config)
+{
+    int res, i;
+    const char *name;
+
+    if (d_config->num_sshms == 0)
+        return 0;
+
+    res = fdt_begin_node(fdt, "reserved-memory");
+    if (res) return res;
+
+    res = fdt_property_cell(fdt, "#address-cells", GUEST_ROOT_ADDRESS_CELLS);
+    if (res) return res;
+
+    res = fdt_property_cell(fdt, "#size-cells", GUEST_ROOT_SIZE_CELLS);
+    if (res) return res;
+
+    res = fdt_property(fdt, "ranges", NULL, 0);
+    if (res) return res;
+
+    for (i = 0; i < d_config->num_sshms; i++) {
+        uint64_t start = d_config->sshms[i].begin +
+                         d_config->sshms[i].offset;
+
+        name = GCSPRINTF("xen-shmem@%"PRIx64, start);
+
+        res = fdt_begin_node(fdt, name);
+        if (res) return res;
+
+        res = fdt_property_regs(gc, fdt, GUEST_ROOT_ADDRESS_CELLS,
+                                GUEST_ROOT_SIZE_CELLS, 1, start,
+                                d_config->sshms[i].size);
+        if (res) return res;
+
+        res = fdt_property_compat(gc, fdt, 1, "xen,shared-memory-v1");
+        if (res) return res;
+
+        res = fdt_property_string(fdt, "xen,id", d_config->sshms[i].id);
+        if (res) return res;
+
+        if (d_config->sshms[i].role == LIBXL_SSHM_ROLE_BORROWER) {
+            res = fdt_property_u64(fdt, "xen,offset",
+                                   d_config->sshms[i].offset);
+            if (res) return res;
+        }
+
+        res = fdt_end_node(fdt);
+        if (res) return res;
+    }
+
+    res = fdt_end_node(fdt);
+    if (res) return res;
+
+    return 0;
+}
+
 static int make_gicv2_node(libxl__gc *gc, void *fdt,
                            uint64_t gicd_base, uint64_t gicd_size,
                            uint64_t gicc_base, uint64_t gicc_size)
@@ -811,10 +868,11 @@ static int copy_partial_fdt(libxl__gc *gc, void *fdt, 
void *pfdt)
 
 #define FDT_MAX_SIZE (1<<20)
 
-static int libxl__prepare_dtb(libxl__gc *gc, libxl_domain_build_info *info,
+static int libxl__prepare_dtb(libxl__gc *gc, libxl_domain_config *d_config,
                               libxl__domain_build_state *state,
                               struct xc_dom_image *dom)
 {
+    libxl_domain_build_info *info = &d_config->b_info;
     void *fdt = NULL;
     void *pfdt = NULL;
     int rc, res;
@@ -897,6 +955,7 @@ next_resize:
         FDT( make_psci_node(gc, fdt) );
 
         FDT( make_memory_nodes(gc, fdt, dom) );
+        FDT( make_reserved_nodes(gc, fdt, d_config) );
 
         switch (info->arch_arm.gic_version) {
         case LIBXL_GIC_VERSION_V2:
@@ -946,12 +1005,13 @@ out:
 }
 
 int libxl__arch_domain_init_hw_description(libxl__gc *gc,
-                                           libxl_domain_build_info *info,
+                                           libxl_domain_config *d_config,
                                            libxl__domain_build_state *state,
                                            struct xc_dom_image *dom)
 {
     int rc;
     uint64_t val;
+    libxl_domain_build_info *info = &d_config->b_info;
 
     if (info->type != LIBXL_DOMAIN_TYPE_PVH) {
         LOG(ERROR, "Unsupported Arm guest type %s",
@@ -971,7 +1031,7 @@ int libxl__arch_domain_init_hw_description(libxl__gc *gc,
     if (rc)
         return rc;
 
-    rc = libxl__prepare_dtb(gc, info, state, dom);
+    rc = libxl__prepare_dtb(gc, d_config, state, dom);
     if (rc) goto out;
 
     if (!libxl_defbool_val(info->acpi)) {
diff --git a/tools/libxl/libxl_dom.c b/tools/libxl/libxl_dom.c
index 8a8a32c..2dc7696 100644
--- a/tools/libxl/libxl_dom.c
+++ b/tools/libxl/libxl_dom.c
@@ -706,7 +706,7 @@ static int libxl__build_dom(libxl__gc *gc, uint32_t domid,
         LOG(ERROR, "xc_dom_parse_image failed");
         goto out;
     }
-    if ( (ret = libxl__arch_domain_init_hw_description(gc, info, state, dom)) 
!= 0 ) {
+    if ( (ret = libxl__arch_domain_init_hw_description(gc, d_config, state, 
dom)) != 0 ) {
         LOGE(ERROR, "libxl__arch_domain_init_hw_description failed");
         goto out;
     }
diff --git a/tools/libxl/libxl_x86.c b/tools/libxl/libxl_x86.c
index dc8c703..b99ec25 100644
--- a/tools/libxl/libxl_x86.c
+++ b/tools/libxl/libxl_x86.c
@@ -367,7 +367,7 @@ int libxl__arch_extra_memory(libxl__gc *gc,
 }
 
 int libxl__arch_domain_init_hw_description(libxl__gc *gc,
-                                           libxl_domain_build_info *info,
+                                           libxl_domain_config *d_config,
                                            libxl__domain_build_state *state,
                                            struct xc_dom_image *dom)
 {
-- 
1.9.1


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