[Qemu-devel] [PATCH 1/9] spapr: Enable dynamic change of the supported hypercalls list

[Alexey Kardashevskiy <aik@ozlabs.ru>]

At the moment the "ibm,hypertas-functions" list is fixed. However some
calls should be listed there if they are supported by QEMU or the host
kernel.

This enables hyperrtas_prop to grow on stack by adding
a SPAPR_HYPERRTAS_ADD macro.

The first user of this is going to be a "multi-tce" property.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
 hw/ppc/spapr.c | 22 +++++++++++++++++++---
 1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 0a61246..e174e04 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -306,8 +306,6 @@ static void *spapr_create_fdt_skel(hwaddr initrd_base,
     CPUState *cs;
     uint32_t start_prop = cpu_to_be32(initrd_base);
     uint32_t end_prop = cpu_to_be32(initrd_base + initrd_size);
-    char hypertas_prop[] = "hcall-pft\0hcall-term\0hcall-dabr\0hcall-interrupt"
-        "\0hcall-tce\0hcall-vio\0hcall-splpar\0hcall-bulk\0hcall-set-mode";
     char qemu_hypertas_prop[] = "hcall-memop1";
     uint32_t refpoints[] = {cpu_to_be32(0x4), cpu_to_be32(0x4)};
     uint32_t interrupt_server_ranges_prop[] = {0, cpu_to_be32(smp_cpus)};
@@ -316,6 +314,24 @@ static void *spapr_create_fdt_skel(hwaddr initrd_base,
     QemuOpts *opts = qemu_opts_find(qemu_find_opts("smp-opts"), NULL);
     unsigned sockets = opts ? qemu_opt_get_number(opts, "sockets", 0) : 0;
     uint32_t cpus_per_socket = sockets ? (smp_cpus / sockets) : 1;
+    char *hypertas_prop = NULL;
+    int hypertas_prop_len = 0;
+
+#define SPAPR_HYPERRTAS_ADD(prop)                                   \
+    do {                                                            \
+        const char proptmp[] = prop;                                \
+        char *httmp = alloca(hypertas_prop_len + sizeof(proptmp));  \
+        if (hypertas_prop_len) {                                    \
+            memcpy(httmp, hypertas_prop, hypertas_prop_len);        \
+        }                                                           \
+        memcpy(httmp + hypertas_prop_len, proptmp, sizeof(proptmp));\
+        hypertas_prop_len += sizeof(proptmp);                       \
+        hypertas_prop = httmp;                                      \
+    } while (0)
+
+    SPAPR_HYPERRTAS_ADD(
+        "hcall-pft\0hcall-term\0hcall-dabr\0hcall-interrupt"
+        "\0hcall-tce\0hcall-vio\0hcall-splpar\0hcall-bulk\0hcall-set-mode");
 
     fdt = g_malloc0(FDT_MAX_SIZE);
     _FDT((fdt_create(fdt, FDT_MAX_SIZE)));
@@ -485,7 +501,7 @@ static void *spapr_create_fdt_skel(hwaddr initrd_base,
     _FDT((fdt_begin_node(fdt, "rtas")));
 
     _FDT((fdt_property(fdt, "ibm,hypertas-functions", hypertas_prop,
-                       sizeof(hypertas_prop))));
+                       hypertas_prop_len)));
     _FDT((fdt_property(fdt, "qemu,hypertas-functions", qemu_hypertas_prop,
                        sizeof(qemu_hypertas_prop))));
 
-- 
1.9.rc0