Implement hcall based RTAS for pSeries machines

On pSeries machines, operating systems can instantiate "RTAS" (Run-Time
Abstraction Services), a runtime component of the firmware which implements
a number of low-level, infrequently used operations.  On logical partitions
under a hypervisor, many of the RTAS functions require hypervisor
privilege.  For simplicity, therefore, hypervisor systems typically
implement the in-partition RTAS as just a tiny wrapper around a hypercall
which actually implements the various RTAS functions.

This patch implements such a hypercall based RTAS for our emulated pSeries
machine.  A tiny in-partition "firmware" calls a new hypercall, which
looks up available RTAS services in a table.

Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>

1 files changed, 23 insertions, 3 deletions

diff --git a/hw/spapr.c b/hw/spapr.c
index 57140d231..c07af1954 100644
--- a/hw/spapr.c
+++ b/hw/spapr.c
@@ -40,6 +40,7 @@
 #define KERNEL_LOAD_ADDR        0x00000000
 #define INITRD_LOAD_ADDR        0x02800000
 #define FDT_MAX_SIZE            0x10000
+#define RTAS_MAX_SIZE           0x10000
 
 #define TIMEBASE_FREQ           512000000ULL
 
@@ -53,6 +54,8 @@ static void *spapr_create_fdt(int *fdt_size, ram_addr_t ramsize,
                               target_phys_addr_t initrd_base,
                               target_phys_addr_t initrd_size,
                               const char *kernel_cmdline,
+                              target_phys_addr_t rtas_addr,
+                              target_phys_addr_t rtas_size,
                               long hash_shift)
 {
     void *fdt;
@@ -195,6 +198,12 @@ static void *spapr_create_fdt(int *fdt_size, ram_addr_t ramsize,
         exit(1);
     }
 
+    /* RTAS */
+    ret = spapr_rtas_device_tree_setup(fdt, rtas_addr, rtas_size);
+    if (ret < 0) {
+        fprintf(stderr, "Couldn't set up RTAS device tree properties\n");
+    }
+
     _FDT((fdt_pack(fdt)));
 
     *fdt_size = fdt_totalsize(fdt);
@@ -224,11 +233,12 @@ static void ppc_spapr_init(ram_addr_t ram_size,
     void *fdt, *htab;
     int i;
     ram_addr_t ram_offset;
-    target_phys_addr_t fdt_addr;
+    target_phys_addr_t fdt_addr, rtas_addr;
     uint32_t kernel_base, initrd_base;
-    long kernel_size, initrd_size, htab_size;
+    long kernel_size, initrd_size, htab_size, rtas_size;
     long pteg_shift = 17;
     int fdt_size;
+    char *filename;
 
     spapr = qemu_malloc(sizeof(*spapr));
     cpu_ppc_hypercall = emulate_spapr_hypercall;
@@ -237,6 +247,8 @@ static void ppc_spapr_init(ram_addr_t ram_size,
      * 2GB, so that it can be processed with 32-bit code if
      * necessary */
     fdt_addr = MIN(ram_size, 0x80000000) - FDT_MAX_SIZE;
+    /* RTAS goes just below that */
+    rtas_addr = fdt_addr - RTAS_MAX_SIZE;
 
     /* init CPUs */
     if (cpu_model == NULL) {
@@ -276,6 +288,14 @@ static void ppc_spapr_init(ram_addr_t ram_size,
         envs[i]->htab_mask = htab_size - 1;
     }
 
+    filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, "spapr-rtas.bin");
+    rtas_size = load_image_targphys(filename, rtas_addr, ram_size - rtas_addr);
+    if (rtas_size < 0) {
+        hw_error("qemu: could not load LPAR rtas '%s'\n", filename);
+        exit(1);
+    }
+    qemu_free(filename);
+
     spapr->vio_bus = spapr_vio_bus_init();
 
     for (i = 0; i < MAX_SERIAL_PORTS; i++) {
@@ -323,7 +343,7 @@ static void ppc_spapr_init(ram_addr_t ram_size,
     /* Prepare the device tree */
     fdt = spapr_create_fdt(&fdt_size, ram_size, cpu_model, envs, spapr,
                            initrd_base, initrd_size, kernel_cmdline,
-                           pteg_shift + 7);
+                           rtas_addr, rtas_size, pteg_shift + 7);
     assert(fdt != NULL);
 
     cpu_physical_memory_write(fdt_addr, fdt, fdt_size);