spapr: Fix implementation of Open Firmware client interface

This addresses the comments from v22.

The functional changes are (the VOF ones need retesting with Pegasos2):

(VOF) setprop will start failing if the machine class callback
did not handle it;
(VOF) unit addresses are lowered in path_offset();
(SPAPR) /chosen/bootargs is initialized from kernel_cmdline if
the client did not change it.

Fixes: 5c991e5d4378 ("spapr: Implement Open Firmware client interface")
Cc: BALATON Zoltan <balaton@eik.bme.hu>
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Message-Id: <20210708065625.548396-1-aik@ozlabs.ru>
Tested-by: BALATON Zoltan <balaton@eik.bme.hu>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

MAINTAINERS

@@ -1362,8 +1362,8 @@ F: include/hw/pci-host/mv64361.h
 
 Virtual Open Firmware (VOF)
 M: Alexey Kardashevskiy <aik@ozlabs.ru>
-M: David Gibson <david@gibson.dropbear.id.au>
-M: Greg Kurz <groug@kaod.org>
+R: David Gibson <david@gibson.dropbear.id.au>
+R: Greg Kurz <groug@kaod.org>
 L: qemu-ppc@nongnu.org
 S: Maintained
 F: hw/ppc/spapr_vof*

hw/ppc/spapr.c

@@ -1645,15 +1645,7 @@ static void spapr_machine_reset(MachineState *machine)
 
     fdt = spapr_build_fdt(spapr, true, FDT_MAX_SIZE);
     if (spapr->vof) {
-        target_ulong stack_ptr = 0;
-
-        spapr_vof_reset(spapr, fdt, &stack_ptr, &error_fatal);
-
-        spapr_cpu_set_entry_state(first_ppc_cpu, SPAPR_ENTRY_POINT,
-                                  stack_ptr, spapr->initrd_base,
-                                  spapr->initrd_size);
-        /* VOF is 32bit BE so enforce MSR here */
-        first_ppc_cpu->env.msr &= ~((1ULL << MSR_SF) | (1ULL << MSR_LE));
+        spapr_vof_reset(spapr, fdt, &error_fatal);
         /*
          * Do not pack the FDT as the client may change properties.
          * VOF client does not expect the FDT so we do not load it to the VM.

hw/ppc/spapr_hcall.c

@@ -1080,7 +1080,7 @@ target_ulong do_client_architecture_support(PowerPCCPU *cpu,
     SpaprOptionVector *ov1_guest, *ov5_guest;
     bool guest_radix;
     bool raw_mode_supported = false;
-    bool guest_xive, reset_fdt = false;
+    bool guest_xive;
     CPUState *cs;
     void *fdt;
     uint32_t max_compat = spapr->max_compat_pvr;
@@ -1233,8 +1233,7 @@ target_ulong do_client_architecture_support(PowerPCCPU *cpu,
         spapr_setup_hpt(spapr);
     }
 
-    reset_fdt = spapr->vof != NULL;
-    fdt = spapr_build_fdt(spapr, reset_fdt, fdt_bufsize);
+    fdt = spapr_build_fdt(spapr, spapr->vof != NULL, fdt_bufsize);
     g_free(spapr->fdt_blob);
     spapr->fdt_size = fdt_totalsize(fdt);
     spapr->fdt_initial_size = spapr->fdt_size;

hw/ppc/spapr_vof.c

@@ -8,6 +8,7 @@
 #include "qapi/error.h"
 #include "hw/ppc/spapr.h"
 #include "hw/ppc/spapr_vio.h"
+#include "hw/ppc/spapr_cpu_core.h"
 #include "hw/ppc/fdt.h"
 #include "hw/ppc/vof.h"
 #include "sysemu/sysemu.h"
@@ -29,13 +30,19 @@ target_ulong spapr_h_vof_client(PowerPCCPU *cpu, SpaprMachineState *spapr,
 void spapr_vof_client_dt_finalize(SpaprMachineState *spapr, void *fdt)
 {
     char *stdout_path = spapr_vio_stdout_path(spapr->vio_bus);
-    int chosen;
 
     vof_build_dt(fdt, spapr->vof);
 
-    _FDT(chosen = fdt_path_offset(fdt, "/chosen"));
-    _FDT(fdt_setprop_string(fdt, chosen, "bootargs",
-                            spapr->vof->bootargs ? : ""));
+    if (spapr->vof->bootargs) {
+        int chosen;
+
+        _FDT(chosen = fdt_path_offset(fdt, "/chosen"));
+        /*
+         * If the client did not change "bootargs", spapr_dt_chosen() must have
+         * stored machine->kernel_cmdline in it before getting here.
+         */
+        _FDT(fdt_setprop_string(fdt, chosen, "bootargs", spapr->vof->bootargs));
+    }
 
     /*
      * SLOF-less setup requires an open instance of stdout for early
@@ -48,20 +55,21 @@ void spapr_vof_client_dt_finalize(SpaprMachineState *spapr, void *fdt)
     }
 }
 
-void spapr_vof_reset(SpaprMachineState *spapr, void *fdt,
-                     target_ulong *stack_ptr, Error **errp)
+void spapr_vof_reset(SpaprMachineState *spapr, void *fdt, Error **errp)
 {
+    target_ulong stack_ptr;
     Vof *vof = spapr->vof;
+    PowerPCCPU *first_ppc_cpu = POWERPC_CPU(first_cpu);
 
     vof_init(vof, spapr->rma_size, errp);
 
-    *stack_ptr = vof_claim(vof, 0, VOF_STACK_SIZE, VOF_STACK_SIZE);
-    if (*stack_ptr == -1) {
+    stack_ptr = vof_claim(vof, 0, VOF_STACK_SIZE, VOF_STACK_SIZE);
+    if (stack_ptr == -1) {
         error_setg(errp, "Memory allocation for stack failed");
         return;
     }
     /* Stack grows downwards plus reserve space for the minimum stack frame */
-    *stack_ptr += VOF_STACK_SIZE - 0x20;
+    stack_ptr += VOF_STACK_SIZE - 0x20;
 
     if (spapr->kernel_size &&
         vof_claim(vof, spapr->kernel_addr, spapr->kernel_size, 0) == -1) {
@@ -77,6 +85,12 @@ void spapr_vof_reset(SpaprMachineState *spapr, void *fdt,
 
     spapr_vof_client_dt_finalize(spapr, fdt);
 
+    spapr_cpu_set_entry_state(first_ppc_cpu, SPAPR_ENTRY_POINT,
+                              stack_ptr, spapr->initrd_base,
+                              spapr->initrd_size);
+    /* VOF is 32bit BE so enforce MSR here */
+    first_ppc_cpu->env.msr &= ~((1ULL << MSR_SF) | (1ULL << MSR_LE));
+
     /*
      * At this point the expected allocation map is:
      *

hw/ppc/vof.c

@@ -144,15 +144,16 @@ static int path_offset(const void *fdt, const char *path)
      * the lower case forms of the hexadecimal digits in the range a..f,
      * suppressing leading zeros".
      */
-    at = strchr(path, '@');
-    if (!at) {
-        return fdt_path_offset(fdt, path);
-    }
-
     p = g_strdup(path);
-    for (at = at - path + p + 1; *at; ++at) {
-        *at = tolower(*at);
+    for (at = strchr(p, '@'); at && *at; ) {
+            if (*at == '/') {
+                at = strchr(at, '@');
+            } else {
+                *at = tolower(*at);
+                ++at;
+            }
     }
+
     return fdt_path_offset(fdt, p);
 }
 
@@ -300,6 +301,7 @@ static uint32_t vof_setprop(MachineState *ms, void *fdt, Vof *vof,
     char trval[64] = "";
     char nodepath[VOF_MAX_PATH] = "";
     Object *vmo = object_dynamic_cast(OBJECT(ms), TYPE_VOF_MACHINE_IF);
+    VofMachineIfClass *vmc;
     g_autofree char *val = NULL;
 
     if (vallen > VOF_MAX_SETPROPLEN) {
@@ -322,13 +324,13 @@ static uint32_t vof_setprop(MachineState *ms, void *fdt, Vof *vof,
         goto trace_exit;
     }
 
-    if (vmo) {
-        VofMachineIfClass *vmc = VOF_MACHINE_GET_CLASS(vmo);
+    if (!vmo) {
+        goto trace_exit;
+    }
 
-        if (vmc->setprop &&
-            !vmc->setprop(ms, nodepath, propname, val, vallen)) {
-            goto trace_exit;
-        }
+    vmc = VOF_MACHINE_GET_CLASS(vmo);
+    if (!vmc->setprop || !vmc->setprop(ms, nodepath, propname, val, vallen)) {
+        goto trace_exit;
     }
 
     ret = fdt_setprop(fdt, offset, propname, val, vallen);
@@ -919,6 +921,8 @@ static uint32_t vof_client_handle(MachineState *ms, void *fdt, Vof *vof,
         ret = -1;
     }
 
+#undef cmpserv
+
     return ret;
 }
 

include/hw/ppc/spapr.h

@@ -964,8 +964,7 @@ void spapr_set_all_lpcrs(target_ulong value, target_ulong mask);
 hwaddr spapr_get_rtas_addr(void);
 bool spapr_memory_hot_unplug_supported(SpaprMachineState *spapr);
 
-void spapr_vof_reset(SpaprMachineState *spapr, void *fdt,
-                     target_ulong *stack_ptr, Error **errp);
+void spapr_vof_reset(SpaprMachineState *spapr, void *fdt, Error **errp);
 void spapr_vof_quiesce(MachineState *ms);
 bool spapr_vof_setprop(MachineState *ms, const char *path, const char *propname,
                        void *val, int vallen);

pc-bios/vof/ci.c

@@ -69,7 +69,7 @@ static int call_ci(const char *service, int nargs, int nret, ...)
     }
 
     if (ci_entry((uint32_t)(&args)) < 0) {
-        return PROM_ERROR;
+        return -1;
     }
 
     return (nret > 0) ? args.args[nargs] : 0;

pc-bios/vof/libc.c

@@ -54,32 +54,6 @@ int memcmp(const void *ptr1, const void *ptr2, size_t n)
     return 0;
 }
 
-void *memmove(void *dest, const void *src, size_t n)
-{
-    char *cdest;
-    const char *csrc;
-    int i;
-
-    /* Do the buffers overlap in a bad way? */
-    if (src < dest && src + n >= dest) {
-        /* Copy from end to start */
-        cdest = dest + n - 1;
-        csrc = src + n - 1;
-        for (i = 0; i < n; i++) {
-            *cdest-- = *csrc--;
-        }
-    } else {
-        /* Normal copy is possible */
-        cdest = dest;
-        csrc = src;
-        for (i = 0; i < n; i++) {
-            *cdest++ = *csrc++;
-        }
-    }
-
-    return dest;
-}
-
 void *memset(void *dest, int c, size_t size)
 {
     unsigned char *d = (unsigned char *)dest;

pc-bios/vof/main.c

@@ -6,7 +6,7 @@ void do_boot(unsigned long addr, unsigned long _r3, unsigned long _r4)
     register unsigned long r4 __asm__("r4") = _r4;
     register unsigned long r5 __asm__("r5") = (unsigned long) _prom_entry;
 
-    ((client *)(uint32_t)addr)();
+    ((void (*)(void))(uint32_t)addr)();
 }
 
 void entry_c(void)

pc-bios/vof/vof.h

@@ -10,11 +10,9 @@ typedef unsigned short uint16_t;
 typedef unsigned long uint32_t;
 typedef unsigned long long uint64_t;
 #define NULL (0)
-#define PROM_ERROR (-1u)
 typedef unsigned long ihandle;
 typedef unsigned long phandle;
 typedef int size_t;
-typedef void client(void);
 
 /* globals */
 extern void _prom_entry(void); /* OF CI entry point (i.e. this firmware) */