Re: [Qemu-devel] [PATCH 2/4] ppc64-dump: Support dump for little endian ppc64

[Alexander Graf]

On 28.04.14 13:29, Greg Kurz wrote:
From: Bharata B Rao <bhar...@linux.vnet.ibm.com>
Fix ppc64 arch specific dump code to work correctly for little endian
guests.

Signed-off-by: Bharata B Rao <bhar...@linux.vnet.ibm.com>
[ rebased on top of current master branch,
   Greg Kurz <gk...@linux.vnet.ibm.com> ]
Signed-off-by: Greg Kurz <gk...@linux.vnet.ibm.com>
---
  target-ppc/arch_dump.c |   62 ++++++++++++++++++++++++++----------------------
  1 file changed, 33 insertions(+), 29 deletions(-)

diff --git a/target-ppc/arch_dump.c b/target-ppc/arch_dump.c
index 9dccf1a..a85c872 100644
--- a/target-ppc/arch_dump.c
+++ b/target-ppc/arch_dump.c
@@ -80,93 +80,95 @@ typedef struct noteStruct {
  } QEMU_PACKED Note;
  
  
-static void ppc64_write_elf64_prstatus(Note *note, PowerPCCPU *cpu)
+static void ppc64_write_elf64_prstatus(Note *note, PowerPCCPU *cpu, int endian)
  {
      int i;
      uint64_t cr;
      struct PPC64ElfPrstatus *prstatus;
      struct PPC64UserRegStruct *reg;
  
-    note->hdr.n_type = cpu_to_be32(NT_PRSTATUS);
+    note->hdr.n_type = cpu_convert_to_target32(NT_PRSTATUS, endian);
  
      prstatus = &note->contents.prstatus;
      memset(prstatus, 0, sizeof(*prstatus));
      reg = &prstatus->pr_reg;
  
      for (i = 0; i < 32; i++) {
-        reg->gpr[i] = cpu_to_be64(cpu->env.gpr[i]);
+        reg->gpr[i] = cpu_convert_to_target64(cpu->env.gpr[i], endian);
      }
-    reg->nip = cpu_to_be64(cpu->env.nip);
-    reg->msr = cpu_to_be64(cpu->env.msr);
-    reg->ctr = cpu_to_be64(cpu->env.ctr);
-    reg->link = cpu_to_be64(cpu->env.lr);
-    reg->xer = cpu_to_be64(cpu_read_xer(&cpu->env));
+    reg->nip = cpu_convert_to_target64(cpu->env.nip, endian);
+    reg->msr = cpu_convert_to_target64(cpu->env.msr, endian);
+    reg->ctr = cpu_convert_to_target64(cpu->env.ctr, endian);
+    reg->link = cpu_convert_to_target64(cpu->env.lr, endian);
+    reg->xer = cpu_convert_to_target64(cpu_read_xer(&cpu->env), endian);

I'm not sure we really care about performance here. Can't we just have a 
local endian helper function that gets a Note * pointer and extracts the 
endianness from there?

If not, maybe we should have an encapsulation struct around the Note and 
pass that around as token.


Alex