[Qemu-devel] [PATCH 2/4] spapr: Register and handle HCALL to receive updated RTAS region

[Aravinda Prasad <aravinda@linux.vnet.ibm.com>]

Receive updates from SLOF about the updated rtas-base.
A separate patch for SLOF [1] adds functionality to invoke
a private HCALL whenever OS issues instantiate-rtas with
a new rtas-base.

This is required as QEMU needs to know the updated rtas-base
as it allocates error reporting structure in RTAS space upon
a machine check exception.

[1] https://lists.ozlabs.org/pipermail/linuxppc-dev/2014-August/120386.html

Signed-off-by: Aravinda Prasad <aravinda@linux.vnet.ibm.com>
---
 hw/ppc/spapr_hcall.c   |    8 ++++++++
 include/hw/ppc/spapr.h |    3 ++-
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c
index 652ddf6..9703ed2 100644
--- a/hw/ppc/spapr_hcall.c
+++ b/hw/ppc/spapr_hcall.c
@@ -580,6 +580,13 @@ static target_ulong h_rtas(PowerPCCPU *cpu, sPAPRMachineState *spapr,
                            nret, rtas_r3 + 12 + 4*nargs);
 }
 
+static target_ulong h_rtas_update(PowerPCCPU *cpu, sPAPRMachineState *spapr,
+                                  target_ulong opcode, target_ulong *args)
+{
+    spapr->rtas_addr = args[0];
+    return 0;
+}
+
 static target_ulong h_logical_load(PowerPCCPU *cpu, sPAPRMachineState *spapr,
                                    target_ulong opcode, target_ulong *args)
 {
@@ -1008,6 +1015,7 @@ static void hypercall_register_types(void)
 
     /* qemu/KVM-PPC specific hcalls */
     spapr_register_hypercall(KVMPPC_H_RTAS, h_rtas);
+    spapr_register_hypercall(KVMPPC_H_RTAS_UPDATE, h_rtas_update);
 
     spapr_register_hypercall(H_SET_MODE, h_set_mode);
 
diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
index 91a61ab..b5cadd7 100644
--- a/include/hw/ppc/spapr.h
+++ b/include/hw/ppc/spapr.h
@@ -347,7 +347,8 @@ struct sPAPRMachineState {
 #define KVMPPC_H_LOGICAL_MEMOP  (KVMPPC_HCALL_BASE + 0x1)
 /* Client Architecture support */
 #define KVMPPC_H_CAS            (KVMPPC_HCALL_BASE + 0x2)
-#define KVMPPC_HCALL_MAX        KVMPPC_H_CAS
+#define KVMPPC_H_RTAS_UPDATE    (KVMPPC_HCALL_BASE + 0x3)
+#define KVMPPC_HCALL_MAX        KVMPPC_H_RTAS_UPDATE
 
 typedef struct sPAPRDeviceTreeUpdateHeader {
     uint32_t version_id;