[Qemu-devel] [RFC 1/3] pseries: Stub hypercalls for HPT resizing

[David Gibson <david@gibson.dropbear.id.au>]

This introduces stub implementations of the H_RESIZE_HPT_PREPARE and
H_RESIZE_HPT_COMMIT hypercalls which we hope to add in a PAPR extension to
allow run time resizing of a guest's hash page table.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
 hw/ppc/spapr_hcall.c   | 29 +++++++++++++++++++++++++++++
 include/hw/ppc/spapr.h |  4 +++-
 trace-events           |  2 ++
 3 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c
index 1a1bea8..01c034c 100644
--- a/hw/ppc/spapr_hcall.c
+++ b/hw/ppc/spapr_hcall.c
@@ -316,6 +316,30 @@ static target_ulong h_read(PowerPCCPU *cpu, sPAPRMachineState *spapr,
     return H_SUCCESS;
 }
 
+static target_ulong h_resize_hpt_prepare(PowerPCCPU *cpu,
+                                         sPAPRMachineState *spapr,
+                                         target_ulong opcode,
+                                         target_ulong *args)
+{
+    target_ulong flags = args[0];
+    target_ulong shift = args[1];
+
+    trace_spapr_h_resize_hpt_prepare(flags, shift);
+    return H_HARDWARE;
+}
+
+static target_ulong h_resize_hpt_commit(PowerPCCPU *cpu,
+                                        sPAPRMachineState *spapr,
+                                        target_ulong opcode,
+                                        target_ulong *args)
+{
+    target_ulong flags = args[0];
+    target_ulong shift = args[1];
+
+    trace_spapr_h_resize_hpt_commit(flags, shift);
+    return H_HARDWARE;
+}
+
 static target_ulong h_set_dabr(PowerPCCPU *cpu, sPAPRMachineState *spapr,
                                target_ulong opcode, target_ulong *args)
 {
@@ -974,6 +998,11 @@ static void hypercall_register_types(void)
     /* hcall-bulk */
     spapr_register_hypercall(H_BULK_REMOVE, h_bulk_remove);
 
+    /* hcall-hpt-resize */
+    spapr_register_hypercall(KVMPPC_H_RESIZE_HPT_PREPARE,
+                             h_resize_hpt_prepare);
+    spapr_register_hypercall(KVMPPC_H_RESIZE_HPT_COMMIT, h_resize_hpt_commit);
+
     /* hcall-dabr */
     spapr_register_hypercall(H_SET_DABR, h_set_dabr);
 
diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
index 53af76a..028afc9 100644
--- a/include/hw/ppc/spapr.h
+++ b/include/hw/ppc/spapr.h
@@ -352,7 +352,9 @@ 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_RESIZE_HPT_PREPARE (KVMPPC_HCALL_BASE + 0x3)
+#define KVMPPC_H_RESIZE_HPT_COMMIT  (KVMPPC_HCALL_BASE + 0x4)
+#define KVMPPC_HCALL_MAX        KVMPPC_H_RESIZE_HPT_COMMIT
 
 typedef struct sPAPRDeviceTreeUpdateHeader {
     uint32_t version_id;
diff --git a/trace-events b/trace-events
index 934a7b6..f0d6e49 100644
--- a/trace-events
+++ b/trace-events
@@ -1403,6 +1403,8 @@ spapr_cas_continue(unsigned long n) "Copy changes to the guest: %ld bytes"
 # hw/ppc/spapr_hcall.c
 spapr_cas_pvr_try(uint32_t pvr) "%x"
 spapr_cas_pvr(uint32_t cur_pvr, bool cpu_match, uint32_t new_pvr, uint64_t pcr) "current=%x, cpu_match=%u, new=%x, compat flags=%"PRIx64
+spapr_h_resize_hpt_prepare(uint64_t flags, uint64_t shift) "flags=0x%"PRIx64", shift=%"PRIu64
+spapr_h_resize_hpt_commit(uint64_t flags, uint64_t shift) "flags=0x%"PRIx64", shift=%"PRIu64
 
 # hw/ppc/spapr_iommu.c
 spapr_iommu_put(uint64_t liobn, uint64_t ioba, uint64_t tce, uint64_t ret) "liobn=%"PRIx64" ioba=0x%"PRIx64" tce=0x%"PRIx64" ret=%"PRId64
-- 
2.5.0