[QEMU-PPC,3/3] target/ppc: Add H-Call H_GET_CPU_CHARACTERISTICS

Commit Message

Suraj Jitindar Singh Jan. 12, 2018, 5:33 a.m. UTC

The new H-Call H_GET_CPU_CHARACTERISTICS is used by the guest to query
behaviours and available characteristics of the cpu.

Implement the handler for this new H-Call which formulates its response
based on the setting of the new capabilities added in the previous
patch.
---
 hw/ppc/spapr_hcall.c   | 78 ++++++++++++++++++++++++++++++++++++++++++++++++++
 include/hw/ppc/spapr.h |  1 +
 2 files changed, 79 insertions(+)

Patch

diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c
index 51eba52e86..b167554771 100644
--- a/hw/ppc/spapr_hcall.c
+++ b/hw/ppc/spapr_hcall.c
@@ -1654,6 +1654,81 @@  static target_ulong h_client_architecture_support(PowerPCCPU *cpu,
     return H_SUCCESS;
 }
 
+/* H_GET_CPU_CHARACTERISTICS return values */
+#define H_CPU_CHAR_SPEC_BAR_ORI31               PPC_BIT(0)
+#define H_CPU_CHAR_BCCTRL_SERIALISED            PPC_BIT(1)
+#define H_CPU_CHAR_L1D_FLUSH_ORI30              PPC_BIT(2)
+#define H_CPU_CHAR_L1D_FLUSH_TRIG2              PPC_BIT(3)
+#define H_CPU_CHAR_L1D_THREAD_PRIV              PPC_BIT(4)
+#define H_CPU_CHAR_HON_BRANCH_HINTS             PPC_BIT(5)
+#define H_CPU_CHAR_THR_RECONF_TRIG              PPC_BIT(6)
+#define H_CPU_BEHAV_FAVOUR_SECURITY             PPC_BIT(0)
+#define H_CPU_BEHAV_L1D_FLUSH_PR                PPC_BIT(1)
+#define H_CPU_BEHAV_BNDS_CHK_SPEC_BAR           PPC_BIT(2)
+
+static target_ulong h_get_cpu_characteristics(PowerPCCPU *cpu,
+                                              sPAPRMachineState *spapr,
+                                              target_ulong opcode,
+                                              target_ulong *args)
+{
+    uint64_t characteristics = H_CPU_CHAR_HON_BRANCH_HINTS &
+			       ~H_CPU_CHAR_THR_RECONF_TRIG;
+    uint64_t behaviour = H_CPU_BEHAV_FAVOUR_SECURITY;
+    uint8_t safe_cache = spapr_get_cap(spapr, SPAPR_CAP_CFPC);
+    uint8_t safe_bounds_check = spapr_get_cap(spapr, SPAPR_CAP_SBBC);
+    uint8_t safe_indirect_branch = spapr_get_cap(spapr, SPAPR_CAP_IBS);
+
+    switch (safe_cache) {
+    case SPAPR_CAP_WORKAROUND:
+        characteristics |= H_CPU_CHAR_L1D_FLUSH_ORI30;
+        characteristics |= H_CPU_CHAR_L1D_FLUSH_TRIG2;
+        characteristics |= H_CPU_CHAR_L1D_THREAD_PRIV;
+        behaviour |= H_CPU_BEHAV_L1D_FLUSH_PR;
+        break;
+    case SPAPR_CAP_FIXED:
+        break;
+    default: /* broken */
+        if (safe_cache != SPAPR_CAP_BROKEN) {
+            error_report("Invalid value for cap-cfpc (%d), assuming broken",
+                         safe_cache);
+        }
+        behaviour |= H_CPU_BEHAV_L1D_FLUSH_PR;
+        break;
+    }
+
+    switch (safe_bounds_check) {
+    case SPAPR_CAP_WORKAROUND:
+        characteristics |= H_CPU_CHAR_SPEC_BAR_ORI31;
+        behaviour |= H_CPU_BEHAV_BNDS_CHK_SPEC_BAR;
+        break;
+    case SPAPR_CAP_FIXED:
+        break;
+    default: /* broken */
+        if (safe_bounds_check != SPAPR_CAP_BROKEN) {
+            error_report("Invalid value for cap-sbbc (%d), assuming broken",
+                         safe_bounds_check);
+        }
+        behaviour |= H_CPU_BEHAV_BNDS_CHK_SPEC_BAR;
+        break;
+    }
+
+    switch (safe_indirect_branch) {
+    case SPAPR_CAP_FIXED:
+        characteristics |= H_CPU_CHAR_BCCTRL_SERIALISED;
+    default: /* broken */
+        if (safe_indirect_branch != SPAPR_CAP_BROKEN) {
+            error_report("Invalid value for cap-ibs (%d), assuming broken",
+                         safe_indirect_branch);
+        }
+        break;
+    }
+
+    args[0] = characteristics;
+    args[1] = behaviour;
+
+    return H_SUCCESS;
+}
+
 static spapr_hcall_fn papr_hypercall_table[(MAX_HCALL_OPCODE / 4) + 1];
 static spapr_hcall_fn kvmppc_hypercall_table[KVMPPC_HCALL_MAX - KVMPPC_HCALL_BASE + 1];
 
@@ -1733,6 +1808,9 @@  static void hypercall_register_types(void)
     spapr_register_hypercall(H_INVALIDATE_PID, h_invalidate_pid);
     spapr_register_hypercall(H_REGISTER_PROC_TBL, h_register_process_table);
 
+    /* hcall-get-cpu-characteristics */
+    spapr_register_hypercall(H_GET_CPU_CHARACTERISTICS, h_get_cpu_characteristics);
+
     /* "debugger" hcalls (also used by SLOF). Note: We do -not- differenciate
      * here between the "CI" and the "CACHE" variants, they will use whatever
      * mapping attributes qemu is using. When using KVM, the kernel will
diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
index 63ffd422b5..98e76d8b9a 100644
--- a/include/hw/ppc/spapr.h
+++ b/include/hw/ppc/spapr.h
@@ -392,6 +392,7 @@  struct sPAPRMachineState {
 #define H_GET_HCA_INFO          0x1B8
 #define H_GET_PERF_COUNT        0x1BC
 #define H_MANAGE_TRACE          0x1C0
+#define H_GET_CPU_CHARACTERISTICS 0x1C8
 #define H_FREE_LOGICAL_LAN_BUFFER 0x1D4
 #define H_QUERY_INT_STATE       0x1E4
 #define H_POLL_PENDING          0x1D8