[PATCH 1/6] hw/ppc: Implement skeleton code for fadump in PSeries

[Aditya Gupta <adityag@linux.ibm.com>]

Implement the handler for "ibm,configure-kernel-dump" rtas call in QEMU.

Currently the handler just does basic checks and handles
register/unregister/invalidate requests from kernel.

Fadump will be enabled in a later patch.

Signed-off-by: Aditya Gupta <adityag@linux.ibm.com>
---
 hw/ppc/spapr_rtas.c    | 99 ++++++++++++++++++++++++++++++++++++++++++
 include/hw/ppc/spapr.h | 59 +++++++++++++++++++++++++
 2 files changed, 158 insertions(+)

diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c
index df2e837632aa..eebdf13b1552 100644
--- a/hw/ppc/spapr_rtas.c
+++ b/hw/ppc/spapr_rtas.c
@@ -341,6 +341,105 @@ static void rtas_ibm_set_system_parameter(PowerPCCPU *cpu,
     rtas_st(rets, 0, ret);
 }
 
+struct fadump_metadata fadump_metadata;
+
+/* Papr Section 7.4.9 ibm,configure-kernel-dump RTAS call */
+static __attribute((unused)) void rtas_configure_kernel_dump(PowerPCCPU *cpu,
+                                   SpaprMachineState *spapr,
+                                   uint32_t token, uint32_t nargs,
+                                   target_ulong args,
+                                   uint32_t nret, target_ulong rets)
+{
+    struct rtas_fadump_section_header header;
+    target_ulong cmd = rtas_ld(args, 0);
+    target_ulong fdm_addr = rtas_ld(args, 1);
+    target_ulong fdm_size = rtas_ld(args, 2);
+
+    /* Number outputs has to be 1 */
+    if (nret != 1) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                "FADUMP: ibm,configure-kernel-dump RTAS called with nret != 1.\n");
+        return;
+    }
+
+    /* Number inputs has to be 3 */
+    if (nargs != 3) {
+        rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
+        return;
+    }
+
+    switch (cmd) {
+    case FADUMP_CMD_REGISTER:
+        if (fadump_metadata.fadump_registered) {
+            /* Fadump already registered */
+            rtas_st(rets, 0, RTAS_OUT_DUMP_ALREADY_REGISTERED);
+            return;
+        }
+
+        if (fadump_metadata.fadump_dump_active == 1) {
+            rtas_st(rets, 0, RTAS_OUT_DUMP_ACTIVE);
+            return;
+        }
+
+        if (fdm_size < sizeof(struct rtas_fadump_section_header)) {
+            qemu_log_mask(LOG_GUEST_ERROR,
+                "FADUMP: Header size is invalid: %lu\n", fdm_size);
+            rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
+            return;
+        }
+
+        /* XXX: Can we ensure fdm_addr points to a valid RMR-memory buffer ? */
+        if (fdm_addr <= 0) {
+            qemu_log_mask(LOG_GUEST_ERROR,
+                "FADUMP: Invalid fdm address: %ld\n", fdm_addr);
+            rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
+            return;
+        }
+
+        /* Verify that we understand the fadump header version */
+        cpu_physical_memory_read(fdm_addr, &header, sizeof(header));
+        if (header.dump_format_version != cpu_to_be32(FADUMP_VERSION)) {
+            qemu_log_mask(LOG_GUEST_ERROR,
+                "FADUMP: Unknown fadump header version: 0x%x\n",
+                header.dump_format_version);
+            rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
+            return;
+        }
+
+        fadump_metadata.fadump_registered = true;
+        fadump_metadata.fadump_dump_active = false;
+        fadump_metadata.fdm_addr = fdm_addr;
+        break;
+    case FADUMP_CMD_UNREGISTER:
+        if (fadump_metadata.fadump_dump_active == 1) {
+            rtas_st(rets, 0, RTAS_OUT_DUMP_ACTIVE);
+            return;
+        }
+
+        fadump_metadata.fadump_registered = false;
+        fadump_metadata.fadump_dump_active = false;
+        fadump_metadata.fdm_addr = -1;
+        break;
+    case FADUMP_CMD_INVALIDATE:
+        if (fadump_metadata.fadump_dump_active) {
+            fadump_metadata.fadump_registered = false;
+            fadump_metadata.fadump_dump_active = false;
+            fadump_metadata.fdm_addr = -1;
+            memset(&fadump_metadata.registered_fdm, 0,
+                    sizeof(fadump_metadata.registered_fdm));
+        } else {
+            hcall_dprintf("fadump: Nothing to invalidate, no dump active.\n");
+        }
+        break;
+    default:
+        hcall_dprintf("Unknown RTAS token 0x%x\n", token);
+        rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
+        return;
+    }
+
+    rtas_st(rets, 0, RTAS_OUT_SUCCESS);
+}
+
 static void rtas_ibm_os_term(PowerPCCPU *cpu,
                             SpaprMachineState *spapr,
                             uint32_t token, uint32_t nargs,
diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
index a6c0547e313d..efa2f891a8a7 100644
--- a/include/hw/ppc/spapr.h
+++ b/include/hw/ppc/spapr.h
@@ -704,6 +704,8 @@ void push_sregs_to_kvm_pr(SpaprMachineState *spapr);
 #define RTAS_OUT_PARAM_ERROR                    -3
 #define RTAS_OUT_NOT_SUPPORTED                  -3
 #define RTAS_OUT_NO_SUCH_INDICATOR              -3
+#define RTAS_OUT_DUMP_ALREADY_REGISTERED        -9
+#define RTAS_OUT_DUMP_ACTIVE                    -10
 #define RTAS_OUT_NOT_AUTHORIZED                 -9002
 #define RTAS_OUT_SYSPARM_PARAM_ERROR            -9999
 
@@ -769,6 +771,63 @@ void push_sregs_to_kvm_pr(SpaprMachineState *spapr);
 
 #define RTAS_TOKEN_MAX                          (RTAS_TOKEN_BASE + 0x2D)
 
+/* Fadump commands */
+#define FADUMP_CMD_REGISTER            1
+#define FADUMP_CMD_UNREGISTER          2
+#define FADUMP_CMD_INVALIDATE          3
+
+#define FADUMP_VERSION    1
+
+/*
+ * The Firmware Assisted Dump Memory structure supports a maximum of 10 sections
+ * in the dump memory structure. Presently, three sections are used for
+ * CPU state data, HPTE & Parameters area, while the remaining seven sections
+ * can be used for boot memory regions.
+ */
+#define FADUMP_MAX_SECTIONS            10
+#define RTAS_FADUMP_MAX_BOOT_MEM_REGS  7
+
+/* Kernel Dump section info */
+struct rtas_fadump_section {
+    __be32    request_flag;
+    __be16    source_data_type;
+    __be16    error_flags;
+    __be64    source_address;
+    __be64    source_len;
+    __be64    bytes_dumped;
+    __be64    destination_address;
+};
+
+/* ibm,configure-kernel-dump header. */
+struct rtas_fadump_section_header {
+    __be32    dump_format_version;
+    __be16    dump_num_sections;
+    __be16    dump_status_flag;
+    __be32    offset_first_dump_section;
+
+    /* Fields for disk dump option. */
+    __be32    dd_block_size;
+    __be64    dd_block_offset;
+    __be64    dd_num_blocks;
+    __be32    dd_offset_disk_path;
+
+    /* Maximum time allowed to prevent an automatic dump-reboot. */
+    __be32    max_time_auto;
+};
+
+struct rtas_fadump_mem_struct {
+    struct rtas_fadump_section_header header;
+    struct rtas_fadump_section        rgn[FADUMP_MAX_SECTIONS];
+};
+
+struct fadump_metadata {
+    bool fadump_registered;
+    bool fadump_dump_active;
+    target_ulong fdm_addr;
+    struct rtas_fadump_mem_struct registered_fdm;
+};
+extern struct fadump_metadata fadump_metadata;
+
 /* RTAS ibm,get-system-parameter token values */
 #define RTAS_SYSPARM_SPLPAR_CHARACTERISTICS      20
 #define RTAS_SYSPARM_DIAGNOSTICS_RUN_MODE        42
-- 
2.48.1