[Qemu-ppc] [PATCH] spapr-rtas: add ibm,get-vpd RTAS interface

[Maxiwell S. Garcia]

This adds a handler for ibm,get-vpd RTAS calls, allowing pseries
guest to collect host information. It is disabled by default to
avoid unwanted information leakage. To enable it, use:
‘-M pseries,vpd-export=on’

Only the SE and TM keywords are returned at the moment:
SE for Machine or Cabinet Serial Number and
TM for Machine Type and Model.

Powerpc-utils tools can dispatch RTAS calls to retrieve host
information using this ibm,get-vpd interface. The 'host-serial'
and 'host-model' nodes of device-tree hold the same information but
in a static manner, which is useless after a migration operation.

Signed-off-by: Maxiwell S. Garcia <address@hidden>
---
 hw/ppc/spapr.c         | 21 ++++++++++
 hw/ppc/spapr_rtas.c    | 93 ++++++++++++++++++++++++++++++++++++++++++
 include/hw/ppc/spapr.h | 17 +++++++-
 3 files changed, 130 insertions(+), 1 deletion(-)

diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index abf9ebce59..09fd9e2ebb 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -3026,6 +3026,20 @@ static char *spapr_get_fw_dev_path(FWPathProvider *p, 
BusState *bus,
     return NULL;
 }
 
+static bool spapr_get_vpd_export(Object *obj, Error **errp)
+{
+    sPAPRMachineState *spapr = SPAPR_MACHINE(obj);
+
+    return spapr->vpd_export;
+}
+
+static void spapr_set_vpd_export(Object *obj, bool value, Error **errp)
+{
+    sPAPRMachineState *spapr = SPAPR_MACHINE(obj);
+
+    spapr->vpd_export = value;
+}
+
 static char *spapr_get_kvm_type(Object *obj, Error **errp)
 {
     sPAPRMachineState *spapr = SPAPR_MACHINE(obj);
@@ -3150,6 +3164,7 @@ static void spapr_instance_init(Object *obj)
     sPAPRMachineClass *smc = SPAPR_MACHINE_GET_CLASS(spapr);
 
     spapr->htab_fd = -1;
+    spapr->vpd_export = false;
     spapr->use_hotplug_event_source = true;
     object_property_add_str(obj, "kvm-type",
                             spapr_get_kvm_type, spapr_set_kvm_type, NULL);
@@ -3182,6 +3197,12 @@ static void spapr_instance_init(Object *obj)
     object_property_add_bool(obj, "vfio-no-msix-emulation",
                              spapr_get_msix_emulation, NULL, NULL);
 
+    object_property_add_bool(obj, "vpd-export", spapr_get_vpd_export,
+                             spapr_set_vpd_export, NULL);
+    object_property_set_description(obj, "vpd-export",
+                                    "Export Host's VPD information to guest",
+                                    &error_abort);
+
     /* The machine class defines the default interrupt controller mode */
     spapr->irq = smc->irq;
     object_property_add_str(obj, "ic-mode", spapr_get_ic_mode,
diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c
index d6a0952154..214e0edfc5 100644
--- a/hw/ppc/spapr_rtas.c
+++ b/hw/ppc/spapr_rtas.c
@@ -287,6 +287,97 @@ static void rtas_ibm_set_system_parameter(PowerPCCPU *cpu,
     rtas_st(rets, 0, ret);
 }
 
+static inline int vpd_st(target_ulong addr, target_ulong len,
+                         const void *val, uint16_t val_len)
+{
+    hwaddr phys = ppc64_phys_to_real(addr);
+    if (len < val_len) {
+        return RTAS_OUT_PARAM_ERROR;
+    }
+    cpu_physical_memory_write(phys, val, val_len);
+    return RTAS_OUT_SUCCESS;
+}
+
+static inline void vpd_ret(target_ulong rets, const int status,
+                           const int next_seq_number, const int bytes_returned)
+{
+    rtas_st(rets, 0, status);
+    rtas_st(rets, 1, next_seq_number);
+    rtas_st(rets, 2, bytes_returned);
+}
+
+static void rtas_ibm_get_vpd(PowerPCCPU *cpu,
+                             sPAPRMachineState *spapr,
+                             uint32_t token, uint32_t nargs,
+                             target_ulong args,
+                             uint32_t nret, target_ulong rets)
+{
+    sPAPRMachineState *sm = SPAPR_MACHINE(spapr);
+    target_ulong loc_code_addr;
+    target_ulong work_area_addr;
+    target_ulong work_area_size;
+    target_ulong seq_number;
+    unsigned char loc_code = 0;
+    unsigned int next_seq_number = 0;
+    int status = RTAS_IBM_GET_VPD_PARAMETER_ERROR;
+    int ret = 0;
+    char *field = '\0';
+
+    if (!sm->vpd_export) {
+        vpd_ret(rets, RTAS_OUT_NOT_AUTHORIZED, 1, 0);
+        return;
+    }
+
+    /* Specific Location Code is not supported */
+    loc_code_addr = rtas_ld(args, 0);
+    cpu_physical_memory_read(loc_code_addr, &loc_code, 1);
+    if (loc_code != 0) {
+        vpd_ret(rets, RTAS_IBM_GET_VPD_PARAMETER_ERROR, 1, 0);
+        return;
+    }
+
+    work_area_addr = rtas_ld(args, 1);
+    work_area_size = rtas_ld(args, 2);
+    seq_number = rtas_ld(args, 3);
+    switch (seq_number) {
+        case RTAS_IBM_VPD_KEYWORD_SE: {
+            char *host_serial;
+            if (kvmppc_get_host_serial(&host_serial)) {
+                /* LoPAPR: SE for Machine or Cabinet Serial Number */
+                field = g_strdup_printf("SE %s", host_serial);
+                ret = vpd_st(work_area_addr, work_area_size,
+                             field, strlen(field) + 1);
+                g_free(host_serial);
+            }
+            break;
+        }
+        case RTAS_IBM_VPD_KEYWORD_TM: {
+            char *host_model;
+            if (kvmppc_get_host_model(&host_model)) {
+                /* LoPAPR: TM for Machine Type and Model */
+                field = g_strdup_printf("TM %s", host_model);
+                ret = vpd_st(work_area_addr, work_area_size,
+                             field, strlen(field) + 1);
+                g_free(host_model);
+            }
+            break;
+        }
+    }
+
+    if (ret == 0) {
+        if (seq_number == RTAS_IBM_VPD_KEYWORD_LAST) {
+            status = RTAS_IBM_GET_VPD_SUCCESS;
+            next_seq_number = 1;
+        } else {
+            status = RTAS_IBM_GET_VPD_CONTINUE;
+            next_seq_number = seq_number + 1;
+        }
+    }
+
+    vpd_ret(rets, status, next_seq_number, strlen(field));
+    g_free(field);
+}
+
 static void rtas_ibm_os_term(PowerPCCPU *cpu,
                             sPAPRMachineState *spapr,
                             uint32_t token, uint32_t nargs,
@@ -485,6 +576,8 @@ static void core_rtas_register_types(void)
                         rtas_ibm_set_system_parameter);
     spapr_rtas_register(RTAS_IBM_OS_TERM, "ibm,os-term",
                         rtas_ibm_os_term);
+    spapr_rtas_register(RTAS_IBM_GET_VPD, "ibm,get-vpd",
+                        rtas_ibm_get_vpd);
     spapr_rtas_register(RTAS_SET_POWER_LEVEL, "set-power-level",
                         rtas_set_power_level);
     spapr_rtas_register(RTAS_GET_POWER_LEVEL, "get-power-level",
diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
index 631fc5103b..235b22340d 100644
--- a/include/hw/ppc/spapr.h
+++ b/include/hw/ppc/spapr.h
@@ -183,6 +183,7 @@ struct sPAPRMachineState {
     sPAPRXive  *xive;
     sPAPRIrq *irq;
     qemu_irq *qirqs;
+    bool vpd_export;
 
     bool cmd_line_caps[SPAPR_CAP_NUM];
     sPAPRCapabilities def, eff, mig;
@@ -605,14 +606,28 @@ target_ulong spapr_hypercall(PowerPCCPU *cpu, 
target_ulong opcode,
 #define RTAS_IBM_CREATE_PE_DMA_WINDOW           (RTAS_TOKEN_BASE + 0x27)
 #define RTAS_IBM_REMOVE_PE_DMA_WINDOW           (RTAS_TOKEN_BASE + 0x28)
 #define RTAS_IBM_RESET_PE_DMA_WINDOW            (RTAS_TOKEN_BASE + 0x29)
+#define RTAS_IBM_GET_VPD                        (RTAS_TOKEN_BASE + 0x2A)
 
-#define RTAS_TOKEN_MAX                          (RTAS_TOKEN_BASE + 0x2A)
+#define RTAS_TOKEN_MAX                          (RTAS_TOKEN_BASE + 0x2B)
 
 /* RTAS ibm,get-system-parameter token values */
 #define RTAS_SYSPARM_SPLPAR_CHARACTERISTICS      20
 #define RTAS_SYSPARM_DIAGNOSTICS_RUN_MODE        42
 #define RTAS_SYSPARM_UUID                        48
 
+/* RTAS ibm,get-vpd status values */
+#define RTAS_IBM_GET_VPD_VPD_CHANGED     -4
+#define RTAS_IBM_GET_VPD_PARAMETER_ERROR -3
+#define RTAS_IBM_GET_VPD_HARDWARE_ERROR  -1
+#define RTAS_IBM_GET_VPD_SUCCESS          0
+#define RTAS_IBM_GET_VPD_CONTINUE         1
+
+/* RTAS ibm,get-vpd keywords index */
+#define RTAS_IBM_VPD_KEYWORD_SE     1
+#define RTAS_IBM_VPD_KEYWORD_TM     2
+
+#define RTAS_IBM_VPD_KEYWORD_LAST   2
+
 /* RTAS indicator/sensor types
  *
  * as defined by PAPR+ 2.7 7.3.5.4, Table 41
-- 
2.20.1