[Qemu-devel] [PATCH v5 2/2] spapr-rtas: add ibm, get-vpd RTAS interface

["Maxiwell S. Garcia" <maxiwell@linux.ibm.com>]

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,host-serial={passthrough|string},host-model={passthrough|string}’

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

The SE and TM keywords are controlled by 'host-serial' and 'host-model'
options, respectively. In the case of 'passthrough', the SE shows the
host 'system-id' information and the TM shows the host 'model' information.

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 <maxiwell@linux.ibm.com>
---
 hw/ppc/spapr_rtas.c    | 110 +++++++++++++++++++++++++++++++++++++++++
 include/hw/ppc/spapr.h |  12 ++++-
 2 files changed, 121 insertions(+), 1 deletion(-)

diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c
index 7a2cb786a3..778abcef91 100644
--- a/hw/ppc/spapr_rtas.c
+++ b/hw/ppc/spapr_rtas.c
@@ -287,6 +287,112 @@ 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 struct {
+    char *keyword;
+    char *value;
+} rtas_get_vpd_fields[RTAS_IBM_GET_VPD_KEYWORDS_MAX + 1];
+
+static void rtas_ibm_get_vpd_fields_register(sPAPRMachineState *sm)
+{
+    int i = 0;
+    char *buf = NULL;
+
+    memset(rtas_get_vpd_fields, 0, sizeof(rtas_get_vpd_fields));
+
+    buf = spapr_get_valid_host_serial(sm);
+    if (buf) {
+        rtas_get_vpd_fields[i].keyword = g_strdup("SE");
+        rtas_get_vpd_fields[i++].value = g_strdup(buf);
+        g_free(buf);
+    }
+    buf = spapr_get_valid_host_model(sm);
+    if (buf) {
+        rtas_get_vpd_fields[i].keyword = g_strdup("TM");
+        rtas_get_vpd_fields[i++].value = g_strdup(buf);
+        g_free(buf);
+    }
+}
+
+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)
+{
+    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 = 1;
+    int status = RTAS_IBM_GET_VPD_PARAMETER_ERROR;
+    int ret = RTAS_OUT_PARAM_ERROR;
+    char *vpd_field = NULL;
+    unsigned int vpd_field_len = 0;
+
+    /* RTAS not authorized if no keywords have been registered */
+    if (!rtas_get_vpd_fields[0].keyword) {
+        vpd_ret(rets, RTAS_OUT_NOT_AUTHORIZED, 1, 0);
+        return;
+    }
+
+    loc_code_addr = rtas_ld(args, 0);
+    work_area_addr = rtas_ld(args, 1);
+    work_area_size = rtas_ld(args, 2);
+    seq_number = rtas_ld(args, 3);
+
+    /* Specific Location Code is not supported and seq_number */
+    /* must be checked to avoid out of bound index error */
+    cpu_physical_memory_read(loc_code_addr, &loc_code, 1);
+    if ((loc_code != 0) || (seq_number <= 0) ||
+        (seq_number > RTAS_IBM_GET_VPD_KEYWORDS_MAX)) {
+        vpd_ret(rets, RTAS_IBM_GET_VPD_PARAMETER_ERROR, 1, 0);
+        return;
+    }
+
+    vpd_field = g_strdup_printf("%s %s",
+                rtas_get_vpd_fields[seq_number - 1].keyword,
+                rtas_get_vpd_fields[seq_number - 1].value);
+
+    if (vpd_field) {
+        vpd_field_len = strlen(vpd_field);
+        ret = vpd_st(work_area_addr, work_area_size,
+                     vpd_field, vpd_field_len + 1);
+
+        if (ret == 0) {
+            next_seq_number = seq_number + 1;
+            if (rtas_get_vpd_fields[next_seq_number - 1].keyword) {
+                status = RTAS_IBM_GET_VPD_CONTINUE;
+            } else {
+                status = RTAS_IBM_GET_VPD_SUCCESS;
+                next_seq_number = 1;
+            }
+        }
+    }
+
+    vpd_ret(rets, status, next_seq_number, vpd_field_len);
+    g_free(vpd_field);
+}
+
 static void rtas_ibm_os_term(PowerPCCPU *cpu,
                             sPAPRMachineState *spapr,
                             uint32_t token, uint32_t nargs,
@@ -464,6 +570,8 @@ void spapr_load_rtas(sPAPRMachineState *spapr, void *fdt, hwaddr addr)
                      fdt_strerror(ret));
         exit(1);
     }
+
+    rtas_ibm_get_vpd_fields_register(spapr);
 }
 
 static void core_rtas_register_types(void)
@@ -485,6 +593,8 @@ 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 f7ea99dc69..84e57c3f34 100644
--- a/include/hw/ppc/spapr.h
+++ b/include/hw/ppc/spapr.h
@@ -608,14 +608,24 @@ 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
+
+#define RTAS_IBM_GET_VPD_KEYWORDS_MAX     2
+
 /* RTAS indicator/sensor types
  *
  * as defined by PAPR+ 2.7 7.3.5.4, Table 41
-- 
2.20.1