Re: [Qemu-ppc] [PATCH v3 2/2] target-ppc: Implement rtas_get_sysparm(PROCESSOR_MODULE_INFO)

[Sukadev Bhattiprolu]

David, Alexey,

Any comments on this patch?

Suka

Sukadev Bhattiprolu address@hidden wrote:
| Implement RTAS_SYSPARM_PROCESSOR_MODULE_INFO parameter to rtas_get_sysparm()
| call in qemu. This call returns the processor module (socket), chip and core
| information as specified in section 7.3.16.17 of LoPAPR v2.7.
| 
| We walk the /proc/device-tree to determine the number of modules(aka sockets),
| chips and cores in the _host_ system and return this info to the guest
| application that makes the rtas_get_sysparm() call.
| 
| We currently hard code the number of module_types to 1 (we currently don't
| have systems with more than one module type) but we should determine that
| dynamically somehow later.
| 
| Thanks to input from Nishanth Aravamudan, Alexey Kardashevskiy, David Gibson,
| Thomas Huth.
| 
| Signed-off-by: Sukadev Bhattiprolu <address@hidden>
| ---
| Changelog[v3]:
|         [David Gibson] Use glob() to simplify pattern matching path names.
|             Move new code into target-ppc/{kvm.c,kvm_ppc.h} to not impact
|             other targets and avoid creating new files.
|         [Alexey Kardashevskiy] Fix indentation, error messages; fold new
|             code into existing files and avoid creating new files for this
|             parameter; since the keys are integer, use g_direct_hash() and
|             GINT_TO_POINTER() and avoid allocating/freeing memory.
| 
| Changelog[v2]:
|         [Alexey Kardashevskiy] Use existing interfaces like ldl_be_p(),
|             stw_be_phys(), g_hash_table_new_full(), error_report() rather
|             than re-inventing; fix indentation, function prottypes etc;
|             Drop the fts() interface (which doesn't seem to be available
|             on mingw32/mingw64) and use opendir() to walk specific
|             directories in the directory tree.
| ---
|  hw/ppc/spapr_rtas.c    |  31 +++++++++++
|  include/hw/ppc/spapr.h |  13 +++++
|  target-ppc/kvm.c       | 141 
+++++++++++++++++++++++++++++++++++++++++++++++++
|  target-ppc/kvm_ppc.h   |   8 +++
|  4 files changed, 193 insertions(+)
| 
| diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c
| index 34b12a3..44b2537 100644
| --- a/hw/ppc/spapr_rtas.c
| +++ b/hw/ppc/spapr_rtas.c
| @@ -38,6 +38,7 @@
| 
|  #include <libfdt.h>
|  #include "hw/ppc/spapr_drc.h"
| +#include "kvm_ppc.h"
| 
|  /* #define DEBUG_SPAPR */
| 
| @@ -240,6 +241,36 @@ static void rtas_ibm_get_system_parameter(PowerPCCPU 
*cpu,
|      target_ulong ret = RTAS_OUT_SUCCESS;
| 
|      switch (parameter) {
| +    case RTAS_SYSPARM_PROCESSOR_MODULE_INFO: {
| +        struct sPAPRRTASModuleInfo modinfo;
| +        int i, size = sizeof(modinfo), offset = 0;
| +
| +        memset(&modinfo, 0, size);
| +        if (kvmppc_rtas_get_module_info(&modinfo)) {
| +            ret = RTAS_OUT_HW_ERROR;
| +            break;
| +        }
| +
| +        stw_be_phys(&address_space_memory, buffer+offset, size);
| +        offset += 2;
| +
| +        stw_be_phys(&address_space_memory, buffer+offset, 
modinfo.module_types);
| +        offset += 2;
| +
| +        for (i = 0; i < modinfo.module_types; i++) {
| +            stw_be_phys(&address_space_memory, buffer+offset,
| +                        modinfo.si[i].sockets);
| +            offset += 2;
| +            stw_be_phys(&address_space_memory, buffer+offset,
| +                        modinfo.si[i].chips);
| +            offset += 2;
| +            stw_be_phys(&address_space_memory, buffer+offset,
| +                        modinfo.si[i].cores_per_chip);
| +            offset += 2;
| +        }
| +        break;
| +    }
| +
|      case RTAS_SYSPARM_SPLPAR_CHARACTERISTICS: {
|          char *param_val = g_strdup_printf("MaxEntCap=%d,"
|                                            "DesMem=%llu,"
| diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
| index 5baa906..f793465 100644
| --- a/include/hw/ppc/spapr.h
| +++ b/include/hw/ppc/spapr.h
| @@ -463,6 +463,7 @@ int spapr_allocate_irq_block(int num, bool lsi, bool msi);
|  /* RTAS ibm,get-system-parameter token values */
|  #define RTAS_SYSPARM_SPLPAR_CHARACTERISTICS      20
|  #define RTAS_SYSPARM_DIAGNOSTICS_RUN_MODE        42
| +#define RTAS_SYSPARM_PROCESSOR_MODULE_INFO       43
|  #define RTAS_SYSPARM_UUID                        48
| 
|  /* RTAS indicator/sensor types
| @@ -646,4 +647,16 @@ int spapr_rng_populate_dt(void *fdt);
|   */
|  #define SPAPR_LMB_FLAGS_ASSIGNED 0x00000008
| 
| +#define SPAPR_MAX_MODULE_TYPES  1
| +
| +struct sPAPRRTASSocketInfo {
| +    unsigned short sockets;
| +    unsigned short chips;
| +    unsigned short cores_per_chip;
| +};
| +struct sPAPRRTASModuleInfo {
| +    unsigned short module_types;
| +    struct sPAPRRTASSocketInfo si[SPAPR_MAX_MODULE_TYPES];
| +};
| +
|  #endif /* !defined (__HW_SPAPR_H__) */
| diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c
| index 9940a90..bbef78c 100644
| --- a/target-ppc/kvm.c
| +++ b/target-ppc/kvm.c
| @@ -15,6 +15,7 @@
|   */
| 
|  #include <dirent.h>
| +#include <glob.h>
|  #include <sys/types.h>
|  #include <sys/ioctl.h>
|  #include <sys/mman.h>
| @@ -2518,3 +2519,143 @@ int kvmppc_enable_hwrng(void)
| 
|      return kvmppc_enable_hcall(kvm_state, H_RANDOM);
|  }
| +
| +/* Read an identifier from the file @path and add the identifier
| + * to the hash table @gt unless its already in the table.
| + */
| +static int kvmppc_hash_file_contents(GHashTable *gt, char *path)
| +{
| +    uint32_t idx;
| +
| +    idx = kvmppc_read_int_dt(path);
| +    if (idx == -1) {
| +        return -1;
| +    }
| +
| +    if (g_hash_table_contains(gt, GINT_TO_POINTER(idx))) {
| +        return 0;
| +    }
| +
| +    if (!g_hash_table_insert(gt, GINT_TO_POINTER(idx), NULL)) {
| +        fprintf(stderr, "%s() Unable to add key %d\n", __func__, idx);
| +        return -1;
| +    }
| +
| +    return 0;
| +}
| +
| +static int kvmppc_glob_count_ids_dt(const char *pattern, int *count)
| +{
| +    int i, rc;
| +    glob_t dtglob;
| +    GHashTable *htbl;
| +
| +    rc = glob(pattern, GLOB_NOSORT, NULL, &dtglob);
| +    if (rc) {
| +        fprintf(stderr, "%s() glob(%s) returns %d, errno %d\n", __func__,
| +                pattern, rc, errno);
| +        return -1;
| +    }
| +
| +    rc = -1;
| +    htbl = g_hash_table_new_full(g_direct_hash, g_direct_equal, NULL, NULL);
| +
| +    for (i = 0; i < dtglob.gl_pathc; i++) {
| +        if (kvmppc_hash_file_contents(htbl, dtglob.gl_pathv[i])) {
| +            goto cleanup;
| +        }
| +    }
| +
| +    *count = g_hash_table_size(htbl);
| +    rc = 0;
| +
| +cleanup:
| +    globfree(&dtglob);
| +    g_hash_table_remove_all(htbl);
| +    g_hash_table_destroy(htbl);
| +
| +    return rc;
| +}
| +
| +/* Each socket's (aka module's) id is contained in the 'ibm,hw-module-id'
| + * file in an "xscom" directory (/proc/device-tree/xscom*). Similarly each
| + * chip's id is contained in the 'ibm,chip-id' file in an xscom directory.
| + *
| + * Since a module can have more than one chip and a chip can have more than
| + * one core, there are likely to be duplicates in the module and chip ids
| + * i.e more than one xscom directory can contain the same module/chip id.
| + *
| + * Search the xscom directories and count the number of _UNIQUE_ modules
| + * and chips in the system.
| + *
| + * Return 0 if one or more modules and chips each are found. Return -1
| + * otherwise.
| + */
| +static int kvmppc_count_sockets_chips_dt(int *num_sockets, int *num_chips)
| +{
| +    const char *chip_pattern = 
"/proc/device-tree/address@hidden/ibm,chip-id";
| +    const char *module_pattern = 
"/proc/device-tree/address@hidden/ibm,hw-module-id";
| +
| +    if (kvmppc_glob_count_ids_dt(module_pattern, num_sockets)
| +        || kvmppc_glob_count_ids_dt(chip_pattern, num_chips)) {
| +        return -1;
| +    }
| +
| +    if (*num_sockets == 0 || *num_chips == 0) {
| +        return -1;
| +    }
| +
| +    return 0;
| +}
| +
| +/* Each core in the system is represented by a directory with the prefix
| + * 'PowerPC,POWER' in directory /proc/device-tree/cpus/.  Process that
| + * directory and count the number of cores in the system.
| + *
| + * Return 0 if one or more cores are found. Return -1 otherwise.
| + */
| +static int kvmppc_count_cores_dt(int *num_cores)
| +{
| +    int rc;
| +    glob_t dtglob;
| +    const char *cpus_pattern = "/proc/device-tree/cpus/PowerPC,POWER*";
| +
| +    rc = glob(cpus_pattern, GLOB_NOSORT, NULL, &dtglob);
| +    if (rc) {
| +        fprintf(stderr, "%s() glob(%s) returns %d, errno %d\n", __func__,
| +                cpus_pattern, rc, errno);
| +        return -1;
| +    }
| +
| +    *num_cores = dtglob.gl_pathc;
| +    globfree(&dtglob);
| +
| +    if (*num_cores == 0) {
| +        return -1;
| +    }
| +
| +    return 0;
| +}
| +
| +int kvmppc_rtas_get_module_info(struct sPAPRRTASModuleInfo *modinfo)
| +{
| +    int cores, chips, sockets;
| +
| +    if (kvmppc_count_sockets_chips_dt(&sockets, &chips)
| +        || kvmppc_count_cores_dt(&cores)) {
| +        return -1;
| +    }
| +
| +    /* TODO: Although the interface allows multiple module types, Power
| +     *       systems currently support only one module type per system -
| +     *       either Single Chip Module(SCM) or Dual Chip Module(DCM),
| +     *       but not both types in the same system. Hard code module_types
| +     *       for now till we can determine it dynamically.
| +     */
| +    modinfo->module_types = 1;
| +    modinfo->si[0].sockets = sockets;
| +    modinfo->si[0].chips = chips;
| +    modinfo->si[0].cores_per_chip = cores / chips;
| +
| +    return 0;
| +}
| diff --git a/target-ppc/kvm_ppc.h b/target-ppc/kvm_ppc.h
| index 309cbe0..46a2768 100644
| --- a/target-ppc/kvm_ppc.h
| +++ b/target-ppc/kvm_ppc.h
| @@ -10,6 +10,7 @@
|  #define __KVM_PPC_H__
| 
|  #define TYPE_HOST_POWERPC_CPU "host-" TYPE_POWERPC_CPU
| +#include "hw/ppc/spapr.h"
| 
|  #ifdef CONFIG_KVM
| 
| @@ -55,6 +56,7 @@ void kvmppc_hash64_write_pte(CPUPPCState *env, target_ulong 
pte_index,
|                               target_ulong pte0, target_ulong pte1);
|  bool kvmppc_has_cap_fixup_hcalls(void);
|  int kvmppc_enable_hwrng(void);
| +int kvmppc_rtas_get_module_info(struct sPAPRRTASModuleInfo *modinfo);
| 
|  #else
| 
| @@ -256,6 +258,12 @@ static inline int kvmppc_enable_hwrng(void)
|  {
|      return -1;
|  }
| +
| +static inline int kvmppc_rtas_get_module_info(struct sPAPRRTASModuleInfo *mi)
| +{
| +    return -1;
| +}
| +
|  #endif
| 
|  #ifndef CONFIG_KVM
| -- 
| 2.1.0
|