Re: [Qemu-devel] [PATCH v6 3/3] tests: add RTAS command in the protocol

[Laurent Vivier]

On 12/09/2016 06:17, David Gibson wrote:
> On Thu, Sep 08, 2016 at 09:00:07PM +0200, Laurent Vivier wrote:
>> Add a first test to validate the protocol:
>>
>> - rtas/get-time-of-day compares the time
>>   from the guest with the time from the host.
>>
>> Signed-off-by: Laurent Vivier <address@hidden>
>> ---
>> v6:
>> - rebase
>>
>> v5:
>> - use qtest_spapr_boot() instead of machine_alloc_init()
>>
>> v4:
>> - use qemu_strtoXXX() instead strtoXX()
>>
>> v3:
>> - use mktimegm() instead of timegm()
>>
>> v2:
>> - add a missing space in qrtas_call() prototype
>>
>>  hw/ppc/spapr_rtas.c         | 19 ++++++++++++
>>  include/hw/ppc/spapr_rtas.h | 10 +++++++
>>  qtest.c                     | 17 +++++++++++
>>  tests/Makefile.include      |  3 ++
>>  tests/libqos/rtas.c         | 71 
>> +++++++++++++++++++++++++++++++++++++++++++++
>>  tests/libqos/rtas.h         | 11 +++++++
>>  tests/libqtest.c            | 10 +++++++
>>  tests/libqtest.h            | 15 ++++++++++
>>  tests/rtas-test.c           | 40 +++++++++++++++++++++++++
>>  9 files changed, 196 insertions(+)
>>  create mode 100644 include/hw/ppc/spapr_rtas.h
>>  create mode 100644 tests/libqos/rtas.c
>>  create mode 100644 tests/libqos/rtas.h
>>  create mode 100644 tests/rtas-test.c
>>
>> diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c
>> index 27b5ad4..b80c1db 100644
>> --- a/hw/ppc/spapr_rtas.c
>> +++ b/hw/ppc/spapr_rtas.c
>> @@ -37,6 +37,7 @@
>>  
>>  #include "hw/ppc/spapr.h"
>>  #include "hw/ppc/spapr_vio.h"
>> +#include "hw/ppc/spapr_rtas.h"
>>  #include "hw/ppc/ppc.h"
>>  #include "qapi-event.h"
>>  #include "hw/boards.h"
>> @@ -692,6 +693,24 @@ target_ulong spapr_rtas_call(PowerPCCPU *cpu, 
>> sPAPRMachineState *spapr,
>>      return H_PARAMETER;
>>  }
>>  
>> +uint64_t qtest_rtas_call(char *cmd, uint32_t nargs, uint64_t args,
>> +                         uint32_t nret, uint64_t rets)
>> +{
>> +    int token;
>> +
>> +    for (token = 0; token < RTAS_TOKEN_MAX - RTAS_TOKEN_BASE; token++) {
>> +        if (strcmp(cmd, rtas_table[token].name) == 0) {
>> +            sPAPRMachineState *spapr = SPAPR_MACHINE(qdev_get_machine());
>> +            PowerPCCPU *cpu = POWERPC_CPU(first_cpu);
>> +
>> +            rtas_table[token].fn(cpu, spapr, token + RTAS_TOKEN_BASE,
>> +                                 nargs, args, nret, rets);
>> +            return H_SUCCESS;
>> +        }
>> +    }
>> +    return H_PARAMETER;
>> +}
> 
> I may be misunderstanding how qtest works here.  But wouldn't it test

>From the point of view of the machine, qtest is an accelerator: so the
CPU is stopped, and the qtest accelerator open a socket allowing another
process to read/write/in/out/... the memory of the machine.
This allows to test the machine hardware or the hypervisor, not the CPU
or the firmware. kvm-unit-tests is better for this kind of test.

The qtest protocol is human readable: the second process sends strings
like "read 0x1000" and the qtest accelerator answers something like "OK
0" or "ERROR". This is why, from my point of view, using the name of the
service rather than the token number seems better.

> a bit more of the common code paths if rather than doing your own
> token lookup here, you actually generated a full guest style rtas
> parameter buffer (token + args + rets in one structure), then dispatch

We can't do the token lookup at the level of the second process as the
token is extracted from the OF device tree and for the moment we don't
have the functions in this process to scan the OF device tree. It is
possible as we can read the guest memory, but the functions are not
here. I plan to add this kind of feature, for instance to read the
memory size, but for the moment nothing is done.

> through h_rtas, or spapr_rtas_call?
> 
>> +
>>  void spapr_rtas_register(int token, const char *name, spapr_rtas_fn fn)
>>  {
>>      assert((token >= RTAS_TOKEN_BASE) && (token < RTAS_TOKEN_MAX));
>> diff --git a/include/hw/ppc/spapr_rtas.h b/include/hw/ppc/spapr_rtas.h
>> new file mode 100644
>> index 0000000..383611f
>> --- /dev/null
>> +++ b/include/hw/ppc/spapr_rtas.h
>> @@ -0,0 +1,10 @@
>> +#ifndef HW_SPAPR_RTAS_H
>> +#define HW_SPAPR_RTAS_H
>> +/*
>> + * This work is licensed under the terms of the GNU GPL, version 2 or later.
>> + * See the COPYING file in the top-level directory.
>> + */
>> +
>> +uint64_t qtest_rtas_call(char *cmd, uint32_t nargs, uint64_t args,
>> +                         uint32_t nret, uint64_t rets);
>> +#endif /* HW_SPAPR_RTAS_H */
>> diff --git a/qtest.c b/qtest.c
>> index 4c94708..beb62b4 100644
>> --- a/qtest.c
>> +++ b/qtest.c
>> @@ -28,6 +28,9 @@
>>  #include "qemu/option.h"
>>  #include "qemu/error-report.h"
>>  #include "qemu/cutils.h"
>> +#ifdef TARGET_PPC64
>> +#include "hw/ppc/spapr_rtas.h"
>> +#endif
>>  
>>  #define MAX_IRQ 256
>>  
>> @@ -531,6 +534,20 @@ static void qtest_process_command(CharDriverState *chr, 
>> gchar **words)
>>  
>>          qtest_send_prefix(chr);
>>          qtest_send(chr, "OK\n");
>> +#ifdef TARGET_PPC64
>> +    } else if (strcmp(words[0], "rtas") == 0) {
>> +        uint64_t res, args, ret;
>> +        unsigned long nargs, nret;
>> +
>> +        g_assert(qemu_strtoul(words[2], NULL, 0, &nargs) == 0);
>> +        g_assert(qemu_strtoull(words[3], NULL, 0, &args) == 0);
>> +        g_assert(qemu_strtoul(words[4], NULL, 0, &nret) == 0);
>> +        g_assert(qemu_strtoull(words[5], NULL, 0, &ret) == 0);
>> +        res = qtest_rtas_call(words[1], nargs, args, nret, ret);
>> +
>> +        qtest_send_prefix(chr);
>> +        qtest_sendf(chr, "OK %"PRIu64"\n", res);
>> +#endif
>>      } else if (qtest_enabled() && strcmp(words[0], "clock_step") == 0) {
>>          int64_t ns;
>>  
>> diff --git a/tests/Makefile.include b/tests/Makefile.include
>> index 91df9f2..fd61f97 100644
>> --- a/tests/Makefile.include
>> +++ b/tests/Makefile.include
>> @@ -265,6 +265,7 @@ check-qtest-ppc64-y += tests/prom-env-test$(EXESUF)
>>  check-qtest-ppc64-y += tests/drive_del-test$(EXESUF)
>>  check-qtest-ppc64-y += tests/postcopy-test$(EXESUF)
>>  check-qtest-ppc64-y += tests/boot-serial-test$(EXESUF)
>> +check-qtest-ppc64-y += tests/rtas-test$(EXESUF)
>>  
>>  check-qtest-sh4-y = tests/endianness-test$(EXESUF)
>>  
>> @@ -578,6 +579,7 @@ libqos-obj-y = tests/libqos/pci.o tests/libqos/fw_cfg.o 
>> tests/libqos/malloc.o
>>  libqos-obj-y += tests/libqos/i2c.o tests/libqos/libqos.o
>>  libqos-spapr-obj-y = $(libqos-obj-y) tests/libqos/malloc-spapr.o
>>  libqos-spapr-obj-y += tests/libqos/libqos-spapr.o
>> +libqos-spapr-obj-y += tests/libqos/rtas.o
>>  libqos-pc-obj-y = $(libqos-obj-y) tests/libqos/pci-pc.o
>>  libqos-pc-obj-y += tests/libqos/malloc-pc.o tests/libqos/libqos-pc.o
>>  libqos-pc-obj-y += tests/libqos/ahci.o
>> @@ -592,6 +594,7 @@ tests/m48t59-test$(EXESUF): tests/m48t59-test.o
>>  tests/endianness-test$(EXESUF): tests/endianness-test.o
>>  tests/spapr-phb-test$(EXESUF): tests/spapr-phb-test.o $(libqos-obj-y)
>>  tests/prom-env-test$(EXESUF): tests/prom-env-test.o $(libqos-obj-y)
>> +tests/rtas-test$(EXESUF): tests/rtas-test.o $(libqos-spapr-obj-y)
>>  tests/fdc-test$(EXESUF): tests/fdc-test.o
>>  tests/ide-test$(EXESUF): tests/ide-test.o $(libqos-pc-obj-y)
>>  tests/ahci-test$(EXESUF): tests/ahci-test.o $(libqos-pc-obj-y)
>> diff --git a/tests/libqos/rtas.c b/tests/libqos/rtas.c
>> new file mode 100644
>> index 0000000..d5f4ced
>> --- /dev/null
>> +++ b/tests/libqos/rtas.c
>> @@ -0,0 +1,71 @@
>> +/*
>> + * This work is licensed under the terms of the GNU GPL, version 2 or later.
>> + * See the COPYING file in the top-level directory.
>> + */
>> +
>> +#include "qemu/osdep.h"
>> +#include "libqtest.h"
>> +#include "libqos/rtas.h"
>> +
>> +static void qrtas_copy_args(uint64_t target_args, uint32_t nargs,
>> +                            uint32_t *args)
>> +{
>> +    int i;
>> +
>> +    for (i = 0; i < nargs; i++) {
>> +        writel(target_args + i * sizeof(uint32_t), args[i]);
>> +    }
>> +}
>> +
>> +static void qrtas_copy_ret(uint64_t target_ret, uint32_t nret, uint32_t 
>> *ret)
>> +{
>> +    int i;
>> +
>> +    for (i = 0; i < nret; i++) {
>> +        ret[i] = readl(target_ret + i * sizeof(uint32_t));
>> +    }
>> +}
>> +
>> +static uint64_t qrtas_call(QGuestAllocator *alloc, const char *name,
>> +                           uint32_t nargs, uint32_t *args,
>> +                           uint32_t nret, uint32_t *ret)
>> +{
>> +    uint64_t res;
>> +    uint64_t target_args, target_ret;
>> +
>> +    target_args = guest_alloc(alloc, (nargs + nret) * sizeof(uint32_t));
>> +    target_ret = guest_alloc(alloc, nret * sizeof(uint32_t));
> 
> Again, possibly I'm misunderstanding something, but it looks like
> you're over-allocating here - target_args seems to get enough space
> for both args and rets, then target_ret gets additional space for the
> rets as well.

You're right.

>> +    qrtas_copy_args(target_args, nargs, args);
>> +    res = qtest_rtas_call(global_qtest, name,
>> +                          nargs, target_args, nret, target_ret);
>> +    qrtas_copy_ret(target_ret, nret, ret);
>> +
>> +    guest_free(alloc, target_ret);
>> +    guest_free(alloc, target_args);
>> +
>> +    return res;
>> +}
>> +
>> +int qrtas_get_time_of_day(QGuestAllocator *alloc, struct tm *tm, uint32_t 
>> *ns)
>> +{
>> +    int res;
>> +    uint32_t ret[8];
>> +
>> +    res = qrtas_call(alloc, "get-time-of-day", 0, NULL, 8, ret);
>> +    if (res != 0) {
>> +        return res;
>> +    }
>> +
>> +    res = ret[0];
>> +    memset(tm, 0, sizeof(*tm));
>> +    tm->tm_year = ret[1] - 1900;
>> +    tm->tm_mon = ret[2] - 1;
>> +    tm->tm_mday = ret[3];
>> +    tm->tm_hour = ret[4];
>> +    tm->tm_min = ret[5];
>> +    tm->tm_sec = ret[6];
>> +    *ns = ret[7];
>> +
>> +    return res;
>> +}
>> diff --git a/tests/libqos/rtas.h b/tests/libqos/rtas.h
>> new file mode 100644
>> index 0000000..a1b60a8
>> --- /dev/null
>> +++ b/tests/libqos/rtas.h
>> @@ -0,0 +1,11 @@
>> +/*
>> + * This work is licensed under the terms of the GNU GPL, version 2 or later.
>> + * See the COPYING file in the top-level directory.
>> + */
>> +
>> +#ifndef LIBQOS_RTAS_H
>> +#define LIBQOS_RTAS_H
>> +#include "libqos/malloc.h"
>> +
>> +int qrtas_get_time_of_day(QGuestAllocator *alloc, struct tm *tm, uint32_t 
>> *ns);
>> +#endif /* LIBQOS_RTAS_H */
>> diff --git a/tests/libqtest.c b/tests/libqtest.c
>> index eb00f13..c9dd57b 100644
>> --- a/tests/libqtest.c
>> +++ b/tests/libqtest.c
>> @@ -751,6 +751,16 @@ void qtest_memread(QTestState *s, uint64_t addr, void 
>> *data, size_t size)
>>      g_strfreev(args);
>>  }
>>  
>> +uint64_t qtest_rtas_call(QTestState *s, const char *name,
>> +                         uint32_t nargs, uint64_t args,
>> +                         uint32_t nret, uint64_t ret)
>> +{
>> +    qtest_sendf(s, "rtas %s %u 0x%"PRIx64" %u 0x%"PRIx64"\n",
>> +                name, nargs, args, nret, ret);
>> +    qtest_rsp(s, 0);
>> +    return 0;
>> +}
>> +
>>  void qtest_add_func(const char *str, void (*fn)(void))
>>  {
>>      gchar *path = g_strdup_printf("/%s/%s", qtest_get_arch(), str);
>> diff --git a/tests/libqtest.h b/tests/libqtest.h
>> index 37f37ad..1badb76 100644
>> --- a/tests/libqtest.h
>> +++ b/tests/libqtest.h
>> @@ -318,6 +318,21 @@ uint64_t qtest_readq(QTestState *s, uint64_t addr);
>>  void qtest_memread(QTestState *s, uint64_t addr, void *data, size_t size);
>>  
>>  /**
>> + * qtest_rtas_call:
>> + * @s: #QTestState instance to operate on.
>> + * @name: name of the command to call.
>> + * @nargs: Number of args.
>> + * @args: Guest address to read args from.
>> + * @nret: Number of return value.
>> + * @ret: Guest address to write return values to.
>> + *
>> + * Call an RTAS function
>> + */
>> +uint64_t qtest_rtas_call(QTestState *s, const char *name,
>> +                         uint32_t nargs, uint64_t args,
>> +                         uint32_t nret, uint64_t ret);
>> +
>> +/**
>>   * qtest_bufread:
>>   * @s: #QTestState instance to operate on.
>>   * @addr: Guest address to read from.
>> diff --git a/tests/rtas-test.c b/tests/rtas-test.c
>> new file mode 100644
>> index 0000000..3bca36b
>> --- /dev/null
>> +++ b/tests/rtas-test.c
>> @@ -0,0 +1,40 @@
>> +#include "qemu/osdep.h"
>> +#include "qemu/cutils.h"
>> +#include "libqtest.h"
>> +
>> +#include "libqos/libqos-spapr.h"
>> +#include "libqos/rtas.h"
>> +
>> +static void test_rtas_get_time_of_day(void)
>> +{
>> +    QOSState *qs;
>> +    struct tm tm;
>> +    uint32_t ns;
>> +    uint64_t ret;
>> +    time_t t1, t2;
>> +
>> +    qs = qtest_spapr_boot("");
>> +
>> +    t1 = time(NULL);
>> +    ret = qrtas_get_time_of_day(qs->alloc, &tm, &ns);
>> +    g_assert_cmpint(ret, ==, 0);
>> +    t2 = mktimegm(&tm);
>> +    g_assert(t2 - t1 < 5); /* 5 sec max to run the test */
>> +
>> +    qtest_spapr_shutdown(qs);
>> +}
>> +
>> +int main(int argc, char *argv[])
>> +{
>> +    const char *arch = qtest_get_arch();
>> +
>> +    g_test_init(&argc, &argv, NULL);
>> +
>> +    if (strcmp(arch, "ppc64") == 0) {
>> +        qtest_add_func("rtas/get-time-of-day", test_rtas_get_time_of_day);
>> +    } else {
>> +        g_assert_not_reached();
>> +    }
>> +
>> +    return g_test_run();
>> +}
>