Re: [Qemu-devel] [RFC v2 1/6] qtest: add test framework

[Luiz Capitulino <lcapitulino@redhat.com>]

On Thu,  1 Dec 2011 12:43:27 -0600
Anthony Liguori <aliguori@us.ibm.com> wrote:

> The idea behind qtest is pretty simple.  Instead of executing a CPU via TCG or
> KVM, rely on an external process to send events to the device model that the CPU
> would normally generate.
> 
> qtest presents itself as an accelerator.  In addition, a new option is added to
> establish a qtest server (-qtest) that takes a character device.  This is what
> allows the external process to send CPU events to the device model.
> 
> This is currently modelled after Xen since the Xen device model does something
> very similar.  Instead of hooking cpu_exec, Xen sticks the CPU in the halted
> state making sure it never gets to execute.  In addition, Xen replaces the LAPIC
> with a dummy interrupt controller that forwards interrupt requests.
> 
> qtest does the exact same thing and uses a simple line based protocol to send
> the events.  Documentation of that protocol is in qtest.c.
> 
> I considered reusing the monitor for this job.  Adding interrupts would be a bit
> difficult.  In addition, logging would also be difficult.
> 
> qtest has extensive logging support.  All protocol commands are logged with
> time stamps using a new command line option (-qtest-log).  Logging is important
> since ultimately, this is a feature for debugging.
> 
> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
> ---
>  Makefile.objs   |    2 +
>  qemu-options.hx |    8 ++
>  qtest.c         |  357 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  qtest.h         |   37 ++++++
>  vl.c            |    8 ++
>  5 files changed, 412 insertions(+), 0 deletions(-)
>  create mode 100644 qtest.c
>  create mode 100644 qtest.h
> 
> diff --git a/Makefile.objs b/Makefile.objs
> index d7a6539..8364ea2 100644
> --- a/Makefile.objs
> +++ b/Makefile.objs
> @@ -293,6 +293,8 @@ hw-obj-$(CONFIG_DP8393X) += dp8393x.o
>  hw-obj-$(CONFIG_DS1225Y) += ds1225y.o
>  hw-obj-$(CONFIG_MIPSNET) += mipsnet.o
>  
> +hw-obj-y += qtest.o
> +
>  # Sound
>  sound-obj-y =
>  sound-obj-$(CONFIG_SB16) += sb16.o
> diff --git a/qemu-options.hx b/qemu-options.hx
> index 681eaf1..ca50988 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -2598,6 +2598,14 @@ the @var{simple} tracing backend.
>  @end table
>  ETEXI
>  
> +DEF("qtest", HAS_ARG, QEMU_OPTION_qtest,
> +    "-qtest CHR      specify tracing options\n",
> +    QEMU_ARCH_ALL)
> +
> +DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log,
> +    "-qtest-log LOG  specify tracing options\n",
> +    QEMU_ARCH_ALL)

Missing good descriptions.

> +
>  HXCOMM This is the last statement. Insert new options before this line!
>  STEXI
>  @end table
> diff --git a/qtest.c b/qtest.c
> new file mode 100644
> index 0000000..f41a9c3
> --- /dev/null
> +++ b/qtest.c
> @@ -0,0 +1,357 @@
> +/*
> + * Test Server
> + *
> + * Copyright IBM, Corp. 2011
> + *
> + * Authors:
> + *  Anthony Liguori   <aliguori@us.ibm.com>
> + *
> + * 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 "qtest.h"
> +#include "qemu-char.h"
> +#include "ioport.h"
> +#include "memory.h"
> +#include "hw/irq.h"
> +#include "sysemu.h"
> +
> +#define MAX_IRQ 256
> +
> +const char *qtest_chrdev;
> +const char *qtest_log;
> +int qtest_allowed = 0;
> +
> +static FILE *qtest_log_fp;
> +static CharDriverState *qtest_chr;
> +static GString *inbuf;
> +static int irq_levels[MAX_IRQ];
> +static struct timeval start_time;
> +static bool qtest_opened;
> +
> +#define FMT_timeval "%" PRId64 ".%06" PRId64
> +
> +/**
> + * QTest Protocol
> + *
> + * Line based protocol, request/response based.  Server can send async messages
> + * so clients should always handle many async messages before the response
> + * comes in.
> + *
> + * Valid requests
> + *
> + *  > outb ADDR VALUE
> + *  < OK
> + *
> + *  > outw ADDR VALUE
> + *  < OK
> + *
> + *  > outl ADDR VALUE
> + *  < OK
> + *
> + *  > inb ADDR
> + *  < OK VALUE
> + *
> + *  > inw ADDR
> + *  < OK VALUE
> + *
> + *  > inl ADDR
> + *  < OK VALUE
> + *
> + *  > read ADDR SIZE
> + *  < OK DATA
> + *
> + *  > write ADDR SIZE DATA
> + *  < OK
> + *
> + * Valid async messages:
> + *
> + *  IRQ raise NUM
> + *  IRQ lower NUM
> + *
> + * ADDR, SIZE, VALUE are all integers parsed with strtoul() with a base of 0.
> + *
> + * DATA is an arbitrarily long hex number prefixed with '0x'.  If it's smaller
> + * than the expected size, the value will be zero filled at the end of the data
> + * sequence.
> + *
> + * NUM is an IRQ number.
> + */
> +
> +static int hex2nib(char ch)
> +{
> +    if (ch >= '0' && ch <= '9') {
> +        return ch - '0';
> +    } else if (ch >= 'a' && ch <= 'f') {
> +        return 10 + (ch - 'a');
> +    } else if (ch >= 'A' && ch <= 'F') {
> +        return 10 + (ch - 'a');
> +    } else {
> +        return -1;
> +    }
> +}
> +
> +static void qtest_get_time(struct timeval *tv)
> +{
> +    gettimeofday(tv, NULL);
> +    tv->tv_sec -= start_time.tv_sec;
> +    tv->tv_usec -= start_time.tv_usec;
> +    if (tv->tv_usec < 0) {
> +        tv->tv_usec += 1000000;
> +        tv->tv_sec -= 1;
> +    }
> +}
> +
> +static void qtest_send_prefix(CharDriverState *chr)
> +{
> +    struct timeval tv;
> +
> +    if (!qtest_log_fp || !qtest_opened) {
> +        return;
> +    }
> +
> +    qtest_get_time(&tv);
> +    fprintf(qtest_log_fp, "[S +" FMT_timeval "] ",
> +            tv.tv_sec, tv.tv_usec);
> +}
> +
> +static void qtest_send(CharDriverState *chr, const char *fmt, ...)
> +{
> +    va_list ap;
> +    char buffer[1024];
> +    size_t len;
> +
> +    va_start(ap, fmt);
> +    len = vsnprintf(buffer, sizeof(buffer), fmt, ap);
> +    va_end(ap);
> +
> +    qemu_chr_fe_write(chr, (uint8_t *)buffer, len);
> +    if (qtest_log_fp && qtest_opened) {
> +        fprintf(qtest_log_fp, "%s", buffer);
> +    }
> +}
> +
> +static void qtest_process_command(CharDriverState *chr, gchar **words)
> +{
> +    const gchar *command;
> +
> +    g_assert(words);
> +
> +    command = words[0];
> +
> +    if (qtest_log_fp) {
> +        struct timeval tv;
> +        int i;
> +
> +        qtest_get_time(&tv);
> +        fprintf(qtest_log_fp, "[R +" FMT_timeval "]",
> +                tv.tv_sec, tv.tv_usec);
> +        for (i = 0; words[i]; i++) {
> +            fprintf(qtest_log_fp, " %s", words[i]);
> +        }
> +        fprintf(qtest_log_fp, "\n");
> +    }
> +
> +    g_assert(command);
> +    if (strcmp(words[0], "outb") == 0 ||
> +        strcmp(words[0], "outw") == 0 ||
> +        strcmp(words[0], "outl") == 0) {
> +        uint16_t addr;
> +        uint32_t value;
> +
> +        g_assert(words[1] && words[2]);
> +        addr = strtol(words[1], NULL, 0);
> +        value = strtol(words[2], NULL, 0);
> +
> +        if (words[0][3] == 'b') {
> +            cpu_outb(addr, value);
> +        } else if (words[0][3] == 'w') {
> +            cpu_outw(addr, value);
> +        } else if (words[0][3] == 'l') {
> +            cpu_outl(addr, value);
> +        }
> +        qtest_send_prefix(chr);
> +        qtest_send(chr, "OK\n");
> +    } else if (strcmp(words[0], "inb") == 0 ||
> +        strcmp(words[0], "inw") == 0 ||
> +        strcmp(words[0], "inl") == 0) {
> +        uint16_t addr;
> +        uint32_t value = -1U;
> +
> +        g_assert(words[1]);
> +        addr = strtol(words[1], NULL, 0);
> +
> +        if (words[0][2] == 'b') {
> +            value = cpu_inb(addr);
> +        } else if (words[0][2] == 'w') {
> +            value = cpu_inw(addr);
> +        } else if (words[0][2] == 'l') {
> +            value = cpu_inl(addr);
> +        }
> +        qtest_send_prefix(chr);
> +        qtest_send(chr, "OK 0x%04x\n", value);
> +    } else if (strcmp(words[0], "read") == 0) {
> +        uint64_t addr, len, i;
> +        uint8_t *data;
> +
> +        g_assert(words[1] && words[2]);
> +        addr = strtoul(words[1], NULL, 0);
> +        len = strtoul(words[2], NULL, 0);
> +
> +        data = g_malloc(len);
> +        cpu_physical_memory_read(addr, data, len);
> +
> +        qtest_send_prefix(chr);
> +        qtest_send(chr, "OK 0x");
> +        for (i = 0; i < len; i++) {
> +            qtest_send(chr, "%02x", data[i]);
> +        }
> +        qtest_send(chr, "\n");
> +
> +        g_free(data);
> +    } else if (strcmp(words[0], "write") == 0) {
> +        uint64_t addr, len, i;
> +        uint8_t *data;
> +        size_t data_len;
> +
> +        g_assert(words[1] && words[2] && words[3]);
> +        addr = strtoul(words[1], NULL, 0);
> +        len = strtoul(words[2], NULL, 0);
> +
> +        data_len = strlen(words[3]);
> +        if (data_len < 3) {
> +            qtest_send(chr, "ERR invalid argument size\n");
> +            return;
> +        }
> +
> +        data = g_malloc(len);
> +        for (i = 0; i < len; i++) {
> +            if ((i * 2 + 4) <= data_len) {
> +                data[i] = hex2nib(words[3][i * 2 + 2]) << 4;
> +                data[i] |= hex2nib(words[3][i * 2 + 3]);
> +            } else {
> +                data[i] = 0;
> +            }
> +        }
> +        cpu_physical_memory_write(addr, data, len);
> +        g_free(data);
> +
> +        qtest_send_prefix(chr);
> +        qtest_send(chr, "OK\n");
> +    } else {
> +        fprintf(stderr, "Unknown command `%s'\n", words[0]);
> +    }
> +}
> +
> +static void qtest_process_inbuf(CharDriverState *chr, GString *inbuf)
> +{
> +    char *end;
> +
> +    while ((end = strchr(inbuf->str, '\n')) != NULL) {
> +        size_t offset;
> +        GString *cmd;
> +        gchar **words;
> +
> +        offset = end - inbuf->str;
> +
> +        cmd = g_string_new_len(inbuf->str, offset);
> +        g_string_erase(inbuf, 0, offset + 1);
> +
> +        words = g_strsplit(cmd->str, " ", 0);
> +        qtest_process_command(chr, words);
> +        g_strfreev(words);
> +
> +        g_string_free(cmd, TRUE);
> +    }
> +}
> +
> +static void qtest_read(void *opaque, const uint8_t *buf, int size)
> +{
> +    CharDriverState *chr = opaque;
> +
> +    g_string_append_len(inbuf, (const gchar *)buf, size);
> +    qtest_process_inbuf(chr, inbuf);
> +}
> +
> +static int qtest_can_read(void *opaque)
> +{
> +    return 1024;
> +}
> +
> +static void qtest_event(void *opaque, int event)
> +{
> +    int i;
> +
> +    switch (event) {
> +    case CHR_EVENT_OPENED:
> +        qemu_system_reset(false);
> +        for (i = 0; i < ARRAY_SIZE(irq_levels); i++) {
> +            irq_levels[i] = 0;
> +        }
> +        gettimeofday(&start_time, NULL);
> +        qtest_opened = true;
> +        if (qtest_log_fp) {
> +            fprintf(qtest_log_fp, "[I " FMT_timeval "] OPENED\n",
> +                    start_time.tv_sec, start_time.tv_usec);
> +        }
> +        break;
> +    case CHR_EVENT_CLOSED:
> +        qtest_opened = false;
> +        if (qtest_log_fp) {
> +            struct timeval tv;
> +            qtest_get_time(&tv);
> +            fprintf(qtest_log_fp, "[I +" FMT_timeval "] CLOSED\n",
> +                    tv.tv_sec, tv.tv_usec);
> +        }
> +        break;
> +    default:
> +        break;
> +    }
> +}
> +
> +static void qtest_set_irq(void *opaque, int irq, int level)
> +{
> +    CharDriverState *chr = qtest_chr;
> +    bool changed;
> +
> +    changed = (irq_levels[irq] != level);
> +    irq_levels[irq] = level;
> +
> +    if (changed) {
> +        qtest_send_prefix(chr);
> +        qtest_send(chr, "IRQ %s %d\n",
> +                   level ? "raise" : "lower", irq);
> +    }
> +}
> +
> +qemu_irq *qtest_interrupt_controller_init(void)
> +{
> +    return qemu_allocate_irqs(qtest_set_irq, NULL, MAX_IRQ);
> +}
> +
> +int qtest_init(void)
> +{
> +    CharDriverState *chr;
> +
> +    g_assert(qtest_chrdev != NULL);
> +
> +    chr = qemu_chr_new("qtest", qtest_chrdev, NULL);
> +
> +    qemu_chr_add_handlers(chr, qtest_can_read, qtest_read, qtest_event, chr);
> +
> +    inbuf = g_string_new("");
> +
> +    if (qtest_log) {
> +        if (strcmp(qtest_log, "none") != 0) {
> +            qtest_log_fp = fopen(qtest_log, "w+");
> +        }
> +    } else {
> +        qtest_log_fp = stderr;
> +    }
> +
> +    qtest_chr = chr;
> +
> +    return 0;
> +}
> diff --git a/qtest.h b/qtest.h
> new file mode 100644
> index 0000000..f0e1377
> --- /dev/null
> +++ b/qtest.h
> @@ -0,0 +1,37 @@
> +/*
> + * Test Server
> + *
> + * Copyright IBM, Corp. 2011
> + *
> + * Authors:
> + *  Anthony Liguori   <aliguori@us.ibm.com>
> + *
> + * 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 QTEST_H
> +#define QTEST_H
> +
> +#include "qemu-common.h"
> +
> +extern int qtest_allowed;
> +extern const char *qtest_chrdev;
> +extern const char *qtest_log;
> +
> +static inline bool qtest_enabled(void)
> +{
> +    return qtest_allowed;
> +}
> +
> +static inline int qtest_available(void)
> +{
> +    return 1;
> +}
> +
> +int qtest_init(void);
> +
> +qemu_irq *qtest_interrupt_controller_init(void);
> +
> +#endif
> diff --git a/vl.c b/vl.c
> index a50842b..1c299e4 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -152,6 +152,7 @@ int main(int argc, char **argv)
>  #ifdef CONFIG_VIRTFS
>  #include "fsdev/qemu-fsdev.h"
>  #endif
> +#include "qtest.h"
>  
>  #include "disas.h"
>  
> @@ -2001,6 +2002,7 @@ static struct {
>      { "tcg", "tcg", tcg_available, tcg_init, &tcg_allowed },
>      { "xen", "Xen", xen_available, xen_init, &xen_allowed },
>      { "kvm", "KVM", kvm_available, kvm_init, &kvm_allowed },
> +    { "qtest", "QTest", qtest_available, qtest_init, &qtest_allowed },
>  };
>  
>  static int configure_accelerator(void)
> @@ -3057,6 +3059,12 @@ int main(int argc, char **argv, char **envp)
>                      fclose(fp);
>                      break;
>                  }
> +            case QEMU_OPTION_qtest:
> +                qtest_chrdev = optarg;
> +                break;
> +            case QEMU_OPTION_qtest_log:
> +                qtest_log = optarg;
> +                break;
>              default:
>                  os_parse_cmd_args(popt->index, optarg);
>              }