Re: [PATCH 4/7] migration/multifd: Add UADK initialization

[Fabiano Rosas <farosas@suse.de>]

Shameer Kolothum via <qemu-devel@nongnu.org> writes:

> Initialize UADK session and allocate buffers required. The actual
> compression/decompression will only be done in a subsequent patch.
>
> Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
> ---
>  migration/multifd-uadk.c | 207 ++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 206 insertions(+), 1 deletion(-)
>
> diff --git a/migration/multifd-uadk.c b/migration/multifd-uadk.c
> index c2bb07535b..3172e4d5ca 100644
> --- a/migration/multifd-uadk.c
> +++ b/migration/multifd-uadk.c
> @@ -12,9 +12,214 @@
>  
>  #include "qemu/osdep.h"
>  #include "qemu/module.h"
> +#include "qapi/error.h"
> +#include "migration.h"
> +#include "multifd.h"
> +#include "options.h"
> +#include "uadk/wd_comp.h"
> +#include "uadk/wd_sched.h"
> +
> +struct wd_data {
> +    handle_t handle;
> +    uint8_t *buf;
> +    uint32_t *buf_hdr;
> +};
> +
> +static bool uadk_hw_initialised(void)

The first time this is called it will actually do the initialization,
no? If so, it should be uadk_hw_init().

> +{
> +    char alg[] = "zlib";
> +    int ret;
> +
> +    ret = wd_comp_init2(alg, SCHED_POLICY_RR, TASK_HW);
> +    if (ret && ret != -WD_EEXIST) {
> +        return false;
> +    } else {
> +        return true;
> +    }
> +}
> +
> +static struct wd_data *multifd_uadk_init_sess(uint32_t count,
> +                                              uint32_t page_size,
> +                                              bool compress, Error **errp)
> +{
> +    struct wd_comp_sess_setup ss = {0};
> +    struct sched_params param = {0};
> +    uint32_t size = count * page_size;
> +    struct wd_data *wd;
> +
> +    if (!uadk_hw_initialised()) {
> +        error_setg(errp, "multifd: UADK hardware not available");

Does the lib provide a software fallback path that we could use like QPL
does?

> +        return NULL;
> +    }
> +
> +    wd = g_new0(struct wd_data, 1);
> +    ss.alg_type = WD_ZLIB;
> +    if (compress) {
> +        ss.op_type = WD_DIR_COMPRESS;
> +        /* Add an additional page for handling output > input */
> +        size += page_size;
> +    } else {
> +        ss.op_type = WD_DIR_DECOMPRESS;
> +    }
> +    param.type = ss.op_type;
> +    ss.sched_param = &param;

What about window size and compression level? Don't we need to set them
here? What do they default to?

> +
> +    wd->handle = wd_comp_alloc_sess(&ss);
> +    if (!wd->handle) {
> +        error_setg(errp, "multifd: failed wd_comp_alloc_sess");
> +        goto out;
> +    }
> +
> +    wd->buf = g_try_malloc(size);
> +    if (!wd->buf) {
> +        error_setg(errp, "multifd: out of mem for uadk buf");
> +        goto out_free_sess;
> +    }
> +    wd->buf_hdr = g_new0(uint32_t, count);
> +    return wd;
> +
> +out_free_sess:
> +    wd_comp_free_sess(wd->handle);
> +out:
> +    wd_comp_uninit2();
> +    g_free(wd);
> +    return NULL;
> +}
> +
> +static void multifd_uadk_uninit_sess(struct wd_data *wd)
> +{
> +    wd_comp_free_sess(wd->handle);
> +    wd_comp_uninit2();
> +    g_free(wd->buf);
> +    g_free(wd->buf_hdr);
> +    g_free(wd);
> +}
> +
> +/**
> + * multifd_uadk_send_setup: setup send side
> + *
> + * Returns 0 for success or -1 for error
> + *
> + * @p: Params for the channel that we are using
> + * @errp: pointer to an error
> + */
> +static int multifd_uadk_send_setup(MultiFDSendParams *p, Error **errp)
> +{
> +    struct wd_data *wd;
> +
> +    wd = multifd_uadk_init_sess(p->page_count, p->page_size, true, errp);
> +    if (!wd) {
> +        return -1;
> +    }
> +
> +    p->compress_data = wd;
> +    assert(p->iov == NULL);
> +    /*
> +     * Each page will be compressed independently and sent using an IOV. The
> +     * additional two IOVs are used to store packet header and compressed data
> +     * length
> +     */
> +
> +    p->iov = g_new0(struct iovec, p->page_count + 2);
> +    return 0;
> +}
> +
> +/**
> + * multifd_uadk_send_cleanup: cleanup send side
> + *
> + * Close the channel and return memory.
> + *
> + * @p: Params for the channel that we are using
> + * @errp: pointer to an error
> + */
> +static void multifd_uadk_send_cleanup(MultiFDSendParams *p, Error **errp)
> +{
> +    struct wd_data *wd = p->compress_data;
> +
> +    multifd_uadk_uninit_sess(wd);
> +    p->compress_data = NULL;
> +}
> +
> +/**
> + * multifd_uadk_send_prepare: prepare data to be able to send
> + *
> + * Create a compressed buffer with all the pages that we are going to
> + * send.
> + *
> + * Returns 0 for success or -1 for error
> + *
> + * @p: Params for the channel that we are using
> + * @errp: pointer to an error
> + */
> +static int multifd_uadk_send_prepare(MultiFDSendParams *p, Error **errp)
> +{
> +    return -1;
> +}
> +
> +/**
> + * multifd_uadk_recv_setup: setup receive side
> + *
> + * Create the compressed channel and buffer.
> + *
> + * Returns 0 for success or -1 for error
> + *
> + * @p: Params for the channel that we are using
> + * @errp: pointer to an error
> + */
> +static int multifd_uadk_recv_setup(MultiFDRecvParams *p, Error **errp)
> +{
> +    struct wd_data *wd;
> +
> +    wd = multifd_uadk_init_sess(p->page_count, p->page_size, false, errp);
> +    if (!wd) {
> +        return -1;
> +    }
> +    p->compress_data = wd;
> +    return 0;
> +}
> +
> +/**
> + * multifd_uadk_recv_cleanup: setup receive side
> + *
> + * For no compression this function does nothing.

This line makes no sense here.

> + *
> + * @p: Params for the channel that we are using
> + */
> +static void multifd_uadk_recv_cleanup(MultiFDRecvParams *p)
> +{
> +    struct wd_data *wd = p->compress_data;
> +
> +    multifd_uadk_uninit_sess(wd);
> +    p->compress_data = NULL;
> +}
> +
> +/**
> + * multifd_uadk_recv: read the data from the channel into actual pages
> + *
> + * Read the compressed buffer, and uncompress it into the actual
> + * pages.
> + *
> + * Returns 0 for success or -1 for error
> + *
> + * @p: Params for the channel that we are using
> + * @errp: pointer to an error
> + */
> +static int multifd_uadk_recv(MultiFDRecvParams *p, Error **errp)
> +{
> +    return -1;
> +}
> +
> +static MultiFDMethods multifd_uadk_ops = {
> +    .send_setup = multifd_uadk_send_setup,
> +    .send_cleanup = multifd_uadk_send_cleanup,
> +    .send_prepare = multifd_uadk_send_prepare,
> +    .recv_setup = multifd_uadk_recv_setup,
> +    .recv_cleanup = multifd_uadk_recv_cleanup,
> +    .recv = multifd_uadk_recv,
> +};
>  
>  static void multifd_uadk_register(void)
>  {
> -    /* noop for now */
> +    multifd_register_ops(MULTIFD_COMPRESSION_UADK, &multifd_uadk_ops);
>  }
>  migration_init(multifd_uadk_register);