Re: [PATCH v4 03/14] util/dsa: Implement DSA device start and stop logic.

[Daniel P . Berrangé]

On Thu, Apr 25, 2024 at 02:21:06AM +0000, Hao Xiang wrote:
> * DSA device open and close.
> * DSA group contains multiple DSA devices.
> * DSA group configure/start/stop/clean.
> 
> Signed-off-by: Hao Xiang <hao.xiang@linux.dev>
> Signed-off-by: Bryan Zhang <bryan.zhang@bytedance.com>
> ---
>  include/qemu/dsa.h |  72 +++++++++++
>  util/dsa.c         | 316 +++++++++++++++++++++++++++++++++++++++++++++
>  util/meson.build   |   1 +
>  3 files changed, 389 insertions(+)
>  create mode 100644 include/qemu/dsa.h
>  create mode 100644 util/dsa.c
> 
> diff --git a/include/qemu/dsa.h b/include/qemu/dsa.h
> new file mode 100644
> index 0000000000..f15c05ee85
> --- /dev/null
> +++ b/include/qemu/dsa.h
> @@ -0,0 +1,72 @@

Missing license header.

> +#ifndef QEMU_DSA_H
> +#define QEMU_DSA_H
> +
> +#include "qemu/error-report.h"
> +#include "qemu/thread.h"
> +#include "qemu/queue.h"
> +
> +#ifdef CONFIG_DSA_OPT
> +
> +#pragma GCC push_options
> +#pragma GCC target("enqcmd")
> +
> +#include <linux/idxd.h>
> +#include "x86intrin.h"
> +
> +/**
> + * @brief Initializes DSA devices.
> + *
> + * @param dsa_parameter A list of DSA device path from migration parameter.
> + *
> + * @return int Zero if successful, otherwise non zero.
> + */
> +int dsa_init(const char *dsa_parameter);
> +
> +/**
> + * @brief Start logic to enable using DSA.
> + */
> +void dsa_start(void);
> +
> +/**
> + * @brief Stop the device group and the completion thread.
> + */
> +void dsa_stop(void);
> +
> +/**
> + * @brief Clean up system resources created for DSA offloading.
> + */
> +void dsa_cleanup(void);
> +
> +/**
> + * @brief Check if DSA is running.
> + *
> + * @return True if DSA is running, otherwise false.
> + */
> +bool dsa_is_running(void);
> +
> +#else
> +
> +static inline bool dsa_is_running(void)
> +{
> +    return false;
> +}
> +
> +static inline int dsa_init(const char *dsa_parameter)
> +{
> +    if (dsa_parameter != NULL && strlen(dsa_parameter) != 0) {
> +        error_report("DSA not supported.");

Using error_report in this code is undesirable, as it means the
migration code has no way to feed error information back to the
mgmt app.

*all* the APIs in dsa.h/dsa.c that can have errors, need to have
an "Error **errp" parameter, so useful info can be propagated
back the caller in the migration code.

> +        return -1;
> +    }
> +
> +    return 0;
> +}
> +
> +static inline void dsa_start(void) {}
> +
> +static inline void dsa_stop(void) {}
> +
> +static inline void dsa_cleanup(void) {}
> +
> +#endif
> +
> +#endif
> diff --git a/util/dsa.c b/util/dsa.c
> new file mode 100644
> index 0000000000..05bbf8e31a
> --- /dev/null
> +++ b/util/dsa.c
> @@ -0,0 +1,316 @@
> +/*
> + * Use Intel Data Streaming Accelerator to offload certain background
> + * operations.
> + *
> + * Copyright (c) 2023 Hao Xiang <hao.xiang@bytedance.com>
> + *                    Bryan Zhang <bryan.zhang@bytedance.com>
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a 
> copy
> + * of this software and associated documentation files (the "Software"), to 
> deal
> + * in the Software without restriction, including without limitation the 
> rights
> + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
> + * copies of the Software, and to permit persons to whom the Software is
> + * furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
> FROM,
> + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
> + * THE SOFTWARE.
> + */

This is an MIT license header, but QEMU's standard license is GPL-2.0-or-later.

Please keep new contributions under QEMU's normal  license unless there's a
reason why you must differ.


With regards,
Daniel
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