Hao Xiang <hao.xi...@bytedance.com> writes: > * DSA device open and close. > * DSA group contains multiple DSA devices. > * DSA group configure/start/stop/clean. > > Signed-off-by: Hao Xiang <hao.xi...@bytedance.com> > Signed-off-by: Bryan Zhang <bryan.zh...@bytedance.com> > --- > include/qemu/dsa.h | 49 +++++++ > util/dsa.c | 338 +++++++++++++++++++++++++++++++++++++++++++++ > util/meson.build | 1 + > 3 files changed, 388 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..30246b507e > --- /dev/null > +++ b/include/qemu/dsa.h > @@ -0,0 +1,49 @@ > +#ifndef QEMU_DSA_H > +#define QEMU_DSA_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" > + > +#endif > + > +/** > + * @brief Initializes DSA devices. > + * > + * @param dsa_parameter A list of DSA device path from migration parameter.
This code seems pretty generic, let's decouple this doc from migration. > + * @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 logic to clean up DSA by halting the device group and > cleaning up > + * the completion thread. "Stop the device group and the completion thread" The mention of "clean/cleaning up" makes this confusing because of dsa_cleanup() below. > + */ > +void dsa_stop(void); > + > +/** > + * @brief Clean up system resources created for DSA offloading. > + * This function is called during QEMU process teardown. This is not called during QEMU process teardown. It's called at the end of migration AFAICS. Maybe just leave this sentence out. > + */ > +void dsa_cleanup(void); > + > +/** > + * @brief Check if DSA is running. > + * > + * @return True if DSA is running, otherwise false. > + */ > +bool dsa_is_running(void); > + > +#endif > \ No newline at end of file > diff --git a/util/dsa.c b/util/dsa.c > new file mode 100644 > index 0000000000..8edaa892ec > --- /dev/null > +++ b/util/dsa.c > @@ -0,0 +1,338 @@ > +/* > + * Use Intel Data Streaming Accelerator to offload certain background > + * operations. > + * > + * Copyright (c) 2023 Hao Xiang <hao.xi...@bytedance.com> > + * Bryan Zhang <bryan.zh...@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. > + */ > + > +#include "qemu/osdep.h" > +#include "qemu/queue.h" > +#include "qemu/memalign.h" > +#include "qemu/lockable.h" > +#include "qemu/cutils.h" > +#include "qemu/dsa.h" > +#include "qemu/bswap.h" > +#include "qemu/error-report.h" > +#include "qemu/rcu.h" > + > +#ifdef CONFIG_DSA_OPT > + > +#pragma GCC push_options > +#pragma GCC target("enqcmd") > + > +#include <linux/idxd.h> > +#include "x86intrin.h" > + > +#define DSA_WQ_SIZE 4096 > +#define MAX_DSA_DEVICES 16 > + > +typedef QSIMPLEQ_HEAD(dsa_task_queue, buffer_zero_batch_task) dsa_task_queue; > + > +struct dsa_device { > + void *work_queue; > +}; > + > +struct dsa_device_group { > + struct dsa_device *dsa_devices; > + int num_dsa_devices; > + uint32_t index; > + bool running; > + QemuMutex task_queue_lock; > + QemuCond task_queue_cond; > + dsa_task_queue task_queue; > +}; > + > +uint64_t max_retry_count; > +static struct dsa_device_group dsa_group; > + > + > +/** > + * @brief This function opens a DSA device's work queue and > + * maps the DSA device memory into the current process. > + * > + * @param dsa_wq_path A pointer to the DSA device work queue's file path. > + * @return A pointer to the mapped memory. > + */ > +static void * > +map_dsa_device(const char *dsa_wq_path) > +{ > + void *dsa_device; > + int fd; > + > + fd = open(dsa_wq_path, O_RDWR); > + if (fd < 0) { > + fprintf(stderr, "open %s failed with errno = %d.\n", > + dsa_wq_path, errno); Use error_report and error_setg* for these. Throughout the series. > + return MAP_FAILED; > + } > + dsa_device = mmap(NULL, DSA_WQ_SIZE, PROT_WRITE, > + MAP_SHARED | MAP_POPULATE, fd, 0); > + close(fd); > + if (dsa_device == MAP_FAILED) { > + fprintf(stderr, "mmap failed with errno = %d.\n", errno); > + return MAP_FAILED; > + } > + return dsa_device; > +} > + > +/** > + * @brief Initializes a DSA device structure. > + * > + * @param instance A pointer to the DSA device. > + * @param work_queue A pointer to the DSA work queue. > + */ > +static void > +dsa_device_init(struct dsa_device *instance, > + void *dsa_work_queue) > +{ > + instance->work_queue = dsa_work_queue; > +} > + > +/** > + * @brief Cleans up a DSA device structure. > + * > + * @param instance A pointer to the DSA device to cleanup. > + */ > +static void > +dsa_device_cleanup(struct dsa_device *instance) > +{ > + if (instance->work_queue != MAP_FAILED) { > + munmap(instance->work_queue, DSA_WQ_SIZE); > + } > +} > + > +/** > + * @brief Initializes a DSA device group. > + * > + * @param group A pointer to the DSA device group. > + * @param num_dsa_devices The number of DSA devices this group will have. > + * > + * @return Zero if successful, non-zero otherwise. > + */ > +static int > +dsa_device_group_init(struct dsa_device_group *group, > + const char *dsa_parameter) The documentation doesn't match the signature. This happens in other places as well, please review all of them. > +{ > + if (dsa_parameter == NULL || strlen(dsa_parameter) == 0) { > + return 0; > + } > + > + int ret = 0; > + char *local_dsa_parameter = g_strdup(dsa_parameter); > + const char *dsa_path[MAX_DSA_DEVICES]; > + int num_dsa_devices = 0; > + char delim[2] = " "; So we're using space separated strings. Let's document this in this file and also on the migration parameter documentation. > + > + char *current_dsa_path = strtok(local_dsa_parameter, delim); > + > + while (current_dsa_path != NULL) { > + dsa_path[num_dsa_devices++] = current_dsa_path; > + if (num_dsa_devices == MAX_DSA_DEVICES) { > + break; > + } > + current_dsa_path = strtok(NULL, delim); > + } > + > + group->dsa_devices = > + malloc(sizeof(struct dsa_device) * num_dsa_devices); Use g_new0() here. > + group->num_dsa_devices = num_dsa_devices; > + group->index = 0; > + > + group->running = false; > + qemu_mutex_init(&group->task_queue_lock); > + qemu_cond_init(&group->task_queue_cond); > + QSIMPLEQ_INIT(&group->task_queue); > + > + void *dsa_wq = MAP_FAILED; > + for (int i = 0; i < num_dsa_devices; i++) { > + dsa_wq = map_dsa_device(dsa_path[i]); > + if (dsa_wq == MAP_FAILED) { > + fprintf(stderr, "map_dsa_device failed MAP_FAILED, " > + "using simulation.\n"); What does "using simulation" means? And how are doing it by returning -1 from this function? > + ret = -1; What about the memory for group->dsa_devices in the failure case? We should either free it here or make sure the client code calls the cleanup routines. > + goto exit; > + } > + dsa_device_init(&dsa_group.dsa_devices[i], dsa_wq); > + } > + > +exit: > + g_free(local_dsa_parameter); > + return ret; > +} > + > +/** > + * @brief Starts a DSA device group. > + * > + * @param group A pointer to the DSA device group. > + * @param dsa_path An array of DSA device path. > + * @param num_dsa_devices The number of DSA devices in the device group. > + */ > +static void > +dsa_device_group_start(struct dsa_device_group *group) > +{ > + group->running = true; > +} > + > +/** > + * @brief Stops a DSA device group. > + * > + * @param group A pointer to the DSA device group. > + */ > +__attribute__((unused)) > +static void > +dsa_device_group_stop(struct dsa_device_group *group) > +{ > + group->running = false; > +} > + > +/** > + * @brief Cleans up a DSA device group. > + * > + * @param group A pointer to the DSA device group. > + */ > +static void > +dsa_device_group_cleanup(struct dsa_device_group *group) > +{ > + if (!group->dsa_devices) { > + return; > + } > + for (int i = 0; i < group->num_dsa_devices; i++) { > + dsa_device_cleanup(&group->dsa_devices[i]); > + } > + free(group->dsa_devices); > + group->dsa_devices = NULL; > + > + qemu_mutex_destroy(&group->task_queue_lock); > + qemu_cond_destroy(&group->task_queue_cond); > +} > + > +/** > + * @brief Returns the next available DSA device in the group. > + * > + * @param group A pointer to the DSA device group. > + * > + * @return struct dsa_device* A pointer to the next available DSA device > + * in the group. > + */ > +__attribute__((unused)) > +static struct dsa_device * > +dsa_device_group_get_next_device(struct dsa_device_group *group) > +{ > + if (group->num_dsa_devices == 0) { > + return NULL; > + } > + uint32_t current = qatomic_fetch_inc(&group->index); The name "index" alone feels a bit opaque. Is there a more representative name we could give it? > + current %= group->num_dsa_devices; > + return &group->dsa_devices[current]; > +} > + > +/** > + * @brief Check if DSA is running. > + * > + * @return True if DSA is running, otherwise false. > + */ > +bool dsa_is_running(void) > +{ > + return false; > +} > + > +static void > +dsa_globals_init(void) > +{ > + max_retry_count = UINT64_MAX; > +} > + > +/** > + * @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) > +{ > + dsa_globals_init(); > + > + return dsa_device_group_init(&dsa_group, dsa_parameter); > +} > + > +/** > + * @brief Start logic to enable using DSA. > + * > + */ > +void dsa_start(void) > +{ > + if (dsa_group.num_dsa_devices == 0) { > + return; > + } > + if (dsa_group.running) { > + return; > + } > + dsa_device_group_start(&dsa_group); > +} > + > +/** > + * @brief Stop logic to clean up DSA by halting the device group and > cleaning up > + * the completion thread. > + * > + */ > +void dsa_stop(void) > +{ > + struct dsa_device_group *group = &dsa_group; > + > + if (!group->running) { > + return; > + } > +} > + > +/** > + * @brief Clean up system resources created for DSA offloading. > + * This function is called during QEMU process teardown. > + * > + */ > +void dsa_cleanup(void) > +{ > + dsa_stop(); > + dsa_device_group_cleanup(&dsa_group); > +} > + > +#else > + > +bool dsa_is_running(void) > +{ > + return false; > +} > + > +int dsa_init(const char *dsa_parameter) > +{ > + fprintf(stderr, "Intel Data Streaming Accelerator is not supported " > + "on this platform.\n"); > + return -1; Nothing checks this later in the series and we end up trying to start a migration when we shouldn't. Fixing the configure step would already stop this happening, but make sure you check this anyway and abort the migration. > +} > + > +void dsa_start(void) {} > + > +void dsa_stop(void) {} > + > +void dsa_cleanup(void) {} > + > +#endif These could all be in the header. > + > diff --git a/util/meson.build b/util/meson.build > index c2322ef6e7..f7277c5e9b 100644 > --- a/util/meson.build > +++ b/util/meson.build > @@ -85,6 +85,7 @@ if have_block or have_ga > endif > if have_block > util_ss.add(files('aio-wait.c')) > + util_ss.add(files('dsa.c')) I find it clearer to add the file conditionally under CONFIG_DSA_OPT here and remove the ifdef from the C file. I'm not sure if we have any guidelines for this, so up to you. > util_ss.add(files('buffer.c')) > util_ss.add(files('bufferiszero.c')) > util_ss.add(files('hbitmap.c'))