devemu_pci_device_stateful_region_host_sample.c

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#include <errno.h>
#include <linux/vfio.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <stdint.h>
#include <unistd.h>
 
#include <common.h>
#include <doca_error.h>
#include <doca_log.h>
 
#include <devemu_pci_host_common.h>
#include <devemu_pci_type_config.h>
 
DOCA_LOG_REGISTER(DEVEMU_PCI_DEVICE_STATEFUL_REGION_HOST);
 
/*
 * Run DOCA Device Emulation Stateful Region Host sample
 *
 * @pci_address [in]: Emulated device PCI address
 * @vfio_group [in]: VFIO group ID
 * @region_index [in]: The index of the stateful region
 * @write_data [in]: The data to write to stateful region
 * @return: DOCA_SUCCESS on success and DOCA_ERROR otherwise
 */
doca_error_t devemu_pci_device_stateful_region_host(const char *pci_address,
                            int vfio_group,
                            int region_index,
                            const char *write_data)
{
    doca_error_t result;
    struct devemu_host_resources resources = {0};
 
    resources.container_fd = -1;
    resources.group_fd = -1;
    resources.device_fd = -1;
 
    if (PCI_TYPE_NUM_BAR_STATEFUL_REGIONS == 0) {
        DOCA_LOG_ERR(
            "No stateful region was configured for type. Please configure at least 1 stateful region to run this sample");
        return DOCA_ERROR_INVALID_VALUE;
    }
 
    const struct bar_region_config *stateful_config = &stateful_configs[region_index];
    size_t data_len = strnlen(write_data, PCI_TYPE_MAX_STATEFUL_REGION_SIZE);
    if (data_len > stateful_configs->size) {
        DOCA_LOG_ERR("Write data size of %zuB exceeds region size of %luB", data_len, stateful_configs->size);
        return DOCA_ERROR_INVALID_VALUE;
    }
 
    result = init_vfio_device(&resources, vfio_group, pci_address);
    if (result != DOCA_SUCCESS) {
        devemu_host_resources_cleanup(&resources);
        return result;
    }
 
    result = map_bar_region_memory(&resources, stateful_config, &resources.stateful_region);
    if (result != DOCA_SUCCESS) {
        devemu_host_resources_cleanup(&resources);
        return result;
    }
 
    struct bar_mapped_region *stateful_region = &resources.stateful_region;
    if (data_len == 0) {
        // Read data
        char *dump = hex_dump(stateful_region->mem, stateful_config->size);
        DOCA_LOG_INFO("Reading stateful region at bar %u start address %zu size %zuB:\n%s",
                  stateful_config->bar_id,
                  stateful_config->start_address,
                  stateful_configs->size,
                  dump);
        free(dump);
    } else {
        // Write data
        DOCA_LOG_INFO("Writing to stateful region at bar %u start address %zu size %zuB:\n",
                  stateful_config->bar_id,
                  stateful_config->start_address,
                  data_len);
        memcpy(stateful_region->mem, write_data, data_len);
    }
 
    return DOCA_SUCCESS;
}