Commit 70c703bb authored by Nikos Dragazis's avatar Nikos Dragazis Committed by Jim Harris
Browse files

vtophys: add vfio no-IOMMU mode support 



Currently, SPDK does not support vfio in no-IOMMU mode. However, it
seems quite easy to extend the vtophys code to add support for this.

vfio in no-IOMMU mode does not support DMA remapping. This implies that
physical DMA addresses are used instead of IOVAs.

This patch checks whether the vfio no-IOMMU mode is enabled using
function rte_vfio_noiommu_is_enabled() from the DPDK RTE vfio interface.
In this case, physical addresses are used for the DMA mappings. This is
the same code path for the DMA translations as when the uio is used as a
kernel driver.

Change-Id: I6fb3c849a345c6f2f2b4141dddb8c17be2581495
Signed-off-by: default avatarNikos Dragazis <ndragazis@arrikto.com>
Reviewed-on: https://review.gerrithub.io/c/441061


Reviewed-by: default avatarDarek Stojaczyk <dariusz.stojaczyk@intel.com>
Reviewed-by: default avatarJim Harris <james.r.harris@intel.com>
Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
parent 20fba4d8

lib/env_dpdk/vtophys.c

+17 −3
Original line number Diff line number Diff line
@@ -77,6 +77,7 @@ struct spdk_vfio_dma_map { 
struct vfio_cfg {

	int fd;

	bool enabled;

	bool noiommu_enabled;

	unsigned device_ref;

	TAILQ_HEAD(, spdk_vfio_dma_map) maps;

	pthread_mutex_t mutex;
@@ -85,6 +86,7 @@ struct vfio_cfg { 
static struct vfio_cfg g_vfio = {

	.fd = -1,

	.enabled = false,

	.noiommu_enabled = false,

	.device_ref = 0,

	.maps = TAILQ_HEAD_INITIALIZER(g_vfio.maps),

	.mutex = PTHREAD_MUTEX_INITIALIZER
@@ -357,7 +359,7 @@ spdk_vtophys_notify(void *cb_ctx, struct spdk_mem_map *map, 
			if (paddr == SPDK_VTOPHYS_ERROR) {

				/* This is not an address that DPDK is managing. */

#if SPDK_VFIO_ENABLED

				if (g_vfio.enabled) {

				if (g_vfio.enabled && !g_vfio.noiommu_enabled) {

					/* We'll use the virtual address as the iova. DPDK

					 * currently uses physical addresses as the iovas (or counts

					 * up from 0 if it can't get physical addresses), so
@@ -400,7 +402,7 @@ spdk_vtophys_notify(void *cb_ctx, struct spdk_mem_map *map, 
				 * This is not an address that DPDK is managing. If vfio is enabled,

				 * we need to unmap the range from the IOMMU

				 */

				if (g_vfio.enabled) {

				if (g_vfio.enabled && !g_vfio.noiommu_enabled) {

					uint64_t buffer_len = VALUE_2MB;

					paddr = spdk_mem_map_translate(map, (uint64_t)vaddr, &buffer_len);

					if (buffer_len != VALUE_2MB) {
@@ -462,6 +464,12 @@ has_iommu_groups(void) 
	return count > 2;

}



static bool

spdk_vfio_noiommu_enabled(void)

{

	return rte_vfio_noiommu_is_enabled();

}



static void

spdk_vtophys_iommu_init(void)

{
@@ -471,7 +479,13 @@ spdk_vtophys_iommu_init(void) 
	DIR *dir;

	struct dirent *d;



	if (!spdk_vfio_enabled() || !has_iommu_groups()) {

	if (!spdk_vfio_enabled()) {

		return;

	}



	if (spdk_vfio_noiommu_enabled()) {

		g_vfio.noiommu_enabled = true;

	} else if (!has_iommu_groups()) {

		return;

	}