Commit 16364fdc authored by Jim Harris's avatar Jim Harris Committed by Tomasz Zawadzki
Browse files

nvme: copy 8 bytes at a time into virtualized CMB 



QEMU won't emulate wide (>8 byte) instructions on an MMIO
region.  We tried to fix this previously but it wasn't sufficient.
So this version adds an explicit copy function that will only
copy 8 bytes at a time from the source cmd pointer into the
SQ cmd point in the virtualized CMB.

Fixes issue #1458.

Signed-off-by: default avatarJim Harris <james.r.harris@intel.com>
Change-Id: I804005a2e8cf3f7365c1608674f82a3f843e59ba

Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/3135


Community-CI: Mellanox Build Bot
Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: default avatarChangpeng Liu <changpeng.liu@intel.com>
Reviewed-by: default avatarShuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: default avatarAleksey Marchuk <alexeymar@mellanox.com>
parent e7625088

lib/nvme/nvme_pcie.c

+17 −1
Original line number Diff line number Diff line
@@ -1153,6 +1153,22 @@ nvme_pcie_qpair_construct(struct spdk_nvme_qpair *qpair, 
	return 0;

}



/* Used when dst points to MMIO (i.e. CMB) in a virtual machine - in these cases we must

 * not use wide instructions because QEMU will not emulate such instructions to MMIO space.

 * So this function ensures we only copy 8 bytes at a time.

 */

static inline void

nvme_pcie_copy_command_mmio(struct spdk_nvme_cmd *dst, const struct spdk_nvme_cmd *src)

{

	uint64_t *dst64 = (uint64_t *)dst;

	const uint64_t *src64 = (const uint64_t *)src;

	uint32_t i;



	for (i = 0; i < sizeof(*dst) / 8; i++) {

		dst64[i] = src64[i];

	}

}



static inline void

nvme_pcie_copy_command(struct spdk_nvme_cmd *dst, const struct spdk_nvme_cmd *src)

{
@@ -1336,7 +1352,7 @@ nvme_pcie_qpair_submit_tracker(struct spdk_nvme_qpair *qpair, struct nvme_tracke 
	 * virtual NVMe controller, the maximum access width is 8 Bytes for one time.

	 */

	if (spdk_unlikely((ctrlr->quirks & NVME_QUIRK_MAXIMUM_PCI_ACCESS_WIDTH) && pqpair->sq_in_cmb)) {

		pqpair->cmd[pqpair->sq_tail] = req->cmd;

		nvme_pcie_copy_command_mmio(&pqpair->cmd[pqpair->sq_tail], &req->cmd);

	} else {

		/* Copy the command from the tracker to the submission queue. */

		nvme_pcie_copy_command(&pqpair->cmd[pqpair->sq_tail], &req->cmd);