Commit 1de99be6 authored by Ben Walker's avatar Ben Walker Committed by Jim Harris
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nvme: Update p2p DMA documentation to indicate how to check for support 



Change-Id: I8d7de13c6c4f8cfb5ffabc21aa2d793774421034
Signed-off-by: default avatarBen Walker <benjamin.walker@intel.com>
Reviewed-on: https://review.gerrithub.io/c/442638


Reviewed-by: default avatarJim Harris <james.r.harris@intel.com>
Reviewed-by: default avatarShuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: default avatarwuzhouhui <wuzhouhui@kingsoft.com>
Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
parent 9ca35dfc

doc/peer_2_peer.md

+11 −1
Original line number Diff line number Diff line
@@ -31,13 +31,23 @@ Key Functions | Description 
------------------------------------------- | -----------

spdk_nvme_ctrlr_alloc_cmb_io_buffer()       | @copybrief spdk_nvme_ctrlr_alloc_cmb_io_buffer()

spdk_nvme_ctrlr_free_cmb_io_buffer()        | @copybrief spdk_nvme_ctrlr_free_cmb_io_buffer()

spdk_nvme_ctrlr_get_regs_cmbsz()            | @copybrief spdk_nvme_ctrlr_get_regs_cmbsz()



# Determining device support {#p2p_support}



SPDK's identify example application displays whether a device has a controller

memory buffer and which operations it supports. Run it as follows:



~~~{.sh}

./examples/nvme/identify/identify -r traddr:<pci id of ssd>

~~~



# cmb_copy: An example P2P Application {#p2p_cmb_copy}



Run the cmb_copy example application.



~~~{.sh}

./examples/nvme/cmb_copy -r <pci id of write ssd>-1-0-1 -w <pci id of write ssd>-1-0-1 -c <pci id of the ssd with cmb>

./examples/nvme/cmb_copy/cmb_copy -r <pci id of write ssd>-1-0-1 -w <pci id of write ssd>-1-0-1 -c <pci id of the ssd with cmb>

~~~

This should copy a single LBA (LBA 0) from namespace 1 on the read

NVMe SSD to LBA 0 on namespace 1 on the write SSD using the CMB as the