| Message ID | 20170425201809.1683-1-jonathan.derrick@intel.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On 04/25/2017 02:18 PM, Jon Derrick wrote: > NVME specifies an EUI64/NGUID in little-endian format, while SCSI > specifies that the Device Identification VPD use big-endian for EUI > formats. The current code copies this bytestream directly from the > Identification Namespace page, meaning we just need to reverse the > bytestream when passing it on to the VPD. > This seems to hold true for NGUID devices, but Keith just pointed out to me that it may not hold true for EUI64 devices. It seems like that case needs byte swiveling within each field. So I'll NAK for now until I can figure out if that's the case.
On Tue, Apr 25, 2017 at 02:18:09PM -0600, Jon Derrick wrote: > NVME specifies an EUI64/NGUID in little-endian format, while SCSI > specifies that the Device Identification VPD use big-endian for EUI > formats. The current code copies this bytestream directly from the > Identification Namespace page, meaning we just need to reverse the > bytestream when passing it on to the VPD. This will break existing setups that rely on VPD 0x83 for device identification (which I think includes older SuSE distros). And once you change the setup anyway please stop using this buggy SCSI emulation.
diff --git a/drivers/nvme/host/scsi.c b/drivers/nvme/host/scsi.c index f49ae27..8f94e77 100644 --- a/drivers/nvme/host/scsi.c +++ b/drivers/nvme/host/scsi.c @@ -598,6 +598,7 @@ static int nvme_fill_device_id_eui64(struct nvme_ns *ns, struct sg_io_hdr *hdr, int nvme_sc, res; size_t len; void *eui; + int i; nvme_sc = nvme_identify_ns(ns->ctrl, ns->ns_id, &id_ns); res = nvme_trans_status_code(hdr, nvme_sc); @@ -628,7 +629,8 @@ static int nvme_fill_device_id_eui64(struct nvme_ns *ns, struct sg_io_hdr *hdr, inq_response[5] = 0x02; /* PIV=0b | Asso=00b | Designator Type=2h */ inq_response[6] = 0x00; /* Rsvd */ inq_response[7] = len; /* Designator Length */ - memcpy(&inq_response[8], eui, len); + for (i = 0; i < len; i++) + inq_response[8 + i] = ((char *)eui)[len - (i + 1)]; res = nvme_trans_copy_to_user(hdr, inq_response, alloc_len); out_free_id:
NVME specifies an EUI64/NGUID in little-endian format, while SCSI specifies that the Device Identification VPD use big-endian for EUI formats. The current code copies this bytestream directly from the Identification Namespace page, meaning we just need to reverse the bytestream when passing it on to the VPD. This results in the correct values being parsed by sg-tools, eg: $ sg_inq -e -p 0x83 /dev/nvme1n1 -vvv open /dev/nvme1n1 with flags=0x800 VPD INQUIRY: Device Identification page inquiry cdb: 12 01 83 00 fc 00 duration=0 ms Designation descriptor number 1, descriptor length: 20 designator_type: EUI-64 based, code_set: Binary associated with the addressed logical unit EUI-64 based 16 byte identifier Identifier extension: 0x100000001 IEEE Company_id: 0x5cd2e4 Vendor Specific Extension Identifier: 0x0 [0x00000001000000015cd2e40000000000] Signed-off-by: Jon Derrick <jonathan.derrick@intel.com> --- drivers/nvme/host/scsi.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)