On Mon, 16 Aug 2021 21:13:59 +0300, Roman Bolshakov wrote: > On Fri, Aug 13, 2021 at 04:52:55PM +0200, David Disseldorp wrote: > > Hi Sergey, > > > > On Thu, 29 Jul 2021 23:19:43 +0300, Sergey Samoylenko wrote: > > > > > The 8Fh VPD page announces the capabilities supported by > > > the TCM XCOPY manager. It helps to expand the coverage of > > > the third-party copy manager with SCSI testing utilities. > > > > Please list which initiators use this VPD page, if you know of any. > > Also, is there any test coverage for this? I don't see anything in > > libiscsi... > > > > Hi David, > > ESXi is one of the hosts that inspects Third Party Copy VPD Page. > Windows detects ODX support using the page [1][2]. Thanks for the links. I haven't seen ESXi attempt to use it, but also haven't checked for some time. It'd be good to get some of this information in the commit message. > The page is also used by libiscsi to detect presence and features of > copy manager as was agreed with Bart in the PR [3]: I'm probably missing something, but why wasn't the 3PC flag in the standard inquiry page an option for this check? > "Implementing REPORT SUPPORTED OPERATION CODES in LIO would require more > work than implementing the third-party copy VPD page. > > I'm fine with relying on the third-party copy VPD page, or in other > words, to skip the copy offloading tests if that page is not supported. > > There are plans to implement XCOPY support in the Linux kernel sd > driver. If nobody else volunteers I plan to work on this myself. I'm > considering to only support SCSI targets that support the third-party > copy VPD page. Or in other words, we will need support for that VPD page > anyway." Okay, fair enough. > > 1. https://www.slideshare.net/CalvinChen5/a-joint-effort-of-the-storage-industry > 2. http://sg.danny.cz/sg/ddpt_xcopy_odx.html > 3. https://github.com/sahlberg/libiscsi/pull/353 > > > > Reviewed-by: Konstantin Shelekhin <k.shelekhin@xxxxxxxxx> > > > Reviewed-by: Dmitry Bogdanov <d.bogdanov@xxxxxxxxx> > > > Reviewed-by: Anastasia Kovaleva <a.kovaleva@xxxxxxxxx> > > > Signed-off-by: Sergey Samoylenko <s.samoylenko@xxxxxxxxx> > > > --- > > > drivers/target/target_core_spc.c | 230 ++++++++++++++++++++++++++++++- > > > 1 file changed, 226 insertions(+), 4 deletions(-) > > > > > > diff --git a/drivers/target/target_core_spc.c b/drivers/target/target_core_spc.c > > > index 22703a0dbd07..169341712b10 100644 > > > --- a/drivers/target/target_core_spc.c > > > +++ b/drivers/target/target_core_spc.c > > ... > > > +/* Third-party Copy VPD page */ > > > +static sense_reason_t > > > +spc_emulate_evpd_8f(struct se_cmd *cmd, unsigned char *buf) > > > +{ > > > + struct se_device *dev = cmd->se_dev; > > > + int off; > > > + u16 page_len; > > > + > > > + if (!dev->dev_attrib.emulate_3pc) > > > + return TCM_INVALID_CDB_FIELD; > > > + > > > + /* > > > + * Since the Third-party copy manager in TCM is quite simple > > > + * and supports only two commands, the function sets > > > + * many descriptor parameters as constants. > > > + * > > > + * As the Copy manager supports the EXTENDED COPY(LID1) command, > > > + * the Third-party Copy VPD page should include five mandatory > > > + * Third-party copy descriptors. Its are: > > > + * 0001h - Supported Commands > > > + * 0004h - Parameter Data > > > + * 0008h - Supported Descriptors > > > + * 000Ch - Supported CSCD Descriptor IDs > > > + * 8001h - General Copy Operations > > > + * > > > + * See spc4 section 7.8.17 > > > + */ > > > + > > > + off = 4; > > > + > > > + /* fill descriptors */ > > > + off += spc_evpd_8f_encode_supp_cmds(&buf[off]); > > > + off += spc_evpd_8f_encode_param_data(&buf[off]); > > > + off += spc_evpd_8f_encode_supp_descrs(&buf[off]); > > > + off += spc_evpd_8f_encode_supp_cscd_descr_id(&buf[off]); > > > + off += spc_evpd_8f_encode_general_copy_ops(&buf[off]); > > > > This looks risky in terms of buf overrun. I think it'd be good to pass > > a @remaining or @buf_end param to these helper functions. > > > > It's doable but would require to change the signature of all existing > VPD handlers. SE_INQUIRY_BUF is hardcoded to 1kb but it's also capped by > EDTL to avoid buffer overruns: > > memcpy(rbuf, buf, min_t(u32, SE_INQUIRY_BUF, cmd->data_length)); That's checking the amount copied into the response buffer. My concern is the prior writes to the staging buf. Cheers, David
