<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"> <head> <meta http-equiv="Content-Type" content="text/html; charset=us-ascii"> <meta name="Generator" content="Microsoft Word 15 (filtered medium)"> <style></style> </head> <body lang="EN-US" link="blue" vlink="purple" style="word-wrap:break-word"> <div class="WordSection1"> <p class="MsoNormal">Thank you, Alexander.<o:p></o:p></p> <p class="MsoNormal"><o:p> </o:p></p> <p class="MsoNormal">The patch looks good to me. With this patch, do you see other problems with VPP?<o:p></o:p></p> <p class="MsoNormal"><o:p> </o:p></p> <p class="MsoNormal">I’d like to get a review from <a id="OWAAMD37C4E80B84A4DBE873F70413713DBD3" href="mailto:samandrew@microsoft.com"> <span style="font-family:"Aptos",sans-serif;text-decoration:none">@Sam Andrew</span></a>.<o:p></o:p></p> <p class="MsoNormal"><o:p> </o:p></p> <p class="MsoNormal">Acked-by: Long Li <longli@microsoft.com><o:p></o:p></p> <p class="MsoNormal"><o:p> </o:p></p> <p class="MsoNormal"><o:p> </o:p></p> <div style="border:none;border-left:solid blue 1.5pt;padding:0in 0in 0in 4.0pt"> <div> <div style="border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in"> <p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">From:</span></b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"> Alexander Skorichenko <askorichenko@netgate.com> <br> <b>Sent:</b> Tuesday, July 2, 2024 1:49 AM<br> <b>To:</b> stephen@networkplumber.org<br> <b>Cc:</b> Sam Andrew <samandrew@microsoft.com>; ferruh.yigit@amd.com; andrew.rybchenko@oktetlabs.ru; Long Li <longli@microsoft.com>; Wei Hu <weh@microsoft.com>; dev@dpdk.org; Matthew Smith <mgsmith@netgate.com><br> <b>Subject:</b> Re: [PATCH] net/netvsc: fix mtu_set in netvsc devices<o:p></o:p></span></p> </div> </div> <p class="MsoNormal"><o:p> </o:p></p> <table class="MsoNormalTable" border="0" cellspacing="0" cellpadding="0" align="left" width="100%" style="width:100.0%"> <tbody> <tr> <td style="background:#A6A6A6;padding:5.25pt 1.5pt 5.25pt 1.5pt"></td> <td width="100%" style="width:100.0%;background:#EAEAEA;padding:5.25pt 3.75pt 5.25pt 11.25pt"> <div> <p class="MsoNormal" style="mso-element:frame;mso-element-frame-hspace:2.25pt;mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:column;mso-height-rule:exactly"> <span style="font-size:9.0pt;font-family:Wf_Segoe-Ui_Normal;color:#212121">You don't often get email from </span><span style="color:black"><a href="mailto:askorichenko@netgate.com"><span style="font-size:9.0pt;font-family:Wf_Segoe-Ui_Normal">askorichenko@netgate.com</span></a></span><span style="font-size:9.0pt;font-family:Wf_Segoe-Ui_Normal;color:#212121">. </span><span style="color:black"><a href="https://aka.ms/LearnAboutSenderIdentification"><span style="font-size:9.0pt;font-family:Wf_Segoe-Ui_Normal">Learn why this is important</span></a></span><span style="font-size:9.0pt;font-family:Wf_Segoe-Ui_Normal;color:#212121"><o:p></o:p></span></p> </div> </td> <td width="75" style="width:56.25pt;background:#EAEAEA;padding:5.25pt 3.75pt 5.25pt 3.75pt;align:left"> </td> </tr> </tbody> </table> <div> <div> <div> <p class="MsoNormal" style="margin-bottom:12.0pt">Hello,<br> The failure happens when running under VPP. In terms of dpdk calls the following sequence of events occurs for a NetVSC device:<br> <br> Durung device probing stage of VPP<br> 1. eth_hn_dev_init() memory for a single primary rx_queue is allocated<br> dev->data->rx_queues[0] = 0, allocated, but not set yet<br> no allocation happened for tx_queues[i] and non-primary rx_queues[i]<br> <br> During device setup stage of VPP from VPP's own generic dpdk_device_setup():<br> 2. rte_eth_dev_set_mtu()<br> currently it segfaults in hn_reinit() when trying to reach into<br> dev->data->rx_queues[i], dev->data->tx_queues[i]<br> 3. rte_eth_tx_queue_setup()<br> dev->data->tx_queues[i] are being allocated and set<br> 4. rte_eth_rx_queue_setup()<br> dev->data->rx_queues[i] get allocated (i > 0) and set<br> <br> So rx_queues[0] could be set in step 1, but rx_queues[i] and tx_queues[i] are still NULL. <br> Allocating all the remaining rx/tx queues in step 1 would prevent the crash, but then in steps 3-4 would go through releasing and allocating all of the queues again. <br> <br> Another comment regarding the uniform condition introduced in hn_reinit() in the patch:<br> if (dev->data->rx_queues[0] != NULL) ...<br> Because of the difference between rx/tx queues described above, it's probably safer to extend the condition to check both rx and tx separately<br> if (dev->data->rx_queues[0] != NULL && dev->data->tx_queues[0] != NULL)<br> <br> - Alexander Skorichenko<o:p></o:p></p> </div> <div> <blockquote style="border:none;border-left:solid #CCCCCC 1.0pt;padding:0in 0in 0in 6.0pt;margin-left:4.8pt;margin-top:5.0pt;margin-right:0in;margin-bottom:5.0pt"> <p class="MsoNormal"><o:p> </o:p></p> </blockquote> </div> </div> </div> </div> </div> </body> </html>