LinuxQuestions.org
Latest LQ Deal: Latest LQ Deals
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Software > Linux - Kernel
User Name
Password
Linux - Kernel This forum is for all discussion relating to the Linux kernel.

Notices


Reply
  Search this Thread
Old 05-17-2021, 10:32 AM   #1
itayav17
LQ Newbie
 
Registered: May 2021
Posts: 1

Rep: Reputation: Disabled
physical address that pinned by get_user_pages_fast is not accessible


I'm writing a Linux kernel driver that pins a user memory in the kernel space and return the physical address, This is done by using the function get_user_pages_fast.

I checked it on a several different kernel versions and I found an issue on a very specific machine - the physical address is not accessible.

I can fix it by modifying the intel_iommu parameter (in /boot/grub2/grub.cfg) from 'on' to 'off' but in all the machines that I tested this flow, the inter_iommu was 'on'

What mechanism is hiding behind the intel_iommu? I believe that this parameter is not the root cause.

What can be the root cause?

Thanks!
 
Old 05-17-2021, 12:10 PM   #2
astrogeek
Moderator
 
Registered: Oct 2008
Distribution: Slackware [64]-X.{0|1|2|37|-current} ::12<=X<=14, FreeBSD_12{.0|.1}
Posts: 5,618
Blog Entries: 11

Rep: Reputation: 3657Reputation: 3657Reputation: 3657Reputation: 3657Reputation: 3657Reputation: 3657Reputation: 3657Reputation: 3657Reputation: 3657Reputation: 3657Reputation: 3657
Moved: This thread is more suitable in Linux Kernel forum and has been moved accordingly to help your thread/question get the exposure it deserves.
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off



Similar Threads
Thread Thread Starter Forum Replies Last Post
LXer: Firefox 36 Won't Bring Native YouTube HTML5 Playback, But Will Sync Pinned Tiles LXer Syndicated Linux News 0 02-15-2015 03:00 PM
Kernel MM replaces pinned physical pages ngoodnight Linux - Kernel 0 06-16-2011 04:03 PM
Synaptic: Cannot unlock pinned packages davcefai Debian 6 01-03-2006 03:47 PM
lisa pinned at 100% KimVette Linux - Networking 0 12-23-2005 07:17 PM
NTFS (winxp) drive is accessible only by root, why NTFS (winxp) drive not accessible Samppa72 Linux - Software 1 07-26-2004 03:13 PM

LinuxQuestions.org > Forums > Linux Forums > Linux - Software > Linux - Kernel

All times are GMT -5. The time now is 08:11 PM.

Main Menu
Advertisement
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Open Source Consulting | Domain Registration