QubesOS 3.1rc1, skylake multiple monitor support

[wahyzcrak]

Has anyone been able to get multiple monitor support for Skylake processors on qubes-os 3.1rc1?

Computer only recognizes 1 display and xrandr gives this message:

xrandr: failed to get size of gamma for output default

[Eric Shelton]

The impression I have gotten with my limited selection of monitors is that the Skylake iGPU is very picky about working with DisplayPort monitors.  For example, one monitor works fine via HDMI, but not DP.  xrandr even displays the correct resolutions when the monitor is hooked up via DP, but it won't actually use the display.  Maybe a different connector will work out?  If not, you will have to rummage through various forums via Google to look for solutions - it is more of a Linux problem than a Qubes problem.

The problem gets even worse with the most recent kernels (the 4.4 rc series) - I cannot do dual monitors under any conditions there. 

Eric

[wahyzcrak]

Thank you for the reply, I will keep digging. I really like qubes so far, and I could probably manage with just one screen given the KDE interface and being able to pop up the task view from the corner quickly. I have just been trying to get it all set up on my new work computer before I start installing stuff in my Windows app vm

[Eric Shelton]

FWIW, the fix most likely involves just getting the right kernel in place, or the right kernel command line options.  Neither of these require are going to require a reinstall of Qubes (few things really do) - just building and/or installing the appropriate RPM.  I would just go ahead with other things, such as installing Windows, and fit in resolving the issue later on.

Eric

[wahyzcrak]

Ok, that is probably the best bet. I am pretty novice at Linux in the scheme of things, especially anything to do with modifying kernel options or building my own packages(though I am particularly interested in learning how to do these things). I have considered reviewing some of the books / reading items listed in the qubes-os site for developer resources so that I can try to be a bit more proficient.

One problem I have had is figuring out how to access the grub.cfg. The way I was reading other posts it seems like I should be able to do it from Dom0 but I couldn't even notice a grub.cfg anywhere in the system by doing a find / -name for it. Learning curve is a bit steep but I think it will be worth it.

[Eric Shelton]

The file is /boot/grub2/grub.cfg.  You need to run sudo to edit it.  For example:

sudo vi /boot/grub2/grub.cfg

A quick way to navigate through the file is to search for occurrences of 'placeholder'.

Eric

[wahyzcrak]

Hmm, that is where I was looking for it the other day based off of some other posts I have seen.

In dom0 should the following command be able to at least see the file? Whenever I would try to use nano in place of vi like you did above I would get a file not found and it was wanting me to edit a blank file.

ls -al /boot/grub2/

I guess, is it even possible for the system to boot properly without a grub.cfg or some other bootloader? I didn't make any changes that I know of that would affect this after installing 3.1rc1 but I did do dom0 updates with current-testing repo enabled.

I did notice today that the usb drive I used to install the operating system had some serious issues and am currently trying to run through a fresh install using one that passed tests for bad blocks. I'll see if I can find the configuration this time once I get it up and going

[wahyzcrak]

Hmm, that is where I was looking for it the other day based off of some other posts I have seen.

In dom0 should the following command be able to at least see the file? Whenever I would try to use nano in place of vi like you did above I would get a file not found and it was wanting me to edit a blank file.

ls -al /boot/grub2/

I guess, is it even possible for the system to boot properly without a grub.cfg or some other bootloader? I didn't make any changes that I know of that would affect this after installing 3.1rc1 but I did do dom0 updates with current-testing repo enabled.

I did notice today that the usb drive I used to install the operating system had some serious issues and am currently trying to run through a fresh install using one that passed tests for bad blocks. I'll see if I can find the configuration this time once I get it up and going

One thing that is still bothering me, and I am not sure if it is actually a problem since the operating system seems to install fine, is that Dracut is saying that it refuses to continue when I test the installation media. It barely even starts and then decides that the media is no good to install from but still puts me into the installer which seems to still work.

Have you noticed anything like this before? 

[wahyzcrak]

I pretty much have no idea where to look for the grub config.

I am using dom0 and the grub.cfg does not exist in /boot/grub or /boot/grub2. Did I miss a step when I was installing somehow?

[wahyzcrak]

I think that I have been plagued by moments of stupidity, but perhaps the next thing I say will make sense.

I think that my motherboard only supports uefi bios, but does support legacy boot options. I notice some configuration items inside /boot/efi/EFI/qubes

Is it possible that my system is just not compatible with GRUB?

I was reading and grub should be uefi compatible so I do not know why it wouldn't be getting used but it does look like Linux also supports EFISTUB. Is it possible for qubes-os to install without grub using the default installer?

"The Linux Kernel (linux>=3.3) supports EFISTUB (EFI BOOT STUB) booting. This feature allows EFI firmware to load the kernel as an EFI executable" - @ https://wiki.archlinux.org/index.php/EFISTUB

I am not sure if this applies here but I suspect that I have been looking to make changes in the wrong place.

[Marek Marczykowski-Górecki]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256

On Tue, Jan 05, 2016 at 03:12:54PM -0800, wahyzcrak wrote:
> I think that I have been plagued by moments of stupidity, but perhaps the
> next thing I say will make sense.
>
> I think that my motherboard only supports uefi bios, but does support
> legacy boot options. I notice some configuration items inside
> /boot/efi/EFI/qubes
>
> Is it possible that my system is just not compatible with GRUB?
>
> I was reading and grub should be uefi compatible so I do not know why it
> wouldn't be getting used but it does look like Linux also supports EFISTUB.
> Is it possible for qubes-os to install without grub using the default
> installer?

By default, if you install Qubes OS in EFI mode (which is the case when
you launch installer as such), grub is not installed at all and Qubes is
configured to boot xen.efi directly from UEFI BIOS.

In that case, xen and kernel command line can be configured in
/boot/efi/EFI/qubes/xen.cfg.

Some details here:
https://github.com/QubesOS/qubes-issues/issues/794


- --
Best Regards,
Marek Marczykowski-Górecki
Invisible Things Lab
A: Because it messes up the order in which people normally read text.
Q: Why is top-posting such a bad thing?
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2

iQEcBAEBCAAGBQJWjE9NAAoJENuP0xzK19csC0cH/R6Reharyw7iRGsaZx4LqRYo
43yAjhLi3gVybSj4kiAvHr0lIedygT6ON9af2R+fHr+j3EIeeBofqRArH/L73nuK
X6+BrItuFMZxhXMueviSsqStWJm23fVqvat5hVCh1VQsGgOoc4sIO/FoTUQQ2gEm
fn3cAowzkMG6Pk6FUTEa6aqU7NLhh4FsOWaXztxGb/innNgJErQ5/DtcYo+0Xr/T
5LxcP3kf5cLThsBfgc9akDTETneRXIb7ym7541fsWU7p4RX0JVLXhjcTXlfhmTKN
Irq2HpJi4hhC5ii3QXzNkwsw911I6Zj53/FPA6Rgs9rcsRK5lXvJOx7ov9uPrc8=
=1fwI
-----END PGP SIGNATURE-----

[wahyzcrak]

By default, if you install Qubes OS in EFI mode (which is the case when
you launch installer as such), grub is not installed at all and Qubes is
configured to boot xen.efi directly from UEFI BIOS.

In that case, xen and kernel command line can be configured in
/boot/efi/EFI/qubes/xen.cfg.

Some details here:
https://github.com/QubesOS/qubes-issues/issues/794


- --
Best Regards,
Marek Marczykowski-Górecki
Invisible Things Lab
A: Because it messes up the order in which people normally read text.
Q: Why is top-posting such a bad thing?
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2

iQEcBAEBCAAGBQJWjE9NAAoJENuP0xzK19csC0cH/R6Reharyw7iRGsaZx4LqRYo
43yAjhLi3gVybSj4kiAvHr0lIedygT6ON9af2R+fHr+j3EIeeBofqRArH/L73nuK
X6+BrItuFMZxhXMueviSsqStWJm23fVqvat5hVCh1VQsGgOoc4sIO/FoTUQQ2gEm
fn3cAowzkMG6Pk6FUTEa6aqU7NLhh4FsOWaXztxGb/innNgJErQ5/DtcYo+0Xr/T
5LxcP3kf5cLThsBfgc9akDTETneRXIb7ym7541fsWU7p4RX0JVLXhjcTXlfhmTKN
Irq2HpJi4hhC5ii3QXzNkwsw911I6Zj53/FPA6Rgs9rcsRK5lXvJOx7ov9uPrc8=
=1fwI
-----END PGP SIGNATURE-----

Thank you for confirming, I feel extremely relieved that it was something relatively simple that I had been overlooking.

 

[wahyzcrak]

Is there any disadvantage / such as security when booting this way? I do not plan on installing any other OS alongside this or dual booting.

[Marek Marczykowski-Górecki]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256

On Tue, Jan 05, 2016 at 04:12:26PM -0800, wahyzcrak wrote:
> Is there any disadvantage / such as security when booting this way? I do
> not plan on installing any other OS alongside this or dual booting.

I'm not sure if Anti Evil Maid is compatible with UEFI (probably not),
but other than that, it is probably the same.
One disadvantage of UEFI is somehow less convenient modifying boot
parameters (kernel and xen cmdline) - not possible from bootloader menu.
But in UEFI you'll get somehow faster system startup - because of
skipping grub.

- --
Best Regards,
Marek Marczykowski-Górecki
Invisible Things Lab
A: Because it messes up the order in which people normally read text.
Q: Why is top-posting such a bad thing?
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2

iQEcBAEBCAAGBQJWjYeqAAoJENuP0xzK19csuH0H/AjYJmHi+shVV5bXwd+GNIay
KvO8nAUsVxV6gn74PQfqOGAw5a6PpKKkKZe7I2pJ/jLQLMfmNIrNOo1xx9QU11kx
mHsAdL5Tu0Ypkdug13A2233hlrRtmVqC7RA8KtiBpfhEJlHGwqJzMZVj/xqk+RCz
DQm4WiCJdTQK4pgvDGDp6qsyZjoQooRzIROUziHKPLM7ZvR9/tM6N4E4Xe655XBC
2mXx17tStfmj/dnnePjwirM9gunyNtfQcKgJZQ3vHQ2Ds9TwQer+hSiTvq04N5Eo
VemvZ4CSK2OeLacv77IcEq09ATXFnfTdCwKWMHp9GYttp7FnGpLmQ8GpigPWXCU=
=wD2T
-----END PGP SIGNATURE-----

[wahyzcrak]

I'm not sure if Anti Evil Maid is compatible with UEFI (probably not),
but other than that, it is probably the same.
One disadvantage of UEFI is somehow less convenient modifying boot
parameters (kernel and xen cmdline) - not possible from bootloader menu.
But in UEFI you'll get somehow faster system startup - because of
skipping grub.

 I'm not sure if I am compatible with anti-evil Maid at the moment anyway because my motherboard does say I have TPM but it is intel PTT, which I enabled. I am just not really sure if it is the same thing as TPM or not. On the other hand my motherboard has the option to add a TPM 2.0 module but I can't find one anywhere for sale after brief searching here and there and the old TPM 1.2 module that I have from ASUS does not fit in the slot. So far I haven't been too worried about it but may try to get it functioning down the road.

[wahyzcrak]

Ok, so now that I had a bit more time today I confirmed that adding i915.preliminary_hw_support=1 works in /boot/efi/EFI/qubes/xen.cfg the same way that it works in grub.cfg

Even better simply adding that line enabled all three of my displays.

I appreciate the help from both of you guys (Eric and Marek). Hopefully I can learn a bit while using qubes and maybe be able to contribute down the road when I know more.

Cheers!