There are so many bits, so little time. I have utterly forgotten how vt-d gets enabled.
Anyway, there's two bits and a lock bit. coreboot very deliberately does nothing with any of them -- this was a design decision a few years ago -- and it leaves them in a state that you can control them. So the 'enable vt-x' part is easy and kvm will do it for you when you load the module, or you can do it with the wrmsr command (for each core! -- if you only do one core it will go badly). ron On Sun, Jul 26, 2015 at 3:40 AM Noah Vesely <[email protected]> wrote: > Thanks Ron! Took bit to get back to you because a Xen hypervisor update > in Qubes seemed to put me in a boot loop. I just installed an Arch > derivative because Arch has good support for this machine and I needed > some type of test environment to actually run this command. > > Anyway, `rdmsr 0x3a` (think this is what you meant to type) returns 0. I > guess this means all 3 bits are not set in the IA32_FEATURE_CONTROL MSR. > > This doesn't immediately make sense to me because (1) the output here > seems to be telling me VT-x is not activated and the vmx cpu flag is > present =><= and (2) I wrote in because `xl info` in Xen was reporting > VT-x, but not VT-d, was activated and I was interested in how I could > activate the former--isn't 0x3a unrelated to VT-d? Hopefully you can > clarify this for me. > > Noah > > On 07/24/2015 11:25 PM, ron minnich wrote: > > what does rdmsr 0 0x3a show you? > > > > ron > > > > On Fri, Jul 24, 2015 at 10:06 PM Noah Vesely <[email protected]> > wrote: > > > >> I've been trying to get VT-d working on John Lewis's build for the 2015 > >> Pixel (samus). You can see our conversation at > >> https://plus.google.com/116173342884039282107/posts/TGA4EXYQMfq and I > >> have also pasted it below. So far, I haven't got anywhere, so I thought > >> I would try asking you all as well. > >> > >> Thanks, > >> Noah > >> > >> &%$#&%$#&%$#&%$#&%$#&%$#&%$#&%$#&%$# > >> > >> Noah Vesely > >> - Jul 16, 2015 > >> > >> Is it possible to get Intel VT-d working on the Chromebook Pixel 2/ > >> Samus? The i7-5600U processor does support it. > >> ARK | Intel® Core™ i7-5600U Processor (4M Cache, up to 3.20 GHz) > >> ark.intel.com > >> ARK | Intel® Core™ i7-5600U Processor (4M Cache, up to 3.20 GHz) quick > >> reference guide including specifications, features, pricing, > >> compatibility, design documentation, ordering codes, spec codes and > more. > >> John Lewis's profile photoNoah Vesely's profile photo > >> 10 comments > >> John Lewis > >> Jul 18, 2015 > >> > >> > >> > >> > >> AFAIK, none of the hardware VT extensions are disabled in the firmware > >> on Samus. Have you tried it? > >> Noah Vesely > >> Jul 18, 2015 > >> > >> > >> > >> > >> Yes. VT-x was enable while VT-d was not. > >> John Lewis > >> Jul 18, 2015 > >> > >> > >> > >> > >> Clone > >> > >> > https://chromium.googlesource.com/chromiumos/third_party/coreboot/+/firmware-samus-6300.B > >> and run menuconfig to see if there's an option for VT-d. > >> Noah Vesely > >> Jul 19, 2015 > >> > >> > >> > >> > >> I can't figure out how to checkout this repository. I cloned the main > >> third_part/coreboot repo then checked out the broadwell branch, but > >> could not find the same directory you linked. Maybe my git fu could use > >> some work. > >> John Lewis > >> Jul 20, 2015 > >> > >> > >> > >> > >> Use the last chunk of the URL as the branch argument i.e. "-b > >> firmware-samus-6300.B". > >> Noah Vesely > >> Jul 20, 2015 > >> > >> > >> > >> > >> Nothing in menuconfig, however, I found the line `#define CONFIG_IOMMU > >> 0` in ./build/config.h. I also found `#define CONFIG_ENABLE_VMX 0`. > >> John Lewis > >> Jul 21, 2015 > >> > >> > >> > >> > >> VMX is already enabled in the firmware. IOMMU is unrelated. I would have > >> to conclude that VT'd is either not supported by that CPU or something > >> more needs to be done in coreboot to get it to work. > >> Noah Vesely > >> Jul 21, 2015 > >> > >> > >> > >> > >> VT-d is supported by this CPU. See original link to Intel Ark. > >> > >> VT-d is Intel's specification for their IOMMU technology, so I don't see > >> how it's unrelated. > >> John Lewis > >> Jul 21, 2015 > >> > >> > >> > >> > >> Take a look at the .config from a shellball ROM (you can extract it > >> using cbfstool). > >> > >> > https://johnlewis.ie/extracting-the-shell-ball-rom-using-a-chromeos-image/ > >> > >> Noah Vesely > >> 9:15 PM > >> > >> > >> > >> > >> I don't see anything relevant to VT-d; no VT-d keywords (e.g., iommu, > >> vt, vmx, hvm, and directio). > >> > >> http://paste.debian.net/hidden/08ac8494/ > >> > >> -- > >> coreboot mailing list: [email protected] > >> http://www.coreboot.org/mailman/listinfo/coreboot > >
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