AMD Publishes Documentation On RDNA 1.0 ISA

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • DRanged
    replied
    Originally posted by mczak View Post
    Nope. A later version of the patch changed it to the universally used (albeit a bit more obscure unless you look up the cpu features docs) clearcpuid approach.
    Thought so. My desktop is a x470 Ryzen 5 3600 with GTX 1070. In dmesg I can see umip entries sofar I have not incurred issues with wine-staging or steam linux, mind you I only play WoW and Diablo3 via Battle.net launcher and Civ5 andCov6 with Steam Linux.
    Only thing I can think of I've been lucky.

    ASRock x470 Master SLI, AMD Ryzen 5 3600, GTX 1070, 16GB mem, Debian testing (bullseye).
    Lenovo Legion y520, Intel i7, GTX 1050, 16GB, 16GB mem, Debian testing (bullseye), with Nvidia drivers, can
    still run for 3 to 5 hrs depending what I do.

    Leave a comment:


  • mczak
    replied
    Originally posted by DRanged View Post
    Did umip=no or umip=novm86 actually make it in to the kernel parameters
    Nope. A later version of the patch changed it to the universally used (albeit a bit more obscure unless you look up the cpu features docs) clearcpuid approach.

    Leave a comment:


  • DRanged
    replied
    Did umip=no or umip=novm86 actually make it in to the kernel parameters, because when I read the whole lot it isn't very clear.
    Besides that I cannot find it on the kernel parameter list (clearcpuid is there)
    Last edited by DRanged; 03 August 2019, 07:34 AM. Reason: typo

    Leave a comment:


  • hwertz
    replied
    Yeah, umip=novm86 or if that doesn't work, umip=no (it's a bit more readable than clearcpuid=514 .)

    Leave a comment:


  • loganj
    replied
    Lynxeye and to quote from your link
    However, unconditionally disabling UMIP for virtual-8086 tasks could be exploited by malicious applications. Hence, disabling UMIP for such kind of tasks is allowed only if the kernel parameter 'umip=novm86' is used. Rather than using the more modern clearcpuid=1234 format for the kernel parameters, we use umip={no|novm86}. This is because the former does cannot cover the three configuration states of UMIP.
    did someone tested
    Code:
    umip=novm86
    ?

    Leave a comment:


  • Lynxeye
    replied
    Originally posted by mlau View Post
    You left out the most interesting part:

    [...]without causing an exception to be generated if CR4.UMIP = 0.

    Does Ryzen 3xxx support UMIP? Then this can be resolved by building a kernel without UMIP support.
    The cover letter of the patchset implementing UMIP even mentions Wine and the kernel parameter (umip=novm86) needed to make it work.

    Leave a comment:


  • moilami
    replied
    Appears RDNA is going to reign in the forthcoming years. Good!

    Leave a comment:


  • mczak
    replied
    Originally posted by dungeon View Post
    Looks like Zen 2 supports it, since it seems properly prevents SGDT instruction to be used.
    I think UMIP could be disabled via clearcpuid=514 on the boot command line, so sgdt from userspace should no longer crash?
    I have no idea if the crash here is legit or not, but it should be noted that Zen 2 is the first widely available cpu which supports this, even though it seems intel specified this extension - cannonlake should support it but doesn't meet the definition of widely available by miles...
    Last edited by mczak; 02 August 2019, 03:43 AM.

    Leave a comment:


  • dungeon
    replied
    Originally posted by mlau View Post
    Does Ryzen 3xxx support UMIP? Then this can be resolved by building a kernel without UMIP support.
    Looks like Zen 2 supports it, since it seems properly prevents SGDT instruction to be used.

    On the other hand i guess some people like to be able to run everything, even viruses Probably UMIP should be build as module, for ease switch off for these who really does not care.

    BTW, i don't have a hardware, just looks like it might be a feature or a bug
    Last edited by dungeon; 02 August 2019, 02:33 AM.

    Leave a comment:


  • shmerl
    replied
    Originally posted by mlau View Post
    Does Ryzen 3xxx support UMIP? Then this can be resolved by building a kernel without UMIP support.
    Apparently Wine worked fine with Zen+, so I doubt Zen 2 is supposed to drop stuff that worked before. What's the way to check if UIMP is supported, is there some flag in cpuinfo?

    Leave a comment:

Working...
X