Re: port-i386/52266: Double fault early in boot with Transmeta Crusoe CPU

[Simon Burge <simonb%NetBSD.org@localhost>]

The following reply was made to PR port-i386/52266; it has been noted by GNATS.

From: Simon Burge <simonb%NetBSD.org@localhost>
To: Kimihiro Nonaka <nonakap%gmail.com@localhost>
Cc: "gnats-bugs%netbsd.org@localhost" <gnats-bugs%netbsd.org@localhost>,
    "gnats-admin%netbsd.org@localhost" <gnats-admin%netbsd.org@localhost>,
    "netbsd-bugs%netbsd.org@localhost" <netbsd-bugs%netbsd.org@localhost>,
    Andreas Gustafsson <gson%gson.org@localhost>
Subject: Re: port-i386/52266: Double fault early in boot with Transmeta Crusoe CPU
Date: Sun, 09 Jul 2017 00:24:35 +1000

 Kimihiro Nonaka wrote:
 
 > Could you try the following patch.
 > 
 > diff --git a/sys/arch/x86/x86/lapic.c b/sys/arch/x86/x86/lapic.c
 > index 20822a67184..372e9f8c0c2 100644
 > --- a/sys/arch/x86/x86/lapic.c
 > +++ b/sys/arch/x86/x86/lapic.c
 > @@ -235,10 +235,12 @@ lapic_enable_x2apic(void)
 >  bool
 >  lapic_is_x2apic(void)
 >  {
 > -    uint64_t r;
 > +    uint64_t msr;
 > 
 > -    r = rdmsr(MSR_APICBASE);
 > -    return (r & (APICBASE_EN | APICBASE_EXTD)) == (APICBASE_EN |
 > APICBASE_EXTD);
 > +    if (rdmsr_safe(MSR_APICBASE, &msr) == EFAULT)
 > +        return false;
 > +    return (msr & (APICBASE_EN | APICBASE_EXTD)) ==
 > +        (APICBASE_EN | APICBASE_EXTD);
 >  }
 > 
 >  /*
 
 This works (tested on netbsd-8 branch).  Thank you!
 
 Can you please commit and pull up to the netbsd-8 branch?
 
 Cheers,
 Simon.