Date: Sat, 17 May 2008 16:37:04 +0100 From: Rui Paulo <rpaulo@FreeBSD.org> To: Andriy Gapon <avg@icyb.net.ua> Cc: freebsd-hackers@freebsd.org Subject: Re: rdmsr from userspace Message-ID: <482EFBA0.30107@FreeBSD.org> In-Reply-To: <482E93C0.4070802@icyb.net.ua> References: <482E93C0.4070802@icyb.net.ua>
next in thread | previous in thread | raw e-mail | index | archive | help
Andriy Gapon wrote: > > It seems that rdmsr instruction can be executed only at the highest > privilege level and thus is not permitted from userland. Maybe we should > provide something like Linux /dev/cpu/msr? > I don't like interface of that device, I think that ioctl approach would > be preferable in this case. > Something like create /dev/cpuN and allow some ioctls on it: > ioctl(cpu_fd, CPU_RDMSR, arg). > What do you think? > While I think this (devcpu) is good for testing and development, I prefer having a device driver to handle that specific MSR than a generic /dev/cpuN where you can issue MSRs. Both for security and reliability reasons. Regards, -- Rui Paulo
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?482EFBA0.30107>