On Fri, Jun 05, 2015 at 12:04:42PM +0200, Ingo Molnar wrote:
> Yeah, so what I think should be done instead is to flip around the API:
> make wrmsrl_safe() the primary API and derive wrmsr_safe() from that,
> because it's the saner API and because we have 3 times more wrmsrl_safe()
> users right now!
>
> And I'd make _that_ mapping inline, which would catch crap like:
>
> ./arch/x86/include/asm/msr.h: return wrmsr_safe(msr, (u32)val, (u32)(val >> 32));
> ./arch/x86/xen/enlighten.c: wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32));
>
> and would turn it back into wrmsrl_safe(pfn)/etc. seemlessly.
>
> In addition to that we might even phase out the high/low API altogether, as code
> like this:
>
> !wrmsr_safe(MSR_EFER,
> header->pmode_efer_low,
> header->pmode_efer_high))
>
> should probably use a single u64.
There's also msr_read()/msr_write() in arch/x86/lib/msr.c.
They're not that straight-forward to use due to that struct msr thing
as the second arg but we could wrap the creation of that thing in a
higher-level caller. The advantage is that you can set both low, high
and the whole u64 values directly and got the error handling of the safe
variants.
> But crappy paravirt indirections get in the way of an easy, trivial
> restructuring, as usual...
Tell me about it. :/
--
Regards/Gruss,
Boris.
ECO tip #101: Trim your mails when you reply.
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