Re: [PATCH v3 3/6] x86/sev: Add support to perform RMP optimizations asynchronously

[Dave Hansen]

On 4/1/26 08:47, Kalra, Ashish wrote:
> For programming the RMPOPT_BASE MSR performance is not really that
> important as it is for issuing the RMPOPT instruction on only thread
> per core, and as we are programming the RMPOPT_BASE MSRs on all CPUs/
> threads to the same (starting) physical address to support all RAM
> up-to 2TB for RMP optimizations, therefore, i don't think it is that
> critical to implement wrmsrq_on_cpumask() and instead we can
> continue to program the RMPOPT_BASE MSR on all CPUs (threads).
I don't mean to be a grammar pedant. But, man, that's hard to parse when
written as a single sentence.

I'm also not quite sure what the resistance is to going and adding the
precise function that is needed:

int wrmsrq_on_cpus(const struct cpumask *mask, u32 msr_no, u64 q)
{
        int err;
        struct msr_info rv;

        memset(&rv, 0, sizeof(rv));

        rv.msr_no = msr_no;
        rv.reg.q = q;

        err = smp_call_function_many(mask, __wrmsr_on_cpu, &rv, 1);

        return err;
}
EXPORT_SYMBOL(wrmsrq_on_cpus);

It's just wrmsrq_on_cpu(), replace the 'cpu' with a cpumask and
s/_single/_many/. I think. Unless I'm missing something.