Re: VMI Interface Proposal Documentation for I386, Part 4

[Pavel Machek <pavel@ucw.cz>]

Hi!

>     6) Interrupts must always be enabled when running code in userspace.

I'd say this breaks userspace.

This code used to work when ran as root:

void
main(void)
{
        int i;
        iopl(3);
        while (1) {
                asm volatile("cli");
                //              for (i=0; i<20000000; i++)
                for (i=0; i<1000000000; i++)
                        asm volatile("");
                asm volatile("sti");
                sleep(1);
        }
}

...and was actually useful.

>     7) IOPL semantics for userspace are changed; although userspace may be
>        granted port access, it can not affect the interrupt flag.

I'm not sure how will X like this.

								Pavel

-- 
57:        MD5CryptoServiceProvider MD5 = new MD5CryptoServiceProvider();