Messages in this thread | | | Date | Mon, 2 Nov 2020 10:09:01 -0600 | From | Segher Boessenkool <> | Subject | Re: [PATCH v5 04/17] x86/acrn: Introduce hypercall interfaces |
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On Mon, Nov 02, 2020 at 03:56:57PM +0100, Borislav Petkov wrote: > On Mon, Oct 19, 2020 at 02:17:50PM +0800, shuo.a.liu@intel.com wrote: > > +static inline long acrn_hypercall0(unsigned long hcall_id) > > +{ > > + long result; > > + > > + asm volatile("movl %1, %%r8d\n\t" > > + "vmcall\n\t" > > + : "=a" (result) > > + : "ir" (hcall_id) > ^^ > > Not "irm"? Or simply "g" in that case?
I think that will work for x86_64. But it won't matter much, most of the time you give an immediate number. It is a tiny bit neater of course (if anyone still remembers what "g" is, you cannot use it much these days).
Segher
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