Messages in this thread | | | From | Arvind Sankar <> | Date | Mon, 19 Oct 2020 18:15:15 -0400 | Subject | Re: [PATCH v5 04/17] x86/acrn: Introduce hypercall interfaces |
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On Mon, Oct 19, 2020 at 02:17:50PM +0800, shuo.a.liu@intel.com wrote: > From: Shuo Liu <shuo.a.liu@intel.com> > > The Service VM communicates with the hypervisor via conventional > hypercalls. VMCALL instruction is used to make the hypercalls. > > ACRN hypercall ABI: > * Hypercall number is in R8 register. > * Up to 2 parameters are in RDI and RSI registers. > * Return value is in RAX register. > > Introduce the ACRN hypercall interfaces. Because GCC doesn't support R8 > register as direct register constraints, use supported constraint as > input with a explicit MOV to R8 in beginning of asm. > > +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)
Is the hypercall id an unsigned long (64 bits) or an unsigned int (32 bits)? This will generate broken assembly if the "r" option is chosen, eg something like movl %rdi, %r8d
> + : "r8", "memory"); > + > + return result; > +} > + > +static inline long acrn_hypercall1(unsigned long hcall_id, > + unsigned long param1) > +{ > + long result; > + > + asm volatile("movl %1, %%r8d\n\t" > + "vmcall\n\t" > + : "=a" (result) > + : "ir" (hcall_id), "D" (param1) > + : "r8", "memory"); > + > + return result; > +} > + > +static inline long acrn_hypercall2(unsigned long hcall_id, > + unsigned long param1, > + unsigned long param2) > +{ > + long result; > + > + asm volatile("movl %1, %%r8d\n\t" > + "vmcall\n\t" > + : "=a" (result) > + : "ir" (hcall_id), "D" (param1), "S" (param2) > + : "r8", "memory"); > + > + return result; > +} > + > #endif /* _ASM_X86_ACRN_H */ > -- > 2.28.0 >
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