Messages in this thread |  | | From | Nick Desaulniers <> | Date | Mon, 19 Oct 2020 14:53:29 -0700 | Subject | Re: [PATCH v5 04/17] x86/acrn: Introduce hypercall interfaces |
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On Sun, Oct 18, 2020 at 11:18 PM <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.
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
> > Originally-by: Yakui Zhao <yakui.zhao@intel.com> > Signed-off-by: Shuo Liu <shuo.a.liu@intel.com> > Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> > Cc: Dave Hansen <dave.hansen@intel.com> > Cc: Sean Christopherson <sean.j.christopherson@intel.com> > Cc: Dan Williams <dan.j.williams@intel.com> > Cc: Fengwei Yin <fengwei.yin@intel.com> > Cc: Zhi Wang <zhi.a.wang@intel.com> > Cc: Zhenyu Wang <zhenyuw@linux.intel.com> > Cc: Yu Wang <yu1.wang@intel.com> > Cc: Reinette Chatre <reinette.chatre@intel.com> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > Cc: Borislav Petkov <bp@alien8.de> > Cc: Arvind Sankar <nivedita@alum.mit.edu> > Cc: Peter Zijlstra <peterz@infradead.org> > Cc: Nick Desaulniers <ndesaulniers@google.com> > Cc: Segher Boessenkool <segher@kernel.crashing.org> > --- > arch/x86/include/asm/acrn.h | 54 +++++++++++++++++++++++++++++++++++++ > 1 file changed, 54 insertions(+) > > diff --git a/arch/x86/include/asm/acrn.h b/arch/x86/include/asm/acrn.h > index a2d4aea3a80d..03e420245505 100644 > --- a/arch/x86/include/asm/acrn.h > +++ b/arch/x86/include/asm/acrn.h > @@ -14,4 +14,58 @@ void acrn_setup_intr_handler(void (*handler)(void)); > void acrn_remove_intr_handler(void); > bool acrn_is_privileged_vm(void); > > +/* > + * Hypercalls for ACRN > + * > + * - VMCALL instruction is used to implement ACRN hypercalls. > + * - ACRN hypercall ABI: > + * - Hypercall number is passed in R8 register. > + * - Up to 2 arguments are passed in RDI, RSI. > + * - Return value will be placed in RAX. > + * > + * 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) > + : "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 >
-- Thanks, ~Nick Desaulniers
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