While using a plain (constant) address works, its use needlessly invokes a SIB addressing mode, making every call site one byte larger than necessary. Instead of using an "i" constraint with address-of operator and a 'c' operand modifier, simply use an ordinary "m" constraint, which the 64-bit compiler will translate to %rip-relative addressing. This way we also tell the compiler the truth about operand usage - the memory location gets actually read, after all. 32-bit code generation is unaffected by the change. Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx> --- a/arch/x86/include/asm/paravirt_types.h +++ b/arch/x86/include/asm/paravirt_types.h @@ -278,7 +278,7 @@ extern void (*paravirt_iret)(void); #define paravirt_type(op) \ [paravirt_typenum] "i" (PARAVIRT_PATCH(op)), \ - [paravirt_opptr] "i" (&(pv_ops.op)) + [paravirt_opptr] "m" (pv_ops.op) #define paravirt_clobber(clobber) \ [paravirt_clobber] "i" (clobber) @@ -315,7 +315,7 @@ int paravirt_disable_iospace(void); */ #define PARAVIRT_CALL \ ANNOTATE_RETPOLINE_SAFE \ - "call *%c[paravirt_opptr];" + "call *%[paravirt_opptr];" /* * These macros are intended to wrap calls through one of the paravirt _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
