[PATCH RESEND] x86-64: use RIP-relative calls for paravirt indirect ones
From: Jan Beulich <hidden>
Date: 2018-08-15 08:09:26
This saves one insn byte per instance, summing up to a savings of over 4k in my (stripped down) configuration. No variant of to be patched in replacement code relies on the one byte larger size. Signed-off-by: Jan Beulich <redacted> Reviewed-by: Juergen Gross <jgross@suse.com> --- Resend to include x86 maintainers, who aren't listed explicitly for the file changed. --- arch/x86/include/asm/paravirt_types.h | 6 ++++++ 1 file changed, 6 insertions(+)
--- 4.18/arch/x86/include/asm/paravirt_types.h
+++ 4.18-x86_64-pvops-call-RIPrel/arch/x86/include/asm/paravirt_types.h@@ -393,9 +393,15 @@ int paravirt_disable_iospace(void); * offset into the paravirt_patch_template structure, and can therefore be * freely converted back into a structure offset. */ +#ifdef CONFIG_X86_32 #define PARAVIRT_CALL \ ANNOTATE_RETPOLINE_SAFE \ "call *%c[paravirt_opptr];" +#else +#define PARAVIRT_CALL \ + ANNOTATE_RETPOLINE_SAFE \ + "call *%c[paravirt_opptr](%%rip);" +#endif /* * These macros are intended to wrap calls through one of the paravirt