Re: [PATCH] x86/paravirt: use %rip-relative addressing in hook calls
From: Jan Beulich via Virtualization <hidden>
Date: 2021-11-23 09:35:37
On 05.10.2021 09:43, Juergen Gross wrote:
On 30.09.21 14:40, Jan Beulich via Virtualization wrote:quoted
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 <redacted>Reviewed-by: Juergen Gross <jgross@suse.com>
Thanks. I notice this wasn't part of your 5.16-rc1 pull request, nor did it make it into Linus'es tree via any other route. May I ask what the plans here are? Jan _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization