Re: [PATCH v4 1/2] x86/unwind: add ORC unwinder

[Peter Zijlstra]

On Wed, Aug 09, 2017 at 10:49:43AM +0200, Juergen Gross wrote:
> > ALTERNATIVE "pushfq; popq %rax", "callq *pv_irq_ops.save_fl",
> > X86_FEATURE_GODDAMN_PV_IRQ_OPS
> 
> You are aware that at least some of the Xen irq pvops functionality is
> patched inline? Your modification would slow down pv guests quite a
> bit, I guess.

Where does that live? I know of the inline patching for native, but
didn't know the guests did any of that too.