Re: [PATCH 04/22] x86/kvm: Don't call kvm_spurious_fault() from .fixup

From: Josh Poimboeuf
Date: Mon Jul 15 2019 - 09:26:02 EST


On Mon, Jul 15, 2019 at 03:05:33PM +0200, Paolo Bonzini wrote:
> On 15/07/19 14:40, Josh Poimboeuf wrote:
> >>> * Hardware virtualization extension instructions may fault if a
> >>> * reboot turns off virtualization while processes are running.
> >>> - * Trap the fault and ignore the instruction if that happens.
> >>> + * If that happens, trap the fault and panic (unless we're rebooting).
> >> Not sure the comment is better than before, but apar from that
> > The previous comment didn't seem to match the code, since we only ignore
> > the instruction if we're rebooting.
> >
>
> "If that happens" refers to "a reboot turns off virtualization while
> processes are running".

Ah, makes sense now. I was reading "if that happens" to mean the fault.

> * Usually after catching the fault we just panic; during reboot
> * instead the instruction is ignored.

Yes, that's much clearer. Assuming you meant to replace the entire
comment. I also moved it to directly above the macro it's describing:


asmlinkage void __noreturn kvm_spurious_fault(void);

/*
* Usually after catching the fault we just panic; during reboot
* instead the instruction is ignored.
*/
#define ____kvm_handle_fault_on_reboot(insn, cleanup_insn) \


--
Josh