Re: [PATCH] KVM: nVMX: Fix some comment typos and coding style

[linmiaohe]

Hi:
Sean Christopherson <sean.j.christopherson@xxxxxxxxx> wrote:
> On Thu, Feb 06, 2020 at 12:32:38PM +0100, Vitaly Kuznetsov wrote:
>> linmiaohe <linmiaohe@xxxxxxxxxx> writes:
>> 
>> 
>> I have to admit that shadow MMU in KVM is not my strong side but this 
>> comment reads weird, I'd appreciate if someone could suggest a better 
>> alternative.
>
>	/* One off flag for a stupid corner case in shadow paging. */
>> 
>> >  	 */
>
>	/*
>	 * Indicates the guest is trying to write a gfn that contains one or
>	 * more of the PTEs used to translate the write itself, i.e. the access
>	 * is changing its own translation in the guest page tables.  KVM exits
>	 * to userspace if emulation of the faulting instruction fails and this
>	 * flag is set, as KVM cannot make forward progress.
>	 *
>	 * If emulation fails for a write to guest page tables, KVM unprotects
>	 * (zaps) the shadow page for the target gfn and resumes the guest to
>	 * retry the non-emulatable instruction (on hardware).  Unprotecting the
>	 * gfn doesn't allow forward progress for a self-changing access because
>	 * doing so also zaps the translation for the gfn, i.e. retrying the
>	 * instruction will hit a !PRESENT fault, which results in a new shadow
>	 * page and sends KVM back to square one.
>	 */
>> >  	bool write_fault_to_shadow_pgtable;

Thanks for your detail comment. This field confused me once.

Thanks to both for review! Will send v2.