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From: Heiko Carstens <hca@linux.ibm.com>
To: Janosch Frank <frankja@linux.ibm.com>
Cc: linux-s390@vger.kernel.org, borntraeger@de.ibm.com,
	gor@linux.ibm.com, imbrenda@linux.ibm.com, kvm@vger.kernel.org,
	david@redhat.com
Subject: Re: [PATCH 1/2] s390x: uv: Add destroy page call
Date: Fri, 4 Sep 2020 14:10:55 +0200	[thread overview]
Message-ID: <20200904121055.GF6075@osiris> (raw)
In-Reply-To: <98237148-bbb4-c6d7-aba2-6fa11fb788b1@linux.ibm.com>

On Fri, Sep 04, 2020 at 01:38:53PM +0200, Janosch Frank wrote:
> >>   * Requests the Ultravisor to encrypt a guest page and make it
> >>   * accessible to the host for paging (export).
> >> diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c
> >> index 373542ca1113..cfb0017f33a7 100644
> >> --- a/arch/s390/mm/gmap.c
> >> +++ b/arch/s390/mm/gmap.c
> >> @@ -2679,7 +2679,7 @@ static int __s390_reset_acc(pte_t *ptep, unsigned long addr,
> >>  	pte_t pte = READ_ONCE(*ptep);
> >>  
> >>  	if (pte_present(pte))
> >> -		WARN_ON_ONCE(uv_convert_from_secure(pte_val(pte) & PAGE_MASK));
> >> +		WARN_ON_ONCE(uv_destroy_page(pte_val(pte) & PAGE_MASK));
> > 
> > Why not put the WARN_ON_ONCE() into uv_destroy_page() and make that
> > function return void?
> > 
> If you prefer that, I'll change the patch.

Seems to be better to me. Otherwise you start to sprinkle WARN_ONs all
over the code, _if_ there would be more callers.

> I think we'd need a proper print of the return codes of the UVC anyway,
> the warn isn't very helpful if you want to debug after the fact.

Maybe a new debug feature? Well, but that's something that hasn't do
anything with this code.

  reply	other threads:[~2020-09-04 12:11 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-03 13:14 [PATCH 0/2] s390x: pv: Fixes and improvements Janosch Frank
2020-09-03 13:14 ` [PATCH 1/2] s390x: uv: Add destroy page call Janosch Frank
2020-09-04 10:39   ` Heiko Carstens
2020-09-04 11:38     ` Janosch Frank
2020-09-04 12:10       ` Heiko Carstens [this message]
2020-09-07  9:50         ` Janosch Frank
2020-09-03 13:14 ` [PATCH 2/2] s390x: Add 3f program exception handler Janosch Frank
2020-09-03 14:20   ` Christian Borntraeger
2020-09-04 10:35   ` Heiko Carstens
2020-09-04 11:33     ` Janosch Frank
2020-09-04 12:14       ` Heiko Carstens

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