From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-1.mimecast.com ([207.211.31.81]:47788 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1730573AbgBYOai (ORCPT ); Tue, 25 Feb 2020 09:30:38 -0500 Date: Tue, 25 Feb 2020 15:30:24 +0100 From: Cornelia Huck Subject: Re: [PATCH v4 20/36] KVM: s390/mm: handle guest unpin events Message-ID: <20200225153024.62e1ed7f.cohuck@redhat.com> In-Reply-To: <2c45d494-8fdf-69c1-e786-0f07c6f09a40@de.ibm.com> References: <20200224114107.4646-1-borntraeger@de.ibm.com> <20200224114107.4646-21-borntraeger@de.ibm.com> <20200225131838.2d68e7f9.cohuck@redhat.com> <2c45d494-8fdf-69c1-e786-0f07c6f09a40@de.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-s390-owner@vger.kernel.org List-ID: To: Christian Borntraeger Cc: Janosch Frank , KVM , David Hildenbrand , Thomas Huth , Ulrich Weigand , Claudio Imbrenda , linux-s390 , Michael Mueller , Vasily Gorbik On Tue, 25 Feb 2020 15:21:42 +0100 Christian Borntraeger wrote: > On 25.02.20 13:18, Cornelia Huck wrote: > > On Mon, 24 Feb 2020 06:40:51 -0500 > > Christian Borntraeger wrote: > > > >> From: Claudio Imbrenda > >> > >> The current code tries to first pin shared pages, if that fails (e.g. > >> because the page is not shared) it will export them. For shared pages > >> this means that we get a new intercept telling us that the guest is > >> unsharing that page. We will make the page secure at that point in time > >> and revoke the host access. This is synchronized with other host events, > >> e.g. the code will wait until host I/O has finished. > >> > >> Signed-off-by: Claudio Imbrenda > >> Acked-by: David Hildenbrand > >> [borntraeger@de.ibm.com: patch merging, splitting, fixing] > >> Signed-off-by: Christian Borntraeger > >> --- > >> arch/s390/kvm/intercept.c | 24 ++++++++++++++++++++++++ > >> 1 file changed, 24 insertions(+) > I will also fixup the misleading patch description: > > The current code tries to first pin shared pages, if that fails (e.g. > because the page is not shared) it will export them. For shared pages > this means that we get a new intercept telling us that the guest is > unsharing that page. We will unpin the page at that point in time, > following the same rules as for make secure. (wait for writeback, no > elevated page refs etc). I'd suggest: "...as for making a page secure (i.e. waiting for writeback, no elevated page references, etc.)" With the touchups, Reviewed-by: Cornelia Huck