From: Martin Schwidefsky <schwidefsky@de.ibm.com>
To: Carsten Otte <cotte@de.ibm.com>
Cc: Avi Kivity <avi@redhat.com>,
Marcelo Tossati <mtosatti@redhat.com>,
borntrae@linux.vnet.ibm.com, heicars2@linux.vnet.ibm.com,
mschwid2@linux.vnet.ibm.com, huckc@linux.vnet.ibm.com,
KVM <kvm@vger.kernel.org>,
Joachim von Buttlar <joachim_von_buttlar@de.ibm.com>,
Jens Freimann <jfrei@de.ibm.com>,
agraf@suse.de
Subject: Re: [patch 10/12] [PATCH] kvm-s390: storage key interface
Date: Thu, 15 Dec 2011 18:14:28 +0100 [thread overview]
Message-ID: <20111215181428.0dca3f01@de.ibm.com> (raw)
In-Reply-To: <4EE9CBB3.3000707@de.ibm.com>
On Thu, 15 Dec 2011 11:28:03 +0100
Carsten Otte <cotte@de.ibm.com> wrote:
> + case KVM_S390_KEYOP_SSKE:
> + if (!(vma->vm_flags & (VM_WRITE | VM_MAYWRITE))) {
> + r = -EACCES;
> + break;
> + }
Unfortunately I just realized while discussing with Heiko that a check
for VM_WRITE is not enough. We could still have a read-only pte that
points to a file backed page which is purely read-only. A write access
is allowed but would cause copy-on-write. But we set the storage key
of the original page which would make the read-only page dirty.
We need to solved the race on the dirty bit in a clean way, otherwise
there always will be a corner case.
--
blue skies,
Martin.
"Reality continues to ruin my life." - Calvin.
next prev parent reply other threads:[~2011-12-15 17:14 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-14 12:23 [patch 00/12] Ucontrol patchset V6 Carsten Otte
2011-12-14 12:23 ` [patch 01/12] [PATCH] kvm-s390: add parameter for KVM_CREATE_VM Carsten Otte
2011-12-14 12:23 ` [patch 02/12] [PATCH] kvm-s390-ucontrol: per vcpu address spaces Carsten Otte
2011-12-14 12:23 ` [patch 03/12] [PATCH] kvm-s390-ucontrol: export page faults to user Carsten Otte
2011-12-14 12:23 ` [patch 04/12] [PATCH] kvm-s390-ucontrol: export SIE control block " Carsten Otte
2011-12-14 12:23 ` [patch 05/12] [PATCH] kvm-s390-ucontrol: disable in-kernel handling of SIE intercepts Carsten Otte
2011-12-14 12:23 ` [patch 06/12] [PATCH] kvm-s390-ucontrol: disable in-kernel irq stack Carsten Otte
2011-12-14 12:23 ` [patch 07/12] [PATCH] kvm-s390-ucontrol: interface to inject faults on a vcpu page table Carsten Otte
2011-12-14 12:23 ` [patch 08/12] [PATCH] kvm-s390-ucontrol: disable sca Carsten Otte
2011-12-14 12:23 ` [patch 09/12] [PATCH] kvm-s390: fix assumption for KVM_MAX_VCPUS Carsten Otte
2011-12-14 12:23 ` [patch 10/12] [PATCH] kvm-s390: storage key interface Carsten Otte
2011-12-15 10:28 ` Carsten Otte
2011-12-15 16:11 ` Heiko Carstens
2011-12-15 16:49 ` Christian Borntraeger
2011-12-15 17:18 ` Heiko Carstens
2011-12-15 17:14 ` Martin Schwidefsky [this message]
2011-12-14 12:23 ` [patch 11/12] [PATCH] kvm-s390-ucontrol: announce capability for user controlled vms Carsten Otte
2011-12-14 12:23 ` [patch 12/12] [PATCH] kvm-s390: Fix return code for unknown ioctl numbers Carsten Otte
-- strict thread matches above, loose matches on Subject: below --
2011-12-10 12:35 [patch 00/12] Ucontrol patchset V5 Carsten Otte
2011-12-10 12:35 ` [patch 10/12] [PATCH] kvm-s390: storage key interface Carsten Otte
2011-12-11 21:57 ` Heiko Carstens
2011-12-12 10:06 ` Martin Schwidefsky
2011-12-09 12:49 [patch 00/12] Ucontrol patchset V4 Carsten Otte
2011-12-09 12:49 ` [patch 10/12] [PATCH] kvm-s390: storage key interface Carsten Otte
2011-12-09 13:46 ` Heiko Carstens
2011-12-10 11:36 ` Carsten Otte
2011-12-09 11:23 [patch 00/12] Ucontrol patches V3 Carsten Otte
2011-12-09 11:23 ` [patch 10/12] [PATCH] kvm-s390: storage key interface Carsten Otte
2011-12-09 12:04 ` Heiko Carstens
[not found] ` <OFEDB7DC8E.0D8BE463-ONC1257961.004633DF-C1257961.0046C1E7@de.ibm.com>
2011-12-09 13:37 ` Carsten Otte
2011-12-08 9:12 [patch 00/12] Ucontrol patchset V2 Carsten Otte
2011-12-08 9:12 ` [patch 10/12] [PATCH] kvm-s390: storage key interface Carsten Otte
2011-12-01 12:57 [patch 00/12] User controlled virtual machines Carsten Otte
2011-12-01 12:57 ` [patch 10/12] [PATCH] kvm-s390: storage key interface Carsten Otte
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