From: Claudio Imbrenda <imbrenda@linux.ibm.com>
To: Nico Boehr <nrb@linux.ibm.com>
Cc: kvm@vger.kernel.org, borntraeger@de.ibm.com,
frankja@linux.ibm.com, thuth@redhat.com, pasic@linux.ibm.com,
david@redhat.com, linux-s390@vger.kernel.org,
linux-kernel@vger.kernel.org, scgl@linux.ibm.com,
mimu@linux.ibm.com
Subject: Re: [PATCH v10 01/19] KVM: s390: pv: leak the topmost page table when destroy fails
Date: Mon, 16 May 2022 17:55:33 +0200 [thread overview]
Message-ID: <20220516175533.4bf3dd93@p-imbrenda> (raw)
In-Reply-To: <560068a1e89c2ceec0d544fcc62fa3f95d390182.camel@linux.ibm.com>
On Mon, 16 May 2022 09:22:09 +0200
Nico Boehr <nrb@linux.ibm.com> wrote:
> On Thu, 2022-04-14 at 10:02 +0200, Claudio Imbrenda wrote:
>
> [...]
> > +/**
> > + * s390_replace_asce - Try to replace the current ASCE of a gmap
> > with
> > + * another equivalent one.
> > + * @gmap the gmap
> > + *
> > + * If the allocation of the new top level page table fails, the ASCE
> > is not
> > + * replaced.
> > + * In any case, the old ASCE is always removed from the list.
> > Therefore the
> > + * caller has to make sure to save a pointer to it beforehands,
> > unless an
> > + * intentional leak is intended.
> > + */
> > +int s390_replace_asce(struct gmap *gmap)
> > +{
> >
> [...]
> > + /* Set new table origin while preserving existing ASCE
> > control bits */
> > + asce = (gmap->asce & ~_ASCE_ORIGIN) | __pa(table);
> > + WRITE_ONCE(gmap->asce, asce);
>
> Can someone concurrently touch the control bits?
should not happen, nobody is using the ASCE while we replace it
moreover, all callers of s390_replace_asce hold kvm->lock, as do all
functions changing the ASCE
next prev parent reply other threads:[~2022-05-16 15:56 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-14 8:02 [PATCH v10 00/19] KVM: s390: pv: implement lazy destroy for reboot Claudio Imbrenda
2022-04-14 8:02 ` [PATCH v10 01/19] KVM: s390: pv: leak the topmost page table when destroy fails Claudio Imbrenda
2022-04-14 11:30 ` Janosch Frank
2022-04-14 12:19 ` Claudio Imbrenda
2022-05-05 14:45 ` Thomas Huth
2022-05-06 11:30 ` Claudio Imbrenda
2022-05-16 7:22 ` Nico Boehr
2022-05-16 15:55 ` Claudio Imbrenda [this message]
2022-04-14 8:02 ` [PATCH v10 02/19] KVM: s390: pv: handle secure storage violations for protected guests Claudio Imbrenda
2022-05-05 17:10 ` Thomas Huth
2022-05-06 11:33 ` Claudio Imbrenda
2022-04-14 8:02 ` [PATCH v10 03/19] KVM: s390: pv: handle secure storage exceptions for normal guests Claudio Imbrenda
2022-04-14 8:02 ` [PATCH v10 04/19] KVM: s390: pv: refactor s390_reset_acc Claudio Imbrenda
2022-05-16 8:04 ` Nico Boehr
2022-05-16 16:11 ` Claudio Imbrenda
2022-05-30 7:40 ` Nico Boehr
2022-05-30 10:50 ` Claudio Imbrenda
2022-04-14 8:02 ` [PATCH v10 05/19] KVM: s390: pv: usage counter instead of flag Claudio Imbrenda
2022-04-14 8:02 ` [PATCH v10 06/19] KVM: s390: pv: add export before import Claudio Imbrenda
2022-04-14 8:02 ` [PATCH v10 07/19] KVM: s390: pv: module parameter to fence lazy destroy Claudio Imbrenda
2022-04-14 8:02 ` [PATCH v10 08/19] KVM: s390: pv: clear the state without memset Claudio Imbrenda
2022-04-14 8:03 ` [PATCH v10 09/19] KVM: s390: pv: Add kvm_s390_cpus_from_pv to kvm-s390.h and add documentation Claudio Imbrenda
2022-04-14 8:03 ` [PATCH v10 10/19] KVM: s390: pv: add mmu_notifier Claudio Imbrenda
2022-04-14 8:03 ` [PATCH v10 11/19] s390/mm: KVM: pv: when tearing down, try to destroy protected pages Claudio Imbrenda
2022-04-14 8:03 ` [PATCH v10 12/19] KVM: s390: pv: refactoring of kvm_s390_pv_deinit_vm Claudio Imbrenda
2022-04-14 8:03 ` [PATCH v10 13/19] KVM: s390: pv: destroy the configuration before its memory Claudio Imbrenda
2022-05-30 7:37 ` Nico Boehr
2022-05-30 12:05 ` Claudio Imbrenda
2022-04-14 8:03 ` [PATCH v10 14/19] KVM: s390: pv: cleanup leftover protected VMs if needed Claudio Imbrenda
2022-05-30 8:11 ` Nico Boehr
2022-05-30 10:43 ` Claudio Imbrenda
2022-04-14 8:03 ` [PATCH v10 15/19] KVM: s390: pv: asynchronous destroy for reboot Claudio Imbrenda
2022-05-30 9:46 ` Nico Boehr
2022-05-30 11:06 ` Claudio Imbrenda
2022-04-14 8:03 ` [PATCH v10 16/19] KVM: s390: pv: api documentation for asynchronous destroy Claudio Imbrenda
2022-05-30 9:47 ` Nico Boehr
2022-04-14 8:03 ` [PATCH v10 17/19] KVM: s390: pv: add KVM_CAP_S390_PROTECTED_ASYNC_DISABLE Claudio Imbrenda
2022-05-30 10:24 ` Nico Boehr
2022-04-14 8:03 ` [PATCH v10 18/19] KVM: s390: pv: avoid export before import if possible Claudio Imbrenda
2022-05-30 10:07 ` Nico Boehr
2022-05-30 11:16 ` Claudio Imbrenda
2022-04-14 8:03 ` [PATCH v10 19/19] KVM: s390: pv: support for Destroy fast UVC Claudio Imbrenda
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