From: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
To: Paul Mackerras <paulus@ozlabs.org>
Cc: linuxram@us.ibm.com, kvm-ppc@vger.kernel.org,
Bharata B Rao <bharata@linux.ibm.com>,
linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH V3 2/2] KVM: PPC: Implement H_SVM_INIT_ABORT hcall
Date: Thu, 19 Dec 2019 13:51:39 -0800 [thread overview]
Message-ID: <20191219215139.GB22629@us.ibm.com> (raw)
In-Reply-To: <20191218053632.GC29890@oak.ozlabs.ibm.com>
Paul Mackerras [paulus@ozlabs.org] wrote:
> On Sat, Dec 14, 2019 at 06:12:08PM -0800, Sukadev Bhattiprolu wrote:
> >
> > Implement the H_SVM_INIT_ABORT hcall which the Ultravisor can use to
> > abort an SVM after it has issued the H_SVM_INIT_START and before the
> > H_SVM_INIT_DONE hcalls. This hcall could be used when Ultravisor
> > encounters security violations or other errors when starting an SVM.
> >
> > Note that this hcall is different from UV_SVM_TERMINATE ucall which
> > is used by HV to terminate/cleanup an VM that has becore secure.
> >
> > The H_SVM_INIT_ABORT should basically undo operations that were done
> > since the H_SVM_INIT_START hcall - i.e page-out all the VM pages back
> > to normal memory, and terminate the SVM.
> >
> > (If we do not bring the pages back to normal memory, the text/data
> > of the VM would be stuck in secure memory and since the SVM did not
> > go secure, its MSR_S bit will be clear and the VM wont be able to
> > access its pages even to do a clean exit).
> >
> > Based on patches and discussion with Paul Mackerras, Ram Pai and
> > Bharata Rao.
> >
> > Signed-off-by: Ram Pai <linuxram@linux.ibm.com>
> > Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.ibm.com>
> > Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
>
> Minor comment below, but not a showstopper. Also, as Bharata noted
> you need to hold the srcu lock for reading.
Yes, I fixed that.
>
> > + for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) {
> > + struct kvm_memory_slot *memslot;
> > + struct kvm_memslots *slots = __kvm_memslots(kvm, i);
> > +
> > + if (!slots)
> > + continue;
> > +
> > + kvm_for_each_memslot(memslot, slots)
> > + kvmppc_uvmem_drop_pages(memslot, kvm, false);
> > + }
>
> Since we use the default KVM_ADDRESS_SPACE_NUM, which is 1, this code
> isn't wrong but it is more verbose than it needs to be. It could be
>
> kvm_for_each_memslot(kvm_memslots(kvm), slots)
> kvmppc_uvmem_drop_pages(memslot, kvm, false);
and simplified this.
Thanks.
Sukadev
next prev parent reply other threads:[~2019-12-19 21:54 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-15 2:11 [PATCH V3 1/2] KVM: PPC: Add skip_page_out parameter Sukadev Bhattiprolu
2019-12-15 2:12 ` [PATCH V3 2/2] KVM: PPC: Implement H_SVM_INIT_ABORT hcall Sukadev Bhattiprolu
2019-12-16 3:29 ` Bharata B Rao
2019-12-19 21:50 ` Sukadev Bhattiprolu
2019-12-18 5:36 ` Paul Mackerras
2019-12-19 21:51 ` Sukadev Bhattiprolu [this message]
2020-01-03 0:18 ` Ram Pai
2020-01-03 0:32 ` Sukadev Bhattiprolu
2020-01-03 2:20 ` Ram Pai
2019-12-18 5:32 ` [PATCH V3 1/2] KVM: PPC: Add skip_page_out parameter Paul Mackerras
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20191219215139.GB22629@us.ibm.com \
--to=sukadev@linux.vnet.ibm.com \
--cc=bharata@linux.ibm.com \
--cc=kvm-ppc@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=linuxram@us.ibm.com \
--cc=paulus@ozlabs.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).