From: Scott Wood <scottwood@freescale.com>
To: Alexander Graf <agraf@suse.de>
Cc: Mihai Caraman <mihai.caraman@freescale.com>,
kvm-ppc@vger.kernel.org, kvm@vger.kernel.org,
linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH 2/2] KVM: PPC: Book3E: Get vcpu's last instruction for emulation
Date: Wed, 10 Jul 2013 00:12:31 +0000 [thread overview]
Message-ID: <1373415151.8183.213@snotra> (raw)
In-Reply-To: <D6991806-B666-4043-8D74-1465B855DE3B@suse.de> (from agraf@suse.de on Tue Jul 9 16:45:10 2013)
On 07/09/2013 04:45:10 PM, Alexander Graf wrote:
>
> On 28.06.2013, at 11:20, Mihai Caraman wrote:
>
> > + /* Get page size */
> > + if (MAS0_GET_TLBSEL(mfspr(SPRN_MAS0)) = 0)
> > + psize_shift = PAGE_SHIFT;
> > + else
> > + psize_shift = MAS1_GET_TSIZE(mas1) + 10;
> > +
> > + mas7_mas3 = (((u64) mfspr(SPRN_MAS7)) << 32) |
> > + mfspr(SPRN_MAS3);
> > + addr = (mas7_mas3 & (~0ULL << psize_shift)) |
> > + (geaddr & ((1ULL << psize_shift) - 1ULL));
> > +
> > + /* Map a page and get guest's instruction */
> > + page = pfn_to_page(addr >> PAGE_SHIFT);
>
> While looking at this I just realized that you're missing a check
> here. What if our IP is in some PCI BAR? Or can't we execute from
> those?
We at least need to check pfn_valid() first. That'll just keep us from
accessing a bad pointer in the host kernel, though -- it won't make the
emulation actually work. If we need that, we'll probably need to
create a temporary TLB entry manually.
-Scott
WARNING: multiple messages have this Message-ID (diff)
From: Scott Wood <scottwood@freescale.com>
To: Alexander Graf <agraf@suse.de>
Cc: Mihai Caraman <mihai.caraman@freescale.com>,
linuxppc-dev@lists.ozlabs.org, kvm@vger.kernel.org,
kvm-ppc@vger.kernel.org
Subject: Re: [PATCH 2/2] KVM: PPC: Book3E: Get vcpu's last instruction for emulation
Date: Tue, 9 Jul 2013 19:12:31 -0500 [thread overview]
Message-ID: <1373415151.8183.213@snotra> (raw)
In-Reply-To: <D6991806-B666-4043-8D74-1465B855DE3B@suse.de> (from agraf@suse.de on Tue Jul 9 16:45:10 2013)
On 07/09/2013 04:45:10 PM, Alexander Graf wrote:
>=20
> On 28.06.2013, at 11:20, Mihai Caraman wrote:
>=20
> > + /* Get page size */
> > + if (MAS0_GET_TLBSEL(mfspr(SPRN_MAS0)) =3D=3D 0)
> > + psize_shift =3D PAGE_SHIFT;
> > + else
> > + psize_shift =3D MAS1_GET_TSIZE(mas1) + 10;
> > +
> > + mas7_mas3 =3D (((u64) mfspr(SPRN_MAS7)) << 32) |
> > + mfspr(SPRN_MAS3);
> > + addr =3D (mas7_mas3 & (~0ULL << psize_shift)) |
> > + (geaddr & ((1ULL << psize_shift) - 1ULL));
> > +
> > + /* Map a page and get guest's instruction */
> > + page =3D pfn_to_page(addr >> PAGE_SHIFT);
>=20
> While looking at this I just realized that you're missing a check =20
> here. What if our IP is in some PCI BAR? Or can't we execute from =20
> those?
We at least need to check pfn_valid() first. That'll just keep us from =20
accessing a bad pointer in the host kernel, though -- it won't make the =20
emulation actually work. If we need that, we'll probably need to =20
create a temporary TLB entry manually.
-Scott=
WARNING: multiple messages have this Message-ID (diff)
From: Scott Wood <scottwood@freescale.com>
To: Alexander Graf <agraf@suse.de>
Cc: Mihai Caraman <mihai.caraman@freescale.com>,
<kvm-ppc@vger.kernel.org>, <kvm@vger.kernel.org>,
<linuxppc-dev@lists.ozlabs.org>
Subject: Re: [PATCH 2/2] KVM: PPC: Book3E: Get vcpu's last instruction for emulation
Date: Tue, 9 Jul 2013 19:12:31 -0500 [thread overview]
Message-ID: <1373415151.8183.213@snotra> (raw)
In-Reply-To: <D6991806-B666-4043-8D74-1465B855DE3B@suse.de> (from agraf@suse.de on Tue Jul 9 16:45:10 2013)
On 07/09/2013 04:45:10 PM, Alexander Graf wrote:
>
> On 28.06.2013, at 11:20, Mihai Caraman wrote:
>
> > + /* Get page size */
> > + if (MAS0_GET_TLBSEL(mfspr(SPRN_MAS0)) == 0)
> > + psize_shift = PAGE_SHIFT;
> > + else
> > + psize_shift = MAS1_GET_TSIZE(mas1) + 10;
> > +
> > + mas7_mas3 = (((u64) mfspr(SPRN_MAS7)) << 32) |
> > + mfspr(SPRN_MAS3);
> > + addr = (mas7_mas3 & (~0ULL << psize_shift)) |
> > + (geaddr & ((1ULL << psize_shift) - 1ULL));
> > +
> > + /* Map a page and get guest's instruction */
> > + page = pfn_to_page(addr >> PAGE_SHIFT);
>
> While looking at this I just realized that you're missing a check
> here. What if our IP is in some PCI BAR? Or can't we execute from
> those?
We at least need to check pfn_valid() first. That'll just keep us from
accessing a bad pointer in the host kernel, though -- it won't make the
emulation actually work. If we need that, we'll probably need to
create a temporary TLB entry manually.
-Scott
next prev parent reply other threads:[~2013-07-10 0:12 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-06 16:11 [PATCH 1/2] KVM: PPC: e500mc: Revert "add load inst fixup" Mihai Caraman
2013-06-06 16:11 ` Mihai Caraman
2013-06-06 16:11 ` Mihai Caraman
2013-06-06 16:11 ` [PATCH 2/2] KVM: PPC: Book3E: Get vcpu's last instruction for emulation Mihai Caraman
2013-06-06 16:11 ` Mihai Caraman
2013-06-06 16:11 ` Mihai Caraman
2013-06-28 9:20 ` [PATCH 1/2] KVM: PPC: e500mc: Revert "add load inst fixup" Mihai Caraman
2013-06-28 9:20 ` Mihai Caraman
2013-06-28 9:20 ` Mihai Caraman
2013-06-28 9:20 ` [PATCH 2/2] KVM: PPC: Book3E: Get vcpu's last instruction for emulation Mihai Caraman
2013-06-28 9:20 ` Mihai Caraman
2013-06-28 9:20 ` Mihai Caraman
2013-07-08 13:39 ` Alexander Graf
2013-07-08 13:39 ` Alexander Graf
2013-07-08 13:39 ` Alexander Graf
2013-07-09 17:13 ` Scott Wood
2013-07-09 17:13 ` Scott Wood
2013-07-09 17:13 ` Scott Wood
2013-07-09 17:44 ` Alexander Graf
2013-07-09 17:44 ` Alexander Graf
2013-07-09 17:44 ` Alexander Graf
2013-07-09 18:46 ` Scott Wood
2013-07-09 18:46 ` Scott Wood
2013-07-09 18:46 ` Scott Wood
2013-07-09 21:44 ` Alexander Graf
2013-07-09 21:44 ` Alexander Graf
2013-07-09 21:44 ` Alexander Graf
2013-07-10 0:06 ` Scott Wood
2013-07-10 0:06 ` Scott Wood
2013-07-10 0:06 ` Scott Wood
2013-07-10 10:15 ` Alexander Graf
2013-07-10 10:15 ` Alexander Graf
2013-07-10 10:15 ` Alexander Graf
2013-07-10 18:42 ` Scott Wood
2013-07-10 18:42 ` Scott Wood
2013-07-10 18:42 ` Scott Wood
2013-07-10 22:50 ` Alexander Graf
2013-07-10 22:50 ` Alexander Graf
2013-07-10 22:50 ` Alexander Graf
2013-07-11 0:15 ` Scott Wood
2013-07-11 0:15 ` Scott Wood
2013-07-11 0:15 ` Scott Wood
2013-07-11 0:17 ` Alexander Graf
2013-07-11 0:17 ` Alexander Graf
2013-07-11 0:17 ` Alexander Graf
2013-07-09 21:45 ` Alexander Graf
2013-07-09 21:45 ` Alexander Graf
2013-07-09 21:45 ` Alexander Graf
2013-07-10 0:12 ` Scott Wood [this message]
2013-07-10 0:12 ` Scott Wood
2013-07-10 0:12 ` Scott Wood
2013-07-10 10:18 ` Alexander Graf
2013-07-10 10:18 ` Alexander Graf
2013-07-10 10:18 ` Alexander Graf
2013-07-10 18:37 ` Scott Wood
2013-07-10 18:37 ` Scott Wood
2013-07-10 18:37 ` Scott Wood
2013-07-10 22:48 ` Alexander Graf
2013-07-10 22:48 ` Alexander Graf
2013-07-10 22:48 ` Alexander Graf
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=1373415151.8183.213@snotra \
--to=scottwood@freescale.com \
--cc=agraf@suse.de \
--cc=kvm-ppc@vger.kernel.org \
--cc=kvm@vger.kernel.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=mihai.caraman@freescale.com \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.