From: Ram Pai <linuxram@us.ibm.com>
To: Laurent Dufour <ldufour@linux.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
kvm-ppc@vger.kernel.org, Bharata B Rao <bharata@linux.ibm.com>
Subject: Re: [PATCH 1/2] KVM: PPC: Book3S HV: check caller of H_SVM_* Hcalls
Date: Fri, 20 Mar 2020 17:40:44 -0700 [thread overview]
Message-ID: <20200321004044.GA5243@oc0525413822.ibm.com> (raw)
In-Reply-To: <20200320102643.15516-2-ldufour@linux.ibm.com>
On Fri, Mar 20, 2020 at 11:26:42AM +0100, Laurent Dufour wrote:
> The Hcall named H_SVM_* are reserved to the Ultravisor. However, nothing
> prevent a malicious VM or SVM to call them. This could lead to weird result
> and should be filtered out.
>
> Checking the Secure bit of the calling MSR ensure that the call is coming
> from either the Ultravisor or a SVM. But any system call made from a SVM
> are going through the Ultravisor, and the Ultravisor should filter out
> these malicious call. This way, only the Ultravisor is able to make such a
> Hcall.
>
> Cc: Bharata B Rao <bharata@linux.ibm.com>
> Cc: Paul Mackerras <paulus@ozlabs.org>
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com>
Reviewed-by: Ram Pai <linuxram@us.ibnm.com>
> ---
> arch/powerpc/kvm/book3s_hv.c | 32 +++++++++++++++++++++-----------
> 1 file changed, 21 insertions(+), 11 deletions(-)
>
next prev parent reply other threads:[~2020-03-21 0:43 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-20 10:26 [PATCH 0/2] Fix SVM hang at startup Laurent Dufour
2020-03-20 10:26 ` [PATCH 1/2] KVM: PPC: Book3S HV: check caller of H_SVM_* Hcalls Laurent Dufour
2020-03-20 12:22 ` Greg Kurz
2020-03-20 14:43 ` Laurent Dufour
2020-03-23 23:43 ` Paul Mackerras
2020-03-24 12:00 ` Greg Kurz
2020-03-24 13:13 ` Laurent Dufour
2020-03-21 0:40 ` Ram Pai [this message]
2020-03-20 10:26 ` [PATCH 2/2] KVM: PPC: Book3S HV: H_SVM_INIT_START must call UV_RETURN Laurent Dufour
2020-03-20 11:24 ` Bharata B Rao
2020-03-20 14:36 ` Laurent Dufour
2020-03-23 4:21 ` Bharata B Rao
2020-03-21 0:47 ` Ram Pai
2020-03-23 14:09 ` Fabiano Rosas
2020-03-24 2:54 ` [PATCH 0/2] Fix SVM hang at startup Paul Mackerras
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