linux-kernel - Re: [PATCH v2] KVM: PPC: Book3S HV: relax check on H_SVM_INIT

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Message-ID: <6bf0ada4-7386-d301-beb0-7e25ac94b0fa@linux.ibm.com>
Date:   Wed, 27 May 2020 11:23:00 +0200
From:   Laurent Dufour <ldufour@...ux.ibm.com>
To:     Paul Mackerras <paulus@...abs.org>
Cc:     kvm-ppc@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org,
        linux-kernel@...r.kernel.org, groug@...d.org, mpe@...erman.id.au,
        sukadev@...ux.ibm.com, linuxram@...ibm.com
Subject: Re: [PATCH v2] KVM: PPC: Book3S HV: relax check on H_SVM_INIT_ABORT

Le 27/05/2020 à 06:16, Paul Mackerras a écrit :
> On Wed, May 20, 2020 at 07:43:08PM +0200, Laurent Dufour wrote:
>> The commit 8c47b6ff29e3 ("KVM: PPC: Book3S HV: Check caller of H_SVM_*
>> Hcalls") added checks of secure bit of SRR1 to filter out the Hcall
>> reserved to the Ultravisor.
>>
>> However, the Hcall H_SVM_INIT_ABORT is made by the Ultravisor passing the
>> context of the VM calling UV_ESM. This allows the Hypervisor to return to
>> the guest without going through the Ultravisor. Thus the Secure bit of SRR1
>> is not set in that particular case.
>>
>> In the case a regular VM is calling H_SVM_INIT_ABORT, this hcall will be
>> filtered out in kvmppc_h_svm_init_abort() because kvm->arch.secure_guest is
>> not set in that case.
>>
>> Fixes: 8c47b6ff29e3 ("KVM: PPC: Book3S HV: Check caller of H_SVM_* Hcalls")
>> Signed-off-by: Laurent Dufour <ldufour@...ux.ibm.com>
> 
> Thanks, applied to my kvm-ppc-next branch.  I expanded the comment in
> the code a little.

Thanks, the comment is more explicit now.

Laurent.