linux-kernel - Re: [PATCH] KVM: PPC: Book3S HV: Fix pending_pri value in kvmppc_xive_get

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 13 Dec 2017 07:18:10 +1100
From:   Benjamin Herrenschmidt <benh@...nel.crashing.org>
To:     Laurent Vivier <lvivier@...hat.com>, kvm-ppc@...r.kernel.org
Cc:     linuxppc-dev@...ts.ozlabs.org, linux-kernel@...r.kernel.org,
        Paul Mackerras <paulus@...abs.org>,
        Michael Ellerman <mpe@...erman.id.au>,
        Cédric Le Goater <clg@...d.org>
Subject: Re: [PATCH] KVM: PPC: Book3S HV: Fix pending_pri value in
 kvmppc_xive_get_icp()

On Tue, 2017-12-12 at 18:23 +0100, Laurent Vivier wrote:
> When we migrate a VM from a POWER8 host (XICS) to a POWER9 host
> (XICS-on-XIVE), we have an error:
> 
> qemu-kvm: Unable to restore KVM interrupt controller state \
>           (0xff000000) for CPU 0: Invalid argument
> 
> This is because kvmppc_xics_set_icp() checks the new state
> is internaly consistent, and especially:
> 
> ...
>    1129         if (xisr == 0) {
>    1130                 if (pending_pri != 0xff)
>    1131                         return -EINVAL;
> ...
> 
> On the other side, kvmppc_xive_get_icp() doesn't set
> neither the pending_pri value, nor the xisr value (set to 0)
> (and kvmppc_xive_set_icp() ignores the pending_pri value)
> 
> As xisr is 0, pending_pri must be set to 0xff.
> 
> Signed-off-by: Laurent Vivier <lvivier@...hat.com>

Acked-by: Benjamin Herrenschmidt <benh@...nel.crashing.org>