[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [PATCH v2 ppc-for-5.0 2/2] ppc/spapr: Support reboot of secure pseri
From: |
Greg Kurz |
Subject: |
Re: [PATCH v2 ppc-for-5.0 2/2] ppc/spapr: Support reboot of secure pseries guest |
Date: |
Thu, 12 Dec 2019 13:32:51 +0100 |
On Thu, 12 Dec 2019 14:23:43 +0530
Bharata B Rao <address@hidden> wrote:
> On Thu, Dec 12, 2019 at 08:34:57AM +0100, Cédric Le Goater wrote:
> > Hello Bharata,
> >
> >
> > On 12/12/2019 06:50, Bharata B Rao wrote:
> > > A pseries guest can be run as a secure guest on Ultravisor-enabled
> > > POWER platforms. When such a secure guest is reset, we need to
> > > release/reset a few resources both on ultravisor and hypervisor side.
> > > This is achieved by invoking this new ioctl KVM_PPC_SVM_OFF from the
> > > machine reset path.
> > >
> > > As part of this ioctl, the secure guest is essentially transitioned
> > > back to normal mode so that it can reboot like a regular guest and
> > > become secure again.
> > >
> > > This ioctl has no effect when invoked for a normal guest. If this ioctl
> > > fails for a secure guest, the guest is terminated.
> >
> > This looks OK.
> >
> > > Signed-off-by: Bharata B Rao <address@hidden>
> > > ---
> > > hw/ppc/spapr.c | 15 +++++++++++++++
> > > target/ppc/kvm.c | 7 +++++++
> > > target/ppc/kvm_ppc.h | 6 ++++++
> > > 3 files changed, 28 insertions(+)
> > >
> > > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> > > index f11422fc41..25e1a3446e 100644
> > > --- a/hw/ppc/spapr.c
> > > +++ b/hw/ppc/spapr.c
> > > @@ -1597,6 +1597,21 @@ static void spapr_machine_reset(MachineState
> > > *machine)
> > > void *fdt;
> > > int rc;
> > >
> > > + /*
> > > + * KVM_PPC_SVM_OFF ioctl can fail for secure guests, check and
> > > + * exit in that case. However check for -ENOTTY explicitly
> > > + * to ensure that we don't terminate normal guests that are
> > > + * running on kernels which don't support this ioctl.
> > > + *
> > > + * Also, this ioctl returns 0 for normal guests on kernels where
> > > + * this ioctl is supported.
> > > + */
> > > + rc = kvmppc_svm_off();
> > > + if (rc && rc != -ENOTTY) {
> >
> > I would put these low level tests under kvmppc_svm_off().
>
> Makes sense.
>
> >
> > > + error_report("Reset of secure guest failed, exiting...");
> > > + exit(EXIT_FAILURE);
> >
> > The exit() could probably go under kvmppc_svm_off() also.
>
> May be not. Then error_report would have also have to go in.
> Doesn't make sense to print this error from there.
>
Why doesn't it make sense ? It seems there's a consensus that the
failure (at least the -EINVAL case) isn't recoverable in any way.
Are there cases where we would call this and the caller could
cope with an error ?
> Regards,
> Bharata.
>
>