On Tue, Dec 10, 2019 at 04:05:36PM +1100, David Gibson wrote: > On Tue, Dec 10, 2019 at 03:03:01PM +1100, Alexey Kardashevskiy wrote: > > > > > > On 10/12/2019 14:50, Bharata B Rao wrote: > > > On Tue, Dec 10, 2019 at 02:28:51PM +1100, David Gibson wrote: > > >> On Mon, Dec 09, 2019 at 12:30:12PM +0530, 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. > > >>> > > >>> Signed-off-by: Bharata B Rao <bhar...@linux.ibm.com> > > >>> --- > > >>> hw/ppc/spapr.c | 1 + > > >>> target/ppc/kvm.c | 7 +++++++ > > >>> target/ppc/kvm_ppc.h | 6 ++++++ > > >>> 3 files changed, 14 insertions(+) > > >>> > > >>> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c > > >>> index f11422fc41..4c7ad3400d 100644 > > >>> --- a/hw/ppc/spapr.c > > >>> +++ b/hw/ppc/spapr.c > > >>> @@ -1597,6 +1597,7 @@ static void spapr_machine_reset(MachineState > > >>> *machine) > > >>> void *fdt; > > >>> int rc; > > >>> > > >>> + kvmppc_svm_off(); > > >> > > >> If you're going to have this return an error value, you should really > > >> check it here. > > > > > > I could, by spapr_machine_reset() and the callers don't propagate the > > > errors up. So may be I could print a warning instead when ioctl fails? > > > > An error here means you cannot restart the machine and should probably > > suspend, or try until it is not EBUSY (==all threads have stopped?). > > Right, if this fails, something has gone badly wrong. You should > absolutely print a message, and in fact it might be appropriate to > quit outright. IIUC the way PEF resets work, a failure here means you > won't be able to boot after the reset, since the guest memory will > still be inaccessible to the host.
Correct. I will send next version with a message and abort() added in the ioctl failure path. Regards, Bharata.
