On Thu, 3 Oct 2019 14:29:46 +0200
Cédric Le Goater <c...@kaod.org> wrote:
> On 03/10/2019 14:01, Greg Kurz wrote:
> > The XICS-on-XIVE KVM devices now has an attribute to configure the number
> > of interrupt servers. This allows to greatly optimize the usage of the VP
> > space in the XIVE HW, and thus to start a lot more VMs.
> >
> > Only set this attribute if available in order to support older POWER9 KVM
> > and pre-POWER9 XICS KVM devices.
> >
> > The XICS-on-XIVE KVM device now reports the exhaustion of VPs upon the
> > connection of the first VCPU. Check that in order to have a chance to
> > provide an hint to the user.
>
> That part would have been better in its own patch. Simpler to review.
>
Yeah, possibly... on the other hand, it's only two fairly simple
hunks. :)
> > Signed-off-by: Greg Kurz <gr...@kaod.org>
>
> Anyhow, if you split or not :
>
> Reviewed-by: Cédric Le Goater <c...@kaod.org>
>
> > ---
> > hw/intc/xics_kvm.c | 24 ++++++++++++++++++++++--
> > 1 file changed, 22 insertions(+), 2 deletions(-)
> >
> > diff --git a/hw/intc/xics_kvm.c b/hw/intc/xics_kvm.c
> > index ba90d6dc966c..12d9524cc432 100644
> > --- a/hw/intc/xics_kvm.c
> > +++ b/hw/intc/xics_kvm.c
> > @@ -165,8 +165,15 @@ void icp_kvm_realize(DeviceState *dev, Error **errp)
> >
> > ret = kvm_vcpu_enable_cap(cs, KVM_CAP_IRQ_XICS, 0, kernel_xics_fd,
> > vcpu_id);
> > if (ret < 0) {
> > - error_setg(errp, "Unable to connect CPU%ld to kernel XICS: %s",
> > vcpu_id,
> > - strerror(errno));
> > + Error *local_err = NULL;
> > +
> > + error_setg(&local_err, "Unable to connect CPU%ld to kernel XICS:
> > %s",
> > + vcpu_id, strerror(errno));
> > + if (errno == ENOSPC) {
> > + error_append_hint(&local_err, "Try -smp maxcpus=N with N <
> > %u\n",
> > + MACHINE(qdev_get_machine())->smp.max_cpus);
> > + }
> > + error_propagate(errp, local_err);
> > return;
> > }
> > enabled_icp = g_malloc(sizeof(*enabled_icp));
> > @@ -344,6 +351,7 @@ void ics_kvm_set_irq(ICSState *ics, int srcno, int val)
> >
> > int xics_kvm_connect(SpaprMachineState *spapr, Error **errp)
> > {
> > + ICSState *ics = spapr->ics;
> > int rc;
> > CPUState *cs;
> > Error *local_err = NULL;
> > @@ -397,6 +405,18 @@ int xics_kvm_connect(SpaprMachineState *spapr, Error
> > **errp)
> > goto fail;
> > }
> >
> > + /* Tell KVM about the # of VCPUs we may have (POWER9 and newer only) */
> > + if (kvm_device_check_attr(rc, KVM_DEV_XICS_GRP_CTRL,
> > + KVM_DEV_XICS_NR_SERVERS)) {
> > + uint32_t nr_servers = xics_nr_servers(ics->xics);
> > +
> > + if (kvm_device_access(rc, KVM_DEV_XICS_GRP_CTRL,
> > + KVM_DEV_XICS_NR_SERVERS, &nr_servers, true,
> > + &local_err)) {
> > + goto fail;
> > + }
> > + }
> > +
> > kernel_xics_fd = rc;
> > kvm_kernel_irqchip = true;
> > kvm_msi_via_irqfd_allowed = true;
> >
>
