On Mon, Sep 11, 2017 at 07:12:14PM +0200, Cédric Le Goater wrote: > On a POWER9 sPAPR machine, the Client Architecture Support (CAS) > negotiation process determines whether the guest operates with an > interrupt controller using the XICS legacy model, as found on POWER8, > or in XIVE exploitation mode, the newer POWER9 interrupt model. This > patchset is a proposal to add XIVE support in POWER9 sPAPR machine. > > Follows a model for the XIVE interrupt controller and support for the > Hypervisor's calls which are used to configure the interrupt sources > and the event/notification queues of the guest. The last patch > integrates XIVE in the sPAPR machine. > > Code is here:
An overall comment: I note in several replies here that I think the way XICS objects are re-used for XIVE is really ugly, and I think it will make future maintenance pretty painful. I'm thinking maybe trying to support the CAS negotiation of interrupt controller from day 1 is warping the design. A better approach might be first to implement XIVE only when given a specific machine option - guest gets one or the other and can't negotiate. That should allow a more natural XIVE design to emerge, *then* we can look at what's necessary to make boot-time negotiation possible. > > https://github.com/legoater/qemu/commits/xive > > Caveats : > > - IRQ allocator : making progress > > The sPAPR machine make uses of the interrupt controller very early > in the initialization sequence to allocate IRQ numbers and populate > the device tree. CAS requires XIVE to be able to switch interrupt > model and consequently have the models share a common IRQ allocator. > > I have chosen to link the sPAPR XICS interrupt source into XIVE to > share the ICSIRQState array which acts as an IRQ allocator. This > can be improved. > > - Interrupt presenter : > > The register data is directly stored under the ICPState structure > which is shared with all other sPAPR interrupt controller models. > > - KVM support : not addressed yet > > The guest needs to be run with kernel_irqchip=off on a POWER9 system. > > - LSI : lightly tested. > > Thanks, > > C. > > Changes since RFC v1: > > - removed initial complexity due to a tentative try to support > PowerNV. This will come later. > - removed specific XIVE interrupt source and presenter models > - renamed files and typedefs > - removed print_info() handler > - introduced a CAS reset to rebuild the device tree > - linked the XIVE model with the sPAPR XICS interrupt source to share > the IRQ allocator > - improved hcall support (still some missing but they are not used > under Linux) > - improved device tree > - should have addressed comments in first RFC > - and much more ... Next version should have a better changelog. > > > Cédric Le Goater (21): > ppc/xive: introduce a skeleton for the sPAPR XIVE interrupt controller > migration: add VMSTATE_STRUCT_VARRAY_UINT32_ALLOC > ppc/xive: define the XIVE internal tables > ppc/xive: provide a link to the sPAPR ICS object under XIVE > ppc/xive: allocate IRQ numbers for the IPIs > ppc/xive: introduce handlers for interrupt sources > ppc/xive: add MMIO handlers for the XIVE interrupt sources > ppc/xive: describe the XIVE interrupt source flags > ppc/xive: extend the interrupt presenter model for XIVE > ppc/xive: add MMIO handlers for the XIVE TIMA > ppc/xive: push the EQ data in OS event queue > ppc/xive: notify the CPU when interrupt priority is more privileged > ppc/xive: handle interrupt acknowledgment by the O/S > ppc/xive: add support for the SET_OS_PENDING command > spapr: modify spapr_populate_pci_dt() to use a 'nr_irqs' argument > spapr: add a XIVE object to the sPAPR machine > ppc/xive: add hcalls support > ppc/xive: add device tree support > ppc/xive: introduce a helper to map the XIVE memory regions > ppc/xics: introduce a qirq_get() helper in the XICSFabric > spapr: activate XIVE exploitation mode > > default-configs/ppc64-softmmu.mak | 1 + > hw/intc/Makefile.objs | 1 + > hw/intc/spapr_xive.c | 821 +++++++++++++++++++++++++++++++++ > hw/intc/spapr_xive_hcall.c | 930 > ++++++++++++++++++++++++++++++++++++++ > hw/intc/xics.c | 11 +- > hw/intc/xive-internal.h | 189 ++++++++ > hw/ppc/spapr.c | 110 ++++- > hw/ppc/spapr_hcall.c | 6 + > hw/ppc/spapr_pci.c | 4 +- > include/hw/pci-host/spapr.h | 2 +- > include/hw/ppc/spapr.h | 17 +- > include/hw/ppc/spapr_xive.h | 75 +++ > include/hw/ppc/xics.h | 7 + > include/migration/vmstate.h | 10 + > 14 files changed, 2169 insertions(+), 15 deletions(-) > create mode 100644 hw/intc/spapr_xive.c > create mode 100644 hw/intc/spapr_xive_hcall.c > create mode 100644 hw/intc/xive-internal.h > create mode 100644 include/hw/ppc/spapr_xive.h > -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson
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