On Sun, Sep 10, 2017 at 09:30:18PM +0200, Cédric Le Goater wrote: > On 09/10/2017 05:19 AM, David Gibson wrote: > > On Fri, Sep 08, 2017 at 04:33:44PM +0200, Cédric Le Goater wrote: > >> When the platform and the guest agree on using the XIVE exploitation > >> mode for interrupts, the "interrupt-controller" node needs to reflect > >> the change and the device tree needs an update. > >> > >> Reseting the guest after the CAS negotiation makes this change > >> possible, as the device tree is built at reset time. We use the > >> 'ov5_cas' field to check which interrupt model was negotiated before > >> reset and populate the tree accordingly. > >> > >> Signed-off-by: Cédric Le Goater <c...@kaod.org> > > > > Looks reasonable, though I'm not going to apply it until we actually > > have something to go.. > > Yes. I agree. A simplified XIVE patchset for sPAPR should be ready > soon for comments. Please see below for one question. > > >> --- > >> hw/ppc/spapr.c | 6 +++++- > >> hw/ppc/spapr_hcall.c | 6 ++++++ > >> 2 files changed, 11 insertions(+), 1 deletion(-) > >> > >> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c > >> index 3e3ff1fbc988..be467ab61ad0 100644 > >> --- a/hw/ppc/spapr.c > >> +++ b/hw/ppc/spapr.c > >> @@ -1073,7 +1073,11 @@ static void *spapr_build_fdt(sPAPRMachineState > >> *spapr, > >> _FDT(fdt_setprop_cell(fdt, 0, "#size-cells", 2)); > >> > >> /* /interrupt controller */ > >> - spapr_dt_xics(xics_max_server_number(), fdt, PHANDLE_XICP); > >> + if (!spapr_ovec_test(spapr->ov5_cas, OV5_XIVE_EXPLOIT)) { > >> + spapr_dt_xics(xics_max_server_number(), fdt, PHANDLE_XICP); > >> + } else { > >> + /* populate device tree for XIVE */ ; > > > > .. here. > > How should we handle the PHANDLE_XICP for xive ? as it is done > for xics ? > > The DT node is now : "interrupt-controller@6030203180000"
Is there just one node that needs to be referenced? If so, then yes, the XICS approach of just using a well known phandle for it should be fine. > > >> + } > >> > >> ret = spapr_populate_memory(spapr, fdt); > >> if (ret < 0) { > >> diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c > >> index 92f1e21358b8..ba00b8d3fdd6 100644 > >> --- a/hw/ppc/spapr_hcall.c > >> +++ b/hw/ppc/spapr_hcall.c > >> @@ -1613,6 +1613,12 @@ static target_ulong > >> h_client_architecture_support(PowerPCCPU *cpu, > >> (spapr_h_cas_compose_response(spapr, args[1], args[2], > >> ov5_updates) != 0); > >> } > >> + > >> + /* We need to rebuild the device tree for XIVE, generate a reset */ > >> + if (!spapr->cas_reboot) { > >> + spapr->cas_reboot = spapr_ovec_test(ov5_updates, > >> OV5_XIVE_EXPLOIT); > >> + } > > > > At some point we may well want to make XIVE exploitation the default > > for POWER9 guests, but that's a detail easily adjusted later. > > ah yes. we can do that. > > Thanks, > > C. > > >> spapr_ovec_cleanup(ov5_updates); > >> > >> if (spapr->cas_reboot) { > > > -- 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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