On Fri, Feb 16, 2018 at 07:58:06PM +0100, Greg Kurz wrote: > Commit 5d0fb1508e2d "spapr: consolidate the VCPU id numbering logic > in a single place" introduced a helper to detect thread0 of a virtual > core based on its VCPU id. This is used to create CPU core nodes in > the DT, but it is broken in TCG. > > $ qemu-system-ppc64 -nographic -accel tcg -machine dumpdtb=dtb.bin \ > -smp cores=16,maxcpus=16,threads=1 > $ dtc -f -O dts dtb.bin | grep POWER8 > PowerPC,POWER8@0 { > PowerPC,POWER8@8 { > > instead of the expected 16 cores that we get with KVM: > > $ dtc -f -O dts dtb.bin | grep POWER8 > PowerPC,POWER8@0 { > PowerPC,POWER8@8 { > PowerPC,POWER8@10 { > PowerPC,POWER8@18 { > PowerPC,POWER8@20 { > PowerPC,POWER8@28 { > PowerPC,POWER8@30 { > PowerPC,POWER8@38 { > PowerPC,POWER8@40 { > PowerPC,POWER8@48 { > PowerPC,POWER8@50 { > PowerPC,POWER8@58 { > PowerPC,POWER8@60 { > PowerPC,POWER8@68 { > PowerPC,POWER8@70 { > PowerPC,POWER8@78 { > > This happens because spapr_get_vcpu_id() maps VCPU ids to > cs->cpu_index in TCG mode. This confuses the code in > spapr_is_thread0_in_vcore(), since it assumes thread0 VCPU > ids to have a spapr->vsmt spacing. > > spapr_get_vcpu_id(cpu) % spapr->vsmt == 0 > > Actually, there's no real reason to expose cs->cpu_index instead > of the VCPU id, since we also generate it with TCG. Also we already > set it explicitly in spapr_set_vcpu_id(), so there's no real reason > either to call kvm_arch_vcpu_id() with KVM. > > This patch unifies spapr_get_vcpu_id() to always return the computed > VCPU id both in TCG and KVM. This is one step forward towards KVM<->TCG > migration. > > Fixes: 5d0fb1508e2d > Reported-by: Cédric Le Goater <c...@kaod.org> > Signed-off-by: Greg Kurz <gr...@kaod.org>
Applied, thanks. > --- > hw/ppc/spapr.c | 8 +------- > 1 file changed, 1 insertion(+), 7 deletions(-) > > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c > index 83c9d66dd56f..d6fd0e666e74 100644 > --- a/hw/ppc/spapr.c > +++ b/hw/ppc/spapr.c > @@ -3810,13 +3810,7 @@ static void > spapr_pic_print_info(InterruptStatsProvider *obj, > > int spapr_get_vcpu_id(PowerPCCPU *cpu) > { > - CPUState *cs = CPU(cpu); > - > - if (kvm_enabled()) { > - return kvm_arch_vcpu_id(cs); > - } else { > - return cs->cpu_index; > - } > + return cpu->vcpu_id; > } > > void spapr_set_vcpu_id(PowerPCCPU *cpu, int cpu_index, Error **errp) > -- 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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