From 14e49ad3b98f01c1ad6fe456469d40a96a43dc3c Mon Sep 17 00:00:00 2001 From: Gavin Shan Date: Wed, 11 May 2022 18:01:35 +0800 Subject: [PATCH 05/16] hw/arm/virt: Fix CPU's default NUMA node ID RH-Author: Gavin Shan RH-MergeRequest: 86: hw/arm/virt: Fix the default CPU topology RH-Commit: [5/6] 5336f62bc0c53c0417db1d71ef89544907bc28c0 (gwshan/qemu-rhel-9) RH-Bugzilla: 2041823 RH-Acked-by: Eric Auger RH-Acked-by: Cornelia Huck RH-Acked-by: Andrew Jones Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2041823 When CPU-to-NUMA association isn't explicitly provided by users, the default one is given by mc->get_default_cpu_node_id(). However, the CPU topology isn't fully considered in the default association and this causes CPU topology broken warnings on booting Linux guest. For example, the following warning messages are observed when the Linux guest is booted with the following command lines. /home/gavin/sandbox/qemu.main/build/qemu-system-aarch64 \ -accel kvm -machine virt,gic-version=host \ -cpu host \ -smp 6,sockets=2,cores=3,threads=1 \ -m 1024M,slots=16,maxmem=64G \ -object memory-backend-ram,id=mem0,size=128M \ -object memory-backend-ram,id=mem1,size=128M \ -object memory-backend-ram,id=mem2,size=128M \ -object memory-backend-ram,id=mem3,size=128M \ -object memory-backend-ram,id=mem4,size=128M \ -object memory-backend-ram,id=mem4,size=384M \ -numa node,nodeid=0,memdev=mem0 \ -numa node,nodeid=1,memdev=mem1 \ -numa node,nodeid=2,memdev=mem2 \ -numa node,nodeid=3,memdev=mem3 \ -numa node,nodeid=4,memdev=mem4 \ -numa node,nodeid=5,memdev=mem5 : alternatives: patching kernel code BUG: arch topology borken the CLS domain not a subset of the MC domain BUG: arch topology borken the DIE domain not a subset of the NODE domain With current implementation of mc->get_default_cpu_node_id(), CPU#0 to CPU#5 are associated with NODE#0 to NODE#5 separately. That's incorrect because CPU#0/1/2 should be associated with same NUMA node because they're seated in same socket. This fixes the issue by considering the socket ID when the default CPU-to-NUMA association is provided in virt_possible_cpu_arch_ids(). With this applied, no more CPU topology broken warnings are seen from the Linux guest. The 6 CPUs are associated with NODE#0/1, but there are no CPUs associated with NODE#2/3/4/5. Signed-off-by: Gavin Shan Reviewed-by: Igor Mammedov Reviewed-by: Yanan Wang Message-id: 20220503140304.855514-6-gshan@redhat.com Signed-off-by: Peter Maydell (cherry picked from commit 4c18bc192386dfbca530e7f550e0992df657818a) Signed-off-by: Gavin Shan --- hw/arm/virt.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/hw/arm/virt.c b/hw/arm/virt.c index a87c8d396a..95d012d6eb 100644 --- a/hw/arm/virt.c +++ b/hw/arm/virt.c @@ -2545,7 +2545,9 @@ virt_cpu_index_to_props(MachineState *ms, unsigned cpu_index) static int64_t virt_get_default_cpu_node_id(const MachineState *ms, int idx) { - return idx % ms->numa_state->num_nodes; + int64_t socket_id = ms->possible_cpus->cpus[idx].props.socket_id; + + return socket_id % ms->numa_state->num_nodes; } static const CPUArchIdList *virt_possible_cpu_arch_ids(MachineState *ms) -- 2.31.1