| Message ID | 20211012063603.166255-2-gshan@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | hw/arm/virt: Fix qemu booting failure on device-tree | expand |
On Tue, Oct 12, 2021 at 02:36:02PM +0800, Gavin Shan wrote: > The following option is used to specify the distance map. It's > possible the option isn't provided by user. In this case, the > distance map isn't populated and exposed to platform. On the > other hand, the empty NUMA node, where no memory resides, is > allowed on ARM64 virt platform. For these empty NUMA nodes, > their corresponding device-tree nodes aren't populated, but > their NUMA IDs should be included in the "/distance-map" > device-tree node, so that kernel can probe them properly if > device-tree is used. > > -numa,dist,src=<numa_id>,dst=<numa_id>,val=<distance> > > So when user doesn't specify distance map, we need to generate > the default distance map, where the local and remote distances > are 10 and 20 separately. However, this is going to change the > hardware description of the guest in this particular scenario. > It's fine as the guest should be tolerant to ignore the distance > map completely or parse it properly by following the device-tree > specification. > > This introduces an extra parameter to the exiting function > complete_init_numa_distance() to generate the default distance > map when no node pair distances are provided by user. > > Signed-off-by: Gavin Shan <gshan@redhat.com> > --- > hw/core/numa.c | 13 +++++++++++-- > 1 file changed, 11 insertions(+), 2 deletions(-) > Reviewed-by: Andrew Jones <drjones@redhat.com>
diff --git a/hw/core/numa.c b/hw/core/numa.c index 510d096a88..c508d857a0 100644 --- a/hw/core/numa.c +++ b/hw/core/numa.c @@ -594,7 +594,7 @@ static void validate_numa_distance(MachineState *ms) } } -static void complete_init_numa_distance(MachineState *ms) +static void complete_init_numa_distance(MachineState *ms, bool is_default) { int src, dst; NodeInfo *numa_info = ms->numa_state->nodes; @@ -609,6 +609,8 @@ static void complete_init_numa_distance(MachineState *ms) if (numa_info[src].distance[dst] == 0) { if (src == dst) { numa_info[src].distance[dst] = NUMA_DISTANCE_MIN; + } else if (is_default) { + numa_info[src].distance[dst] = NUMA_DISTANCE_DEFAULT; } else { numa_info[src].distance[dst] = numa_info[dst].distance[src]; } @@ -716,13 +718,20 @@ void numa_complete_configuration(MachineState *ms) * A->B != distance B->A, then that means the distance table is * asymmetric. In this case, the distances for both directions * of all node pairs are required. + * + * The default node pair distances, which are 10 and 20 for the + * local and remote nodes separately, are provided if user doesn't + * specify any node pair distances. */ if (ms->numa_state->have_numa_distance) { /* Validate enough NUMA distance information was provided. */ validate_numa_distance(ms); /* Validation succeeded, now fill in any missing distances. */ - complete_init_numa_distance(ms); + complete_init_numa_distance(ms, false); + } else { + complete_init_numa_distance(ms, true); + ms->numa_state->have_numa_distance = true; } } }
The following option is used to specify the distance map. It's possible the option isn't provided by user. In this case, the distance map isn't populated and exposed to platform. On the other hand, the empty NUMA node, where no memory resides, is allowed on ARM64 virt platform. For these empty NUMA nodes, their corresponding device-tree nodes aren't populated, but their NUMA IDs should be included in the "/distance-map" device-tree node, so that kernel can probe them properly if device-tree is used. -numa,dist,src=<numa_id>,dst=<numa_id>,val=<distance> So when user doesn't specify distance map, we need to generate the default distance map, where the local and remote distances are 10 and 20 separately. However, this is going to change the hardware description of the guest in this particular scenario. It's fine as the guest should be tolerant to ignore the distance map completely or parse it properly by following the device-tree specification. This introduces an extra parameter to the exiting function complete_init_numa_distance() to generate the default distance map when no node pair distances are provided by user. Signed-off-by: Gavin Shan <gshan@redhat.com> --- hw/core/numa.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-)