Running a guest with 128 NUMA nodes crashes QEMU:
../../util/error.c:59: error_setv: Assertion `*errp == NULL' failed.
The crash happens when setting the FWNMI migration blocker:
2861 if (spapr_get_cap(spapr, SPAPR_CAP_FWNMI) == SPAPR_CAP_ON) {
2862 /* Create the error string for live migration blocker */
2863 error_setg(&spapr->fwnmi_migration_blocker,
2864 "A machine check is being handled during migration. The
handler"
2865 "may run and log hardware error on the destination");
2866 }
Inspection reveals that papr->fwnmi_migration_blocker isn't NULL:
(gdb) p spapr->fwnmi_migration_blocker
$1 = (Error *) 0x8000000004000000
Since this is the only place where papr->fwnmi_migration_blocker is
set, this means someone wrote there in our back. Further analysis
points to spapr_numa_associativity_init(), especially the part
that initializes the associative arrays for NVLink GPUs:
max_nodes_with_gpus = nb_numa_nodes + NVGPU_MAX_NUM;
ie. max_nodes_with_gpus = 128 + 6, but the array isn't sized to
accommodate the 6 extra nodes:
#define MAX_NODES 128
struct SpaprMachineState {
.
.
.
uint32_t numa_assoc_array[MAX_NODES][NUMA_ASSOC_SIZE];
Error *fwnmi_migration_blocker;
};
and the following loops happily overwrite spapr->fwnmi_migration_blocker,
and probably more:
for (i = nb_numa_nodes; i < max_nodes_with_gpus; i++) {
spapr->numa_assoc_array[i][0] = cpu_to_be32(MAX_DISTANCE_REF_POINTS);
for (j = 1; j < MAX_DISTANCE_REF_POINTS; j++) {
uint32_t gpu_assoc = smc->pre_5_1_assoc_refpoints ?
SPAPR_GPU_NUMA_ID : cpu_to_be32(i);
spapr->numa_assoc_array[i][j] = gpu_assoc;
}
spapr->numa_assoc_array[i][MAX_DISTANCE_REF_POINTS] = cpu_to_be32(i);
}
Fix the size of the array. This requires "hw/ppc/spapr.h" to see
NVGPU_MAX_NUM. Including "hw/pci-host/spapr.h" introduces a
circular dependency that breaks the build, so this moves the
definition of NVGPU_MAX_NUM to "hw/ppc/spapr.h" instead.
Reported-by: Min Deng <mdeng@redhat.com>
BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1908693
Fixes: dd7e1d7ae431 ("spapr_numa: move NVLink2 associativity handling to
spapr_numa.c")
Cc: danielhb413@gmail.com
Signed-off-by: Greg Kurz <groug@kaod.org>
---
include/hw/pci-host/spapr.h | 2 --
include/hw/ppc/spapr.h | 5 ++++-
2 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/include/hw/pci-host/spapr.h b/include/hw/pci-host/spapr.h
index 4f58f0223b56..bd014823a933 100644
--- a/include/hw/pci-host/spapr.h
+++ b/include/hw/pci-host/spapr.h
@@ -115,8 +115,6 @@ struct SpaprPhbState {
#define SPAPR_PCI_NV2RAM64_WIN_BASE SPAPR_PCI_LIMIT
#define SPAPR_PCI_NV2RAM64_WIN_SIZE (2 * TiB) /* For up to 6 GPUs 256GB each
*/
-/* Max number of these GPUsper a physical box */
-#define NVGPU_MAX_NUM 6
/* Max number of NVLinks per GPU in any physical box */
#define NVGPU_MAX_LINKS 3
diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
index 06a5b4259f20..1cc19575f548 100644
--- a/include/hw/ppc/spapr.h
+++ b/include/hw/ppc/spapr.h
@@ -112,6 +112,9 @@ typedef enum {
#define NUMA_ASSOC_SIZE (MAX_DISTANCE_REF_POINTS + 1)
#define VCPU_ASSOC_SIZE (NUMA_ASSOC_SIZE + 1)
+/* Max number of these GPUsper a physical box */
+#define NVGPU_MAX_NUM 6
+
typedef struct SpaprCapabilities SpaprCapabilities;
struct SpaprCapabilities {
uint8_t caps[SPAPR_CAP_NUM];
@@ -240,7 +243,7 @@ struct SpaprMachineState {
unsigned gpu_numa_id;
SpaprTpmProxy *tpm_proxy;
- uint32_t numa_assoc_array[MAX_NODES][NUMA_ASSOC_SIZE];
+ uint32_t numa_assoc_array[MAX_NODES + NVGPU_MAX_NUM][NUMA_ASSOC_SIZE];
Error *fwnmi_migration_blocker;
};