From: Eduardo Habkost <ehabk...@redhat.com> Currently, Using the fisrt node without memory on the machine makes QEMU unhappy. With this example command line: ... \ -m 1024M,slots=4,maxmem=32G \ -numa node,nodeid=0 \ -numa node,mem=1024M,nodeid=1 \ -numa node,nodeid=2 \ -numa node,nodeid=3 \ Guest reports "No NUMA configuration found" and the NUMA topology is wrong.
This is because when QEMU builds ACPI SRAT, it regards node 0 as the default node to deal with the memory hole(640K-1M). this means the node0 must have some memory(>1M), but, actually it can have no memory. Fix this problem by cut out the 640K hole in the same way the PCI 4G hole does. Also do some cleanup. Signed-off-by: Eduardo Habkost <ehabk...@redhat.com> Signed-off-by: Dou Liyang <douly.f...@cn.fujitsu.com> --- hw/i386/acpi-build.c | 30 +++++++++++++++++++++++------- 1 file changed, 23 insertions(+), 7 deletions(-) diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c index 98dd424..48525a1 100644 --- a/hw/i386/acpi-build.c +++ b/hw/i386/acpi-build.c @@ -2318,6 +2318,9 @@ build_tpm2(GArray *table_data, BIOSLinker *linker) (void *)tpm2_ptr, "TPM2", sizeof(*tpm2_ptr), 4, NULL, NULL); } +#define HOLE_640K_START (640 * 1024) +#define HOLE_640K_END (1024 * 1024) + static void build_srat(GArray *table_data, BIOSLinker *linker, MachineState *machine) { @@ -2373,17 +2376,30 @@ build_srat(GArray *table_data, BIOSLinker *linker, MachineState *machine) next_base = 0; numa_start = table_data->len; - numamem = acpi_data_push(table_data, sizeof *numamem); - build_srat_memory(numamem, 0, 640 * 1024, 0, MEM_AFFINITY_ENABLED); - next_base = 1024 * 1024; for (i = 1; i < pcms->numa_nodes + 1; ++i) { mem_base = next_base; mem_len = pcms->node_mem[i - 1]; - if (i == 1) { - mem_len -= 1024 * 1024; - } next_base = mem_base + mem_len; + /* Cut out the 640K hole */ + if (mem_base <= HOLE_640K_START && + next_base > HOLE_640K_START) { + mem_len -= next_base - HOLE_640K_START; + if (mem_len > 0) { + numamem = acpi_data_push(table_data, sizeof *numamem); + build_srat_memory(numamem, mem_base, mem_len, i - 1, + MEM_AFFINITY_ENABLED); + } + + /* Check for the rare case: 640K < RAM < 1M */ + if (next_base <= HOLE_640K_END) { + next_base = HOLE_640K_END; + continue; + } + mem_base = HOLE_640K_END; + mem_len = next_base - HOLE_640K_END; + } + /* Cut out the ACPI_PCI hole */ if (mem_base <= pcms->below_4g_mem_size && next_base > pcms->below_4g_mem_size) { @@ -2395,7 +2411,7 @@ build_srat(GArray *table_data, BIOSLinker *linker, MachineState *machine) } mem_base = 1ULL << 32; mem_len = next_base - pcms->below_4g_mem_size; - next_base += (1ULL << 32) - pcms->below_4g_mem_size; + next_base = mem_base + mem_len; } numamem = acpi_data_push(table_data, sizeof *numamem); build_srat_memory(numamem, mem_base, mem_len, i - 1, -- 2.5.5