On Thu, Apr 06, 2017 at 10:18:53AM +0800, He Chen wrote:
> This patch is going to add SLIT table support in QEMU, and provides
> additional option `dist` for command `-numa` to allow user set vNUMA
> distance by QEMU command.
>
> With this patch, when a user wants to create a guest that contains
> several vNUMA nodes and also wants to set distance among those nodes,
> the QEMU command would like:
>
> ```
> -numa node,nodeid=0,cpus=0 \
> -numa node,nodeid=1,cpus=1 \
> -numa node,nodeid=2,cpus=2 \
> -numa node,nodeid=3,cpus=3 \
> -numa dist,src=0,dst=1,val=21 \
> -numa dist,src=0,dst=2,val=31 \
> -numa dist,src=0,dst=3,val=41 \
> -numa dist,src=1,dst=2,val=21 \
> -numa dist,src=1,dst=3,val=31 \
> -numa dist,src=2,dst=3,val=21 \
> ```
>
> Signed-off-by: He Chen <he.c...@linux.intel.com>
> ---
> hw/acpi/aml-build.c | 25 +++++++++
> hw/i386/acpi-build.c | 2 +
> include/hw/acpi/aml-build.h | 1 +
> include/sysemu/numa.h | 1 +
> include/sysemu/sysemu.h | 4 ++
> numa.c | 121
> ++++++++++++++++++++++++++++++++++++++++++++
> qapi-schema.json | 30 ++++++++++-
> qemu-options.hx | 17 ++++++-
> 8 files changed, 198 insertions(+), 3 deletions(-)
>
> diff --git a/hw/acpi/aml-build.c b/hw/acpi/aml-build.c
> index c6f2032..2c6ab07 100644
> --- a/hw/acpi/aml-build.c
> +++ b/hw/acpi/aml-build.c
> @@ -24,6 +24,7 @@
> #include "hw/acpi/aml-build.h"
> #include "qemu/bswap.h"
> #include "qemu/bitops.h"
> +#include "sysemu/numa.h"
>
> static GArray *build_alloc_array(void)
> {
> @@ -1609,3 +1610,27 @@ void build_srat_memory(AcpiSratMemoryAffinity
> *numamem, uint64_t base,
> numamem->base_addr = cpu_to_le64(base);
> numamem->range_length = cpu_to_le64(len);
> }
> +
> +/*
> + * ACPI spec 5.2.17 System Locality Distance Information Table
> + * (Revision 2.0 or later)
> + */
> +void build_slit(GArray *table_data, BIOSLinker *linker)
> +{
> + int slit_start, i, j;
> + slit_start = table_data->len;
> +
> + acpi_data_push(table_data, sizeof(AcpiTableHeader));
> +
> + build_append_int_noprefix(table_data, nb_numa_nodes, 8);
> + for (i = 0; i < nb_numa_nodes; i++) {
> + for (j = 0; j < nb_numa_nodes; j++) {
> + build_append_int_noprefix(table_data, numa_info[i].distance[j],
> 1);
> + }
> + }
> +
> + build_header(linker, table_data,
> + (void *)(table_data->data + slit_start),
> + "SLIT",
> + table_data->len - slit_start, 1, NULL, NULL);
> +}
> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> index 2073108..12730ea 100644
> --- a/hw/i386/acpi-build.c
> +++ b/hw/i386/acpi-build.c
> @@ -2678,6 +2678,8 @@ void acpi_build(AcpiBuildTables *tables, MachineState
> *machine)
> if (pcms->numa_nodes) {
> acpi_add_table(table_offsets, tables_blob);
> build_srat(tables_blob, tables->linker, machine);
> + acpi_add_table(table_offsets, tables_blob);
> + build_slit(tables_blob, tables->linker);
We could make the generation of the SLIT dependent on have_numa_distance.
> }
> if (acpi_get_mcfg(&mcfg)) {
> acpi_add_table(table_offsets, tables_blob);
> diff --git a/include/hw/acpi/aml-build.h b/include/hw/acpi/aml-build.h
> index 00c21f1..329a0d0 100644
> --- a/include/hw/acpi/aml-build.h
> +++ b/include/hw/acpi/aml-build.h
> @@ -389,4 +389,5 @@ GCC_FMT_ATTR(2, 3);
> void build_srat_memory(AcpiSratMemoryAffinity *numamem, uint64_t base,
> uint64_t len, int node, MemoryAffinityFlags flags);
>
> +void build_slit(GArray *table_data, BIOSLinker *linker);
> #endif
> diff --git a/include/sysemu/numa.h b/include/sysemu/numa.h
> index 8f09dcf..2f7a941 100644
> --- a/include/sysemu/numa.h
> +++ b/include/sysemu/numa.h
> @@ -21,6 +21,7 @@ typedef struct node_info {
> struct HostMemoryBackend *node_memdev;
> bool present;
> QLIST_HEAD(, numa_addr_range) addr; /* List to store address ranges */
> + uint8_t distance[MAX_NODES];
> } NodeInfo;
>
> extern NodeInfo numa_info[MAX_NODES];
> diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
> index 576c7ce..6999545 100644
> --- a/include/sysemu/sysemu.h
> +++ b/include/sysemu/sysemu.h
> @@ -169,6 +169,10 @@ extern int mem_prealloc;
>
> #define MAX_NODES 128
> #define NUMA_NODE_UNASSIGNED MAX_NODES
> +#define NUMA_DISTANCE_MIN 10
> +#define NUMA_DISTANCE_DEFAULT 20
> +#define NUMA_DISTANCE_MAX 254
> +#define NUMA_DISTANCE_UNREACHABLE 255
>
> #define MAX_OPTION_ROMS 16
> typedef struct QEMUOptionRom {
> diff --git a/numa.c b/numa.c
> index 6fc2393..838e45a 100644
> --- a/numa.c
> +++ b/numa.c
> @@ -52,6 +52,7 @@ static int max_numa_nodeid; /* Highest specified NUMA node
> ID, plus one.
> */
> int nb_numa_nodes;
> NodeInfo numa_info[MAX_NODES];
> +static bool have_numa_distance;
>
> void numa_set_mem_node_id(ram_addr_t addr, uint64_t size, uint32_t node)
> {
> @@ -212,6 +213,41 @@ static void numa_node_parse(NumaNodeOptions *node,
> QemuOpts *opts, Error **errp)
> max_numa_nodeid = MAX(max_numa_nodeid, nodenr + 1);
> }
>
> +static void numa_distance_parse(NumaDistOptions *dist, QemuOpts *opts, Error
> **errp)
> +{
> + uint16_t src = dist->src;
> + uint16_t dst = dist->dst;
> + uint8_t val = dist->val;
> +
> + if (!numa_info[src].present || !numa_info[dst].present) {
> + error_setg(errp, "Source/Destination NUMA node is missing. "
> + "Please use '-numa node' option to declare it first.");
> + return;
> + }
> +
> + if (src >= MAX_NODES || dst >= MAX_NODES) {
> + error_setg(errp, "Max number of NUMA nodes reached: %"
> + PRIu16 "", src > dst ? src : dst);
This should probably output what the max is (MAX_NODES) rather than
the largest of the two inputs. What if both were too large? In that
case the smallest of the two would make more sense.
> + return;
> + }
> +
> + if (val < NUMA_DISTANCE_MIN) {
> + error_setg(errp, "NUMA distance (%" PRIu8 ") is invalid, "
> + "it should be larger than %d.",
> + val, NUMA_DISTANCE_MIN);
> + return;
> + }
> +
> + if (src == dst && val != NUMA_DISTANCE_MIN) {
> + error_setg(errp, "Local distance of node %d should be %d.",
> + src, NUMA_DISTANCE_MIN);
> + return;
> + }
> +
> + numa_info[src].distance[dst] = val;
> + have_numa_distance = true;
> +}
> +
> static int parse_numa(void *opaque, QemuOpts *opts, Error **errp)
> {
> NumaOptions *object = NULL;
> @@ -235,6 +271,12 @@ static int parse_numa(void *opaque, QemuOpts *opts,
> Error **errp)
> }
> nb_numa_nodes++;
> break;
> + case NUMA_OPTIONS_TYPE_DIST:
> + numa_distance_parse(&object->u.dist, opts, &err);
> + if (err) {
> + goto end;
> + }
> + break;
> default:
> abort();
> }
> @@ -294,6 +336,84 @@ static void validate_numa_cpus(void)
> g_free(seen_cpus);
> }
>
> +static void validate_numa_distance(void)
> +{
> + int src, dst, s, d;
> + bool is_asymmetrical = false;
> + bool opposite_miss = false;
opposite_missing
> +
> + if (!have_numa_distance) {
> + for (src = 0; src < nb_numa_nodes; src++) {
> + for (dst = 0; dst < nb_numa_nodes; dst++) {
> + if (numa_info[src].present && numa_info[dst].present) {
> + if (src == dst) {
> + numa_info[src].distance[dst] = NUMA_DISTANCE_MIN;
> + } else {
> + numa_info[src].distance[dst] = NUMA_DISTANCE_DEFAULT;
> + }
> + }
> + }
> + }
> +
> + return;
> + }
We could drop the above and just not provide an SLIT at all when
have_numa_distance is false, because, per the ACPI spec, the SLIT is
an optional table.
> +
> + for (src = 0; src < nb_numa_nodes; src++) {
> + for (dst = src; dst < nb_numa_nodes; dst++) {
> + s = src;
> + d = dst;
> +
> + if (numa_info[s].present && numa_info[d].present) {
> + if (numa_info[s].distance[d] == 0 &&
> + numa_info[d].distance[s] == 0) {
> + if (s == d) {
> + numa_info[s].distance[d] = NUMA_DISTANCE_MIN;
> + continue;
> + } else {
> + error_report("The distance between node %d and %d is
> missing, "
> + "please provide all unique node pair's
> distance.",
s/pair's distance/pair distances/
> + s, d);
> + exit(EXIT_FAILURE);
> + }
> + }
> +
> + if (s == d && numa_info[s].distance[d] != NUMA_DISTANCE_MIN)
> {
> + error_report("The local distance of node %d should be
> %d.",
> + s, NUMA_DISTANCE_MIN);
> + exit(EXIT_FAILURE);
> + }
Is it possible for the above condition to ever be true? Isn't already
disallowed by numa_distance_parse(), right?
> +
> + if (numa_info[s].distance[d] == 0) {
> + s = dst;
> + d = src;
> + }
> +
> + if (numa_info[d].distance[s] == 0) {
> + opposite_miss = true;
> + }
> +
> + if ((numa_info[d].distance[s] != 0) &&
> + (numa_info[s].distance[d] != numa_info[d].distance[s])) {
> + is_asymmetrical = true;
> + }
> +
> + if (is_asymmetrical) {
> + if (opposite_miss) {
> + error_report("At least one asymmetrical pair of
> distance "
distances
> + "is given, please provide all node
> pairs' "
> + "distance value for both directions.");
...is given, please provide distances for both directions of all node pairs.
> + exit(EXIT_FAILURE);
> + }
> + } else {
> + numa_info[d].distance[s] = numa_info[s].distance[d];
> + }
> + }
> + }
> + }
> +
> + return;
pointless 'return'
> +}
> +
> void parse_numa_opts(MachineClass *mc)
> {
> int i;
> @@ -390,6 +510,7 @@ void parse_numa_opts(MachineClass *mc)
> }
>
> validate_numa_cpus();
> + validate_numa_distance();
> } else {
> numa_set_mem_node_id(0, ram_size, 0);
> }
> diff --git a/qapi-schema.json b/qapi-schema.json
> index 250e4dc..7552777 100644
> --- a/qapi-schema.json
> +++ b/qapi-schema.json
> @@ -5673,10 +5673,14 @@
> ##
> # @NumaOptionsType:
> #
> +# @node: NUMA nodes configuration
> +#
> +# @dist: NUMA distance configuration (since 2.10)
> +#
> # Since: 2.1
> ##
> { 'enum': 'NumaOptionsType',
> - 'data': [ 'node' ] }
> + 'data': [ 'node', 'dist' ] }
>
> ##
> # @NumaOptions:
> @@ -5689,7 +5693,8 @@
> 'base': { 'type': 'NumaOptionsType' },
> 'discriminator': 'type',
> 'data': {
> - 'node': 'NumaNodeOptions' }}
> + 'node': 'NumaNodeOptions',
> + 'dist': 'NumaDistOptions' }}
>
> ##
> # @NumaNodeOptions:
> @@ -5718,6 +5723,27 @@
> '*memdev': 'str' }}
>
> ##
> +# @NumaDistOptions:
> +#
> +# Set the distance between 2 NUMA nodes.
> +#
> +# @src: source NUMA node.
> +#
> +# @dst: destination NUMA node.
> +#
> +# @val: NUMA distance from source node to destination node.
> +# When a node is unreachable from another node, set the distance
> +# to 255.
When a node is unreachable from another node, set the distance between
them to 255.
> +#
> +# Since: 2.10
> +##
> +{ 'struct': 'NumaDistOptions',
> + 'data': {
> + 'src': 'uint16',
> + 'dst': 'uint16',
> + 'val': 'uint8' }}
> +
> +##
> # @HostMemPolicy:
> #
> # Host memory policy types
> diff --git a/qemu-options.hx b/qemu-options.hx
> index 99af8ed..2318d85 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -139,12 +139,15 @@ ETEXI
>
> DEF("numa", HAS_ARG, QEMU_OPTION_numa,
> "-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n"
> - "-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n",
> QEMU_ARCH_ALL)
> + "-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n"
> + "-numa dist,src=source,dst=destination,val=distance\n", QEMU_ARCH_ALL)
> STEXI
> @item -numa
> node[,mem=@var{size}][,cpus=@var{firstcpu}[-@var{lastcpu}]][,nodeid=@var{node}]
> @itemx -numa
> node[,memdev=@var{id}][,cpus=@var{firstcpu}[-@var{lastcpu}]][,nodeid=@var{node}]
> +@itemx -numa dist,src=@var{source},dst=@var{destination},val=@var{distance}
> @findex -numa
> Define a NUMA node and assign RAM and VCPUs to it.
> +Set the NUMA distance from a source node to a destination node.
>
> @var{firstcpu} and @var{lastcpu} are CPU indexes. Each
> @samp{cpus} option represent a contiguous range of CPU indexes
> @@ -167,6 +170,18 @@ split equally between them.
> @samp{mem} and @samp{memdev} are mutually exclusive. Furthermore,
> if one node uses @samp{memdev}, all of them have to use it.
>
> +@var{source} and @var{destination} are NUMA node IDs.
> +@var{distance} is the NUMA distance from @var{source} to @var{destination}.
> +The distance from a node to itself is always 10. If no distance values
> +are given for node pairs, then the default distance of 20 is used for each
> +pair. If any pair of nodes is given a distance, then all pairs must be
> +given distances. Although, when distances are only given in one direction
> +for each pair of nodes, then the distances in the opposite directions are
> +assumed to be the same. If, however, an asymmetrical pair of distances is
> +given for even one node pair, then all node pairs must be provided
> +distance values for both directions, even when they are symmetrical. When
> +a node is unreachable from another node, set the pair's distance to 255.
We'll need to tweak/remove the 'default distance of 20' part of this if we
decide to not generate the SLIT at all when no distances are given.
> +
> Note that the -@option{numa} option doesn't allocate any of the
> specified resources, it just assigns existing resources to NUMA
> nodes. This means that one still has to use the @option{-m},
> --
> 2.7.4
>
>
Thanks,
drew
