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Re: [PATCH v4 09/16] target/i386: Cleanup and use the EPYC mode topology
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From: |
Igor Mammedov |
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Subject: |
Re: [PATCH v4 09/16] target/i386: Cleanup and use the EPYC mode topology functions |
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Date: |
Tue, 3 Mar 2020 09:47:13 +0100 |
On Mon, 2 Mar 2020 11:09:14 -0600
Babu Moger <address@hidden> wrote:
> On 2/25/20 1:49 AM, Igor Mammedov wrote:
> > On Mon, 24 Feb 2020 11:29:37 -0600
> > Babu Moger <address@hidden> wrote:
> >
> >> On 2/24/20 2:52 AM, Igor Mammedov wrote:
> >>> On Thu, 13 Feb 2020 12:17:25 -0600
> >>> Babu Moger <address@hidden> wrote:
> >>>
> >>>> Use the new functions from topology.h and delete the unused code. Given
> >>>> the
> >>>> sockets, nodes, cores and threads, the new functions generate apic id
> >>>> for EPYC
> >>>> mode. Removes all the hardcoded values.
> >>>>
> >>>> Signed-off-by: Babu Moger <address@hidden>
> >>>
> >>> modulo MAX() macro, looks fine to me
> >>
> >> Igor, Sorry. What do you mean here?
> >
> > I meant s/MAX(topo_info->nodes_per_pkg, 1)/topo_info->nodes_per_pkg/
> >
> > after it's made sure that topo_info->nodes_per_pkg is always valid.
> >
> Noticed that we cannot change it in all the places and assign to valid
> value 1. We need this information to know weather the system is numa
> configured in topology.h. This is similar to ms->numa_state->num_nodes.
> This value is > 0 if system is numa configured else it is 0. I need this
> information while generating the apicid. I have added comments about it in
> topology.h. Hope this is not a problem.
It should be fine as far as that's the only and best way to handle it
and it's clear from patches why it's done this way.
> >
> > (I believe I've commented on that somewhere. Series isn't split nicely,
> > so I've ended up applying it all and then reviewing so comments might
> > look out of the place sometimes, hopefully next revision will be easier
> > to review)
> >
> >>>
> >>>> ---
> >>>> target/i386/cpu.c | 162
> >>>> +++++++++++------------------------------------------
> >>>> 1 file changed, 35 insertions(+), 127 deletions(-)
> >>>>
> >>>> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> >>>> index 5d6edfd09b..19675eb696 100644
> >>>> --- a/target/i386/cpu.c
> >>>> +++ b/target/i386/cpu.c
> >>>> @@ -338,68 +338,15 @@ static void
> >>>> encode_cache_cpuid80000006(CPUCacheInfo *l2,
> >>>> }
> >>>> }
> >>>>
> >>>> -/*
> >>>> - * Definitions used for building CPUID Leaf 0x8000001D and 0x8000001E
> >>>> - * Please refer to the AMD64 Architecture Programmer’s Manual Volume 3.
> >>>> - * Define the constants to build the cpu topology. Right now, TOPOEXT
> >>>> - * feature is enabled only on EPYC. So, these constants are based on
> >>>> - * EPYC supported configurations. We may need to handle the cases if
> >>>> - * these values change in future.
> >>>> - */
> >>>> -/* Maximum core complexes in a node */
> >>>> -#define MAX_CCX 2
> >>>> -/* Maximum cores in a core complex */
> >>>> -#define MAX_CORES_IN_CCX 4
> >>>> -/* Maximum cores in a node */
> >>>> -#define MAX_CORES_IN_NODE 8
> >>>> -/* Maximum nodes in a socket */
> >>>> -#define MAX_NODES_PER_SOCKET 4
> >>>> -
> >>>> -/*
> >>>> - * Figure out the number of nodes required to build this config.
> >>>> - * Max cores in a node is 8
> >>>> - */
> >>>> -static int nodes_in_socket(int nr_cores)
> >>>> -{
> >>>> - int nodes;
> >>>> -
> >>>> - nodes = DIV_ROUND_UP(nr_cores, MAX_CORES_IN_NODE);
> >>>> -
> >>>> - /* Hardware does not support config with 3 nodes, return 4 in that
> >>>> case */
> >>>> - return (nodes == 3) ? 4 : nodes;
> >>>> -}
> >>>> -
> >>>> -/*
> >>>> - * Decide the number of cores in a core complex with the given nr_cores
> >>>> using
> >>>> - * following set constants MAX_CCX, MAX_CORES_IN_CCX, MAX_CORES_IN_NODE
> >>>> and
> >>>> - * MAX_NODES_PER_SOCKET. Maintain symmetry as much as possible
> >>>> - * L3 cache is shared across all cores in a core complex. So, this will
> >>>> also
> >>>> - * tell us how many cores are sharing the L3 cache.
> >>>> - */
> >>>> -static int cores_in_core_complex(int nr_cores)
> >>>> -{
> >>>> - int nodes;
> >>>> -
> >>>> - /* Check if we can fit all the cores in one core complex */
> >>>> - if (nr_cores <= MAX_CORES_IN_CCX) {
> >>>> - return nr_cores;
> >>>> - }
> >>>> - /* Get the number of nodes required to build this config */
> >>>> - nodes = nodes_in_socket(nr_cores);
> >>>> -
> >>>> - /*
> >>>> - * Divide the cores accros all the core complexes
> >>>> - * Return rounded up value
> >>>> - */
> >>>> - return DIV_ROUND_UP(nr_cores, nodes * MAX_CCX);
> >>>> -}
> >>>> -
> >>>> /* Encode cache info for CPUID[8000001D] */
> >>>> -static void encode_cache_cpuid8000001d(CPUCacheInfo *cache, CPUState
> >>>> *cs,
> >>>> - uint32_t *eax, uint32_t *ebx,
> >>>> - uint32_t *ecx, uint32_t *edx)
> >>>> +static void encode_cache_cpuid8000001d(CPUCacheInfo *cache,
> >>>> + X86CPUTopoInfo *topo_info,
> >>>> + uint32_t *eax, uint32_t *ebx,
> >>>> + uint32_t *ecx, uint32_t *edx)
> >>>> {
> >>>> uint32_t l3_cores;
> >>>> + unsigned nodes = MAX(topo_info->nodes_per_pkg, 1);
> >>>> +
> >>>> assert(cache->size == cache->line_size * cache->associativity *
> >>>> cache->partitions * cache->sets);
> >>>>
> >>>> @@ -408,10 +355,13 @@ static void
> >>>> encode_cache_cpuid8000001d(CPUCacheInfo *cache, CPUState *cs,
> >>>>
> >>>> /* L3 is shared among multiple cores */
> >>>> if (cache->level == 3) {
> >>>> - l3_cores = cores_in_core_complex(cs->nr_cores);
> >>>> - *eax |= ((l3_cores * cs->nr_threads) - 1) << 14;
> >>>> + l3_cores = DIV_ROUND_UP((topo_info->dies_per_pkg *
> >>>> + topo_info->cores_per_die *
> >>>> + topo_info->threads_per_core),
> >>>> + nodes);
> >>>> + *eax |= (l3_cores - 1) << 14;
> >>>> } else {
> >>>> - *eax |= ((cs->nr_threads - 1) << 14);
> >>>> + *eax |= ((topo_info->threads_per_core - 1) << 14);
> >>>> }
> >>>>
> >>>> assert(cache->line_size > 0);
> >>>> @@ -431,55 +381,17 @@ static void
> >>>> encode_cache_cpuid8000001d(CPUCacheInfo *cache, CPUState *cs,
> >>>> (cache->complex_indexing ? CACHE_COMPLEX_IDX : 0);
> >>>> }
> >>>>
> >>>> -/* Data structure to hold the configuration info for a given core index
> >>>> */
> >>>> -struct core_topology {
> >>>> - /* core complex id of the current core index */
> >>>> - int ccx_id;
> >>>> - /*
> >>>> - * Adjusted core index for this core in the topology
> >>>> - * This can be 0,1,2,3 with max 4 cores in a core complex
> >>>> - */
> >>>> - int core_id;
> >>>> - /* Node id for this core index */
> >>>> - int node_id;
> >>>> - /* Number of nodes in this config */
> >>>> - int num_nodes;
> >>>> -};
> >>>> -
> >>>> -/*
> >>>> - * Build the configuration closely match the EPYC hardware. Using the
> >>>> EPYC
> >>>> - * hardware configuration values (MAX_CCX, MAX_CORES_IN_CCX,
> >>>> MAX_CORES_IN_NODE)
> >>>> - * right now. This could change in future.
> >>>> - * nr_cores : Total number of cores in the config
> >>>> - * core_id : Core index of the current CPU
> >>>> - * topo : Data structure to hold all the config info for this core
> >>>> index
> >>>> - */
> >>>> -static void build_core_topology(int nr_cores, int core_id,
> >>>> - struct core_topology *topo)
> >>>> -{
> >>>> - int nodes, cores_in_ccx;
> >>>> -
> >>>> - /* First get the number of nodes required */
> >>>> - nodes = nodes_in_socket(nr_cores);
> >>>> -
> >>>> - cores_in_ccx = cores_in_core_complex(nr_cores);
> >>>> -
> >>>> - topo->node_id = core_id / (cores_in_ccx * MAX_CCX);
> >>>> - topo->ccx_id = (core_id % (cores_in_ccx * MAX_CCX)) / cores_in_ccx;
> >>>> - topo->core_id = core_id % cores_in_ccx;
> >>>> - topo->num_nodes = nodes;
> >>>> -}
> >>>> -
> >>>> /* Encode cache info for CPUID[8000001E] */
> >>>> -static void encode_topo_cpuid8000001e(CPUState *cs, X86CPU *cpu,
> >>>> +static void encode_topo_cpuid8000001e(X86CPUTopoInfo *topo_info, X86CPU
> >>>> *cpu,
> >>>> uint32_t *eax, uint32_t *ebx,
> >>>> uint32_t *ecx, uint32_t *edx)
> >>>> {
> >>>> - struct core_topology topo = {0};
> >>>> - unsigned long nodes;
> >>>> + X86CPUTopoIDs topo_ids = {0};
> >>>> + unsigned long nodes = MAX(topo_info->nodes_per_pkg, 1);
> >>>> int shift;
> >>>>
> >>>> - build_core_topology(cs->nr_cores, cpu->core_id, &topo);
> >>>> + x86_topo_ids_from_apicid_epyc(cpu->apic_id, topo_info, &topo_ids);
> >>>> +
> >>>> *eax = cpu->apic_id;
> >>>> /*
> >>>> * CPUID_Fn8000001E_EBX
> >>>> @@ -496,12 +408,8 @@ static void encode_topo_cpuid8000001e(CPUState *cs,
> >>>> X86CPU *cpu,
> >>>> * 3 Core complex id
> >>>> * 1:0 Core id
> >>>> */
> >>>> - if (cs->nr_threads - 1) {
> >>>> - *ebx = ((cs->nr_threads - 1) << 8) | (topo.node_id << 3) |
> >>>> - (topo.ccx_id << 2) | topo.core_id;
> >>>> - } else {
> >>>> - *ebx = (topo.node_id << 4) | (topo.ccx_id << 3) | topo.core_id;
> >>>> - }
> >>>> + *ebx = ((topo_info->threads_per_core - 1) << 8) | (topo_ids.node_id
> >>>> << 3) |
> >>>> + (topo_ids.core_id);
> >>>> /*
> >>>> * CPUID_Fn8000001E_ECX
> >>>> * 31:11 Reserved
> >>>> @@ -510,9 +418,9 @@ static void encode_topo_cpuid8000001e(CPUState *cs,
> >>>> X86CPU *cpu,
> >>>> * 2 Socket id
> >>>> * 1:0 Node id
> >>>> */
> >>>> - if (topo.num_nodes <= 4) {
> >>>> - *ecx = ((topo.num_nodes - 1) << 8) | (cpu->socket_id << 2) |
> >>>> - topo.node_id;
> >>>> +
> >>>> + if (nodes <= 4) {
> >>>> + *ecx = ((nodes - 1) << 8) | (topo_ids.pkg_id << 2) |
> >>>> topo_ids.node_id;
> >>>> } else {
> >>>> /*
> >>>> * Node id fix up. Actual hardware supports up to 4 nodes. But
> >>>> with
> >>>> @@ -527,10 +435,10 @@ static void encode_topo_cpuid8000001e(CPUState
> >>>> *cs, X86CPU *cpu,
> >>>> * number of nodes. find_last_bit returns last set bit(0
> >>>> based). Left
> >>>> * shift(+1) the socket id to represent all the nodes.
> >>>> */
> >>>> - nodes = topo.num_nodes - 1;
> >>>> + nodes -= 1;
> >>>> shift = find_last_bit(&nodes, 8);
> >>>> - *ecx = ((topo.num_nodes - 1) << 8) | (cpu->socket_id << (shift
> >>>> + 1)) |
> >>>> - topo.node_id;
> >>>> + *ecx = (nodes << 8) | (topo_ids.pkg_id << (shift + 1)) |
> >>>> + topo_ids.node_id;
> >>>> }
> >>>> *edx = 0;
> >>>> }
> >>>> @@ -5318,6 +5226,7 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t
> >>>> index, uint32_t count,
> >>>> uint32_t signature[3];
> >>>> X86CPUTopoInfo topo_info;
> >>>>
> >>>> + topo_info.nodes_per_pkg = env->nr_nodes;
> >>>> topo_info.dies_per_pkg = env->nr_dies;
> >>>> topo_info.cores_per_die = cs->nr_cores;
> >>>> topo_info.threads_per_core = cs->nr_threads;
> >>>> @@ -5737,20 +5646,20 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t
> >>>> index, uint32_t count,
> >>>> }
> >>>> switch (count) {
> >>>> case 0: /* L1 dcache info */
> >>>> - encode_cache_cpuid8000001d(env->cache_info_amd.l1d_cache,
> >>>> cs,
> >>>> - eax, ebx, ecx, edx);
> >>>> + encode_cache_cpuid8000001d(env->cache_info_amd.l1d_cache,
> >>>> + &topo_info, eax, ebx, ecx, edx);
> >>>> break;
> >>>> case 1: /* L1 icache info */
> >>>> - encode_cache_cpuid8000001d(env->cache_info_amd.l1i_cache,
> >>>> cs,
> >>>> - eax, ebx, ecx, edx);
> >>>> + encode_cache_cpuid8000001d(env->cache_info_amd.l1i_cache,
> >>>> + &topo_info, eax, ebx, ecx, edx);
> >>>> break;
> >>>> case 2: /* L2 cache info */
> >>>> - encode_cache_cpuid8000001d(env->cache_info_amd.l2_cache, cs,
> >>>> - eax, ebx, ecx, edx);
> >>>> + encode_cache_cpuid8000001d(env->cache_info_amd.l2_cache,
> >>>> + &topo_info, eax, ebx, ecx, edx);
> >>>> break;
> >>>> case 3: /* L3 cache info */
> >>>> - encode_cache_cpuid8000001d(env->cache_info_amd.l3_cache, cs,
> >>>> - eax, ebx, ecx, edx);
> >>>> + encode_cache_cpuid8000001d(env->cache_info_amd.l3_cache,
> >>>> + &topo_info, eax, ebx, ecx, edx);
> >>>> break;
> >>>> default: /* end of info */
> >>>> *eax = *ebx = *ecx = *edx = 0;
> >>>> @@ -5759,8 +5668,7 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t
> >>>> index, uint32_t count,
> >>>> break;
> >>>> case 0x8000001E:
> >>>> assert(cpu->core_id <= 255);
> >>>> - encode_topo_cpuid8000001e(cs, cpu,
> >>>> - eax, ebx, ecx, edx);
> >>>> + encode_topo_cpuid8000001e(&topo_info, cpu, eax, ebx, ecx, edx);
> >>>> break;
> >>>> case 0xC0000000:
> >>>> *eax = env->cpuid_xlevel2;
> >>>>
> >>>
> >>
> >
>