From patchwork Wed Jun 26 16:28:34 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alejandro Vallejo X-Patchwork-Id: 13713168 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 48FB8C27C4F for ; Wed, 26 Jun 2024 16:28:59 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.749275.1157359 (Exim 4.92) (envelope-from ) id 1sMVVp-0007OU-O9; Wed, 26 Jun 2024 16:28:49 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 749275.1157359; Wed, 26 Jun 2024 16:28:49 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1sMVVp-0007N2-IB; Wed, 26 Jun 2024 16:28:49 +0000 Received: by outflank-mailman (input) for mailman id 749275; Wed, 26 Jun 2024 16:28:48 +0000 Received: from se1-gles-sth1-in.inumbo.com ([159.253.27.254] helo=se1-gles-sth1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1sMVVn-0006MH-VA for xen-devel@lists.xenproject.org; Wed, 26 Jun 2024 16:28:48 +0000 Received: from mail-lj1-x22e.google.com (mail-lj1-x22e.google.com [2a00:1450:4864:20::22e]) by se1-gles-sth1.inumbo.com (Halon) with ESMTPS id 29aaca38-33d9-11ef-90a3-e314d9c70b13; Wed, 26 Jun 2024 18:28:47 +0200 (CEST) Received: by mail-lj1-x22e.google.com with SMTP id 38308e7fff4ca-2ec002caf3eso104744071fa.1 for ; Wed, 26 Jun 2024 09:28:47 -0700 (PDT) Received: from EMEAENGAAD19049.citrite.net ([160.101.139.1]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-a7291af7912sm42791866b.128.2024.06.26.09.28.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 26 Jun 2024 09:28:46 -0700 (PDT) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 29aaca38-33d9-11ef-90a3-e314d9c70b13 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cloud.com; s=cloud; t=1719419326; x=1720024126; darn=lists.xenproject.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=l+xOouMfNTmMxHo9v7bAjCWITyqn06N8bTQ+zZ/tKIw=; b=OYFEbiTnClOEsBRLewytNPp7hQYeYjUX6ji1S+VYKmIL4ODLRQgM3Z5ptDqcYlwoI6 Q+Ehq0m6IzqdSwCkWXARzCuEaq3Dl3QolxLyei7kxfhZyUzA8Q3soPbunRde0u+epwTk eSSS6Lwh+47LbYl2Qu79dLnp4QvAWKQA8YGHM= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1719419326; x=1720024126; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=l+xOouMfNTmMxHo9v7bAjCWITyqn06N8bTQ+zZ/tKIw=; b=YBZnIXrv3RWbpAD7s0W4V0QovipOpzvVO1x6g51wtASB32RiWpVvQKBWut2SbHU2Os q1xtoKnW/mPy+iCrQTCzylZ6nnzo5vl/zsN62EQvG8KNPJYNOLJ+zR0e3sB7M0znl1jA s34+luSTAwyncADyAy61Dr6GXzxcUZ3kiVnWCECWBoFx5Qub87aq6mWtlJpT2t0lO4qb Hw/wZJIsJBs8u02DYYmGXQP8L4FD9DpBhZ5BIphxIaszevtzaAQOb+nQIHOKiHQS+cGZ flm7HjA8xeU96RxlPcRH3uXNgsYkDBll6CAH96dXaxDmTErS+YoT3rKGOcNAxtg8nq6Y egVw== X-Gm-Message-State: AOJu0YyP4Ll9gm8NNsOCvGAuBdjbGahFt+YfRNdHKUsN5XJ9ItiGr7k9 92yDAG/SmhXUSimIoHjDB3tWbYRb/yerB0dQ2c1p17DpQN/tXpTLQtLtzfsdBpi0PF7H2o2R0VN nKgM= X-Google-Smtp-Source: AGHT+IF3IPdvzxA3JXkykkYNidfujye+/BWcALPxMJdj71ZMCRp0vGOO+OeWys7ok3Dm5kfg6BdS0w== X-Received: by 2002:a2e:885a:0:b0:2eb:fca8:7f37 with SMTP id 38308e7fff4ca-2ec5b2e628fmr89509191fa.28.1719419326484; Wed, 26 Jun 2024 09:28:46 -0700 (PDT) From: Alejandro Vallejo To: Xen-devel Cc: Alejandro Vallejo , Jan Beulich , Andrew Cooper , =?utf-8?q?Roger_Pau_Monn=C3=A9?= , Anthony PERARD Subject: [PATCH v4 07/10] xen/lib: Add topology generator for x86 Date: Wed, 26 Jun 2024 17:28:34 +0100 Message-Id: <5ab2cb62745bca462ab3768ea1eb826d2b6e2c76.1719416329.git.alejandro.vallejo@cloud.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: References: MIME-Version: 1.0 Add a helper to populate topology leaves in the cpu policy from threads/core and cores/package counts. It's unit-tested in test-cpu-policy.c, but it's not connected to the rest of the code yet. Adds the ASSERT() macro to xen/lib/x86/private.h, as it was missing. Signed-off-by: Alejandro Vallejo --- v4: * v1->v2 introduced a bug. lppp must be MIN(0xff, threads_per_pkg). * Add missing MIN() when setting p->extd.nc (should've been done in v2) --- tools/tests/cpu-policy/test-cpu-policy.c | 133 +++++++++++++++++++++++ xen/include/xen/lib/x86/cpu-policy.h | 16 +++ xen/lib/x86/policy.c | 88 +++++++++++++++ xen/lib/x86/private.h | 4 + 4 files changed, 241 insertions(+) diff --git a/tools/tests/cpu-policy/test-cpu-policy.c b/tools/tests/cpu-policy/test-cpu-policy.c index 301df2c00285..849d7cebaa7c 100644 --- a/tools/tests/cpu-policy/test-cpu-policy.c +++ b/tools/tests/cpu-policy/test-cpu-policy.c @@ -650,6 +650,137 @@ static void test_is_compatible_failure(void) } } +static void test_topo_from_parts(void) +{ + static const struct test { + unsigned int threads_per_core; + unsigned int cores_per_pkg; + struct cpu_policy policy; + } tests[] = { + { + .threads_per_core = 3, .cores_per_pkg = 1, + .policy = { + .x86_vendor = X86_VENDOR_AMD, + .topo.subleaf = { + { .nr_logical = 3, .level = 0, .type = 1, .id_shift = 2, }, + { .nr_logical = 1, .level = 1, .type = 2, .id_shift = 2, }, + }, + }, + }, + { + .threads_per_core = 1, .cores_per_pkg = 3, + .policy = { + .x86_vendor = X86_VENDOR_AMD, + .topo.subleaf = { + { .nr_logical = 1, .level = 0, .type = 1, .id_shift = 0, }, + { .nr_logical = 3, .level = 1, .type = 2, .id_shift = 2, }, + }, + }, + }, + { + .threads_per_core = 7, .cores_per_pkg = 5, + .policy = { + .x86_vendor = X86_VENDOR_AMD, + .topo.subleaf = { + { .nr_logical = 7, .level = 0, .type = 1, .id_shift = 3, }, + { .nr_logical = 5, .level = 1, .type = 2, .id_shift = 6, }, + }, + }, + }, + { + .threads_per_core = 2, .cores_per_pkg = 128, + .policy = { + .x86_vendor = X86_VENDOR_AMD, + .topo.subleaf = { + { .nr_logical = 2, .level = 0, .type = 1, .id_shift = 1, }, + { .nr_logical = 128, .level = 1, .type = 2, + .id_shift = 8, }, + }, + }, + }, + { + .threads_per_core = 3, .cores_per_pkg = 1, + .policy = { + .x86_vendor = X86_VENDOR_INTEL, + .topo.subleaf = { + { .nr_logical = 3, .level = 0, .type = 1, .id_shift = 2, }, + { .nr_logical = 3, .level = 1, .type = 2, .id_shift = 2, }, + }, + }, + }, + { + .threads_per_core = 1, .cores_per_pkg = 3, + .policy = { + .x86_vendor = X86_VENDOR_INTEL, + .topo.subleaf = { + { .nr_logical = 1, .level = 0, .type = 1, .id_shift = 0, }, + { .nr_logical = 3, .level = 1, .type = 2, .id_shift = 2, }, + }, + }, + }, + { + .threads_per_core = 7, .cores_per_pkg = 5, + .policy = { + .x86_vendor = X86_VENDOR_INTEL, + .topo.subleaf = { + { .nr_logical = 7, .level = 0, .type = 1, .id_shift = 3, }, + { .nr_logical = 35, .level = 1, .type = 2, .id_shift = 6, }, + }, + }, + }, + { + .threads_per_core = 2, .cores_per_pkg = 128, + .policy = { + .x86_vendor = X86_VENDOR_INTEL, + .topo.subleaf = { + { .nr_logical = 2, .level = 0, .type = 1, .id_shift = 1, }, + { .nr_logical = 256, .level = 1, .type = 2, + .id_shift = 8, }, + }, + }, + }, + }; + + printf("Testing topology synthesis from parts:\n"); + + for ( size_t i = 0; i < ARRAY_SIZE(tests); ++i ) + { + const struct test *t = &tests[i]; + struct cpu_policy actual = { .x86_vendor = t->policy.x86_vendor }; + int rc = x86_topo_from_parts(&actual, t->threads_per_core, + t->cores_per_pkg); + + if ( rc || memcmp(&actual.topo, &t->policy.topo, sizeof(actual.topo)) ) + { +#define TOPO(n, f) t->policy.topo.subleaf[(n)].f, actual.topo.subleaf[(n)].f + fail("FAIL[%d] - '%s %u t/c, %u c/p'\n", + rc, + x86_cpuid_vendor_to_str(t->policy.x86_vendor), + t->threads_per_core, t->cores_per_pkg); + printf(" subleaf=%u expected_n=%u actual_n=%u\n" + " expected_lvl=%u actual_lvl=%u\n" + " expected_type=%u actual_type=%u\n" + " expected_shift=%u actual_shift=%u\n", + 0, + TOPO(0, nr_logical), + TOPO(0, level), + TOPO(0, type), + TOPO(0, id_shift)); + + printf(" subleaf=%u expected_n=%u actual_n=%u\n" + " expected_lvl=%u actual_lvl=%u\n" + " expected_type=%u actual_type=%u\n" + " expected_shift=%u actual_shift=%u\n", + 1, + TOPO(1, nr_logical), + TOPO(1, level), + TOPO(1, type), + TOPO(1, id_shift)); +#undef TOPO + } + } +} + int main(int argc, char **argv) { printf("CPU Policy unit tests\n"); @@ -667,6 +798,8 @@ int main(int argc, char **argv) test_is_compatible_success(); test_is_compatible_failure(); + test_topo_from_parts(); + if ( nr_failures ) printf("Done: %u failures\n", nr_failures); else diff --git a/xen/include/xen/lib/x86/cpu-policy.h b/xen/include/xen/lib/x86/cpu-policy.h index d26012c6da78..79fdf9045a1b 100644 --- a/xen/include/xen/lib/x86/cpu-policy.h +++ b/xen/include/xen/lib/x86/cpu-policy.h @@ -542,6 +542,22 @@ int x86_cpu_policies_are_compatible(const struct cpu_policy *host, const struct cpu_policy *guest, struct cpu_policy_errors *err); +/** + * Synthesise topology information in `p` given high-level constraints + * + * Topology is given in various fields accross several leaves, some of + * which are vendor-specific. This function uses the policy itself to + * derive such leaves from threads/core and cores/package. + * + * @param p CPU policy of the domain. + * @param threads_per_core threads/core. Doesn't need to be a power of 2. + * @param cores_per_package cores/package. Doesn't need to be a power of 2. + * @return 0 on success; -errno on failure + */ +int x86_topo_from_parts(struct cpu_policy *p, + unsigned int threads_per_core, + unsigned int cores_per_pkg); + #endif /* !XEN_LIB_X86_POLICIES_H */ /* diff --git a/xen/lib/x86/policy.c b/xen/lib/x86/policy.c index f033d22785be..72b67b44a893 100644 --- a/xen/lib/x86/policy.c +++ b/xen/lib/x86/policy.c @@ -2,6 +2,94 @@ #include +static unsigned int order(unsigned int n) +{ + ASSERT(n); /* clz(0) is UB */ + + return 8 * sizeof(n) - __builtin_clz(n); +} + +int x86_topo_from_parts(struct cpu_policy *p, + unsigned int threads_per_core, + unsigned int cores_per_pkg) +{ + unsigned int threads_per_pkg = threads_per_core * cores_per_pkg; + unsigned int apic_id_size; + + if ( !p || !threads_per_core || !cores_per_pkg ) + return -EINVAL; + + p->basic.max_leaf = MAX(0xb, p->basic.max_leaf); + + memset(p->topo.raw, 0, sizeof(p->topo.raw)); + + /* thread level */ + p->topo.subleaf[0].nr_logical = threads_per_core; + p->topo.subleaf[0].id_shift = 0; + p->topo.subleaf[0].level = 0; + p->topo.subleaf[0].type = 1; + if ( threads_per_core > 1 ) + p->topo.subleaf[0].id_shift = order(threads_per_core - 1); + + /* core level */ + p->topo.subleaf[1].nr_logical = cores_per_pkg; + if ( p->x86_vendor == X86_VENDOR_INTEL ) + p->topo.subleaf[1].nr_logical = threads_per_pkg; + p->topo.subleaf[1].id_shift = p->topo.subleaf[0].id_shift; + p->topo.subleaf[1].level = 1; + p->topo.subleaf[1].type = 2; + if ( cores_per_pkg > 1 ) + p->topo.subleaf[1].id_shift += order(cores_per_pkg - 1); + + apic_id_size = p->topo.subleaf[1].id_shift; + + /* + * Contrary to what the name might seem to imply. HTT is an enabler for + * SMP and there's no harm in setting it even with a single vCPU. + */ + p->basic.htt = true; + p->basic.lppp = MIN(0xff, threads_per_pkg); + + switch ( p->x86_vendor ) + { + case X86_VENDOR_INTEL: { + struct cpuid_cache_leaf *sl = p->cache.subleaf; + + for ( size_t i = 0; sl->type && + i < ARRAY_SIZE(p->cache.raw); i++, sl++ ) + { + sl->cores_per_package = cores_per_pkg - 1; + sl->threads_per_cache = threads_per_core - 1; + if ( sl->type == 3 /* unified cache */ ) + sl->threads_per_cache = threads_per_pkg - 1; + } + break; + } + + case X86_VENDOR_AMD: + case X86_VENDOR_HYGON: + /* Expose p->basic.lppp */ + p->extd.cmp_legacy = true; + + /* Clip NC to the maximum value it can hold */ + p->extd.nc = MIN(0xff, threads_per_pkg - 1); + + /* TODO: Expose leaf e1E */ + p->extd.topoext = false; + + /* + * Clip APIC ID to 8 bits, as that's what high core-count machines do. + * + * That's what AMD EPYC 9654 does with >256 CPUs. + */ + p->extd.apic_id_size = MIN(8, apic_id_size); + + break; + } + + return 0; +} + int x86_cpu_policies_are_compatible(const struct cpu_policy *host, const struct cpu_policy *guest, struct cpu_policy_errors *err) diff --git a/xen/lib/x86/private.h b/xen/lib/x86/private.h index 60bb82a400b7..2ec9dbee33c2 100644 --- a/xen/lib/x86/private.h +++ b/xen/lib/x86/private.h @@ -4,6 +4,7 @@ #ifdef __XEN__ #include +#include #include #include #include @@ -17,6 +18,7 @@ #else +#include #include #include #include @@ -28,6 +30,8 @@ #include +#define ASSERT(x) assert(x) + static inline bool test_bit(unsigned int bit, const void *vaddr) { const char *addr = vaddr;