From patchwork Sat Apr 20 15:17:16 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Atish Kumar Patra X-Patchwork-Id: 1925752 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; dkim=pass (2048-bit key; secure) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=2zO/aK8P; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=rivosinc-com.20230601.gappssmtp.com header.i=@rivosinc-com.20230601.gappssmtp.com header.a=rsa-sha256 header.s=20230601 header.b=t/xFVR3d; dkim-atps=neutral Authentication-Results: legolas.ozlabs.org; spf=none (no SPF record) smtp.mailfrom=lists.infradead.org (client-ip=2607:7c80:54:3::133; helo=bombadil.infradead.org; envelope-from=kvm-riscv-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org; receiver=patchwork.ozlabs.org) Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:3::133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (secp384r1) server-digest SHA384) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4VLrtQ2J6fz1yZP for ; Sat, 20 Apr 2024 09:47:58 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-Id:Date:Subject:Cc :To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=Jv8TRkgp+cNBwr7bLjQi1jCZgFVSa04MWYSBre4dsWE=; b=2zO/aK8PYWu5NA jFv4r3QR0vkfuvmqNT9FUcMcsEKgA3F31wtC8A8xb198AMT5v/MGiyDoHrTvnRoiMD3qr+YQs2Qcs vslI6gJcVYQO0JdmP4oR4l8yUVsxtdgG6UA4JY8oj+0/T5003hcRQKyyDsFnJ8r3z0lOvGVuclztz CtiR/pNrQU6FGzaAM4t0SvIfvCFaWaQGt476wrnKrImjs5jkNQTTViHbFU9BhJiJi/+5zf1aTgkI2 mb1/qxt9KlSlrYa+Go9uNwVFEAFV84SjnnB1ELI2o6jM8vkAHXYePXjBEqaxbaNTiMyi/qS3i9V7Y Y5V5A/v9tubiNNV6Qi1A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rxxxU-00000007IcO-41ec; Fri, 19 Apr 2024 23:47:56 +0000 Received: from mail-pl1-x636.google.com ([2607:f8b0:4864:20::636]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1rxxxM-00000007IUO-1Uht for kvm-riscv@lists.infradead.org; Fri, 19 Apr 2024 23:47:51 +0000 Received: by mail-pl1-x636.google.com with SMTP id d9443c01a7336-1e2bbc2048eso22759915ad.3 for ; Fri, 19 Apr 2024 16:47:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rivosinc-com.20230601.gappssmtp.com; s=20230601; t=1713570464; x=1714175264; darn=lists.infradead.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=IzaB9st3cascud7CCOjToOIM1+WmFI5tBLPZbxENCL0=; b=t/xFVR3d/z4LbbYxq9QThaembGIhvCx9PcWKo8KykJbW/3+Y0rGxruJDlZSp0G5yry 9PbN26ojx9ndr3QE7d9bKcAjl/rjaNLzU66EY+HL0CUM1otSI0EADfQ4tEq16vbtPUXr muSywmeWjFcU209FOWQVc97jwRtudrH23oQ7B5zohrRts27zdhIRGte1JQvz/0Lich89 VFRetyeHRAh8fVQuaTqRoh0fKzX6KdWUKyEijVsgaClQdXDvWyLgz7sy6lvRObh8P0Sc PLwizXe3wwYxww/KqW7UTqtLlX1/DbVvriPCF2qsjs+XFBS36/CwWdYIUZ0E60Fe+Op3 XCLA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1713570464; x=1714175264; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=IzaB9st3cascud7CCOjToOIM1+WmFI5tBLPZbxENCL0=; b=kDGArP0i+Vg1aUuQaNniYxf7dTW46+rlvipTB/xphHaN6rleIaI/X2wxaLhNPeRN5k qy0p8MwsbhQ9/RlmwZGFGVXHbOCyylAF9sgXG3HBHm8a1voNhIuwy8PAXJfSYPn8/oGp bQrgVoMqrtChh/IoxxBH/XsxtO0Am4XQmZfGgDR+81aRzlRM4nFoq2SzmAaibBQFV12+ CKeUayTApIBae0Omikfb8r/MiYq7xxNmezWRr7N772zRqhqSkkE3vEgz/4C+uycskNdQ TJ8brqleFqNhcplIlwpk1RZgM7GtNRLiL8oZlmMHomt/9Yqpu2lVXPWAWW7cfb8QuCvt 36Rg== X-Forwarded-Encrypted: i=1; AJvYcCUMEU7wUpXSAIOjpNSCX5ySRpOnAfnfv5hrDp/PoNs8fRwey+Zu6CWnHAWSqr6S6K/9fBTwsSbkWyvj0EOkRiFK7pwlqmUC18Vx16v0+w== X-Gm-Message-State: AOJu0YwOlic0MMo4KhAooiOyC26UR1/wINY78byeYDK8Dmh9HlJn13DL ZncLLgAfjQI4w3dzO/Njb7v4A3X/7dEvMKm1r0ZWBgNi3rKIgJpYV2EiMIzKE9s= X-Google-Smtp-Source: AGHT+IF/y+aOm/HBwIYKFW0r+Cx1DkitScqMAK3OsUhT+f7GJ7yy/Ulu5NdR5WE9Q+D2RzAVuxG1Gg== X-Received: by 2002:a17:902:da83:b0:1e5:4f00:3754 with SMTP id j3-20020a170902da8300b001e54f003754mr4675193plx.8.1713570464325; Fri, 19 Apr 2024 16:47:44 -0700 (PDT) Received: from atishp.ba.rivosinc.com ([64.71.180.162]) by smtp.gmail.com with ESMTPSA id w17-20020a170902d11100b001e42f215f33sm3924017plw.85.2024.04.19.16.47.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 19 Apr 2024 16:47:43 -0700 (PDT) From: Atish Patra To: linux-kernel@vger.kernel.org Cc: Atish Patra , Ajay Kaher , Albert Ou , Alexandre Ghiti , Andrew Jones , Anup Patel , samuel.holland@sifive.com, Conor Dooley , Juergen Gross , kvm-riscv@lists.infradead.org, kvm@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-riscv@lists.infradead.org, Mark Rutland , Palmer Dabbelt , Paolo Bonzini , Paul Walmsley , Shuah Khan , virtualization@lists.linux.dev, Will Deacon , x86@kernel.org Subject: [PATCH v8 00/24] RISC-V SBI v2.0 PMU improvements and Perf sampling in KVM guest Date: Sat, 20 Apr 2024 08:17:16 -0700 Message-Id: <20240420151741.962500-1-atishp@rivosinc.com> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240419_164748_466123_DE21C2BE X-CRM114-Status: GOOD ( 24.40 ) X-Spam-Score: 2.5 (++) X-Spam-Report: Spam detection software, running on the system "bombadil.infradead.org", has NOT identified this incoming email as spam. The original message has been attached to this so you can view it or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: This series implements SBI PMU improvements done in SBI v2.0[1] i.e. PMU snapshot and fw_read_hi() functions. SBI v2.0 introduced PMU snapshot feature which allows the SBI implementation to provide counter information (i.e. values/overflow status) via a shared memory between the SBI implementation and supervi [...] Content analysis details: (2.5 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at https://www.dnswl.org/, no trust [2607:f8b0:4864:20:0:0:0:636 listed in] [list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature 2.5 DATE_IN_FUTURE_12_24 Date: is 12 to 24 hours after Received: date X-BeenThere: kvm-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "kvm-riscv" Errors-To: kvm-riscv-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org This series implements SBI PMU improvements done in SBI v2.0[1] i.e. PMU snapshot and fw_read_hi() functions. SBI v2.0 introduced PMU snapshot feature which allows the SBI implementation to provide counter information (i.e. values/overflow status) via a shared memory between the SBI implementation and supervisor OS. This allows to minimize the number of traps in when perf being used inside a kvm guest as it relies on SBI PMU + trap/emulation of the counters. The current set of ratified RISC-V specification also doesn't allow scountovf to be trap/emulated by the hypervisor. The SBI PMU snapshot bridges the gap in ISA as well and enables perf sampling in the guest. However, LCOFI in the guest only works via IRQ filtering in AIA specification. That's why, AIA has to be enabled in the hardware (at least the Ssaia extension) in order to use the sampling support in the perf. Here are the patch wise implementation details. PATCH 1,4,7,8,9,10,11,15 : Generic cleanups/improvements. PATCH 2,3,14 : FW_READ_HI function implementation PATCH 5-6: Add PMU snapshot feature in sbi pmu driver PATCH 12-13: KVM implementation for snapshot and sampling in kvm guests PATCH 16-17: Generic improvements for kvm selftests PATCH 18-22: KVM selftests for SBI PMU extension The series is based on v6.9-rc4 and is available at: https://github.com/atishp04/linux/tree/kvm_pmu_snapshot_v8 The kvmtool patch is also available at: https://github.com/atishp04/kvmtool/tree/sscofpmf It also requires Ssaia ISA extension to be present in the hardware in order to get perf sampling support in the guest. In Qemu virt machine, it can be done by the following config. ``` -cpu rv64,sscofpmf=true,x-ssaia=true ``` There is no other dependencies on AIA apart from that. Thus, Ssaia must be disabled for the guest if AIA patches are not available. Here is the example command. ``` ./lkvm-static run -m 256 -c2 --console serial -p "console=ttyS0 earlycon" --disable-ssaia -k ./Image --debug ``` The series has been tested only in Qemu. Here is the snippet of the perf running inside a kvm guest. =================================================== $ perf record -e cycles -e instructions perf bench sched messaging -g 5 ... $ Running 'sched/messaging' benchmark: ... [ 45.928723] perf_duration_warn: 2 callbacks suppressed [ 45.929000] perf: interrupt took too long (484426 > 483186), lowering kernel.perf_event_max_sample_rate to 250 $ 20 sender and receiver processes per group $ 5 groups == 200 processes run Total time: 14.220 [sec] [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.117 MB perf.data (1942 samples) ] $ perf report --stdio $ To display the perf.data header info, please use --header/--header-only optio> $ $ $ Total Lost Samples: 0 $ $ Samples: 943 of event 'cycles' $ Event count (approx.): 5128976844 $ $ Overhead Command Shared Object Symbol > $ ........ ............... ........................... .....................> $ 7.59% sched-messaging [kernel.kallsyms] [k] memcpy 5.48% sched-messaging [kernel.kallsyms] [k] percpu_counter_ad> 5.24% sched-messaging [kernel.kallsyms] [k] __sbi_rfence_v02_> 4.00% sched-messaging [kernel.kallsyms] [k] _raw_spin_unlock_> 3.79% sched-messaging [kernel.kallsyms] [k] set_pte_range 3.72% sched-messaging [kernel.kallsyms] [k] next_uptodate_fol> 3.46% sched-messaging [kernel.kallsyms] [k] filemap_map_pages 3.31% sched-messaging [kernel.kallsyms] [k] handle_mm_fault 3.20% sched-messaging [kernel.kallsyms] [k] finish_task_switc> 3.16% sched-messaging [kernel.kallsyms] [k] clear_page 3.03% sched-messaging [kernel.kallsyms] [k] mtree_range_walk 2.42% sched-messaging [kernel.kallsyms] [k] flush_icache_pte =================================================== [1] https://github.com/riscv-non-isa/riscv-sbi-doc Changes from v7->v8: 1. Updated event states so that shared memory is updated only during stop operations. 2. Avoid clobbering lower XLEN counter/overflow values in shared memory by maintaining a temporary copy for RV32. 3. Improved overflow handling in snapshot case by supporting all 64 values. 4. Minor cleanups based on suggestions on v7. Changes from v6->v7: 1. Used SBI_SHMEM_DISABLE in the driver. 2. Added RB Tags. 3. Improved the sbi_pmu_test commandline to allow disabling multiple tests. Changes from v5->v6: 1. Added a patch for command line option for the sbi pmu tests. 2. Removed redundant prints and restructure the code little bit. 3. Added a patch for computing the sbi minor version correctly. 4. Addressed all other comments on v5. Changes from v4->v5: 1. Moved sbi related definitions to its own header file from processor.h 2. Added few helper functions for selftests. 3. Improved firmware counter read and RV32 start/stop functions. 4. Converted all the shifting operations to use BIT macro 5. Addressed all other comments on v4. Changes from v3->v4: 1. Added selftests. 2. Fixed an issue to clear the interrupt pending bits. 3. Fixed the counter index in snapshot memory start function. Changes from v2->v3: 1. Fixed a patchwork warning on patch6. 2. Fixed a comment formatting & nit fix in PATCH 3 & 5. 3. Moved the hvien update and sscofpmf enabling to PATCH 9 from PATCH 8. Changes from v1->v2: 1. Fixed warning/errors from patchwork CI. 2. Rebased on top of kvm-next. 3. Added Acked-by tags. Changes from RFC->v1: 1. Addressed all the comments on RFC series. 2. Removed PATCH2 and merged into later patches. 3. Added 2 more patches for minor fixes. 4. Fixed KVM boot issue without Ssaia and made sscofpmf in guest dependent on Ssaia in the host. Atish Patra (24): RISC-V: Fix the typo in Scountovf CSR name RISC-V: Add FIRMWARE_READ_HI definition drivers/perf: riscv: Read upper bits of a firmware counter drivers/perf: riscv: Use BIT macro for shifting operations RISC-V: Add SBI PMU snapshot definitions RISC-V: KVM: Rename the SBI_STA_SHMEM_DISABLE to a generic name RISC-V: Use the minor version mask while computing sbi version drivers/perf: riscv: Fix counter mask iteration for RV32 drivers/perf: riscv: Implement SBI PMU snapshot function RISC-V: KVM: Fix the initial sample period value RISC-V: KVM: No need to update the counter value during reset RISC-V: KVM: No need to exit to the user space if perf event failed RISC-V: KVM: Implement SBI PMU Snapshot feature RISC-V: KVM: Add perf sampling support for guests RISC-V: KVM: Support 64 bit firmware counters on RV32 RISC-V: KVM: Improve firmware counter read function KVM: riscv: selftests: Move sbi definitions to its own header file KVM: riscv: selftests: Add helper functions for extension checks KVM: riscv: selftests: Add Sscofpmf to get-reg-list test KVM: riscv: selftests: Add SBI PMU extension definitions KVM: riscv: selftests: Add SBI PMU selftest KVM: riscv: selftests: Add a test for PMU snapshot functionality KVM: riscv: selftests: Add a test for counter overflow KVM: riscv: selftests: Add commandline option for SBI PMU test arch/riscv/include/asm/csr.h | 5 +- arch/riscv/include/asm/kvm_vcpu_pmu.h | 16 +- arch/riscv/include/asm/sbi.h | 38 +- arch/riscv/include/uapi/asm/kvm.h | 1 + arch/riscv/kernel/paravirt.c | 6 +- arch/riscv/kvm/aia.c | 5 + arch/riscv/kvm/vcpu.c | 15 +- arch/riscv/kvm/vcpu_onereg.c | 6 + arch/riscv/kvm/vcpu_pmu.c | 260 ++++++- arch/riscv/kvm/vcpu_sbi_pmu.c | 17 +- arch/riscv/kvm/vcpu_sbi_sta.c | 4 +- drivers/perf/riscv_pmu.c | 1 + drivers/perf/riscv_pmu_sbi.c | 309 +++++++- include/linux/perf/riscv_pmu.h | 6 + tools/testing/selftests/kvm/Makefile | 1 + .../selftests/kvm/include/riscv/processor.h | 49 +- .../testing/selftests/kvm/include/riscv/sbi.h | 141 ++++ .../selftests/kvm/include/riscv/ucall.h | 1 + .../selftests/kvm/lib/riscv/processor.c | 12 + .../testing/selftests/kvm/riscv/arch_timer.c | 2 +- .../selftests/kvm/riscv/get-reg-list.c | 4 + .../selftests/kvm/riscv/sbi_pmu_test.c | 681 ++++++++++++++++++ tools/testing/selftests/kvm/steal_time.c | 4 +- 23 files changed, 1467 insertions(+), 117 deletions(-) create mode 100644 tools/testing/selftests/kvm/include/riscv/sbi.h create mode 100644 tools/testing/selftests/kvm/riscv/sbi_pmu_test.c --- 2.34.1