From patchwork Fri Mar 15 08:07:03 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bibo Mao X-Patchwork-Id: 13593152 Received: from mail.loongson.cn (mail.loongson.cn [114.242.206.163]) by smtp.subspace.kernel.org (Postfix) with ESMTP id EA408EEC4; Fri, 15 Mar 2024 08:07:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=114.242.206.163 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710490046; cv=none; b=UPLVFIdDfBR5VJrwy9Dkhdn3dkU7WMVILHoIsk/rSfCMBZhJOdvwZecpQxG0tTyUWOzyrJhBkvt4ECgHACQ0Khj8qxYEsRQGbpt7z3xWcNRVdslzvnP52qqdgDStzS8NKwa/XGfLePzWDCxwpPCtIhbzkFy5eTW2NTCs2aKwvaY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710490046; c=relaxed/simple; bh=yS/ThWdcky27h+yGYrh7nmkWzopcZ9gUz7yXOHT971M=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=QWr+PIpxvIVmuqDzSTNKBx0o+bHS7GaOYSAGI5CTfVXHww2oRA1XqEupg7TvIyae5mCkGuQxMRKJQdxy7vkrC/7XiLI4Bv9urW5puKGLPV0jVXr7JuAA6fBbWjLWmvPYeTiHdz8mDSZLm2zP86kCPZvPOP5Dp6bWSSNywvYum+Y= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=loongson.cn; spf=pass smtp.mailfrom=loongson.cn; arc=none smtp.client-ip=114.242.206.163 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=loongson.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=loongson.cn Received: from loongson.cn (unknown [10.2.5.213]) by gateway (Coremail) with SMTP id _____8CxWOizAfRlMmUZAA--.41703S3; Fri, 15 Mar 2024 16:07:15 +0800 (CST) Received: from localhost.localdomain (unknown [10.2.5.213]) by localhost.localdomain (Coremail) with SMTP id AQAAf8Cx_c6uAfRl4MZaAA--.41676S2; Fri, 15 Mar 2024 16:07:10 +0800 (CST) From: Bibo Mao To: Huacai Chen , Tianrui Zhao , WANG Xuerui , Juergen Gross , Paolo Bonzini , Jonathan Corbet Cc: loongarch@lists.linux.dev, linux-kernel@vger.kernel.org, virtualization@lists.linux.dev, kvm@vger.kernel.org Subject: [PATCH v7 0/7] LoongArch: Add pv ipi support on LoongArch VM Date: Fri, 15 Mar 2024 16:07:03 +0800 Message-Id: <20240315080710.2812974-1-maobibo@loongson.cn> X-Mailer: git-send-email 2.39.3 Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-CM-TRANSID: AQAAf8Cx_c6uAfRl4MZaAA--.41676S2 X-CM-SenderInfo: xpdruxter6z05rqj20fqof0/ X-Coremail-Antispam: 1Uk129KBj93XoW3Xw17Gw4xGF15Kr4fWFW8KrX_yoW7XF1fpF WUurn3Wr4kGr93Awnxtas3ur98Jw4xG3yaq3WayrW8CrW2qFyUZr48Kr98Aas5Jws3JFW0 qF1rGw1Yg3WDAabCm3ZEXasCq-sJn29KB7ZKAUJUUUUx529EdanIXcx71UUUUU7KY7ZEXa sCq-sGcSsGvfJ3Ic02F40EFcxC0VAKzVAqx4xG6I80ebIjqfuFe4nvWSU5nxnvy29KBjDU 0xBIdaVrnRJUUUBIb4IE77IF4wAFF20E14v26r1j6r4UM7CY07I20VC2zVCF04k26cxKx2 IYs7xG6rWj6s0DM7CIcVAFz4kK6r1a6r1DM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48v e4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Xr0_Ar1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI 0_Gr0_Cr1l84ACjcxK6I8E87Iv67AKxVW8Jr0_Cr1UM28EF7xvwVC2z280aVCY1x0267AK xVW8Jr0_Cr1UM2kKe7AKxVWUAVWUtwAS0I0E0xvYzxvE52x082IY62kv0487Mc804VCY07 AIYIkI8VC2zVCFFI0UMc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7IYx2IY67AKxVWU tVWrXwAv7VC2z280aVAFwI0_Gr0_Cr1lOx8S6xCaFVCjc4AY6r1j6r4UM4x0Y48IcxkI7V AKI48JMxkF7I0En4kS14v26r126r1DMxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY 6r1j6r4UMxCIbckI1I0E14v26r126r1DMI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7 xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxVWUtVW8ZwCIc40Y0x0EwIxGrwCI42IY6xII jxv20xvE14v26r4j6ryUMIIF0xvE2Ix0cI8IcVCY1x0267AKxVW8JVWxJwCI42IY6xAIw2 0EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Gr0_Cr1lIxAIcVC2z280aVCY1x02 67AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7IU14v3UUUUUU== On physical machine, ipi HW uses IOCSR registers, however there is trap into hypervisor when vcpu accesses IOCSR registers if system is in VM mode. SWI is a interrupt mechanism like SGI on ARM, software can send interrupt to CPU, only that on LoongArch SWI can only be sent to local CPU now. So SWI can not used for IPI on real HW system, however it can be used on VM when combined with hypercall method. IPI can be sent with hypercall method and SWI interrupt is injected to vcpu, vcpu can treat SWI interrupt as IPI. With PV IPI supported, there is one trap with IPI sending, however with IPI receiving there is no trap. with IOCSR HW ipi method, there will be one trap with IPI sending and two trap with ipi receiving. Also IPI multicast support is added for VM, the idea comes from x86 PV ipi. IPI can be sent to 128 vcpus in one time. With IPI multicast support, trap will be reduced greatly. Here is the microbenchmarck data with "perf bench futex wake" testcase on 3C5000 single-way machine, there are 16 cpus on 3C5000 single-way machine, VM has 16 vcpus also. The benchmark data is ms time unit to wakeup 16 threads, the performance is better if data is smaller. physical machine 0.0176 ms VM original 0.1140 ms VM with pv ipi patch 0.0481 ms It passes to boot with 128/256 vcpus, and passes to run runltp command with package ltp-20230516. --- Change in v7: 1. Refine LoongArch virt document by review comments. 2. Add function kvm_read_reg()/kvm_write_reg() in hypercall emulation, and later it can be used for other trap emulations. Change in V6: 1. Add privilege checking when emulating cpucfg at index 0x4000000 -- 0x400000FF, return 0 if not executed at kernel mode. 2. Add document about LoongArch pv ipi with new creatly directory Documentation/virt/kvm/loongarch/ 3. Fix pv ipi handling in kvm backend function kvm_pv_send_ipi(), where min should plus BITS_PER_LONG with second bitmap, otherwise VM with more than 64 vpus fails to boot. 4. Adjust patch order and code refine with review comments. Change in V5: 1. Refresh function/macro name from review comments. Change in V4: 1. Modfiy pv ipi hook function name call_func_ipi() and call_func_single_ipi() with send_ipi_mask()/send_ipi_single(), since pv ipi is used for both remote function call and reschedule notification. 2. Refresh changelog. Change in V3: 1. Add 128 vcpu ipi multicast support like x86 2. Change cpucfg base address from 0x10000000 to 0x40000000, in order to avoid confliction with future hw usage 3. Adjust patch order in this patchset, move patch Refine-ipi-ops-on-LoongArch-platform to the first one. Change in V2: 1. Add hw cpuid map support since ipi routing uses hw cpuid 2. Refine changelog description 3. Add hypercall statistic support for vcpu 4. Set percpu pv ipi message buffer aligned with cacheline 5. Refine pv ipi send logic, do not send ipi message with if there is pending ipi message. --- Bibo Mao (7): LoongArch/smp: Refine some ipi functions on LoongArch platform LoongArch: KVM: Add hypercall instruction emulation support LoongArch: KVM: Add cpucfg area for kvm hypervisor LoongArch: KVM: Add vcpu search support from physical cpuid LoongArch: KVM: Add pv ipi support on kvm side LoongArch: Add pv ipi support on guest kernel side Documentation: KVM: Add hypercall for LoongArch Documentation/virt/kvm/index.rst | 1 + .../virt/kvm/loongarch/hypercalls.rst | 82 +++++++++ Documentation/virt/kvm/loongarch/index.rst | 10 ++ arch/loongarch/Kconfig | 9 + arch/loongarch/include/asm/Kbuild | 1 - arch/loongarch/include/asm/hardirq.h | 5 + arch/loongarch/include/asm/inst.h | 1 + arch/loongarch/include/asm/irq.h | 10 +- arch/loongarch/include/asm/kvm_host.h | 27 +++ arch/loongarch/include/asm/kvm_para.h | 155 ++++++++++++++++++ arch/loongarch/include/asm/kvm_vcpu.h | 11 ++ arch/loongarch/include/asm/loongarch.h | 11 ++ arch/loongarch/include/asm/paravirt.h | 27 +++ .../include/asm/paravirt_api_clock.h | 1 + arch/loongarch/include/asm/smp.h | 31 ++-- arch/loongarch/include/uapi/asm/Kbuild | 2 - arch/loongarch/kernel/Makefile | 1 + arch/loongarch/kernel/irq.c | 24 +-- arch/loongarch/kernel/paravirt.c | 151 +++++++++++++++++ arch/loongarch/kernel/perf_event.c | 14 +- arch/loongarch/kernel/smp.c | 62 ++++--- arch/loongarch/kernel/time.c | 12 +- arch/loongarch/kvm/exit.c | 141 ++++++++++++++-- arch/loongarch/kvm/vcpu.c | 94 ++++++++++- arch/loongarch/kvm/vm.c | 11 ++ 25 files changed, 792 insertions(+), 102 deletions(-) create mode 100644 Documentation/virt/kvm/loongarch/hypercalls.rst create mode 100644 Documentation/virt/kvm/loongarch/index.rst create mode 100644 arch/loongarch/include/asm/kvm_para.h create mode 100644 arch/loongarch/include/asm/paravirt.h create mode 100644 arch/loongarch/include/asm/paravirt_api_clock.h delete mode 100644 arch/loongarch/include/uapi/asm/Kbuild create mode 100644 arch/loongarch/kernel/paravirt.c base-commit: 480e035fc4c714fb5536e64ab9db04fedc89e910