From patchwork Mon Aug 3 17:58:46 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Atish Patra X-Patchwork-Id: 11698509 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 928CA912 for ; Mon, 3 Aug 2020 17:59:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9C89522CE3 for ; Mon, 3 Aug 2020 17:59:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=wdc.com header.i=@wdc.com header.b="S7yypu5q" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728661AbgHCR7V (ORCPT ); Mon, 3 Aug 2020 13:59:21 -0400 Received: from esa4.hgst.iphmx.com ([216.71.154.42]:64728 "EHLO esa4.hgst.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728608AbgHCR7T (ORCPT ); Mon, 3 Aug 2020 13:59:19 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=wdc.com; i=@wdc.com; q=dns/txt; s=dkim.wdc.com; t=1596477558; x=1628013558; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=NetUIh98Lh3twSMeBSYk+d3Kbtv98SHWIpPw/siizNE=; b=S7yypu5q1Wtpc75cy4bwS33Q+5olIS9R4ifCrS76bwq0yzjf99T2kxBC LN9h9Pu92Ao7DPgPYdttRATZSyIK0KzK31oG6d9imbwK9RTldBOejahAh XXP12SlgR/pxXJ3JqO9eGHTcmZRt5eiz+CaHye7xqPQE4px/1OBkZA7Cm DzgSGQncYjPdCF8exUJtipn3VWHbsBfPVZXHOGFbCmJpmtQQFVZrXHtNX T2gbyCJgRuMXlvadlt2Pk3Bbdf7OnmHX/EjGWYKz4EHfwIuwlGf0jMIM0 e847KDgbSeOKdSXG2LKu6wQJJJeiAUNvSTPE393cJ2ka9XTRlpp7kpWFn Q==; IronPort-SDR: +cqPQVBLj0cY/M+eu7sZSydhwKwiUKRfWmyzSzyt6uaYe9NHeIvadLQbiCHi2F8jK2ROe6cEE1 syD1UPkRxjr+CXXRw3rCnA+zYVCyW0Kit26vb5ILmu46d949NyURo8L01dtDzGUQiQKkHagXYP 0VQTiYJSFBWIkxHLSThPWlPqr3OdbBJfE5MCDXkKDu+ClYRE9nnBZ72sK6mUELbGMLoVw787Ln SIzeWgdzEwbzZp+lfmajmlrVs/NNvWDF5guvpmG07gn8I/QqxfhuSmsjsKIGkKZojo63sK620O /J8= X-IronPort-AV: E=Sophos;i="5.75,430,1589212800"; d="scan'208";a="144033188" Received: from h199-255-45-14.hgst.com (HELO uls-op-cesaep01.wdc.com) ([199.255.45.14]) by ob1.hgst.iphmx.com with ESMTP; 04 Aug 2020 01:59:07 +0800 IronPort-SDR: Ad2+ucYIEEFTnT7EL0k2nG8uTHgHswcGGSc+Fk+RUl0MuwKKqVFXji4ld/2XMaI2FzebZO7wPC TtEOH2PcKFsA== Received: from uls-op-cesaip01.wdc.com ([10.248.3.36]) by uls-op-cesaep01.wdc.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Aug 2020 10:47:09 -0700 IronPort-SDR: 7X+6upqgL4IKeTt7Dwe+wA4Ydqh+2t9rQWgGRVP6Oub5IbMwTdcLxybcvMUXZQzYh6OcQ00nD+ oAvQYMf10Thw== WDCIronportException: Internal Received: from cnf007830.ad.shared (HELO jedi-01.hgst.com) ([10.86.58.196]) by uls-op-cesaip01.wdc.com with ESMTP; 03 Aug 2020 10:59:06 -0700 From: Atish Patra To: kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org Cc: Atish Patra , Albert Ou , Anup Patel , Kefeng Wang , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Palmer Dabbelt , Paul Walmsley , Thomas Gleixner , Alexander Graf , Paolo Bonzini , Alistair Francis Subject: [PATCH 6/6] RISC-V: Add SBI HSM extension in KVM Date: Mon, 3 Aug 2020 10:58:46 -0700 Message-Id: <20200803175846.26272-7-atish.patra@wdc.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20200803175846.26272-1-atish.patra@wdc.com> References: <20200803175846.26272-1-atish.patra@wdc.com> MIME-Version: 1.0 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org SBI HSM extension allows OS to start/stop harts any time. It also allows ordered booting of harts instead of random booting. Implement SBI HSM exntesion and designate the vcpu 0 as the boot vcpu id. All other non-zero non-booting vcpus should be brought up by the OS implementing HSM extension. If the guest OS doesn't implement HSM extension, only single vcpu will be available to OS. Signed-off-by: Atish Patra --- arch/riscv/include/asm/sbi.h | 1 + arch/riscv/kvm/Makefile | 2 +- arch/riscv/kvm/vcpu.c | 19 ++++++ arch/riscv/kvm/vcpu_sbi.c | 4 ++ arch/riscv/kvm/vcpu_sbi_hsm.c | 109 ++++++++++++++++++++++++++++++++++ 5 files changed, 134 insertions(+), 1 deletion(-) create mode 100644 arch/riscv/kvm/vcpu_sbi_hsm.c diff --git a/arch/riscv/include/asm/sbi.h b/arch/riscv/include/asm/sbi.h index 7d8f2b389253..e18ba15fc9e1 100644 --- a/arch/riscv/include/asm/sbi.h +++ b/arch/riscv/include/asm/sbi.h @@ -90,6 +90,7 @@ enum sbi_hsm_hart_status { #define SBI_ERR_INVALID_PARAM -3 #define SBI_ERR_DENIED -4 #define SBI_ERR_INVALID_ADDRESS -5 +#define SBI_ERR_ALREADY_AVAILABLE -6 extern unsigned long sbi_spec_version; struct sbiret { diff --git a/arch/riscv/kvm/Makefile b/arch/riscv/kvm/Makefile index b0e8b760fda0..5c3c40636067 100644 --- a/arch/riscv/kvm/Makefile +++ b/arch/riscv/kvm/Makefile @@ -10,5 +10,5 @@ kvm-objs := $(common-objs-y) kvm-objs += main.o vm.o vmid.o tlb.o mmu.o kvm-objs += vcpu.o vcpu_exit.o vcpu_switch.o vcpu_timer.o -kvm-objs += vcpu_sbi.o vcpu_sbi_base.o vcpu_sbi_legacy.o vcpu_sbi_replace.o +kvm-objs += vcpu_sbi.o vcpu_sbi_base.o vcpu_sbi_legacy.o vcpu_sbi_replace.o vcpu_sbi_hsm.o obj-$(CONFIG_KVM) += kvm.o diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c index adb0815951aa..f921d7771f40 100644 --- a/arch/riscv/kvm/vcpu.c +++ b/arch/riscv/kvm/vcpu.c @@ -130,6 +130,13 @@ static void kvm_riscv_reset_vcpu(struct kvm_vcpu *vcpu) struct kvm_vcpu_csr *reset_csr = &vcpu->arch.guest_reset_csr; struct kvm_cpu_context *cntx = &vcpu->arch.guest_context; struct kvm_cpu_context *reset_cntx = &vcpu->arch.guest_reset_context; + bool loaded; + + /* Disable preemption to avoid race with preempt notifiers */ + preempt_disable(); + loaded = (vcpu->cpu != -1); + if (loaded) + kvm_arch_vcpu_put(vcpu); memcpy(csr, reset_csr, sizeof(*csr)); @@ -141,6 +148,11 @@ static void kvm_riscv_reset_vcpu(struct kvm_vcpu *vcpu) WRITE_ONCE(vcpu->arch.irqs_pending, 0); WRITE_ONCE(vcpu->arch.irqs_pending_mask, 0); + + /* Reset the guest CSRs for hotplug usecase */ + if (loaded) + kvm_arch_vcpu_load(vcpu, smp_processor_id()); + preempt_enable(); } int kvm_arch_vcpu_precreate(struct kvm *kvm, unsigned int id) @@ -182,6 +194,13 @@ int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu) void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu) { + /** + * vcpu with id 0 is the designated boot cpu. + * Keep all vcpus with non-zero cpu id in power-off state so that they + * can brought to online using SBI HSM extension. + */ + if (vcpu->vcpu_idx != 0) + kvm_riscv_vcpu_power_off(vcpu); } void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu) diff --git a/arch/riscv/kvm/vcpu_sbi.c b/arch/riscv/kvm/vcpu_sbi.c index 8c3ca522dddb..2f59b56d8640 100644 --- a/arch/riscv/kvm/vcpu_sbi.c +++ b/arch/riscv/kvm/vcpu_sbi.c @@ -25,6 +25,8 @@ static int kvm_linux_err_map_sbi(int err) return SBI_ERR_INVALID_ADDRESS; case -ENOTSUPP: return SBI_ERR_NOT_SUPPORTED; + case -EALREADY: + return SBI_ERR_ALREADY_AVAILABLE; default: return SBI_ERR_FAILURE; }; @@ -35,6 +37,7 @@ extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_base; extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_time; extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_ipi; extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_rfence; +extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_hsm; static const struct kvm_vcpu_sbi_extension *sbi_ext[] = { &vcpu_sbi_ext_legacy, @@ -42,6 +45,7 @@ static const struct kvm_vcpu_sbi_extension *sbi_ext[] = { &vcpu_sbi_ext_time, &vcpu_sbi_ext_ipi, &vcpu_sbi_ext_rfence, + &vcpu_sbi_ext_hsm, }; void kvm_riscv_vcpu_sbi_forward(struct kvm_vcpu *vcpu, struct kvm_run *run) diff --git a/arch/riscv/kvm/vcpu_sbi_hsm.c b/arch/riscv/kvm/vcpu_sbi_hsm.c new file mode 100644 index 000000000000..f8ab64f5f344 --- /dev/null +++ b/arch/riscv/kvm/vcpu_sbi_hsm.c @@ -0,0 +1,109 @@ +// SPDX-License-Identifier: GPL-2.0 +/** + * Copyright (c) 2020 Western Digital Corporation or its affiliates. + * + * Authors: + * Atish Patra + */ + +#include +#include +#include +#include +#include +#include + +static int kvm_sbi_hsm_vcpu_start(struct kvm_vcpu *vcpu) +{ + struct kvm_cpu_context *reset_cntx; + struct kvm_cpu_context *cp = &vcpu->arch.guest_context; + struct kvm_vcpu *target_vcpu; + unsigned long target_vcpuid = cp->a0; + + target_vcpu = kvm_get_vcpu_by_id(vcpu->kvm, target_vcpuid); + if (!target_vcpu) + return -EINVAL; + if (!target_vcpu->arch.power_off) + return -EALREADY; + + reset_cntx = &target_vcpu->arch.guest_reset_context; + /* start address */ + reset_cntx->sepc = cp->a1; + /* target vcpu id to start */ + reset_cntx->a0 = target_vcpuid; + /* private data passed from kernel */ + reset_cntx->a1 = cp->a2; + kvm_make_request(KVM_REQ_VCPU_RESET, target_vcpu); + + /* Make sure that the reset request is enqueued before power on */ + smp_wmb(); + kvm_riscv_vcpu_power_on(target_vcpu); + + return 0; +} + +static int kvm_sbi_hsm_vcpu_stop(struct kvm_vcpu *vcpu) +{ + if ((!vcpu) || (vcpu->arch.power_off)) + return -EINVAL; + + kvm_riscv_vcpu_power_off(vcpu); + + return 0; +} + +static int kvm_sbi_hsm_vcpu_get_status(struct kvm_vcpu *vcpu) +{ + struct kvm_cpu_context *cp = &vcpu->arch.guest_context; + unsigned long target_vcpuid = cp->a0; + struct kvm_vcpu *target_vcpu; + + target_vcpu = kvm_get_vcpu_by_id(vcpu->kvm, target_vcpuid); + if (!target_vcpu) + return -EINVAL; + if (!target_vcpu->arch.power_off) + return SBI_HSM_HART_STATUS_STARTED; + else + return SBI_HSM_HART_STATUS_STOPPED; +} + +static int kvm_sbi_ext_hsm_handler(struct kvm_vcpu *vcpu, struct kvm_run *run, + unsigned long *out_val, + struct kvm_cpu_trap *utrap, + bool *exit) +{ + int ret = 0; + struct kvm_cpu_context *cp = &vcpu->arch.guest_context; + struct kvm *kvm = vcpu->kvm; + unsigned long funcid = cp->a6; + + if (!cp) + return -EINVAL; + switch (funcid) { + case SBI_EXT_HSM_HART_START: + mutex_lock(&kvm->lock); + ret = kvm_sbi_hsm_vcpu_start(vcpu); + mutex_unlock(&kvm->lock); + break; + case SBI_EXT_HSM_HART_STOP: + ret = kvm_sbi_hsm_vcpu_stop(vcpu); + break; + case SBI_EXT_HSM_HART_STATUS: + ret = kvm_sbi_hsm_vcpu_get_status(vcpu); + if (ret >= 0) { + *out_val = ret; + ret = 0; + } + break; + default: + ret = -ENOTSUPP; + } + + return ret; +} + +const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_hsm = { + .extid_start = SBI_EXT_HSM, + .extid_end = SBI_EXT_HSM, + .handler = kvm_sbi_ext_hsm_handler, +};