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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6E5C0C433EF for ; Tue, 4 Jan 2022 13:19:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233429AbiADNTx (ORCPT ); Tue, 4 Jan 2022 08:19:53 -0500 Received: from gloria.sntech.de ([185.11.138.130]:38740 "EHLO gloria.sntech.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231189AbiADNTw (ORCPT ); Tue, 4 Jan 2022 08:19:52 -0500 Received: from ip5b412258.dynamic.kabel-deutschland.de ([91.65.34.88] helo=diego.localnet) by gloria.sntech.de with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1n4jj4-0004br-8W; Tue, 04 Jan 2022 14:19:42 +0100 From: Heiko =?ISO-8859-1?Q?St=FCbner?= To: linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org Cc: Atish Patra , Anup Patel , Atish Patra , Albert Ou , Heinrich Schuchardt , Kefeng Wang , kvm-riscv@lists.infradead.org, kvm@vger.kernel.org, linux-riscv@lists.infradead.org, Palmer Dabbelt , Paul Walmsley , Atish Patra Subject: Re: [PATCH v5 1/5] RISC-V: KVM: Mark the existing SBI implementation as v01 Date: Tue, 04 Jan 2022 14:19:41 +0100 Message-ID: <6615284.qex3tTltCR@diego> In-Reply-To: <20211118083912.981995-2-atishp@rivosinc.com> References: <20211118083912.981995-1-atishp@rivosinc.com> <20211118083912.981995-2-atishp@rivosinc.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Atish, Am Donnerstag, 18. November 2021, 09:39:08 CET schrieb Atish Patra: > From: Atish Patra > > The existing SBI specification impelementation follows v0.1 > specification. The latest specification allows more > scalability and performance improvements. > > Rename the existing implementation as v01 and provide a way to allow > future extensions. > > Reviewed-by: Anup Patel > Signed-off-by: Atish Patra > Signed-off-by: Atish Patra > --- > diff --git a/arch/riscv/kvm/vcpu_sbi.c b/arch/riscv/kvm/vcpu_sbi.c > index eb3c045edf11..32376906ff20 100644 > --- a/arch/riscv/kvm/vcpu_sbi.c > +++ b/arch/riscv/kvm/vcpu_sbi.c > @@ -1,5 +1,5 @@ > // SPDX-License-Identifier: GPL-2.0 > -/** > +/* > * Copyright (c) 2019 Western Digital Corporation or its affiliates. > * > * Authors: This got already fixed by [0] commit 0e2e64192100 ("riscv: kvm: fix non-kernel-doc comment block") so this patch doesn't apply cleanly anymore. This looks like it is a prerequisite for the sparse-hart-id series, so a respin might be in order. Heiko [0] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0e2e641921000ffc647b12918cdfcc504a9f6e3b > @@ -12,9 +12,25 @@ > #include > #include > #include > +#include > > -#define SBI_VERSION_MAJOR 0 > -#define SBI_VERSION_MINOR 1 > +static int kvm_linux_err_map_sbi(int err) > +{ > + switch (err) { > + case 0: > + return SBI_SUCCESS; > + case -EPERM: > + return SBI_ERR_DENIED; > + case -EINVAL: > + return SBI_ERR_INVALID_PARAM; > + case -EFAULT: > + return SBI_ERR_INVALID_ADDRESS; > + case -EOPNOTSUPP: > + return SBI_ERR_NOT_SUPPORTED; > + default: > + return SBI_ERR_FAILURE; > + }; > +} > > static void kvm_riscv_vcpu_sbi_forward(struct kvm_vcpu *vcpu, > struct kvm_run *run) > @@ -72,21 +88,19 @@ static void kvm_sbi_system_shutdown(struct kvm_vcpu *vcpu, > run->exit_reason = KVM_EXIT_SYSTEM_EVENT; > } > > -int kvm_riscv_vcpu_sbi_ecall(struct kvm_vcpu *vcpu, struct kvm_run *run) > +static int kvm_sbi_ext_v01_handler(struct kvm_vcpu *vcpu, struct kvm_run *run, > + unsigned long *out_val, > + struct kvm_cpu_trap *utrap, > + bool *exit) > { > ulong hmask; > - int i, ret = 1; > + int i, ret = 0; > u64 next_cycle; > struct kvm_vcpu *rvcpu; > - bool next_sepc = true; > struct cpumask cm, hm; > struct kvm *kvm = vcpu->kvm; > - struct kvm_cpu_trap utrap = { 0 }; > struct kvm_cpu_context *cp = &vcpu->arch.guest_context; > > - if (!cp) > - return -EINVAL; > - > switch (cp->a7) { > case SBI_EXT_0_1_CONSOLE_GETCHAR: > case SBI_EXT_0_1_CONSOLE_PUTCHAR: > @@ -95,8 +109,7 @@ int kvm_riscv_vcpu_sbi_ecall(struct kvm_vcpu *vcpu, struct kvm_run *run) > * handled in kernel so we forward these to user-space > */ > kvm_riscv_vcpu_sbi_forward(vcpu, run); > - next_sepc = false; > - ret = 0; > + *exit = true; > break; > case SBI_EXT_0_1_SET_TIMER: > #if __riscv_xlen == 32 > @@ -104,47 +117,42 @@ int kvm_riscv_vcpu_sbi_ecall(struct kvm_vcpu *vcpu, struct kvm_run *run) > #else > next_cycle = (u64)cp->a0; > #endif > - kvm_riscv_vcpu_timer_next_event(vcpu, next_cycle); > + ret = kvm_riscv_vcpu_timer_next_event(vcpu, next_cycle); > break; > case SBI_EXT_0_1_CLEAR_IPI: > - kvm_riscv_vcpu_unset_interrupt(vcpu, IRQ_VS_SOFT); > + ret = kvm_riscv_vcpu_unset_interrupt(vcpu, IRQ_VS_SOFT); > break; > case SBI_EXT_0_1_SEND_IPI: > if (cp->a0) > hmask = kvm_riscv_vcpu_unpriv_read(vcpu, false, cp->a0, > - &utrap); > + utrap); > else > hmask = (1UL << atomic_read(&kvm->online_vcpus)) - 1; > - if (utrap.scause) { > - utrap.sepc = cp->sepc; > - kvm_riscv_vcpu_trap_redirect(vcpu, &utrap); > - next_sepc = false; > + if (utrap->scause) > break; > - } > + > for_each_set_bit(i, &hmask, BITS_PER_LONG) { > rvcpu = kvm_get_vcpu_by_id(vcpu->kvm, i); > - kvm_riscv_vcpu_set_interrupt(rvcpu, IRQ_VS_SOFT); > + ret = kvm_riscv_vcpu_set_interrupt(rvcpu, IRQ_VS_SOFT); > + if (ret < 0) > + break; > } > break; > case SBI_EXT_0_1_SHUTDOWN: > kvm_sbi_system_shutdown(vcpu, run, KVM_SYSTEM_EVENT_SHUTDOWN); > - next_sepc = false; > - ret = 0; > + *exit = true; > break; > case SBI_EXT_0_1_REMOTE_FENCE_I: > case SBI_EXT_0_1_REMOTE_SFENCE_VMA: > case SBI_EXT_0_1_REMOTE_SFENCE_VMA_ASID: > if (cp->a0) > hmask = kvm_riscv_vcpu_unpriv_read(vcpu, false, cp->a0, > - &utrap); > + utrap); > else > hmask = (1UL << atomic_read(&kvm->online_vcpus)) - 1; > - if (utrap.scause) { > - utrap.sepc = cp->sepc; > - kvm_riscv_vcpu_trap_redirect(vcpu, &utrap); > - next_sepc = false; > + if (utrap->scause) > break; > - } > + > cpumask_clear(&cm); > for_each_set_bit(i, &hmask, BITS_PER_LONG) { > rvcpu = kvm_get_vcpu_by_id(vcpu->kvm, i); > @@ -154,22 +162,97 @@ int kvm_riscv_vcpu_sbi_ecall(struct kvm_vcpu *vcpu, struct kvm_run *run) > } > riscv_cpuid_to_hartid_mask(&cm, &hm); > if (cp->a7 == SBI_EXT_0_1_REMOTE_FENCE_I) > - sbi_remote_fence_i(cpumask_bits(&hm)); > + ret = sbi_remote_fence_i(cpumask_bits(&hm)); > else if (cp->a7 == SBI_EXT_0_1_REMOTE_SFENCE_VMA) > - sbi_remote_hfence_vvma(cpumask_bits(&hm), > + ret = sbi_remote_hfence_vvma(cpumask_bits(&hm), > cp->a1, cp->a2); > else > - sbi_remote_hfence_vvma_asid(cpumask_bits(&hm), > + ret = sbi_remote_hfence_vvma_asid(cpumask_bits(&hm), > cp->a1, cp->a2, cp->a3); > break; > default: > + ret = -EINVAL; > + break; > + } > + > + return ret; > +} > + > +const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_v01 = { > + .extid_start = SBI_EXT_0_1_SET_TIMER, > + .extid_end = SBI_EXT_0_1_SHUTDOWN, > + .handler = kvm_sbi_ext_v01_handler, > +}; > + > +static const struct kvm_vcpu_sbi_extension *sbi_ext[] = { > + &vcpu_sbi_ext_v01, > +}; > + > +const struct kvm_vcpu_sbi_extension *kvm_vcpu_sbi_find_ext(unsigned long extid) > +{ > + int i = 0; > + > + for (i = 0; i < ARRAY_SIZE(sbi_ext); i++) { > + if (sbi_ext[i]->extid_start <= extid && > + sbi_ext[i]->extid_end >= extid) > + return sbi_ext[i]; > + } > + > + return NULL; > +} > + > +int kvm_riscv_vcpu_sbi_ecall(struct kvm_vcpu *vcpu, struct kvm_run *run) > +{ > + int ret = 1; > + bool next_sepc = true; > + bool userspace_exit = false; > + struct kvm_cpu_context *cp = &vcpu->arch.guest_context; > + const struct kvm_vcpu_sbi_extension *sbi_ext; > + struct kvm_cpu_trap utrap = { 0 }; > + unsigned long out_val = 0; > + bool ext_is_v01 = false; > + > + sbi_ext = kvm_vcpu_sbi_find_ext(cp->a7); > + if (sbi_ext && sbi_ext->handler) { > + if (cp->a7 >= SBI_EXT_0_1_SET_TIMER && > + cp->a7 <= SBI_EXT_0_1_SHUTDOWN) > + ext_is_v01 = true; > + ret = sbi_ext->handler(vcpu, run, &out_val, &utrap, &userspace_exit); > + } else { > /* Return error for unsupported SBI calls */ > cp->a0 = SBI_ERR_NOT_SUPPORTED; > - break; > + goto ecall_done; > + } > + > + /* Handle special error cases i.e trap, exit or userspace forward */ > + if (utrap.scause) { > + /* No need to increment sepc or exit ioctl loop */ > + ret = 1; > + utrap.sepc = cp->sepc; > + kvm_riscv_vcpu_trap_redirect(vcpu, &utrap); > + next_sepc = false; > + goto ecall_done; > } > > + /* Exit ioctl loop or Propagate the error code the guest */ > + if (userspace_exit) { > + next_sepc = false; > + ret = 0; > + } else { > + /** > + * SBI extension handler always returns an Linux error code. Convert > + * it to the SBI specific error code that can be propagated the SBI > + * caller. > + */ > + ret = kvm_linux_err_map_sbi(ret); > + cp->a0 = ret; > + ret = 1; > + } > +ecall_done: > if (next_sepc) > cp->sepc += 4; > + if (!ext_is_v01) > + cp->a1 = out_val; > > return ret; > } >