From mboxrd@z Thu Jan 1 00:00:00 1970 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B70AAC433F5 for ; Sat, 6 Nov 2021 04:42:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9BDFE60041 for ; Sat, 6 Nov 2021 04:42:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233489AbhKFEom (ORCPT ); Sat, 6 Nov 2021 00:44:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47132 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233419AbhKFEol (ORCPT ); Sat, 6 Nov 2021 00:44:41 -0400 Received: from mail-wm1-x333.google.com (mail-wm1-x333.google.com [IPv6:2a00:1450:4864:20::333]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7F5F0C061714 for ; Fri, 5 Nov 2021 21:42:00 -0700 (PDT) Received: by mail-wm1-x333.google.com with SMTP id b184-20020a1c1bc1000000b0033140bf8dd5so7770116wmb.5 for ; Fri, 05 Nov 2021 21:42:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=brainfault-org.20210112.gappssmtp.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=osEIpX8HJMe4eqljvoWc7K0MtnOg5c1wtCe6RJRNR8M=; b=53Qr0ABaQ8ml3mHx+ViHygFYO9Srx0xQy+ISPh7F6XVQFmLMiuri80XNs5pD8EFW4K Qx0mJ6L5UUh06No8eriU5r0tcxPJy1M+g28gVN7X5kKn1WLAoANgRHsD4ww8q0Db5XD5 tJZGC4a/Lz3x8KmMiHAfzyn+5Hvg0NW9n29ijUV9S76/wPwTKD++LsKm8u6yinVxkSsm DjsO+2GbUFdeo9B8RdBvUCbeGLzvkZpTx33Ocy9EpPP/+/19NCeVePCUfpY8C4wu7+T3 0w+GgFbP9o2zOGbkuPeYXNiT3HwfLMvgb5XXz6AGcst9SvtNacvAMHJpP9astfvlIrgu rj8Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=osEIpX8HJMe4eqljvoWc7K0MtnOg5c1wtCe6RJRNR8M=; b=Zc/+F/x9gqVioHtMPT6d16LEgLFZuhQCZ5KU5EErD8aRb7BBtLBDtydy5yzn0kohkS ZzL1hplYHuHD/hbmKILoORkGYFmXpiB45uP+Ou/+z1Jz0rN72R2dlSgmhDk5PWvkV4uT 9ytB/ZaVZL/h6ZO/UHgLzra087GRmssF/4a3002Zcp7hRIEonucWMwkX0107NiSmsj1m tMlLyr+5MQ6J4p/wLAo/KtQ6xYl4drjljqY12fdRQLf+aCyDYfya6BOIREb62Oxz3I/r 9LY0pMLVoo0+q9M4FxOZSfOGOPUmUq0rl1hXt2u3pmpTLGD5lm4IpHSdc/MoD0PXTFTo 0LJQ== X-Gm-Message-State: AOAM5311jZHZ5wP0q8dB84dnG15eaHmt+74NUSY8+Um4Cm4eiMuEQguw h3SdcxaQljr8CQ0+tFNJwADtIlBb0nr5D3aYoTNRY7d6mGg= X-Google-Smtp-Source: ABdhPJypkd5sBHzja14SC9/fasrrg1DA0Xr2PRjxlUd/BvBypMtqSepxh9GIJpjpN/CvbfbTr2eIdkdAn4/yotGsddw= X-Received: by 2002:a05:600c:354f:: with SMTP id i15mr18645457wmq.59.1636173718854; Fri, 05 Nov 2021 21:41:58 -0700 (PDT) MIME-Version: 1.0 References: <20211105235852.3011900-1-atish.patra@wdc.com> <20211105235852.3011900-2-atish.patra@wdc.com> In-Reply-To: <20211105235852.3011900-2-atish.patra@wdc.com> From: Anup Patel Date: Sat, 6 Nov 2021 10:11:47 +0530 Message-ID: Subject: Re: [PATCH v4 1/5] RISC-V: KVM: Mark the existing SBI implementation as v01 To: Atish Patra Cc: "linux-kernel@vger.kernel.org List" , Anup Patel , Heinrich Schuchardt , kvm-riscv@lists.infradead.org, KVM General , linux-riscv , Palmer Dabbelt , Paul Walmsley , Vincent Chen , Paolo Bonzini , Sean Christopherson Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Sat, Nov 6, 2021 at 5:29 AM Atish Patra wrote: > > The existing SBI specification impelementation follows v0.1 > specification. The latest specification known as v0.2 allows more > scalability and performance improvements. Please update commit description to not mention v0.2 as the latest SBI specification. > > Rename the existing implementation as v01 and provide a way to allow > future extensions. > > Signed-off-by: Atish Patra Otherwise it looks good to me. Reviewed-by: Anup Patel Regards, Anup > --- > arch/riscv/include/asm/kvm_vcpu_sbi.h | 29 +++++ > arch/riscv/kvm/vcpu_sbi.c | 147 +++++++++++++++++++++----- > 2 files changed, 147 insertions(+), 29 deletions(-) > create mode 100644 arch/riscv/include/asm/kvm_vcpu_sbi.h > > diff --git a/arch/riscv/include/asm/kvm_vcpu_sbi.h b/arch/riscv/include/asm/kvm_vcpu_sbi.h > new file mode 100644 > index 000000000000..1a4cb0db2d0b > --- /dev/null > +++ b/arch/riscv/include/asm/kvm_vcpu_sbi.h > @@ -0,0 +1,29 @@ > +/* SPDX-License-Identifier: GPL-2.0-only */ > +/** > + * Copyright (c) 2021 Western Digital Corporation or its affiliates. > + * > + * Authors: > + * Atish Patra > + */ > + > +#ifndef __RISCV_KVM_VCPU_SBI_H__ > +#define __RISCV_KVM_VCPU_SBI_H__ > + > +#define KVM_SBI_VERSION_MAJOR 0 > +#define KVM_SBI_VERSION_MINOR 2 > + > +struct kvm_vcpu_sbi_extension { > + unsigned long extid_start; > + unsigned long extid_end; > + /** > + * SBI extension handler. It can be defined for a given extension or group of > + * extension. But it should always return linux error codes rather than SBI > + * specific error codes. > + */ > + int (*handler)(struct kvm_vcpu *vcpu, struct kvm_run *run, > + unsigned long *out_val, struct kvm_cpu_trap *utrap, > + bool *exit); > +}; > + > +const struct kvm_vcpu_sbi_extension *kvm_vcpu_sbi_find_ext(unsigned long extid); > +#endif /* __RISCV_KVM_VCPU_SBI_H__ */ > diff --git a/arch/riscv/kvm/vcpu_sbi.c b/arch/riscv/kvm/vcpu_sbi.c > index eb3c045edf11..05cab5f27eee 100644 > --- a/arch/riscv/kvm/vcpu_sbi.c > +++ b/arch/riscv/kvm/vcpu_sbi.c > @@ -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) > @@ -72,16 +88,17 @@ 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) > @@ -95,8 +112,7 @@ 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 +120,42 @@ 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 +165,100 @@ 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; > + > + if (!cp) > + return -EINVAL; > + > + 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; > } > -- > 2.31.1 >