From patchwork Fri Oct 20 07:21:34 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anup Patel X-Patchwork-Id: 736547 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 C3B6BCDB474 for ; Fri, 20 Oct 2023 07:22:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1376444AbjJTHWL (ORCPT ); Fri, 20 Oct 2023 03:22:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41592 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235626AbjJTHWH (ORCPT ); Fri, 20 Oct 2023 03:22:07 -0400 Received: from mail-pf1-x42a.google.com (mail-pf1-x42a.google.com [IPv6:2607:f8b0:4864:20::42a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9430DD73 for ; Fri, 20 Oct 2023 00:22:04 -0700 (PDT) Received: by mail-pf1-x42a.google.com with SMTP id d2e1a72fcca58-6b1e46ca282so499423b3a.2 for ; Fri, 20 Oct 2023 00:22:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ventanamicro.com; s=google; t=1697786524; x=1698391324; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=m3zCDz3wNvDFZIfhQp3mdMMGRfliX9zzX2s9SoD5fk8=; b=eWZlqXMTae+4e206soGPMi6RkzcMLXzh8ofE7F7z06HK/UrklYWeHlBX0krBYyDGu8 N1+7InlbG1xoUhzYLYSEZut5c9x47hgaVeoVXKYwcqkGbDCfeZRvSNQ288wV/tzz4lAY jjG5rimOYT78L7XcF/kSbsZyKRIfaOGoiyq9zi1YVxY0JT7VQ4d6xiVArGccQwcSAGru JuCa7R9f2bXmti6sovoFiVA4BoF5ZlpOA/9eTX+yf50EeEzU/WHwHIRjs1fa95YdwuWc wnsL4lSVed+c8cL5i0bxQCpCRVKDmuNfN8UHJTg0g/0rZQlq9SYaPqido46ndoIwePlu sWUA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1697786524; x=1698391324; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=m3zCDz3wNvDFZIfhQp3mdMMGRfliX9zzX2s9SoD5fk8=; b=Bo42RuhyzNxBNmfP42FHnzyTchxdAOBeupKON0S6Iq9iJEGgnz8INo3Pa6a6hja02G ivytDEpngp+b1+gCJ/aW8MmL2u//EH8mOV4xOFTlAFBRY5gzl7fCPupyqYVUA73+9QnH PXtd8HCVJFCJi7UyYbb07vLzNOT2NVXetzi31EUxw/VVgFZzlFLjYn+0whU/KUVkdjjp oaC+S+fFkMlfIjniP5hC9dmrpyHTgqpuzsPu6eA+0XA6at9psmr6MrXl7+vNFaySgumy gRFBbbsZ2B1EavEHiMafkI9xTn7SCrxvp3LOeNt/68kmIn2o6dhHXjzb7wEv4fuFbyQP gI1Q== X-Gm-Message-State: AOJu0YwsNR7HV849PzqoBZGn4JNP026gGOK9Z1CA1qsz/WXvf/JJ9ftu TaVSCoo+4nAwbO5RBJMFGBk3mQ== X-Google-Smtp-Source: AGHT+IG244Unqcch61/RKDkaln/AZV8DtWkK/fAUAz824/pCQp9YvCbi/8qrpjv0yroTiFuFOsikCg== X-Received: by 2002:aa7:962b:0:b0:690:38b6:b2db with SMTP id r11-20020aa7962b000000b0069038b6b2dbmr951624pfg.6.1697786523600; Fri, 20 Oct 2023 00:22:03 -0700 (PDT) Received: from anup-ubuntu-vm.localdomain ([171.76.83.81]) by smtp.gmail.com with ESMTPSA id v12-20020a63f20c000000b005b32d6b4f2fsm828204pgh.81.2023.10.20.00.21.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 20 Oct 2023 00:22:03 -0700 (PDT) From: Anup Patel To: Paolo Bonzini , Atish Patra , Palmer Dabbelt , Paul Walmsley , Greg Kroah-Hartman , Jiri Slaby Cc: Conor Dooley , Andrew Jones , kvm@vger.kernel.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-serial@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Anup Patel Subject: [PATCH v3 3/9] RISC-V: KVM: Allow some SBI extensions to be disabled by default Date: Fri, 20 Oct 2023 12:51:34 +0530 Message-Id: <20231020072140.900967-4-apatel@ventanamicro.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231020072140.900967-1-apatel@ventanamicro.com> References: <20231020072140.900967-1-apatel@ventanamicro.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org Currently, all SBI extensions are enabled by default which is problematic for SBI extensions (such as DBCN) which are forwarded to the KVM user-space because we might have an older KVM user-space which is not aware/ready to handle newer SBI extensions. Ideally, the SBI extensions forwarded to the KVM user-space must be disabled by default. To address above, we allow certain SBI extensions to be disabled by default so that KVM user-space must explicitly enable such SBI extensions to receive forwarded calls from Guest VCPU. Signed-off-by: Anup Patel --- arch/riscv/include/asm/kvm_vcpu_sbi.h | 4 ++ arch/riscv/kvm/vcpu.c | 6 +++ arch/riscv/kvm/vcpu_sbi.c | 57 +++++++++++++-------------- 3 files changed, 38 insertions(+), 29 deletions(-) diff --git a/arch/riscv/include/asm/kvm_vcpu_sbi.h b/arch/riscv/include/asm/kvm_vcpu_sbi.h index 8d6d4dce8a5e..c02bda5559d7 100644 --- a/arch/riscv/include/asm/kvm_vcpu_sbi.h +++ b/arch/riscv/include/asm/kvm_vcpu_sbi.h @@ -35,6 +35,9 @@ struct kvm_vcpu_sbi_return { struct kvm_vcpu_sbi_extension { unsigned long extid_start; unsigned long extid_end; + + bool default_unavail; + /** * 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 @@ -59,6 +62,7 @@ int kvm_riscv_vcpu_get_reg_sbi_ext(struct kvm_vcpu *vcpu, const struct kvm_vcpu_sbi_extension *kvm_vcpu_sbi_find_ext( struct kvm_vcpu *vcpu, unsigned long extid); int kvm_riscv_vcpu_sbi_ecall(struct kvm_vcpu *vcpu, struct kvm_run *run); +void kvm_riscv_vcpu_sbi_init(struct kvm_vcpu *vcpu); #ifdef CONFIG_RISCV_SBI_V01 extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_v01; diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c index c061a1c5fe98..e087c809073c 100644 --- a/arch/riscv/kvm/vcpu.c +++ b/arch/riscv/kvm/vcpu.c @@ -141,6 +141,12 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu) if (rc) return rc; + /* + * Setup SBI extensions + * NOTE: This must be the last thing to be initialized. + */ + kvm_riscv_vcpu_sbi_init(vcpu); + /* Reset VCPU */ kvm_riscv_reset_vcpu(vcpu); diff --git a/arch/riscv/kvm/vcpu_sbi.c b/arch/riscv/kvm/vcpu_sbi.c index 9cd97091c723..bda8b0b33343 100644 --- a/arch/riscv/kvm/vcpu_sbi.c +++ b/arch/riscv/kvm/vcpu_sbi.c @@ -155,14 +155,8 @@ static int riscv_vcpu_set_sbi_ext_single(struct kvm_vcpu *vcpu, if (!sext) return -ENOENT; - /* - * We can't set the extension status to available here, since it may - * have a probe() function which needs to confirm availability first, - * but it may be too early to call that here. We can set the status to - * unavailable, though. - */ - if (!reg_val) - scontext->ext_status[sext->ext_idx] = + scontext->ext_status[sext->ext_idx] = (reg_val) ? + KVM_RISCV_SBI_EXT_AVAILABLE : KVM_RISCV_SBI_EXT_UNAVAILABLE; return 0; @@ -188,16 +182,8 @@ static int riscv_vcpu_get_sbi_ext_single(struct kvm_vcpu *vcpu, if (!sext) return -ENOENT; - /* - * If the extension status is still uninitialized, then we should probe - * to determine if it's available, but it may be too early to do that - * here. The best we can do is report that the extension has not been - * disabled, i.e. we return 1 when the extension is available and also - * when it only may be available. - */ - *reg_val = scontext->ext_status[sext->ext_idx] != - KVM_RISCV_SBI_EXT_UNAVAILABLE; - + *reg_val = scontext->ext_status[sext->ext_idx] == + KVM_RISCV_SBI_EXT_AVAILABLE; return 0; } @@ -337,18 +323,8 @@ const struct kvm_vcpu_sbi_extension *kvm_vcpu_sbi_find_ext( scontext->ext_status[entry->ext_idx] == KVM_RISCV_SBI_EXT_AVAILABLE) return ext; - if (scontext->ext_status[entry->ext_idx] == - KVM_RISCV_SBI_EXT_UNAVAILABLE) - return NULL; - if (ext->probe && !ext->probe(vcpu)) { - scontext->ext_status[entry->ext_idx] = - KVM_RISCV_SBI_EXT_UNAVAILABLE; - return NULL; - } - scontext->ext_status[entry->ext_idx] = - KVM_RISCV_SBI_EXT_AVAILABLE; - return ext; + return NULL; } } @@ -419,3 +395,26 @@ int kvm_riscv_vcpu_sbi_ecall(struct kvm_vcpu *vcpu, struct kvm_run *run) return ret; } + +void kvm_riscv_vcpu_sbi_init(struct kvm_vcpu *vcpu) +{ + struct kvm_vcpu_sbi_context *scontext = &vcpu->arch.sbi_context; + const struct kvm_riscv_sbi_extension_entry *entry; + const struct kvm_vcpu_sbi_extension *ext; + int i; + + for (i = 0; i < ARRAY_SIZE(sbi_ext); i++) { + entry = &sbi_ext[i]; + ext = entry->ext_ptr; + + if (ext->probe && !ext->probe(vcpu)) { + scontext->ext_status[entry->ext_idx] = + KVM_RISCV_SBI_EXT_UNAVAILABLE; + continue; + } + + scontext->ext_status[entry->ext_idx] = ext->default_unavail ? + KVM_RISCV_SBI_EXT_UNAVAILABLE : + KVM_RISCV_SBI_EXT_AVAILABLE; + } +}