From patchwork Thu Oct 12 05:15:05 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anup Patel X-Patchwork-Id: 13418337 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 8879ECDB46E for ; Thu, 12 Oct 2023 05:15:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=Y8kfrvOozIUYBpvgLY+hLeKjLt5sjHGzkakJ1KVaKT8=; b=NDQUQVxlX5zOE5 +i7pa4umyqzhmRe9On8+0ZJhDeWIdMPiWZrBrIAy5f0K8Flfr/adEu5r/Ur8l2/52I6NhGAQo97Nv d35XzB5ZEB9kdvvTCp4ijWoTwi/w5gz+pteA0mIczTrUUdiETOg79o67jHJVu5ggSGf7FXT4L25VU 5stw7+HAxUcY0yOyZAT9EFV1JrSRPY0tgW1YS59aK81FdTnSRNsCSFXD2CjmsEuhJ0RhyH9IH0eoy YRzvZA2MMiqHpNvwryjl7AyqEj+BmWhBPH5EPX63XbrBqVlG4NcainyqgvroZxW3hPoD82sas4Tsg Ht0hlIf6SDmxT1s0EkyQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qqo2w-00HRFw-1i; Thu, 12 Oct 2023 05:15:42 +0000 Received: from mail-pl1-x633.google.com ([2607:f8b0:4864:20::633]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qqo2t-00HRCS-2p for linux-riscv@lists.infradead.org; Thu, 12 Oct 2023 05:15:41 +0000 Received: by mail-pl1-x633.google.com with SMTP id d9443c01a7336-1c9d407bb15so5427845ad.0 for ; Wed, 11 Oct 2023 22:15:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ventanamicro.com; s=google; t=1697087737; x=1697692537; darn=lists.infradead.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=5F82Co3/cdirw9N8c47oejx7W6gl4Raymf8m/hgF9mg=; b=C4kv0uXO4Nfh2B8OoFHYz340A7EdxhMm/NwzGFO0mjcSqAwQm0jmaxrbv06YzHZ3ws nUFP1UFyuyg3XNNpYPFNoQxqu9s2Gn2/XYtLGbAmke6F3s6X/Osf4Sqj/h0xnJycnKcf UBeW9qJvrabWXqMWQmvIImK3RwuxIP+UZBTqdIJv9ekC+EfP04xI9qw7OlBNXnEbyKGR vioSxAc5pLc/oQKekYqjZQJA5L+IFgx8LC3+oV8H0pG4yuxope1IghOxzOXKC3PYiWP7 80wg/G3Tf4WMrOcXcQjj2Drt2E5eVzJ1YhKJ4dHvq9IxQnpGBxtbpOqTOQgkWBNvC7cj eRjA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1697087737; x=1697692537; 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=5F82Co3/cdirw9N8c47oejx7W6gl4Raymf8m/hgF9mg=; b=iFnIFicTr0rST40oc1hQVrsCqf3eBBH/S+5vl4ANIAzK0g3TlIk254MjM5c2CGhNo+ TLNtsjat2DiWsIZmHl/yC6ZkXBCldhl8IGXbzjM7+zJAV4tdM2jyPa5E3adPxly5Bnx0 ljxx5z6/eSyJ3cM8/yFeQDTSLLkVUEdu48opnW0NB1nzRUQ++Jt6aZAEFQUSl9dyW7Ou vrMGyDfDZYYI2PQmdJaz9e1FxtIQsHtgDpFCNpZKyiNwRWiYDumgIlgM36Ou1+Yg9HLx nzDtjA9HJZfvcOp8TBMKovYIkfnTUrbFlD6rjJdPRpAqpYpSzk90WLeg70KaBGYRAUGu zXeQ== X-Gm-Message-State: AOJu0YxKcaFXfhSzvUWeu+A7YG16iURqs8uqvPpbhKrhITfyH60DZxUp 5FEqvK6pbOcqxRBoC2Q77mf81A== X-Google-Smtp-Source: AGHT+IFZ9PIs/5Xdz63daF5WgvnqI8HA2E47f1F59gFa33dzVCANlp1ZCJBRk4958EXc+DlXohYaDw== X-Received: by 2002:a17:902:d48f:b0:1c9:d358:b3c9 with SMTP id c15-20020a170902d48f00b001c9d358b3c9mr2956911plg.19.1697087736652; Wed, 11 Oct 2023 22:15:36 -0700 (PDT) Received: from anup-ubuntu-vm.localdomain ([106.51.83.242]) by smtp.gmail.com with ESMTPSA id s18-20020a17090330d200b001b9d95945afsm851309plc.155.2023.10.11.22.15.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 11 Oct 2023 22:15:36 -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 v2 4/8] RISC-V: KVM: Forward SBI DBCN extension to user-space Date: Thu, 12 Oct 2023 10:45:05 +0530 Message-Id: <20231012051509.738750-5-apatel@ventanamicro.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231012051509.738750-1-apatel@ventanamicro.com> References: <20231012051509.738750-1-apatel@ventanamicro.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231011_221539_911126_9EB7A0AC X-CRM114-Status: GOOD ( 14.06 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org The frozen SBI v2.0 specification defines the SBI debug console (DBCN) extension which replaces the legacy SBI v0.1 console functions namely sbi_console_getchar() and sbi_console_putchar(). The SBI DBCN extension needs to be emulated in the KVM user-space (i.e. QEMU-KVM or KVMTOOL) so we forward SBI DBCN calls from KVM guest to the KVM user-space which can then redirect the console input/output to wherever it wants (e.g. telnet, file, stdio, etc). The SBI debug console is simply a early console available to KVM guest for early prints and it does not intend to replace the proper console devices such as 8250, VirtIO console, etc. Signed-off-by: Anup Patel Reviewed-by: Andrew Jones --- arch/riscv/include/asm/kvm_vcpu_sbi.h | 1 + arch/riscv/include/uapi/asm/kvm.h | 1 + arch/riscv/kvm/vcpu_sbi.c | 4 ++++ arch/riscv/kvm/vcpu_sbi_replace.c | 32 +++++++++++++++++++++++++++ 4 files changed, 38 insertions(+) diff --git a/arch/riscv/include/asm/kvm_vcpu_sbi.h b/arch/riscv/include/asm/kvm_vcpu_sbi.h index c02bda5559d7..6a453f7f8b56 100644 --- a/arch/riscv/include/asm/kvm_vcpu_sbi.h +++ b/arch/riscv/include/asm/kvm_vcpu_sbi.h @@ -73,6 +73,7 @@ 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_srst; extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_hsm; +extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_dbcn; extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_experimental; extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_vendor; diff --git a/arch/riscv/include/uapi/asm/kvm.h b/arch/riscv/include/uapi/asm/kvm.h index 917d8cc2489e..60d3b21dead7 100644 --- a/arch/riscv/include/uapi/asm/kvm.h +++ b/arch/riscv/include/uapi/asm/kvm.h @@ -156,6 +156,7 @@ enum KVM_RISCV_SBI_EXT_ID { KVM_RISCV_SBI_EXT_PMU, KVM_RISCV_SBI_EXT_EXPERIMENTAL, KVM_RISCV_SBI_EXT_VENDOR, + KVM_RISCV_SBI_EXT_DBCN, KVM_RISCV_SBI_EXT_MAX, }; diff --git a/arch/riscv/kvm/vcpu_sbi.c b/arch/riscv/kvm/vcpu_sbi.c index 1b1cee86efda..bb76c3cf633f 100644 --- a/arch/riscv/kvm/vcpu_sbi.c +++ b/arch/riscv/kvm/vcpu_sbi.c @@ -66,6 +66,10 @@ static const struct kvm_riscv_sbi_extension_entry sbi_ext[] = { .ext_idx = KVM_RISCV_SBI_EXT_PMU, .ext_ptr = &vcpu_sbi_ext_pmu, }, + { + .ext_idx = KVM_RISCV_SBI_EXT_DBCN, + .ext_ptr = &vcpu_sbi_ext_dbcn, + }, { .ext_idx = KVM_RISCV_SBI_EXT_EXPERIMENTAL, .ext_ptr = &vcpu_sbi_ext_experimental, diff --git a/arch/riscv/kvm/vcpu_sbi_replace.c b/arch/riscv/kvm/vcpu_sbi_replace.c index 7c4d5d38a339..23b57c931b15 100644 --- a/arch/riscv/kvm/vcpu_sbi_replace.c +++ b/arch/riscv/kvm/vcpu_sbi_replace.c @@ -175,3 +175,35 @@ const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_srst = { .extid_end = SBI_EXT_SRST, .handler = kvm_sbi_ext_srst_handler, }; + +static int kvm_sbi_ext_dbcn_handler(struct kvm_vcpu *vcpu, + struct kvm_run *run, + struct kvm_vcpu_sbi_return *retdata) +{ + struct kvm_cpu_context *cp = &vcpu->arch.guest_context; + unsigned long funcid = cp->a6; + + switch (funcid) { + case SBI_EXT_DBCN_CONSOLE_WRITE: + case SBI_EXT_DBCN_CONSOLE_READ: + case SBI_EXT_DBCN_CONSOLE_WRITE_BYTE: + /* + * The SBI debug console functions are unconditionally + * forwarded to the userspace. + */ + kvm_riscv_vcpu_sbi_forward(vcpu, run); + retdata->uexit = true; + break; + default: + retdata->err_val = SBI_ERR_NOT_SUPPORTED; + } + + return 0; +} + +const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_dbcn = { + .extid_start = SBI_EXT_DBCN, + .extid_end = SBI_EXT_DBCN, + .default_unavail = true, + .handler = kvm_sbi_ext_dbcn_handler, +};