From nobody Thu Dec 18 15:44:31 2025 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 79C4EC6FD18 for ; Wed, 19 Apr 2023 22:52:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231286AbjDSWwB (ORCPT ); Wed, 19 Apr 2023 18:52:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52424 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229499AbjDSWv7 (ORCPT ); Wed, 19 Apr 2023 18:51:59 -0400 Received: from mail-oa1-x34.google.com (mail-oa1-x34.google.com [IPv6:2001:4860:4864:20::34]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 35B2B1701 for ; Wed, 19 Apr 2023 15:51:57 -0700 (PDT) Received: by mail-oa1-x34.google.com with SMTP id 586e51a60fabf-187e041b08aso219060fac.2 for ; Wed, 19 Apr 2023 15:51:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rivosinc-com.20221208.gappssmtp.com; s=20221208; t=1681944716; x=1684536716; 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=8fg2apWNkO7XMTsfLYU3rTZlWorsx4wHesUuN9ZGrN4=; b=WUbj02UeMcy41XsHfO98vaNJDQDNXOQqCfRLlmEVm+ZZFRt6mhnFrbDdTfkc/I1z79 unuw4UFr4ejB6HTO31GuZYdxMlyioQUJLEEV7XA1gad9fEVKDdcEASFYXDTKgEMBlPP4 S4XhPju/QU8A7ExikNsYonS/aqhxnqeM8OUdNDEOlE8VJN4NPf5s/b1nAEXe7872N6Tk 88iAlzzgE9pw87Adp8YHXdgS7/5WUMtESFJXxZJEi+XklFQPr7GwS/3TrawtWlZnDc+6 zauOLx4Uku9QIWyggawkI82lC1+om8T/kjgLhnbllz6HB6vRk3t3L6/x6h9Wf2FM0xB7 EfQQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1681944716; x=1684536716; 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=8fg2apWNkO7XMTsfLYU3rTZlWorsx4wHesUuN9ZGrN4=; b=lzYa2F6UGmC6dCuIBblK5pqMbQHO6DCeTMDhn3id7wTfz9LAbMidGb8SSptjMcx5Vr AYQmLR+MH6YKnMKx8qWfPG9B/3aHpdWHFYZYOann+Dk8+dMDiPhxZ7Jsobjc+ZMKXOIK cfNFPAcSPATnRUwZfO5Bxo4urDeVMtIqjwr3gUH98A7HtfNNMvFct/yYtbIzw1T0BXdS 0ZvyKGTWM6g8+bf2vykopsz1PoLBENjXMX53RfPO9hSdOUdORM/fuaEL9qFnMS90R8DM O8WgXQWtklDzfTSaQbihgv4VQeGDceqJ2LdnwlQJ6Z5ZVBNyLCYqUuUZtkXYw6Yd4ILw G3rg== X-Gm-Message-State: AAQBX9dGTs0rv/57933lWuTtTdiWXCdjxri5kfjf7b9vNAQnktjIJm5Q m6PU6hzRdW4RMnWiToitXjngahaHA27n0tmRy5w= X-Google-Smtp-Source: AKy350bcbgE/EJ3Ej08OUUDHS562dStL1nY59dRLyQva3UBkO8qD2X/slMFNk57ZH7aSQKcUf51qPw== X-Received: by 2002:a17:902:a504:b0:1a1:be45:9857 with SMTP id s4-20020a170902a50400b001a1be459857mr6646673plq.1.1681942754165; Wed, 19 Apr 2023 15:19:14 -0700 (PDT) Received: from atishp.ba.rivosinc.com ([66.220.2.162]) by smtp.gmail.com with ESMTPSA id jn11-20020a170903050b00b00196807b5189sm11619190plb.292.2023.04.19.15.19.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 19 Apr 2023 15:19:13 -0700 (PDT) From: Atish Patra To: linux-kernel@vger.kernel.org Cc: Rajnesh Kanwal , Atish Patra , Alexandre Ghiti , Andrew Jones , Andrew Morton , Anup Patel , Atish Patra , =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= , Suzuki K Poulose , Will Deacon , Marc Zyngier , Sean Christopherson , linux-coco@lists.linux.dev, Dylan Reid , abrestic@rivosinc.com, Samuel Ortiz , Christoph Hellwig , Conor Dooley , Greg Kroah-Hartman , Guo Ren , Heiko Stuebner , Jiri Slaby , kvm-riscv@lists.infradead.org, kvm@vger.kernel.org, linux-mm@kvack.org, linux-riscv@lists.infradead.org, Mayuresh Chitale , Palmer Dabbelt , Paolo Bonzini , Paul Walmsley , Uladzislau Rezki Subject: [RFC 47/48] RISC-V: Add shared bounce buffer to support DBCN for CoVE Guest. Date: Wed, 19 Apr 2023 15:17:15 -0700 Message-Id: <20230419221716.3603068-48-atishp@rivosinc.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230419221716.3603068-1-atishp@rivosinc.com> References: <20230419221716.3603068-1-atishp@rivosinc.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Rajnesh Kanwal Early console buffer needs to be shared with the host for CoVE Guest. Signed-off-by: Rajnesh Kanwal Signed-off-by: Atish Patra --- drivers/tty/serial/earlycon-riscv-sbi.c | 51 ++++++++++++++++++++++++- 1 file changed, 49 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/earlycon-riscv-sbi.c b/drivers/tty/serial/e= arlycon-riscv-sbi.c index 311a4f8..9033cca 100644 --- a/drivers/tty/serial/earlycon-riscv-sbi.c +++ b/drivers/tty/serial/earlycon-riscv-sbi.c @@ -9,6 +9,14 @@ #include #include #include +#include +#include +#include + +#ifdef CONFIG_RISCV_COVE_GUEST +#define DBCN_BOUNCE_BUF_SIZE (PAGE_SIZE) +static char dbcn_buf[DBCN_BOUNCE_BUF_SIZE] __aligned(PAGE_SIZE); +#endif =20 #ifdef CONFIG_RISCV_SBI_V01 static void sbi_putc(struct uart_port *port, unsigned char c) @@ -24,6 +32,33 @@ static void sbi_0_1_console_write(struct console *con, } #endif =20 +#ifdef CONFIG_RISCV_COVE_GUEST +static void sbi_dbcn_console_write_cove(struct console *con, const char *s, + unsigned int n) +{ + phys_addr_t pa =3D __pa(dbcn_buf); + unsigned int off =3D 0; + + while (off < n) { + const unsigned int rem =3D n - off; + const unsigned int size =3D + rem > DBCN_BOUNCE_BUF_SIZE ? DBCN_BOUNCE_BUF_SIZE : rem; + + memcpy(dbcn_buf, &s[off], size); + + sbi_ecall(SBI_EXT_DBCN, SBI_EXT_DBCN_CONSOLE_WRITE, +#ifdef CONFIG_32BIT + size, pa, (u64)pa >> 32, +#else + size, pa, 0, +#endif + 0, 0, 0); + + off +=3D size; + } +} +#endif + static void sbi_dbcn_console_write(struct console *con, const char *s, unsigned n) { @@ -45,14 +80,26 @@ static int __init early_sbi_setup(struct earlycon_devic= e *device, =20 /* TODO: Check for SBI debug console (DBCN) extension */ if ((sbi_spec_version >=3D sbi_mk_version(1, 0)) && - (sbi_probe_extension(SBI_EXT_DBCN) > 0)) + (sbi_probe_extension(SBI_EXT_DBCN) > 0)) { +#ifdef CONFIG_RISCV_COVE_GUEST + if (is_cove_guest()) { + ret =3D sbi_covg_share_memory(__pa(dbcn_buf), + DBCN_BOUNCE_BUF_SIZE); + if (ret) + return ret; + + device->con->write =3D sbi_dbcn_console_write_cove; + return 0; + } +#endif device->con->write =3D sbi_dbcn_console_write; - else + } else { #ifdef CONFIG_RISCV_SBI_V01 device->con->write =3D sbi_0_1_console_write; #else ret =3D -ENODEV; #endif + } =20 return ret; } --=20 2.25.1