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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (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 D4C51CD8CAC for ; Tue, 10 Oct 2023 17:16:36 +0000 (UTC) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=kdZiTe7H; dkim-atps=neutral Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4S4jHR3xq2z3vcf for ; Wed, 11 Oct 2023 04:16:35 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=kdZiTe7H; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=linuxfoundation.org (client-ip=2604:1380:4601:e00::1; helo=ams.source.kernel.org; envelope-from=gregkh@linuxfoundation.org; receiver=lists.ozlabs.org) Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4S4jGS5RKqz2xps for ; Wed, 11 Oct 2023 04:15:43 +1100 (AEDT) Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by ams.source.kernel.org (Postfix) with ESMTP id 8DA13B81CD0; Tue, 10 Oct 2023 17:15:41 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5F03DC433C7; Tue, 10 Oct 2023 17:15:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1696958140; bh=zjSBxk6UATy9y4pqLcR+ifaY1dYuZQpAMHpPto23JUA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=kdZiTe7HCo50JWD0c5xwApJlmA9waTfbHKBmCL81h7/HGrq4Cm8fJxyWIYw3pemxr r6Q7kWEFiWquLyBo30s1WMkjWM0VnBmGyDUJnb7X4iGGqYbdWxUnY+UMyQOHkZj8CB MQj4XFDDpT/q2vtHSuAn2tBPx9taEVwTSaFuCWwA= Date: Tue, 10 Oct 2023 19:15:38 +0200 From: Greg Kroah-Hartman To: Anup Patel Subject: Re: [PATCH 3/6] RISC-V: KVM: Forward SBI DBCN extension to user-space Message-ID: <2023101048-attach-drift-d77b@gregkh> References: <20231010170503.657189-1-apatel@ventanamicro.com> <20231010170503.657189-4-apatel@ventanamicro.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20231010170503.657189-4-apatel@ventanamicro.com> X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-serial@vger.kernel.org, kvm@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, Atish Patra , linux-kernel@vger.kernel.org, Conor Dooley , Palmer Dabbelt , kvm-riscv@lists.infradead.org, Paul Walmsley , Paolo Bonzini , linux-riscv@lists.infradead.org, Jiri Slaby , Andrew Jones Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Tue, Oct 10, 2023 at 10:35:00PM +0530, Anup Patel wrote: > The SBI DBCN extension needs to be emulated in user-space Why? > so let > us forward console_puts() call to user-space. What could go wrong! Why does userspace have to get involved in a console message? Why is this needed at all? The kernel can not handle userspace consoles as obviously they have to be re-entrant and irq safe. > > Signed-off-by: Anup Patel > --- > 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 | 31 +++++++++++++++++++++++++++ > 4 files changed, 37 insertions(+) > > diff --git a/arch/riscv/include/asm/kvm_vcpu_sbi.h b/arch/riscv/include/asm/kvm_vcpu_sbi.h > index 8d6d4dce8a5e..a85f95eb6e85 100644 > --- a/arch/riscv/include/asm/kvm_vcpu_sbi.h > +++ b/arch/riscv/include/asm/kvm_vcpu_sbi.h > @@ -69,6 +69,7 @@ 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, You just broke a user/kernel ABI here, why? thanks, greg k-h