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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DED79CD8CA9 for ; Tue, 10 Oct 2023 17:15:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233690AbjJJRPo (ORCPT ); Tue, 10 Oct 2023 13:15:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36396 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233824AbjJJRPn (ORCPT ); Tue, 10 Oct 2023 13:15:43 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 558638E; Tue, 10 Oct 2023 10:15:41 -0700 (PDT) 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 Cc: Paolo Bonzini , Atish Patra , Palmer Dabbelt , Paul Walmsley , Jiri Slaby , 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 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> Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org 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