From patchwork Fri Feb 21 19:56:32 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nuno Das Neves X-Patchwork-Id: 13986227 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 C5BBBC021B3 for ; Fri, 21 Feb 2025 19:58:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Message-Id:Date:Subject:Cc: To:From:Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Owner; bh=DXWUYYhpDF9cbvi+OP+J5thVCYC8+IMsDBUcsoZlY8E=; b=IS+0E8DtYTcuGQkIFBjh9gn+Z7 gDBGOJfZA+A1fM6TpqSig68FFf5gpoT5s8KaOIv+F6/Jrp36mSJaLtVB0oCfJCBx245J1KLP4kBC8 melCKdSY6Es40kFQpHjuhRBAptbkNF6r3IGVn36pr0WaK+cHX9YxboOnxu37mHcGhRITdJL0RAjWf jM0WWYtpSPfZnUXRq1Ficc6DfLP93DrUpBQCyV8Y3HoAUk75OsU60Ux1wmdyyWHCmbzKQvqdz+RE/ LhbUR70nvocg5Fothg2r7Hz0DsYfIQZuotDWIJtsAoMtp43FW6W8eTtiH2NzeLxkEWypaBDQSob6N Z8MJm1WA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tlZA7-00000006htY-0Z2b; Fri, 21 Feb 2025 19:58:15 +0000 Received: from linux.microsoft.com ([13.77.154.182]) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tlZ8d-00000006hcf-36Bw for linux-arm-kernel@lists.infradead.org; Fri, 21 Feb 2025 19:56:44 +0000 Received: from linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net (linux.microsoft.com [13.77.154.182]) by linux.microsoft.com (Postfix) with ESMTPSA id B6B57204E5BC; Fri, 21 Feb 2025 11:56:42 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com B6B57204E5BC DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1740167802; bh=DXWUYYhpDF9cbvi+OP+J5thVCYC8+IMsDBUcsoZlY8E=; h=From:To:Cc:Subject:Date:From; b=LlJcvvQOgZJVX/Q2UUmFgjRVcib/5LYeSbCdU4Zbdhu4HAApNkZgNkHXz9Jrx1nZ6 MryWgCW5svmFC9BEHwNZRdQGNVrTMSnT0pNorXrYQvcVL52PRKF8rWic1hWlsT8hP/ b6O/RTJ2oaU7gllhyjwO7VBYtZBjNVSNyrI+fOKM= From: Nuno Das Neves To: linux-hyperv@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, iommu@lists.linux.dev, mhklinux@outlook.com, eahariha@linux.microsoft.com, mukeshrathor@microsoft.com Cc: kys@microsoft.com, haiyangz@microsoft.com, wei.liu@kernel.org, decui@microsoft.com, catalin.marinas@arm.com, will@kernel.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, daniel.lezcano@linaro.org, joro@8bytes.org, robin.murphy@arm.com, arnd@arndb.de, jinankjain@linux.microsoft.com, muminulrussell@gmail.com, skinsburskii@linux.microsoft.com Subject: [PATCH v2 0/3] Introduce CONFIG_MSHV_ROOT for root partition code Date: Fri, 21 Feb 2025 11:56:32 -0800 Message-Id: <1740167795-13296-1-git-send-email-nunodasneves@linux.microsoft.com> X-Mailer: git-send-email 1.8.3.1 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250221_115643_821438_C4E84104 X-CRM114-Status: GOOD ( 14.25 ) X-BeenThere: linux-arm-kernel@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-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Running in the root partition is a unique and specialized case that requires additional code. CONFIG_MSHV_ROOT allows Hyper-V guest kernels to exclude this code, which is important since significant additional code specific to the root partition is expected to be added over time. To do this, change hv_root_partition to be a function which is stubbed out to return false if CONFIG_MSHV_ROOT=n, and don't compile hv_proc.c at all, stubbing out those functions with inline versions. Store the partition type (guest or root) in an enum hv_curr_partition_type, which can be extended beyond just guest and root partition. While at it, introduce hv_result_to_errno() to convert Hyper-V status codes to regular linux errors. This is useful because the caller of a hypercall helper function (such as those in hv_proc.c) usually can't and doesn't interpret the Hyper-V status, so it is better to convert it to an error code and reduce the possibility of misinterpreting it. This also alows the stubbed versions of the hv_proc.c functions to just return a linux error code. Signed-off-by: Nuno Das Neves Reviewed-by: Easwar Hariharan --- Changes in v3: * Fix a typo [Easwar Hariharan] * Fix ret being initialized to HV_STATUS_SUCCESS in some hypercall helpers [Michael Kelley] * Fix CONFIG_MSHV_ROOT being used in patch 2, before it is defined [Michael Kelley] * Shorten hv_current_partition_type to hv_curr_partition_type [Mukesh Rathor] Changes in v2: * Add patch to convert hypercall statuses to linux error codes [Easwar Hariharan] * While at it, split the original patch into two logical pieces, one to change hv_root_partition into a function, and one to introduce MSHV_CONFIG_ROOT * Improve the clarity of and add an error message to hv_identify_partition_type() [Easwar Hariharan] [Michael Kelley] * Better explain *why* the patches are useful, in the commit messages [Michael Kelley] * Add a Kconfig comment explaining why PAGE_SIZE_4KB is needed [Michael Kelley] * Minor style and typo fixes Nuno Das Neves (3): hyperv: Convert hypercall statuses to linux error codes hyperv: Change hv_root_partition into a function hyperv: Add CONFIG_MSHV_ROOT to gate root partition support arch/arm64/hyperv/mshyperv.c | 2 + arch/x86/hyperv/hv_init.c | 10 ++--- arch/x86/kernel/cpu/mshyperv.c | 24 +---------- drivers/clocksource/hyperv_timer.c | 4 +- drivers/hv/Kconfig | 16 +++++++ drivers/hv/Makefile | 3 +- drivers/hv/hv.c | 10 ++--- drivers/hv/hv_common.c | 69 +++++++++++++++++++++++++++--- drivers/hv/hv_proc.c | 10 ++--- drivers/hv/vmbus_drv.c | 2 +- drivers/iommu/hyperv-iommu.c | 4 +- include/asm-generic/mshyperv.h | 40 ++++++++++++++--- 12 files changed, 139 insertions(+), 55 deletions(-)