From patchwork Mon Sep 21 16:28:09 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "gregkh@linuxfoundation.org" X-Patchwork-Id: 263703 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-14.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 95040C43466 for ; Mon, 21 Sep 2020 16:42:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 52DFA239D1 for ; Mon, 21 Sep 2020 16:42:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600706520; bh=neZeJyo/vrJWlGXfGrMWd1Maus0uo5g1Kgtkd1PsBV0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=eyX4h2vAT76g+5R8qi9PoTyB4fzIy/m9YzVInKfb6AZSA6UiU0fVXRGm/yWSDg6GA k+dzfLqd8LQqNlWSH6fm9q457f2bKZ34DMvfJBVzswd83rcKc4Y0QwT2J1oijfQtmy 7zbjdYuhvHkmxCc06CSTBcJWJA9ZrKTpajnR4f/A= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729163AbgIUQls (ORCPT ); Mon, 21 Sep 2020 12:41:48 -0400 Received: from mail.kernel.org ([198.145.29.99]:45018 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728308AbgIUQl2 (ORCPT ); Mon, 21 Sep 2020 12:41:28 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 1B4B123998; Mon, 21 Sep 2020 16:41:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600706487; bh=neZeJyo/vrJWlGXfGrMWd1Maus0uo5g1Kgtkd1PsBV0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Sj7SHi9veREEmnEF4T2+bwC/XnpMdpIEPPZsE7gHFm79T73Z3kRpWR4ozH5C0F3Rg gwJibyFDqHXlvmU18/abDOzHXvA2eU5B+syyvcgRVTSXxosYhtQ+yOvE8beiI8w+wm bUI3NMVoizXSoeCoruSi/VHJfNbfyQq5StH58x4M= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Huacai Chen , Paolo Bonzini , Sasha Levin Subject: [PATCH 4.19 25/49] KVM: MIPS: Change the definition of kvm type Date: Mon, 21 Sep 2020 18:28:09 +0200 Message-Id: <20200921162035.764498563@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200921162034.660953761@linuxfoundation.org> References: <20200921162034.660953761@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Huacai Chen [ Upstream commit 15e9e35cd1dec2bc138464de6bf8ef828df19235 ] MIPS defines two kvm types: #define KVM_VM_MIPS_TE 0 #define KVM_VM_MIPS_VZ 1 In Documentation/virt/kvm/api.rst it is said that "You probably want to use 0 as machine type", which implies that type 0 be the "automatic" or "default" type. And, in user-space libvirt use the null-machine (with type 0) to detect the kvm capability, which returns "KVM not supported" on a VZ platform. I try to fix it in QEMU but it is ugly: https://lists.nongnu.org/archive/html/qemu-devel/2020-08/msg05629.html And Thomas Huth suggests me to change the definition of kvm type: https://lists.nongnu.org/archive/html/qemu-devel/2020-09/msg03281.html So I define like this: #define KVM_VM_MIPS_AUTO 0 #define KVM_VM_MIPS_VZ 1 #define KVM_VM_MIPS_TE 2 Since VZ and TE cannot co-exists, using type 0 on a TE platform will still return success (so old user-space tools have no problems on new kernels); the advantage is that using type 0 on a VZ platform will not return failure. So, the only problem is "new user-space tools use type 2 on old kernels", but if we treat this as a kernel bug, we can backport this patch to old stable kernels. Signed-off-by: Huacai Chen Message-Id: <1599734031-28746-1-git-send-email-chenhc@lemote.com> Signed-off-by: Paolo Bonzini Signed-off-by: Sasha Levin --- arch/mips/kvm/mips.c | 2 ++ include/uapi/linux/kvm.h | 5 +++-- 2 files changed, 5 insertions(+), 2 deletions(-) diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c index e7f5ef6bed0fe..79485790f7b56 100644 --- a/arch/mips/kvm/mips.c +++ b/arch/mips/kvm/mips.c @@ -131,6 +131,8 @@ void kvm_arch_check_processor_compat(void *rtn) int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) { switch (type) { + case KVM_VM_MIPS_AUTO: + break; #ifdef CONFIG_KVM_MIPS_VZ case KVM_VM_MIPS_VZ: #else diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 66ce6659ecb69..c297abc4e6697 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -746,9 +746,10 @@ struct kvm_ppc_resize_hpt { #define KVM_VM_PPC_HV 1 #define KVM_VM_PPC_PR 2 -/* on MIPS, 0 forces trap & emulate, 1 forces VZ ASE */ -#define KVM_VM_MIPS_TE 0 +/* on MIPS, 0 indicates auto, 1 forces VZ ASE, 2 forces trap & emulate */ +#define KVM_VM_MIPS_AUTO 0 #define KVM_VM_MIPS_VZ 1 +#define KVM_VM_MIPS_TE 2 #define KVM_S390_SIE_PAGE_OFFSET 1