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 X-Spam-Level: X-Spam-Status: No, score=-8.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 261D4C433DB for ; Wed, 31 Mar 2021 04:54:54 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 42B576195C for ; Wed, 31 Mar 2021 04:54:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 42B576195C Authentication-Results: mail.kernel.org; dmarc=pass (p=none dis=none) header.from=ozlabs.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4F9DWb3qS2z3cBB for ; Wed, 31 Mar 2021 15:54:51 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; secure) header.d=ozlabs.org header.i=@ozlabs.org header.a=rsa-sha256 header.s=201707 header.b=Sanvvyq1; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=ozlabs.org (client-ip=203.11.71.1; helo=ozlabs.org; envelope-from=paulus@ozlabs.org; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; secure) header.d=ozlabs.org header.i=@ozlabs.org header.a=rsa-sha256 header.s=201707 header.b=Sanvvyq1; dkim-atps=neutral Received: from ozlabs.org (ozlabs.org [203.11.71.1]) (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 4F9DW83gQrz3bvs for ; Wed, 31 Mar 2021 15:54:27 +1100 (AEDT) Received: by ozlabs.org (Postfix, from userid 1003) id 4F9DW64NTnz9sWK; Wed, 31 Mar 2021 15:54:26 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ozlabs.org; s=201707; t=1617166466; bh=FaGAi7HK2sa7P5Q8laMqiKFN+VBVfksKAS//ipGKleo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Sanvvyq14AVrCu3meNVlc+Yg6gvQ9TF8WpIOJaOuVMo0mv5y8Vif45ww0MX3DXCg4 Yzo+bp2n0qCmNdZHct2s64et8JP34UVLYzqI6pVI4uGPAl4JXqnc3US9QkWv2fKfrg kpCWFTCrOu1RL82tkXWZmrQrDS1NAeZBJ+zaQ9lToO4U1wxwlEPOe6jpjY4FtmPOiO Bq47DJCQBxmSAyDdtWlS2OSIDzGaTbRqHWYWYLx/EPGXjuLYUZbgjJK9Rrce/GNqBE 3rIGeLwROI1vr+pPOAzYfKxKvcPWuO0v6a9HmSGwUpJGNIt03mT6VOmD9WCsLoO5oX SflwekldAFOzQ== Date: Wed, 31 Mar 2021 15:54:20 +1100 From: Paul Mackerras To: Nicholas Piggin Subject: Re: [PATCH v4 09/46] powerpc/64s: remove KVM SKIP test from instruction breakpoint handler Message-ID: References: <20210323010305.1045293-1-npiggin@gmail.com> <20210323010305.1045293-10-npiggin@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210323010305.1045293-10-npiggin@gmail.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: Fabiano Rosas , linuxppc-dev@lists.ozlabs.org, kvm-ppc@vger.kernel.org, Daniel Axtens Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Tue, Mar 23, 2021 at 11:02:28AM +1000, Nicholas Piggin wrote: > The code being executed in KVM_GUEST_MODE_SKIP is hypervisor code with > MSR[IR]=0, so the faults of concern are the d-side ones caused by access > to guest context by the hypervisor. > > Instruction breakpoint interrupts are not a concern here. It's unlikely > any good would come of causing breaks in this code, but skipping the > instruction that caused it won't help matters (e.g., skip the mtmsr that > sets MSR[DR]=0 or clears KVM_GUEST_MODE_SKIP). > > Reviewed-by: Daniel Axtens > Reviewed-by: Fabiano Rosas > Signed-off-by: Nicholas Piggin It might be worth noting in the commit message that the 0x1300 interrupt was dropped from the architecture a long time ago and is not generated by P7, P8, P9 or P10. Acked-by: Paul Mackerras