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 E2744C6FD1D for ; Fri, 17 Mar 2023 19:30:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230004AbjCQTa1 (ORCPT ); Fri, 17 Mar 2023 15:30:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41660 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229604AbjCQTa0 (ORCPT ); Fri, 17 Mar 2023 15:30:26 -0400 Received: from out-34.mta1.migadu.com (out-34.mta1.migadu.com [IPv6:2001:41d0:203:375::22]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B59004DE20 for ; Fri, 17 Mar 2023 12:30:20 -0700 (PDT) Date: Fri, 17 Mar 2023 19:30:15 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1679081418; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=0jCdRBqGA2tu6XOLfbhVwiAxzNSGs6ak27904LkdISc=; b=caTATcZwwRvg6ataeUUzdzgwg+ByMYM+CAsVmV9XfkdXgJOLYmiNOLkHsKsmjWaLmli0Ey Y50HTdrVYKEfzJ+axLkuvGxlmnaKQQZXJT3+dvDZQ8rlUVOGXh5Q4TeL/JLvS3PpghHe0V gFLBVHuu8kyGWZsQUavy6a2MV53AdkU= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Oliver Upton To: Anish Moorthy Cc: Isaku Yamahata , Marc Zyngier , seanjc@google.com, jthoughton@google.com, kvm@vger.kernel.org Subject: Re: [WIP Patch v2 04/14] KVM: x86: Add KVM_CAP_X86_MEMORY_FAULT_EXIT and associated kvm_run field Message-ID: References: <20230315021738.1151386-1-amoorthy@google.com> <20230315021738.1151386-5-amoorthy@google.com> <20230317000226.GA408922@ls.amr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Migadu-Flow: FLOW_OUT Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Fri, Mar 17, 2023 at 11:33:38AM -0700, Anish Moorthy wrote: > On Thu, Mar 16, 2023 at 5:02 PM Isaku Yamahata wrote: > > > > +7.34 KVM_CAP_X86_MEMORY_FAULT_EXIT > > > +---------------------------------- > > > + > > > +:Architectures: x86 > > > > Why x86 specific? > > Sean was the only one to bring this functionality up and originally > did so in the context of some x86-specific functions, so I assumed > that x86 was the only ask and that maybe the other architectures had > alternative solutions. Admittedly I also wanted to avoid wading > through another big set of -EFAULT references :/ There isn't much :) Sanity checks in mmu.c and some currently unhandled failures to write guest memory in pvtime.c > Those are the only reasons though. Marc, Oliver, should I bring this > capability to Arm as well? The x86 implementation shouldn't preclude UAPI reuse, but I'm not strongly motivated in either direction on this. A clear use case where the exit information is actionable rather than just informational would make the change more desirable. -- Thanks, Oliver