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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7DA7CC433EF for ; Thu, 21 Oct 2021 23:14:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 59E526135F for ; Thu, 21 Oct 2021 23:14:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232173AbhJUXQh (ORCPT ); Thu, 21 Oct 2021 19:16:37 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:57886 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231515AbhJUXQg (ORCPT ); Thu, 21 Oct 2021 19:16:36 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1634858059; 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=iofDD8CWYU8TSSLGexX/eY5SZalt9OSL5XJ8kkqgP9M=; b=FtgzjNETDae96Dy84jcqf3mJI2Bdv//mBbPGDOCHOuRqBlSxKwa3g6U4dvUDM93MqcW+Xi REolA/mPovt8Pub49Jei6Cp1wv/TRNflMAp/FCmfNynDCu3CI5LnQKbpSg0SBz9aXg/uwl fxzB3p87btg8FeLUGpLRaylEbDDVQbM= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-364-xRqOTb31PEKQavQaj9lLTw-1; Thu, 21 Oct 2021 19:14:14 -0400 X-MC-Unique: xRqOTb31PEKQavQaj9lLTw-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 6C173802B7E; Thu, 21 Oct 2021 23:14:13 +0000 (UTC) Received: from starship (unknown [10.40.192.246]) by smtp.corp.redhat.com (Postfix) with ESMTP id 593F010016FC; Thu, 21 Oct 2021 23:14:06 +0000 (UTC) Message-ID: <1ae6a54626342dd2391d04a3566bd680c6831e93.camel@redhat.com> Subject: Re: [PATCH 4/8] KVM: SEV-ES: clean up kvm_sev_es_ins/outs From: Maxim Levitsky To: Paolo Bonzini , linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: fwilhelm@google.com, seanjc@google.com, oupton@google.com, stable@vger.kernel.org Date: Fri, 22 Oct 2021 02:14:05 +0300 In-Reply-To: <20211013165616.19846-5-pbonzini@redhat.com> References: <20211013165616.19846-1-pbonzini@redhat.com> <20211013165616.19846-5-pbonzini@redhat.com> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.36.5 (3.36.5-2.fc32) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2021-10-13 at 12:56 -0400, Paolo Bonzini wrote: > Remove the data argument and pull setting vcpu->arch.sev_pio_data into > the caller; remove unnecessary clearing of vcpu->arch.pio.count when > emulation is done by the kernel. You forgot to mention that you inlined the call to emulator_pio_out_emulated/emulator_pio_in_emulated. > > No functional change intended. > > Cc: stable@vger.kernel.org > Fixes: 7ed9abfe8e9f ("KVM: SVM: Support string IO operations for an SEV-ES guest") > Signed-off-by: Paolo Bonzini > --- > arch/x86/kvm/x86.c | 31 +++++++++++++++---------------- > 1 file changed, 15 insertions(+), 16 deletions(-) > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 218877e297e5..8880dc36a2b4 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -12382,34 +12382,32 @@ static int complete_sev_es_emulated_ins(struct kvm_vcpu *vcpu) > } > > static int kvm_sev_es_outs(struct kvm_vcpu *vcpu, unsigned int size, > - unsigned int port, void *data, unsigned int count) > + unsigned int port, unsigned int count) > { > - int ret; > + int ret = emulator_pio_out(vcpu, size, port, > + vcpu->arch.sev_pio_data, count); > > - ret = emulator_pio_out_emulated(vcpu->arch.emulate_ctxt, size, port, > - data, count); > - if (ret) > + if (ret) { > + /* Emulation done by the kernel. */ ^^ This is a very good comment to have here! > return ret; > + } > > vcpu->arch.pio.count = 0; ^^^ I wonder what the rules are for clearing vcpu->arch.pio.count for userspace PIO vm exits. Looks like complete_fast_pio_out clears it, but otherwise the only other place that clears it in this case is x86_emulate_instruction when it restarts the instuction. Do I miss something? > - > return 0; > } > > static int kvm_sev_es_ins(struct kvm_vcpu *vcpu, unsigned int size, > - unsigned int port, void *data, unsigned int count) > + unsigned int port, unsigned int count) > { > - int ret; > + int ret = emulator_pio_in(vcpu, size, port, > + vcpu->arch.sev_pio_data, count); > > - ret = emulator_pio_in_emulated(vcpu->arch.emulate_ctxt, size, port, > - data, count); > if (ret) { > - vcpu->arch.pio.count = 0; > - } else { > - vcpu->arch.sev_pio_data = data; > - vcpu->arch.complete_userspace_io = complete_sev_es_emulated_ins; > + /* Emulation done by the kernel. */ > + return ret; > } > > + vcpu->arch.complete_userspace_io = complete_sev_es_emulated_ins; > return 0; > } > > @@ -12417,8 +12415,9 @@ int kvm_sev_es_string_io(struct kvm_vcpu *vcpu, unsigned int size, > unsigned int port, void *data, unsigned int count, > int in) > { > - return in ? kvm_sev_es_ins(vcpu, size, port, data, count) > - : kvm_sev_es_outs(vcpu, size, port, data, count); > + vcpu->arch.sev_pio_data = data; > + return in ? kvm_sev_es_ins(vcpu, size, port, count) > + : kvm_sev_es_outs(vcpu, size, port, count); > } > EXPORT_SYMBOL_GPL(kvm_sev_es_string_io); > Looks OK to me, I might have missed something though. Reviewed-by: Maxim Levitsky Best regards, Maxim Levitsky