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 C027CC433EF for ; Mon, 25 Oct 2021 19:53:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AB51F604DA for ; Mon, 25 Oct 2021 19:53:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238022AbhJYT4G (ORCPT ); Mon, 25 Oct 2021 15:56:06 -0400 Received: from mail.kernel.org ([198.145.29.99]:38048 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237176AbhJYTvA (ORCPT ); Mon, 25 Oct 2021 15:51:00 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 59A8F610D2; Mon, 25 Oct 2021 19:42:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1635190970; bh=dMm0c36jhVP2kmnmO/Kv1dL2mOS6lCfp27SNnoJrt7I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PghqIdX15IxjZLDHITYbAouDJn9s8vyxLYh3OEoTiWl4wO0cd0nNcsvNJTMvuVT9g LIOt2DQ6A6uGlhroe8yyK4/o6osG5jebjm0RIb0Vh6McGRxo8p3lGyB+NTzytNnyrc b2+yqrW9Qb4zGiFdg+1Urh/ML602PzMCfyUsZDp4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Paolo Bonzini Subject: [PATCH 5.14 114/169] KVM: x86: split the two parts of emulator_pio_in Date: Mon, 25 Oct 2021 21:14:55 +0200 Message-Id: <20211025191032.421237349@linuxfoundation.org> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211025191017.756020307@linuxfoundation.org> References: <20211025191017.756020307@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Paolo Bonzini commit 3b27de27183911d461afedf50c6fa30c59740c07 upstream. emulator_pio_in handles both the case where the data is pending in vcpu->arch.pio.count, and the case where I/O has to be done via either an in-kernel device or a userspace exit. For SEV-ES we would like to split these, to identify clearly the moment at which the sev_pio_data is consumed. To this end, create two different functions: __emulator_pio_in fills in vcpu->arch.pio.count, while complete_emulator_pio_in clears it and releases vcpu->arch.pio.data. Because this patch has to be backported, things are left a bit messy. kernel_pio() operates on vcpu->arch.pio, which leads to emulator_pio_in() having with two calls to complete_emulator_pio_in(). It will be fixed in the next release. While at it, remove the unused void* val argument of emulator_pio_in_out. The function currently hardcodes vcpu->arch.pio_data as the source/destination buffer, which sucks but will be fixed after the more severe SEV-ES buffer overflow. 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 Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/x86.c | 45 ++++++++++++++++++++++++++++----------------- 1 file changed, 28 insertions(+), 17 deletions(-) --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -6907,7 +6907,7 @@ static int kernel_pio(struct kvm_vcpu *v } static int emulator_pio_in_out(struct kvm_vcpu *vcpu, int size, - unsigned short port, void *val, + unsigned short port, unsigned int count, bool in) { vcpu->arch.pio.port = port; @@ -6928,26 +6928,38 @@ static int emulator_pio_in_out(struct kv return 0; } -static int emulator_pio_in(struct kvm_vcpu *vcpu, int size, - unsigned short port, void *val, unsigned int count) +static int __emulator_pio_in(struct kvm_vcpu *vcpu, int size, + unsigned short port, unsigned int count) { - int ret; + WARN_ON(vcpu->arch.pio.count); + memset(vcpu->arch.pio_data, 0, size * count); + return emulator_pio_in_out(vcpu, size, port, count, true); +} - if (vcpu->arch.pio.count) - goto data_avail; +static void complete_emulator_pio_in(struct kvm_vcpu *vcpu, int size, + unsigned short port, void *val) +{ + memcpy(val, vcpu->arch.pio_data, size * vcpu->arch.pio.count); + trace_kvm_pio(KVM_PIO_IN, port, size, vcpu->arch.pio.count, vcpu->arch.pio_data); + vcpu->arch.pio.count = 0; +} - memset(vcpu->arch.pio_data, 0, size * count); +static int emulator_pio_in(struct kvm_vcpu *vcpu, int size, + unsigned short port, void *val, unsigned int count) +{ + if (vcpu->arch.pio.count) { + /* Complete previous iteration. */ + } else { + int r = __emulator_pio_in(vcpu, size, port, count); + if (!r) + return r; - ret = emulator_pio_in_out(vcpu, size, port, val, count, true); - if (ret) { -data_avail: - memcpy(val, vcpu->arch.pio_data, size * count); - trace_kvm_pio(KVM_PIO_IN, port, size, count, vcpu->arch.pio_data); - vcpu->arch.pio.count = 0; - return 1; + /* Results already available, fall through. */ } - return 0; + WARN_ON(count != vcpu->arch.pio.count); + complete_emulator_pio_in(vcpu, size, port, val); + return 1; } static int emulator_pio_in_emulated(struct x86_emulate_ctxt *ctxt, @@ -6966,12 +6978,11 @@ static int emulator_pio_out(struct kvm_v memcpy(vcpu->arch.pio_data, val, size * count); trace_kvm_pio(KVM_PIO_OUT, port, size, count, vcpu->arch.pio_data); - ret = emulator_pio_in_out(vcpu, size, port, (void *)val, count, false); + ret = emulator_pio_in_out(vcpu, size, port, count, false); if (ret) vcpu->arch.pio.count = 0; return ret; - } static int emulator_pio_out_emulated(struct x86_emulate_ctxt *ctxt,