From patchwork Tue May 10 13:08:26 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "gregkh@linuxfoundation.org" X-Patchwork-Id: 571510 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 016E9C433FE for ; Tue, 10 May 2022 14:10:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245156AbiEJOOO (ORCPT ); Tue, 10 May 2022 10:14:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43284 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1343553AbiEJOHI (ORCPT ); Tue, 10 May 2022 10:07:08 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F306920791E; Tue, 10 May 2022 06:41:09 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id DF936B81DA0; Tue, 10 May 2022 13:41:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4610EC385A6; Tue, 10 May 2022 13:41:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1652190065; bh=84Cf+kNuFriqtENNa1ezqce+lu2J/desx9OHStUV0J4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HrI50niXBIv5+GldavaT87HYTmlwvZBvTBdYT6zhtQp+wJ1kj20jgCv+RL61ivnsP ijpNfJUxTvqIBbb+Y4yCGIAij4Lj2N5s0lNPMr1JoByXNHOTgazyfrrUvyGX1xU8Z6 ZTOf78fNr5zqt+s85e84myhtuLqNCrvLBh44ll08= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Chao Gao , Sean Christopherson , Paolo Bonzini , Sasha Levin Subject: [PATCH 5.17 116/140] KVM: x86: Do not change ICR on write to APIC_SELF_IPI Date: Tue, 10 May 2022 15:08:26 +0200 Message-Id: <20220510130744.922507518@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220510130741.600270947@linuxfoundation.org> References: <20220510130741.600270947@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Paolo Bonzini [ Upstream commit d22a81b304a27fca6124174a8e842e826c193466 ] Emulating writes to SELF_IPI with a write to ICR has an unwanted side effect: the value of ICR in vAPIC page gets changed. The lists SELF_IPI as write-only, with no associated MMIO offset, so any write should have no visible side effect in the vAPIC page. Reported-by: Chao Gao Reviewed-by: Sean Christopherson Signed-off-by: Paolo Bonzini Signed-off-by: Sasha Levin --- arch/x86/kvm/lapic.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 2a10d0033c96..6b6f9359d29e 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -2125,10 +2125,9 @@ int kvm_lapic_reg_write(struct kvm_lapic *apic, u32 reg, u32 val) break; case APIC_SELF_IPI: - if (apic_x2apic_mode(apic)) { - kvm_lapic_reg_write(apic, APIC_ICR, - APIC_DEST_SELF | (val & APIC_VECTOR_MASK)); - } else + if (apic_x2apic_mode(apic)) + kvm_apic_send_ipi(apic, APIC_DEST_SELF | (val & APIC_VECTOR_MASK), 0); + else ret = 1; break; default: