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 E07D8C433EF for ; Wed, 27 Apr 2022 15:58:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241307AbiD0P7x (ORCPT ); Wed, 27 Apr 2022 11:59:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56940 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240518AbiD0P6P (ORCPT ); Wed, 27 Apr 2022 11:58:15 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7631C78397; Wed, 27 Apr 2022 08:54:40 -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 8A33EB8287E; Wed, 27 Apr 2022 15:54:35 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1D48EC385A7; Wed, 27 Apr 2022 15:54:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1651074874; bh=qotNt6/xEPZX16CKagFcCW/pd3anehroTyUMB8vdWR0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vMrAiDNJe9pfDMMz9tVN1e3hwYLAEbKJ6qT3yWAmEmtjmexQzvMnE5JLBTDkZkyO9 y4RWtuE0kfGKMFsFNutppwFsAccmHhcO629rPhAXV/b6UvlnWueXMp98bqs4QD9Hy4 wFI7S+J2HczmgCpqu+t41DEwlqyngS0kpiElpqpIjwcSeAx4IVzGoy6eBxUkMry+ag cgufHxFB7RFW85psr/7bIHQ7lG4HuMX2vZ+M9d0JwVqlgKpUnoNSOFd86Q/hqaiuWi Alub1UHkK3hz6cJXWa+zAAnM5EP3QWj1q5MvxWfdVMLLYeRbH1G7IUzXP5AhOAlipJ rT/D7bNCn0IOQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Paolo Bonzini , Chao Gao , Sean Christopherson , Sasha Levin , tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, kvm@vger.kernel.org Subject: [PATCH MANUALSEL 5.15 5/7] KVM: x86: Do not change ICR on write to APIC_SELF_IPI Date: Wed, 27 Apr 2022 11:54:25 -0400 Message-Id: <20220427155431.19458-5-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220427155431.19458-1-sashal@kernel.org> References: <20220427155431.19458-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 4d92fb4fdf69..83d1743a1dd0 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: -- 2.35.1