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 X-Spam-Level: X-Spam-Status: No, score=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 747A1C169C4 for ; Tue, 29 Jan 2019 11:45:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 463C520882 for ; Tue, 29 Jan 2019 11:45:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548762329; bh=jBAvyyvdUS3A9m5WVPOugNXzymzv4yetnLohzc9ZJq0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=i78NTb+mHQjITlTWXH2rYXSFRGoYF5yZYg8mrVHfW4+p4Mq8oa+zZo6PWUkBtIPX+ bGi8fo4OreCFRMaqjA65WosVo7SvH2eiegEoNIeqFMkPWMw0A+M/UdH/plzoYV+2A/ +qg2yEwu/Cdsdj8eMwhaS4ZaMUW5viYdIuv+9Ys0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730772AbfA2Lp2 (ORCPT ); Tue, 29 Jan 2019 06:45:28 -0500 Received: from mail.kernel.org ([198.145.29.99]:35860 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729611AbfA2LpZ (ORCPT ); Tue, 29 Jan 2019 06:45:25 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7937E2083B; Tue, 29 Jan 2019 11:45:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548762325; bh=jBAvyyvdUS3A9m5WVPOugNXzymzv4yetnLohzc9ZJq0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HkkzOcpy1AIayO6brb/ALlG1n0rRLO7D4S12Jx9i7fBGqsNELVkux7BxJ2qrBV2m3 s2Ijr9HCi526Kq1fP8ic3OHBzQr+McFtzCvMP22QdW2wsVF9jYeaqWY/LVPLCcgazZ UEbCPpw8JQfaFIYsdOlv/RR+h78lUY+eS9TrekiA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Wanpeng Li , Sean Christopherson , Paolo Bonzini Subject: [PATCH 4.19 069/103] KVM: x86: WARN_ONCE if sending a PV IPI returns a fatal error Date: Tue, 29 Jan 2019 12:35:46 +0100 Message-Id: <20190129113204.772388391@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190129113159.567154026@linuxfoundation.org> References: <20190129113159.567154026@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sean Christopherson commit de81c2f912ef57917bdc6d63b410c534c3e07982 upstream. KVM hypercalls return a negative value error code in case of a fatal error, e.g. when the hypercall isn't supported or was made with invalid parameters. WARN_ONCE on fatal errors when sending PV IPIs as any such error all but guarantees an SMP system will hang due to a missing IPI. Fixes: aaffcfd1e82d ("KVM: X86: Implement PV IPIs in linux guest") Cc: stable@vger.kernel.org Cc: Wanpeng Li Signed-off-by: Sean Christopherson Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/kvm.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -457,6 +457,7 @@ static void __send_ipi_mask(const struct #else u64 ipi_bitmap = 0; #endif + long ret; if (cpumask_empty(mask)) return; @@ -482,8 +483,9 @@ static void __send_ipi_mask(const struct } else if (apic_id < min + KVM_IPI_CLUSTER_SIZE) { max = apic_id < max ? max : apic_id; } else { - kvm_hypercall4(KVM_HC_SEND_IPI, (unsigned long)ipi_bitmap, + ret = kvm_hypercall4(KVM_HC_SEND_IPI, (unsigned long)ipi_bitmap, (unsigned long)(ipi_bitmap >> BITS_PER_LONG), min, icr); + WARN_ONCE(ret < 0, "KVM: failed to send PV IPI: %ld", ret); min = max = apic_id; ipi_bitmap = 0; } @@ -491,8 +493,9 @@ static void __send_ipi_mask(const struct } if (ipi_bitmap) { - kvm_hypercall4(KVM_HC_SEND_IPI, (unsigned long)ipi_bitmap, + ret = kvm_hypercall4(KVM_HC_SEND_IPI, (unsigned long)ipi_bitmap, (unsigned long)(ipi_bitmap >> BITS_PER_LONG), min, icr); + WARN_ONCE(ret < 0, "KVM: failed to send PV IPI: %ld", ret); } local_irq_restore(flags);