From patchwork Wed May 4 16:43:48 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 569836 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 E0B0AC433F5 for ; Wed, 4 May 2022 16:59:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344134AbiEDRCs (ORCPT ); Wed, 4 May 2022 13:02:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39452 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1354610AbiEDQ6y (ORCPT ); Wed, 4 May 2022 12:58:54 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 70D4724BD2; Wed, 4 May 2022 09:50:48 -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 19E4FB82752; Wed, 4 May 2022 16:50:47 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A2B3AC385AF; Wed, 4 May 2022 16:50:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1651683045; bh=ytEVOFy2eVY4xN2PbAqT0GNK6yzV4i4nIrFvtm0JN+8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=W1C+SxeBbsKelBlAliSnUptWNTcdoLv5jO6fPEc4NdxNZSCSrL0JqQ3o4Wtohwqz3 WYnYEzYPM2RqM1v5hpeYQ489FacuPslZx9ZtIXxwQG2296qi95ZB54x08mKqki6hd+ NRj4Az/J3pTPJPI49vhhWiop37W4P+bcLVYgSpnU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jeremi Piotrowski , Dusty Mabe , Salvatore Bonaccorso , Thomas Gleixner , Noah Meyerhans Subject: [PATCH 5.10 036/129] x86/pci/xen: Disable PCI/MSI[-X] masking for XEN_HVM guests Date: Wed, 4 May 2022 18:43:48 +0200 Message-Id: <20220504153024.088119748@linuxfoundation.org> X-Mailer: git-send-email 2.36.0 In-Reply-To: <20220504153021.299025455@linuxfoundation.org> References: <20220504153021.299025455@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Thomas Gleixner commit 7e0815b3e09986d2fe651199363e135b9358132a upstream. When a XEN_HVM guest uses the XEN PIRQ/Eventchannel mechanism, then PCI/MSI[-X] masking is solely controlled by the hypervisor, but contrary to XEN_PV guests this does not disable PCI/MSI[-X] masking in the PCI/MSI layer. This can lead to a situation where the PCI/MSI layer masks an MSI[-X] interrupt and the hypervisor grants the write despite the fact that it already requested the interrupt. As a consequence interrupt delivery on the affected device is not happening ever. Set pci_msi_ignore_mask to prevent that like it's done for XEN_PV guests already. Fixes: 809f9267bbab ("xen: map MSIs into pirqs") Reported-by: Jeremi Piotrowski Reported-by: Dusty Mabe Reported-by: Salvatore Bonaccorso Signed-off-by: Thomas Gleixner Tested-by: Noah Meyerhans Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/87tuaduxj5.ffs@tglx Signed-off-by: Greg Kroah-Hartman --- arch/x86/pci/xen.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/arch/x86/pci/xen.c +++ b/arch/x86/pci/xen.c @@ -476,7 +476,6 @@ static __init void xen_setup_pci_msi(voi xen_msi_ops.setup_msi_irqs = xen_setup_msi_irqs; } xen_msi_ops.teardown_msi_irqs = xen_pv_teardown_msi_irqs; - pci_msi_ignore_mask = 1; } else if (xen_hvm_domain()) { xen_msi_ops.setup_msi_irqs = xen_hvm_setup_msi_irqs; xen_msi_ops.teardown_msi_irqs = xen_teardown_msi_irqs; @@ -490,6 +489,11 @@ static __init void xen_setup_pci_msi(voi * in allocating the native domain and never use it. */ x86_init.irqs.create_pci_msi_domain = xen_create_pci_msi_domain; + /* + * With XEN PIRQ/Eventchannels in use PCI/MSI[-X] masking is solely + * controlled by the hypervisor. + */ + pci_msi_ignore_mask = 1; } #else /* CONFIG_PCI_MSI */