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 EA0EDC71153 for ; Tue, 29 Aug 2023 15:13:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234857AbjH2PN3 (ORCPT ); Tue, 29 Aug 2023 11:13:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43474 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230128AbjH2PM7 (ORCPT ); Tue, 29 Aug 2023 11:12:59 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D3181BD for ; Tue, 29 Aug 2023 08:12:56 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 586FD61058 for ; Tue, 29 Aug 2023 15:12:56 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B58E8C433C8; Tue, 29 Aug 2023 15:12:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1693321975; bh=7cZGRo8fUE3rcCsnCSIDZFr+/XhzQ583j9LmFP88nHE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=jbuEj0JqcCbVco7CN8RK1cLBB9MoUmYoJm0dzTbhK141vpSiLKECQ4ModkMUkGY0r Xr+X7VkVYMV+C3udjcVLykut71JSkVQx9Hw9GW1fNUHCJwrdapqDQgqzFKultuKpGu G2E4J6LXwSPd0Vq2D6AN8A5CJ2Ae/33qIDdgWTmFVjIStyUEbAcCJ7lxlQG+3vMDdn IWO/utjNAJ9NZlFJtcQjAhzm1Vq5jn2kuQT0zEcpg2oxL2xJcXCW7XVAvRmpQpBMyL Pqn12hRk57UUjags2AqCVcvbcYuLnRx3kvkL2L1LdRQG8rh3uepbEvU7mmTip69Idl tarj1JT/6b9ig== Date: Tue, 29 Aug 2023 17:12:51 +0200 From: Lorenzo Pieralisi To: Nirmal Patel Cc: linux-pci@vger.kernel.org Subject: Re: [PATCH v4] PCI: vmd: Do not change the BIOS Hotplug setting on VMD rootports Message-ID: References: <20230829051022.1328383-1-nirmal.patel@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230829051022.1328383-1-nirmal.patel@linux.intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Tue, Aug 29, 2023 at 01:10:22AM -0400, Nirmal Patel wrote: > Currently during Host boot up, VMD UEFI driver loads and configures > all the VMD endpoints devices and devices behind VMD. Then during > VMD rootport creation, VMD driver honors ACPI settings for Hotplug, > AER, DPC, PM and enables these features based on BIOS settings. > > During the Guest boot up, ACPI settings along with VMD UEFI driver are > not present in Guest BIOS which results in assigning default values to > Hotplug, AER, DPC, etc. As a result hotplug is disabled on the VMD > rootports in the Guest OS. > > VMD driver in Guest should be able to see the same settings as seen > by Host VMD driver. Because of the missing implementation of VMD UEFI > driver in Guest BIOS, the Hotplug is disabled on VMD rootport in > Guest OS. Hot inserted drives don't show up and hot removed drives > do not disappear even if VMD supports Hotplug in Guest. This > behavior is observed in various combinations of guest OSes i.e. RHEL, > SLES and hypervisors i.e. KVM and ESXI. > > This change will make the VMD Host and Guest Driver to keep the settings > implemented by the UEFI VMD DXE driver and thus honoring the user > selections for hotplug in the BIOS. > > Signed-off-by: Nirmal Patel > --- > v3->v4: Rewrite the commit log. > v2->v3: Update the commit log. > v1->v2: Update the commit log. > --- > drivers/pci/controller/vmd.c | 2 -- > 1 file changed, 2 deletions(-) > > diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c > index 769eedeb8802..52c2461b4761 100644 > --- a/drivers/pci/controller/vmd.c > +++ b/drivers/pci/controller/vmd.c > @@ -701,8 +701,6 @@ static int vmd_alloc_irqs(struct vmd_dev *vmd) > static void vmd_copy_host_bridge_flags(struct pci_host_bridge *root_bridge, > struct pci_host_bridge *vmd_bridge) > { > - vmd_bridge->native_pcie_hotplug = root_bridge->native_pcie_hotplug; > - vmd_bridge->native_shpc_hotplug = root_bridge->native_shpc_hotplug; How is the host bridge probed in the guest if there is no ACPI support ? I would like to understand this better how this works. > vmd_bridge->native_aer = root_bridge->native_aer; > vmd_bridge->native_pme = root_bridge->native_pme; > vmd_bridge->native_ltr = root_bridge->native_ltr; I don't get why *only* the hotplug flag should not be copied. Either you want to preserve them all or none. I assume the issue is that in the host, the _OSC method is used to probe for flags whereas in the guest you can't rely on it ? Is there a use case where you *do* want to copy the flags from the root_bridge to the vmd_bridge ? This does not look solid to me. Thanks, Lorenzo