From patchwork Wed Sep 14 07:09:42 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Frank Heimes X-Patchwork-Id: 1677670 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.ubuntu.com (client-ip=91.189.94.19; helo=huckleberry.canonical.com; envelope-from=kernel-team-bounces@lists.ubuntu.com; receiver=) Authentication-Results: legolas.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=canonical.com header.i=@canonical.com header.a=rsa-sha256 header.s=20210705 header.b=a0cmUO+v; dkim-atps=neutral Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4MSBLG10YWz1ypZ for ; Wed, 14 Sep 2022 17:10:12 +1000 (AEST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.86_2) (envelope-from ) id 1oYMWz-0007Vu-Ow; Wed, 14 Sep 2022 07:09:57 +0000 Received: from smtp-relay-canonical-0.internal ([10.131.114.83] helo=smtp-relay-canonical-0.canonical.com) by huckleberry.canonical.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1oYMWx-0007VX-Vw for kernel-team@lists.ubuntu.com; Wed, 14 Sep 2022 07:09:55 +0000 Received: from T570.fritz.box (p54abbb95.dip0.t-ipconnect.de [84.171.187.149]) (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 smtp-relay-canonical-0.canonical.com (Postfix) with ESMTPSA id A7A0C3FA02 for ; Wed, 14 Sep 2022 07:09:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=canonical.com; s=20210705; t=1663139395; bh=E8nMC6RhCCtG/gF7uAaR543n2jPVLbROLePVzr9F9CM=; h=From:To:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=a0cmUO+vjkXNULGn1UFLHDET1ULxPIKjmLoB2FezF9cOOKu4wM4Z6/5NE//ALkF6b Qds/HCkUhaS+qjjchG2Q0uxuSGZ/CPC1DlzLc5j2qHkNrj3XCUZ5Rl2ueZUZlM0obx OLkBxiXjWapEa6ggL0WH31JvqAhzf9Tr2gg5F80Ig6ZcelsKBSp2EorsBTEEeB94g5 EIMGA178PjfazOeGWQgnLEaFod8X+ym8bCt7KNJZaVpHM+DevkCBwsPK3bMJTMJ6cZ 1iP2dnxWWSetyXPQFkNJmDNUWG/pmlppXkhcWcj3/r/22LDvb18TNz+j30ulrgT5iB cTN9f7D9N4cNw== From: frank.heimes@canonical.com To: kernel-team@lists.ubuntu.com Subject: [K][PATCH 3/5] PCI: Move jailhouse's isolated function handling to pci_scan_slot() Date: Wed, 14 Sep 2022 09:09:42 +0200 Message-Id: <20220914070944.919437-4-frank.heimes@canonical.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220914070944.919437-1-frank.heimes@canonical.com> References: <20220914070944.919437-1-frank.heimes@canonical.com> MIME-Version: 1.0 X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.20 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: "kernel-team" From: Niklas Schnelle BugLink: https://bugs.launchpad.net/bugs/1959542 The special case of the jailhouse hypervisor passing through individual PCI functions handles scanning for PCI functions even if function 0 does not exist. Previously this was done with an extra loop duplicating the one in pci_scan_slot(). By incorporating the check for jailhouse_paravirt() into pci_scan_slot() we can instead do this as part of the normal slot scan. Note that with the assignment of dev->multifunction gated by fn > 0 we set dev->multifunction unconditionally for all functions if function 0 is missing just as in the existing jailhouse loop. The only functional change is that we now call pcie_aspm_init_link_state() for these functions, but this already happened if function 0 was passed through and should not be a problem. Link: https://lore.kernel.org/linux-pci/20220408224514.GA353445@bhelgaas/ Suggested-by: Bjorn Helgaas Link: https://lore.kernel.org/r/20220628143100.3228092-4-schnelle@linux.ibm.com Signed-off-by: Niklas Schnelle Signed-off-by: Bjorn Helgaas Reviewed-by: Pierre Morel Cc: Jan Kiszka (cherry picked from commit db360b1ea7faef290471bc1b2a7463b96fd20a07) Signed-off-by: Frank Heimes --- drivers/pci/probe.c | 30 ++++++++++-------------------- 1 file changed, 10 insertions(+), 20 deletions(-) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index d62885519df3..1f91ed67b5c5 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -2663,8 +2663,13 @@ int pci_scan_slot(struct pci_bus *bus, int devfn) if (fn > 0) dev->multifunction = 1; } else if (fn == 0) { - /* function 0 is required */ - break; + /* + * Function 0 is required unless we are running on + * a hypervisor that passes through individual PCI + * functions. + */ + if (!jailhouse_paravirt()) + break; } fn = next_fn(bus, dev, fn); } while (fn >= 0); @@ -2863,29 +2868,14 @@ static unsigned int pci_scan_child_bus_extend(struct pci_bus *bus, { unsigned int used_buses, normal_bridges = 0, hotplug_bridges = 0; unsigned int start = bus->busn_res.start; - unsigned int devfn, fn, cmax, max = start; + unsigned int devfn, cmax, max = start; struct pci_dev *dev; - int nr_devs; dev_dbg(&bus->dev, "scanning bus\n"); /* Go find them, Rover! */ - for (devfn = 0; devfn < 256; devfn += 8) { - nr_devs = pci_scan_slot(bus, devfn); - - /* - * The Jailhouse hypervisor may pass individual functions of a - * multi-function device to a guest without passing function 0. - * Look for them as well. - */ - if (jailhouse_paravirt() && nr_devs == 0) { - for (fn = 1; fn < 8; fn++) { - dev = pci_scan_single_device(bus, devfn + fn); - if (dev) - dev->multifunction = 1; - } - } - } + for (devfn = 0; devfn < 256; devfn += 8) + pci_scan_slot(bus, devfn); /* Reserve buses for SR-IOV capability */ used_buses = pci_iov_bus_range(bus);