From mboxrd@z Thu Jan 1 00:00:00 1970 From: Olaf Hering Subject: Re: xl pci-attach silently fails the first time Date: Mon, 1 Dec 2014 14:32:44 +0100 Message-ID: <20141201133244.GA24600@aepfle.de> References: <20141201125712.GA21576@aepfle.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20141201125712.GA21576@aepfle.de> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org On Mon, Dec 01, Olaf Hering wrote: > # xl pci-assignable-add 01:10.0 > # xl pci-assignable-list > 0000:01:10.0 > # xl create -f domU.cfg > # xl console domU > ## lspci gives just emulated PCI devices ttyS0:Rescue:~ # lspci 00:00.0 Host bridge: Intel Corporation 440FX - 82441FX PMC [Natoma] (rev 02) 00:01.0 ISA bridge: Intel Corporation 82371SB PIIX3 ISA [Natoma/Triton II] 00:01.1 IDE interface: Intel Corporation 82371SB PIIX3 IDE [Natoma/Triton II] 00:01.3 Bridge: Intel Corporation 82371AB/EB/MB PIIX4 ACPI (rev 03) 00:02.0 Unassigned class [ff80]: XenSource, Inc. Xen Platform Device (rev 01) 00:03.0 VGA compatible controller: Cirrus Logic GD 5446 00:04.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL-8100/8101L/8139 PCI Fast Ethernet Adapter (rev ff) > ## detach from domU console > # xl pci-attach domU 0000:01:10.0 > # xl pci-list domU > Vdev Device > 04.0 0000:01:10.0 > > # xl console domU > ## lspci gives just emulated PCI devices ttyS0:Rescue:~ # lspci 00:00.0 Host bridge: Intel Corporation 440FX - 82441FX PMC [Natoma] (rev 02) 00:01.0 ISA bridge: Intel Corporation 82371SB PIIX3 ISA [Natoma/Triton II] 00:01.1 IDE interface: Intel Corporation 82371SB PIIX3 IDE [Natoma/Triton II] 00:01.3 Bridge: Intel Corporation 82371AB/EB/MB PIIX4 ACPI (rev 03) 00:02.0 Unassigned class [ff80]: XenSource, Inc. Xen Platform Device (rev 01) 00:03.0 VGA compatible controller: Cirrus Logic GD 5446 00:04.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL-8100/8101L/8139 PCI Fast Ethernet Adapter (rev 01) > ## detach from domU console > # xl pci-detach domU 0000:01:10.0 Now lspci shows that the emulated network card is gone. ttyS0:Rescue:~ # lspci 00:00.0 Host bridge: Intel Corporation 440FX - 82441FX PMC [Natoma] (rev 02) 00:01.0 ISA bridge: Intel Corporation 82371SB PIIX3 ISA [Natoma/Triton II] 00:01.1 IDE interface: Intel Corporation 82371SB PIIX3 IDE [Natoma/Triton II] 00:01.3 Bridge: Intel Corporation 82371AB/EB/MB PIIX4 ACPI (rev 03) 00:02.0 Unassigned class [ff80]: XenSource, Inc. Xen Platform Device (rev 01) 00:03.0 VGA compatible controller: Cirrus Logic GD 5446 > # xl pci-attach domU 0000:01:10.0 > # xl pci-list domU > Vdev Device > 04.0 0000:01:10.0 > # xl console domU > ## lspci shows now also the assigned host device So the actual bug is that the very first time after pci-attach the guests "00:04.0" PCI device is (most likely) replaced with the host PCI device. Just the guest does not notice that "00:04.0" was actually already gone after unplug. I wonder why the unplug code in xen_platform.c does just a qdev_free() instead of a real pci-detach kind of thing. I'm sure this could be done at least for emulated network cards. Olaf