From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: [PATCH] device-assignment: register a reset function Date: Mon, 15 Nov 2010 13:08:44 +0100 Message-ID: <4CE122CC.6050700@siemens.com> References: <1284740181.14301.15.camel@x201> <1289820837-24254-1-git-send-email-bernhard.kohl@nsn.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Cc: alex.williamson@redhat.com, Thomas Ostler , kvm , "Michael S. Tsirkin" To: Bernhard Kohl Return-path: Received: from thoth.sbs.de ([192.35.17.2]:17751 "EHLO thoth.sbs.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754665Ab0KOMJH (ORCPT ); Mon, 15 Nov 2010 07:09:07 -0500 In-Reply-To: <1289820837-24254-1-git-send-email-bernhard.kohl@nsn.com> Sender: kvm-owner@vger.kernel.org List-ID: [Wrong list, it's not upstream yet. I'm migrating the thread to kvm.] Am 15.11.2010 12:33, Bernhard Kohl wrote: > This is necessary because during reboot of a VM the assigned devices > continue DMA transfers which causes memory corruption. > > Signed-off-by: Thomas Ostler > Signed-off-by: Bernhard Kohl > --- > Sorry for for the long delay. Finally we added Alex' suggestions > and rebased the patch. > > Thanks > Bernhard > --- > hw/device-assignment.c | 12 ++++++++++++ > 1 files changed, 12 insertions(+), 0 deletions(-) > > diff --git a/hw/device-assignment.c b/hw/device-assignment.c > index 5f5bde1..3f8de66 100644 > --- a/hw/device-assignment.c > +++ b/hw/device-assignment.c > @@ -1434,6 +1434,17 @@ static void assigned_dev_unregister_msix_mmio(AssignedDevice *dev) > dev->msix_table_page = NULL; > } > > +static void reset_assigned_device(DeviceState *dev) > +{ > + PCIDevice *d = DO_UPCAST(PCIDevice, qdev, dev); > + uint32_t conf; > + > + /* reset the bus master bit to avoid further DMA transfers */ > + conf = assigned_dev_pci_read_config(d, PCI_COMMAND, 2); > + conf &= ~PCI_COMMAND_MASTER; > + assigned_dev_pci_write_config(d, PCI_COMMAND, conf, 2); What about writing to /sys/bus/pci/devices/$DEVICE/reset? You probably still need to put the command word into the reset state (ie. no RMW in any case, just write 0), but the hardware should receive a reset as well - if it is capable of doing a function-level reset, but we should at least try. > +} > + > static int assigned_initfn(struct PCIDevice *pci_dev) > { > AssignedDevice *dev = DO_UPCAST(AssignedDevice, dev, pci_dev); > @@ -1544,6 +1555,7 @@ static PCIDeviceInfo assign_info = { > .qdev.name = "pci-assign", > .qdev.desc = "pass through host pci devices to the guest", > .qdev.size = sizeof(AssignedDevice), > + .qdev.reset = reset_assigned_device, > .init = assigned_initfn, > .exit = assigned_exitfn, > .config_read = assigned_dev_pci_read_config, Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux