| Message ID | 20110317212413.14852.67041.stgit@s20.home (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Mar 17, 2011 at 02:55:42PM -0700, Chris Wright wrote: > * Alex Williamson (alex.williamson@redhat.com) wrote: > > On system reset, we currently try to quiesce DMA by clearing the > > command register. This assumes that nothing re-enables bus master > > support without first de-programming the device. Use a bigger > > hammer to help the guest not shoot itself by issuing a function > > reset via sysfs on each system reset. > > > > Signed-off-by: Alex Williamson <alex.williamson@redhat.com> > > Looks good. > > Acked-by: Chris Wright <chrisw@redhat.com> Applied, thanks. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, Mar 17, 2011 at 03:24:31PM -0600, Alex Williamson wrote: > On system reset, we currently try to quiesce DMA by clearing the > command register. This assumes that nothing re-enables bus master > support without first de-programming the device. Use a bigger > hammer to help the guest not shoot itself by issuing a function > reset via sysfs on each system reset. > > Signed-off-by: Alex Williamson <alex.williamson@redhat.com> > --- > > v2: Fix segment support > > hw/device-assignment.c | 24 ++++++++++++++++++++++-- Applied, thanks. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/hw/device-assignment.c b/hw/device-assignment.c index db82e73..4997b6e 100644 --- a/hw/device-assignment.c +++ b/hw/device-assignment.c @@ -1693,13 +1693,33 @@ static const VMStateDescription vmstate_assigned_device = { static void reset_assigned_device(DeviceState *dev) { - PCIDevice *d = DO_UPCAST(PCIDevice, qdev, dev); + PCIDevice *pci_dev = DO_UPCAST(PCIDevice, qdev, dev); + AssignedDevice *adev = DO_UPCAST(AssignedDevice, dev, pci_dev); + char reset_file[64]; + const char reset[] = "1"; + int fd, ret; + + snprintf(reset_file, sizeof(reset_file), + "/sys/bus/pci/devices/%04x:%02x:%02x.%01x/reset", + adev->host.seg, adev->host.bus, adev->host.dev, adev->host.func); + + /* + * Issue a device reset via pci-sysfs. Note that we use write(2) here + * and ignore the return value because some kernels have a bug that + * returns 0 rather than bytes written on success, sending us into an + * infinite retry loop using other write mechanisms. + */ + fd = open(reset_file, O_WRONLY); + if (fd != -1) { + ret = write(fd, reset, strlen(reset)); + close(fd); + } /* * When a 0 is written to the command register, the device is logically * disconnected from the PCI bus. This avoids further DMA transfers. */ - assigned_dev_pci_write_config(d, PCI_COMMAND, 0, 2); + assigned_dev_pci_write_config(pci_dev, PCI_COMMAND, 0, 2); } static int assigned_initfn(struct PCIDevice *pci_dev)