On Tue, 2010-11-16 at 15:05 +0100, 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 <thomas.ostler@xxxxxxx>
> Signed-off-by: Bernhard Kohl <bernhard.kohl@xxxxxxx>
> ---
> Changes v1 -> v2:
> - use defined macros, e.g. PCI_COMMAND
> - write all zero to the command register to disconnect the device logically
> ---
> hw/device-assignment.c | 12 ++++++++++++
> 1 files changed, 12 insertions(+), 0 deletions(-)
Looks good to me.
Acked-by: Alex Williamson <alex.williamson@xxxxxxxxxx>
> diff --git a/hw/device-assignment.c b/hw/device-assignment.c
> index 5f5bde1..8d5a609 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);
> +
> + /*
> + * 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);
> +}
> +
> 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,
--
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