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[Qemu-devel] Re: [PATCH] device-assignment: register a reset function
From: |
Jan Kiszka |
Subject: |
[Qemu-devel] Re: [PATCH] device-assignment: register a reset function |
Date: |
Mon, 15 Nov 2010 13:08:44 +0100 |
User-agent: |
Mozilla/5.0 (X11; U; Linux i686 (x86_64); de; rv:1.8.1.12) Gecko/20080226 SUSE/2.0.0.12-1.1 Thunderbird/2.0.0.12 Mnenhy/0.7.5.666 |
[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 <address@hidden>
> Signed-off-by: Bernhard Kohl <address@hidden>
> ---
> 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
--
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