| Message ID | 715D42877B251141A38726ABF5CABF2C01A11B66ED@pdsmsx503.ccr.corp.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Han, Weidong wrote: > When user wants to assign device with IOMMU, but IOMMU is not > enabled, add warning messages to prompt user this situation, and > return error. Or device will be assigned but it cannot work. > If the device has does not do DMA (say a serial port) then it can be assigned. Can we check the device for dma capability and allow this special case?
Avi Kivity wrote: > Han, Weidong wrote: >> When user wants to assign device with IOMMU, but IOMMU is not >> enabled, add warning messages to prompt user this situation, and >> return error. Or device will be assigned but it cannot work. >> > > If the device has does not do DMA (say a serial port) then it can be > assigned. Can we check the device for dma capability and allow this > special case? Do you have any hint to check it? This warning be triggered only when user wants to assign device with IOMMU. If user doesn't want to use IOMMU to assign device, he can use "-pcidevice host=xx:yy.z,dma=none". Regards, Weidong -- 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/qemu/hw/device-assignment.c b/qemu/hw/device-assignment.c index b7f9fa6..cef7c8a 100644 --- a/qemu/hw/device-assignment.c +++ b/qemu/hw/device-assignment.c @@ -616,6 +616,11 @@ static int assign_device(AssignedDevInfo *adev) r = kvm_check_extension(kvm_context, KVM_CAP_IOMMU); if (r && !adev->disable_iommu) assigned_dev_data.flags |= KVM_DEV_ASSIGN_ENABLE_IOMMU; + else if (!adev->disable_iommu && r == 0) { + fprintf(stderr, "IOMMU is not enabled. You cannot use " + "it to assign device!\n"); + return -EINVAL; + } #endif r = kvm_assign_pci_device(kvm_context, &assigned_dev_data);
When user wants to assign device with IOMMU, but IOMMU is not enabled, add warning messages to prompt user this situation, and return error. Or device will be assigned but it cannot work. Signed-off-by: Weidong Han <weidong.han@intel.com> --- qemu/hw/device-assignment.c | 5 +++++ 1 files changed, 5 insertions(+), 0 deletions(-)