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Re: [Qemu-devel] [RFC PATCH v2 02/13] spapr_iommu: Disable in-kernel IOM
From: |
Alexander Graf |
Subject: |
Re: [Qemu-devel] [RFC PATCH v2 02/13] spapr_iommu: Disable in-kernel IOMMU tables for >4GB windows |
Date: |
Wed, 27 Aug 2014 11:27:49 +0200 |
User-agent: |
Mozilla/5.0 (Macintosh; Intel Mac OS X 10.9; rv:31.0) Gecko/20100101 Thunderbird/31.0 |
On 15.08.14 12:12, Alexey Kardashevskiy wrote:
> The existing KVM_CREATE_SPAPR_TCE ioctl only support 4G windows max.
> We are going to add huge DMA windows support so this will create small
> window and unexpectedly fail later.
>
> This disables KVM_CREATE_SPAPR_TCE for windows bigger that 4GB. Since
> those windows are normally mapped at the boot time, there will be no
> performance impact.
>
> Signed-off-by: Alexey Kardashevskiy <address@hidden>
> ---
> hw/ppc/spapr_iommu.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/hw/ppc/spapr_iommu.c b/hw/ppc/spapr_iommu.c
> index f6e32a4..36f5d27 100644
> --- a/hw/ppc/spapr_iommu.c
> +++ b/hw/ppc/spapr_iommu.c
> @@ -113,11 +113,11 @@ static MemoryRegionIOMMUOps spapr_iommu_ops = {
> static int spapr_tce_table_realize(DeviceState *dev)
> {
> sPAPRTCETable *tcet = SPAPR_TCE_TABLE(dev);
> + uint64_t window_size = tcet->nb_table << tcet->page_shift;
>
> - if (kvm_enabled()) {
> + if (kvm_enabled() && !(window_size >> 32)) {
Please add a comment here that explains the reasoning.
Alex
- Re: [Qemu-devel] [RFC PATCH v2 08/13] spapr_pci: Enable DDW, (continued)
- [Qemu-devel] [RFC PATCH v2 03/13] spapr_pci: Make find_phb()/find_dev() public, Alexey Kardashevskiy, 2014/08/15
- [Qemu-devel] [RFC PATCH v2 05/13] spapr_pci: Introduce a liobn number generating macros, Alexey Kardashevskiy, 2014/08/15
- [Qemu-devel] [RFC PATCH v2 04/13] spapr_iommu: Make spapr_tce_find_by_liobn() public, Alexey Kardashevskiy, 2014/08/15
- [Qemu-devel] [RFC PATCH v2 02/13] spapr_iommu: Disable in-kernel IOMMU tables for >4GB windows, Alexey Kardashevskiy, 2014/08/15
- [Qemu-devel] [RFC PATCH v2 10/13] linux headers update for DDW, Alexey Kardashevskiy, 2014/08/15
[Qemu-devel] [RFC PATCH v2 07/13] spapr_rtas: Add Dynamic DMA windows (DDW) RTAS calls support, Alexey Kardashevskiy, 2014/08/15
[Qemu-devel] [RFC PATCH v2 09/13] spapr_pci_vfio: Call spapr_pci::reset on reset, Alexey Kardashevskiy, 2014/08/15