Re: [Qemu-devel] [PATCH] hw/arm/virt: mark the PCIe host controller as DMA coherent in the DT

[Peter Maydell]

On 28 June 2016 at 18:14, Ard Biesheuvel <address@hidden> wrote:
> Since QEMU performs cacheable accesses to guest memory when doing DMA
> as part of the implementation of emulated PCI devices, guest drivers
> should use cacheable accesses as well when running under KVM. Since this
> essentially means that emulated PCI devices are DMA coherent, set the
> 'dma-coherent' DT property on the PCIe host controller DT node.
>
> Signed-off-by: Ard Biesheuvel <address@hidden>
> ---
>  hw/arm/virt.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/hw/arm/virt.c b/hw/arm/virt.c
> index c5c125e9204a..6e098afd1fe5 100644
> --- a/hw/arm/virt.c
> +++ b/hw/arm/virt.c
> @@ -1021,6 +1021,7 @@ static void create_pcie(const VirtBoardInfo *vbi, 
> qemu_irq *pic,
>      qemu_fdt_setprop_cell(vbi->fdt, nodename, "#size-cells", 2);
>      qemu_fdt_setprop_cells(vbi->fdt, nodename, "bus-range", 0,
>                             nr_pcie_buses - 1);
> +    qemu_fdt_setprop(vbi->fdt, nodename, "dma-coherent", NULL, 0);
>
>      if (vbi->v2m_phandle) {
>          qemu_fdt_setprop_cells(vbi->fdt, nodename, "msi-parent",
> --
> 2.7.4

Applied, thanks.

-- PMM