Commit 054bb7b2 authored by Alexander Graf's avatar Alexander Graf Committed by Peter Maydell
Browse files

target-arm: Declare virtio-mmio as dma-coherent in dt 



QEMU emulated hardware is always dma coherent with its guest. We do
annotate that correctly on the PCI host controller, but left out
virtio-mmio.

Recent kernels have started to interpret that flag rather than take
dma coherency as granted with virtio-mmio. While that is considered
a kernel bug, as it breaks previously working systems, it showed that
our dt description is incomplete.

This patch adds the respective marker that allows guest OSs to evaluate
that our virtio-mmio devices are indeed cache coherent.

Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
Reviewed-by: default avatarLaszlo Ersek <lersek@redhat.com>
Reviewed-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Message-id: 1486644810-33181-2-git-send-email-agraf@suse.de
Signed-off-by: default avatarPeter Maydell <peter.maydell@linaro.org>
parent d6f02ce3

hw/arm/vexpress.c

+1 −0
Original line number Diff line number Diff line
@@ -452,6 +452,7 @@ static int add_virtio_mmio_node(void *fdt, uint32_t acells, uint32_t scells, 
                                       acells, addr, scells, size);

    qemu_fdt_setprop_cells(fdt, nodename, "interrupt-parent", intc);

    qemu_fdt_setprop_cells(fdt, nodename, "interrupts", 0, irq, 1);

    qemu_fdt_setprop(fdt, nodename, "dma-coherent", NULL, 0);

    g_free(nodename);

    if (rc) {

        return -1;

hw/arm/virt.c

+1 −0
Original line number Diff line number Diff line
@@ -797,6 +797,7 @@ static void create_virtio_devices(const VirtMachineState *vms, qemu_irq *pic) 
        qemu_fdt_setprop_cells(vms->fdt, nodename, "interrupts",

                               GIC_FDT_IRQ_TYPE_SPI, irq,

                               GIC_FDT_IRQ_FLAGS_EDGE_LO_HI);

        qemu_fdt_setprop(vms->fdt, nodename, "dma-coherent", NULL, 0);

        g_free(nodename);

    }

}