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Re: [Qemu-ppc] [PATCH 4/4] spapr_pci: Allow VFIO devices to work on the
From: |
Thomas Huth |
Subject: |
Re: [Qemu-ppc] [PATCH 4/4] spapr_pci: Allow VFIO devices to work on the normal PCI host bridge |
Date: |
Wed, 30 Sep 2015 12:09:16 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 |
On 30/09/15 05:48, David Gibson wrote:
> The core VFIO infrastructure more or less allows VFIO devices to work
> on any normal guest PCI host bridge (PHB) without extra logic.
> However, the "spapr-pci-host-bridge" device (as opposed to the special
> "spapr-pci-vfio-host-bridge" device) breaks this by using a partially
> KVM accelerated implementation of the guest kernel IOMMU which won't
> work with VFIO devices, without additional kernel support.
>
> This patch allows VFIO devices to work on the spapr-pci-host-bridge,
> by having it switch off KVM TCE acceleration when a VFIO device is
> added to the PHB (either on startup, or by hotplug).
>
> Signed-off-by: David Gibson <address@hidden>
> ---
> hw/ppc/spapr_pci.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
> index cb7c351..55fa8db 100644
> --- a/hw/ppc/spapr_pci.c
> +++ b/hw/ppc/spapr_pci.c
> @@ -1083,6 +1083,12 @@ static void spapr_phb_add_pci_device(sPAPRDRConnector
> *drc,
> void *fdt = NULL;
> int fdt_start_offset = 0, fdt_size;
>
> + if (object_dynamic_cast(OBJECT(pdev), "vfio-pci")) {
> + sPAPRTCETable *tcet = spapr_tce_find_by_liobn(phb->dma_liobn);
> +
> + spapr_tce_set_need_vfio(tcet, true);
> + }
> +
> if (dev->hotplugged) {
> fdt = create_device_tree(&fdt_size);
> fdt_start_offset = spapr_create_pci_child_dt(phb, pdev, fdt, 0);
Reviewed-by: Thomas Huth <address@hidden>