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Re: [Qemu-ppc] [PATCH qemu v17 09/12] vfio: Add host side DMA window cap
From: |
Alex Williamson |
Subject: |
Re: [Qemu-ppc] [PATCH qemu v17 09/12] vfio: Add host side DMA window capabilities |
Date: |
Fri, 3 Jun 2016 10:32:02 -0600 |
On Wed, 1 Jun 2016 18:57:40 +1000
Alexey Kardashevskiy <address@hidden> wrote:
> There are going to be multiple IOMMUs per a container. This moves
> the single host IOMMU parameter set to a list of VFIOHostDMAWindow.
>
> This should cause no behavioral change and will be used later by
> the SPAPR TCE IOMMU v2 which will also add a vfio_host_win_del() helper.
>
> Signed-off-by: Alexey Kardashevskiy <address@hidden>
> Reviewed-by: David Gibson <address@hidden>
> ---
> Changes:
> v17:
> * vfio_host_win_add() uses vfio_host_win_lookup() for overlap check and
> aborts if any found instead of returning an error (as recovery is not
> possible anyway)
> * hw_error() when overlapped iommu is detected
>
> v16:
> * adjusted commit log with changes from v15
>
> v15:
> * s/vfio_host_iommu_add/vfio_host_win_add/
> * s/VFIOHostIOMMU/VFIOHostDMAWindow/
> ---
> hw/vfio/common.c | 59
> +++++++++++++++++++++++++++++++------------
> include/hw/vfio/vfio-common.h | 9 +++++--
> 2 files changed, 50 insertions(+), 18 deletions(-)
>
> diff --git a/hw/vfio/common.c b/hw/vfio/common.c
> index 770f630..52b08fd 100644
> --- a/hw/vfio/common.c
> +++ b/hw/vfio/common.c
> @@ -29,6 +29,7 @@
> #include "exec/memory.h"
> #include "hw/hw.h"
> #include "qemu/error-report.h"
> +#include "qemu/range.h"
> #include "sysemu/kvm.h"
> #ifdef CONFIG_KVM
> #include "linux/kvm.h"
> @@ -242,6 +243,38 @@ static int vfio_dma_map(VFIOContainer *container, hwaddr
> iova,
> return -errno;
> }
>
> +static VFIOHostDMAWindow *vfio_host_win_lookup(VFIOContainer *container,
> + hwaddr min_iova, hwaddr
> max_iova)
> +{
> + VFIOHostDMAWindow *hostwin;
> +
> + QLIST_FOREACH(hostwin, &container->hostwin_list, hostwin_next) {
> + if (hostwin->min_iova <= min_iova && max_iova <= hostwin->max_iova) {
> + return hostwin;
> + }
> + }
> +
> + return NULL;
> +}
> +
> +static void vfio_host_win_add(VFIOContainer *container,
> + hwaddr min_iova, hwaddr max_iova,
> + uint64_t iova_pgsizes)
> +{
> + VFIOHostDMAWindow *hostwin;
> +
> + if (vfio_host_win_lookup(container, min_iova, max_iova)) {
> + hw_error("%s: Overlapped IOMMU are not enabled", __func__);
> + }
> +
> + hostwin = g_malloc0(sizeof(*hostwin));
> +
> + hostwin->min_iova = min_iova;
> + hostwin->max_iova = max_iova;
> + hostwin->iova_pgsizes = iova_pgsizes;
> + QLIST_INSERT_HEAD(&container->hostwin_list, hostwin, hostwin_next);
> +}
> +
> static bool vfio_listener_skipped_section(MemoryRegionSection *section)
> {
> return (!memory_region_is_ram(section->mr) &&
> @@ -355,7 +388,7 @@ static void vfio_listener_region_add(MemoryListener
> *listener,
> }
> end = int128_get64(int128_sub(llend, int128_one()));
>
> - if ((iova < container->min_iova) || (end > container->max_iova)) {
> + if (!vfio_host_win_lookup(container, iova, end)) {
> error_report("vfio: IOMMU container %p can't map guest IOVA region"
> " 0x%"HWADDR_PRIx"..0x%"HWADDR_PRIx,
> container, iova, end);
> @@ -370,10 +403,6 @@ static void vfio_listener_region_add(MemoryListener
> *listener,
>
> trace_vfio_listener_region_add_iommu(iova, end);
> /*
> - * FIXME: We should do some checking to see if the
> - * capabilities of the host VFIO IOMMU are adequate to model
> - * the guest IOMMU
> - *
> * FIXME: For VFIO iommu types which have KVM acceleration to
> * avoid bouncing all map/unmaps through qemu this way, this
> * would be the right place to wire that up (tell the KVM
> @@ -880,17 +909,14 @@ static int vfio_connect_container(VFIOGroup *group,
> AddressSpace *as)
> * existing Type1 IOMMUs generally support any IOVA we're
> * going to actually try in practice.
> */
> - container->min_iova = 0;
> - container->max_iova = (hwaddr)-1;
> -
> - /* Assume just 4K IOVA page size */
> - container->iova_pgsizes = 0x1000;
> info.argsz = sizeof(info);
> ret = ioctl(fd, VFIO_IOMMU_GET_INFO, &info);
> /* Ignore errors */
> - if ((ret == 0) && (info.flags & VFIO_IOMMU_INFO_PGSIZES)) {
> - container->iova_pgsizes = info.iova_pgsizes;
> + if (ret || !(info.flags & VFIO_IOMMU_INFO_PGSIZES)) {
> + /* Assume 4k IOVA page size */
> + info.iova_pgsizes = 4096;
> }
> + vfio_host_win_add(container, 0, (hwaddr)-1, info.iova_pgsizes);
> } else if (ioctl(fd, VFIO_CHECK_EXTENSION, VFIO_SPAPR_TCE_IOMMU) ||
> ioctl(fd, VFIO_CHECK_EXTENSION, VFIO_SPAPR_TCE_v2_IOMMU)) {
> struct vfio_iommu_spapr_tce_info info;
> @@ -946,11 +972,12 @@ static int vfio_connect_container(VFIOGroup *group,
> AddressSpace *as)
> ret = -errno;
> goto listener_release_exit;
> }
> - container->min_iova = info.dma32_window_start;
> - container->max_iova = container->min_iova + info.dma32_window_size -
> 1;
>
> - /* Assume just 4K IOVA pages for now */
> - container->iova_pgsizes = 0x1000;
> + /* The default table uses 4K pages */
> + vfio_host_win_add(container, info.dma32_window_start,
> + info.dma32_window_start +
> + info.dma32_window_size - 1,
> + 0x1000);
> } else {
> error_report("vfio: No available IOMMU models");
> ret = -EINVAL;
> diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
> index 405c3b2..c76ddc4 100644
> --- a/include/hw/vfio/vfio-common.h
> +++ b/include/hw/vfio/vfio-common.h
> @@ -82,9 +82,8 @@ typedef struct VFIOContainer {
> * contiguous IOVA window. We may need to generalize that in
> * future
> */
> - hwaddr min_iova, max_iova;
> - uint64_t iova_pgsizes;
> QLIST_HEAD(, VFIOGuestIOMMU) giommu_list;
> + QLIST_HEAD(, VFIOHostDMAWindow) hostwin_list;
> QLIST_HEAD(, VFIOGroup) group_list;
> QLIST_ENTRY(VFIOContainer) next;
> } VFIOContainer;
> @@ -97,6 +96,12 @@ typedef struct VFIOGuestIOMMU {
> QLIST_ENTRY(VFIOGuestIOMMU) giommu_next;
> } VFIOGuestIOMMU;
>
> +typedef struct VFIOHostDMAWindow {
> + hwaddr min_iova, max_iova;
nit, let's not obscure structure entries on the same line like we do
function variables. Modulo the bug David identified in
vfio_host_win_add(), this looks ok to me.
> + uint64_t iova_pgsizes;
> + QLIST_ENTRY(VFIOHostDMAWindow) hostwin_next;
> +} VFIOHostDMAWindow;
> +
> typedef struct VFIODeviceOps VFIODeviceOps;
>
> typedef struct VFIODevice {