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Re: [Qemu-devel] [PATCH qemu v16 18/19] vfio/spapr: Create DMA window dy
From: |
Alex Williamson |
Subject: |
Re: [Qemu-devel] [PATCH qemu v16 18/19] vfio/spapr: Create DMA window dynamically (SPAPR IOMMU v2) |
Date: |
Fri, 13 May 2016 16:26:34 -0600 |
On Wed, 4 May 2016 16:52:30 +1000
Alexey Kardashevskiy <address@hidden> wrote:
> New VFIO_SPAPR_TCE_v2_IOMMU type supports dynamic DMA window management.
> This adds ability to VFIO common code to dynamically allocate/remove
> DMA windows in the host kernel when new VFIO container is added/removed.
>
> This adds VFIO_IOMMU_SPAPR_TCE_CREATE ioctl to vfio_listener_region_add
> and adds just created IOMMU into the host IOMMU list; the opposite
> action is taken in vfio_listener_region_del.
>
> When creating a new window, this uses heuristic to decide on the TCE table
> levels number.
>
> This should cause no guest visible change in behavior.
>
> Signed-off-by: Alexey Kardashevskiy <address@hidden>
> ---
> Changes:
> v16:
> * used memory_region_iommu_get_page_sizes() in vfio_listener_region_add()
> * enforced no intersections between windows
>
> v14:
> * new to the series
> ---
> hw/vfio/common.c | 133
> ++++++++++++++++++++++++++++++++++++++++++++++++++-----
> trace-events | 2 +
> 2 files changed, 125 insertions(+), 10 deletions(-)
>
> diff --git a/hw/vfio/common.c b/hw/vfio/common.c
> index 03daf88..bd2dee8 100644
> --- a/hw/vfio/common.c
> +++ b/hw/vfio/common.c
> @@ -240,6 +240,18 @@ static int vfio_dma_map(VFIOContainer *container, hwaddr
> iova,
> return -errno;
> }
>
> +static bool range_contains(hwaddr start, hwaddr end, hwaddr addr)
> +{
> + return start <= addr && addr <= end;
> +}
a) If you want a "range_foo" function then put it in range.h
b) I suspect there are already range.h functions that can do this.
> +
> +static bool vfio_host_win_intersects(VFIOHostDMAWindow *hostwin,
> + hwaddr min_iova, hwaddr max_iova)
> +{
> + return range_contains(hostwin->min_iova, hostwin->min_iova, min_iova) ||
> + range_contains(min_iova, max_iova, hostwin->min_iova);
> +}
How is this different than ranges_overlap()?
> +
> static VFIOHostDMAWindow *vfio_host_win_lookup(VFIOContainer *container,
> hwaddr min_iova, hwaddr
> max_iova)
> {
> @@ -279,6 +291,14 @@ static int vfio_host_win_add(VFIOContainer *container,
> return 0;
> }
>
> +static void vfio_host_win_del(VFIOContainer *container, hwaddr min_iova)
> +{
> + VFIOHostDMAWindow *hostwin = vfio_host_win_lookup(container, min_iova,
> 1);
> +
> + g_assert(hostwin);
Handle the error please.
> + QLIST_REMOVE(hostwin, hostwin_next);
> +}
> +
> static bool vfio_listener_skipped_section(MemoryRegionSection *section)
> {
> return (!memory_region_is_ram(section->mr) &&
> @@ -392,6 +412,69 @@ static void vfio_listener_region_add(MemoryListener
> *listener,
> }
> end = int128_get64(int128_sub(llend, int128_one()));
>
> + if (container->iommu_type == VFIO_SPAPR_TCE_v2_IOMMU) {
> + VFIOHostDMAWindow *hostwin;
> + unsigned pagesizes = memory_region_iommu_get_page_sizes(section->mr);
> + unsigned pagesize = (hwaddr)1 << ctz64(pagesizes);
> + unsigned entries, pages;
> + struct vfio_iommu_spapr_tce_create create = { .argsz =
> sizeof(create) };
> +
> + trace_vfio_listener_region_add_iommu(iova, end);
> + /*
> + * 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
> + * device emulation the VFIO iommu handles to use).
> + */
> + create.window_size = int128_get64(section->size);
> + create.page_shift = ctz64(pagesize);
> + /*
> + * SPAPR host supports multilevel TCE tables, there is some
> + * heuristic to decide how many levels we want for our table:
> + * 0..64 = 1; 65..4096 = 2; 4097..262144 = 3; 262145.. = 4
> + */
> + entries = create.window_size >> create.page_shift;
> + pages = MAX((entries * sizeof(uint64_t)) / getpagesize(), 1);
> + pages = MAX(pow2ceil(pages) - 1, 1); /* Round up */
> + create.levels = ctz64(pages) / 6 + 1;
> +
> + /* For now intersections are not allowed, we may relax this later */
> + QLIST_FOREACH(hostwin, &container->hostwin_list, hostwin_next) {
> + if (vfio_host_win_intersects(hostwin,
> + section->offset_within_address_space,
> + section->offset_within_address_space +
> + create.window_size - 1)) {
> + goto fail;
> + }
> + }
> +
> + ret = ioctl(container->fd, VFIO_IOMMU_SPAPR_TCE_CREATE, &create);
> + if (ret) {
> + error_report("Failed to create a window, ret = %d (%m)", ret);
> + goto fail;
> + }
> +
> + if (create.start_addr != section->offset_within_address_space) {
> + struct vfio_iommu_spapr_tce_remove remove = {
> + .argsz = sizeof(remove),
> + .start_addr = create.start_addr
> + };
> + error_report("Host doesn't support DMA window at %"HWADDR_PRIx",
> must be %"PRIx64,
> + section->offset_within_address_space,
> + create.start_addr);
> + ioctl(container->fd, VFIO_IOMMU_SPAPR_TCE_REMOVE, &remove);
> + ret = -EINVAL;
> + goto fail;
> + }
> + trace_vfio_spapr_create_window(create.page_shift,
> + create.window_size,
> + create.start_addr);
> +
> + vfio_host_win_add(container, create.start_addr,
> + create.start_addr + create.window_size - 1,
> + 1ULL << create.page_shift);
> + }
This is a function on its own, split it out and why not stop pretending
prereg is some sort of generic interface and let's just make a spapr
support file.
> +
> 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,
> @@ -566,6 +649,22 @@ static void vfio_listener_region_del(MemoryListener
> *listener,
> container, iova, int128_get64(llsize), ret);
> }
>
> + if (container->iommu_type == VFIO_SPAPR_TCE_v2_IOMMU) {
> + struct vfio_iommu_spapr_tce_remove remove = {
> + .argsz = sizeof(remove),
> + .start_addr = section->offset_within_address_space,
> + };
> + ret = ioctl(container->fd, VFIO_IOMMU_SPAPR_TCE_REMOVE, &remove);
> + if (ret) {
> + error_report("Failed to remove window at %"PRIx64,
> + remove.start_addr);
> + }
> +
> + vfio_host_win_del(container, section->offset_within_address_space);
> +
> + trace_vfio_spapr_remove_window(remove.start_addr);
> + }
This would be in that spapr file too.
> +
> if (iommu && iommu->iommu_ops && iommu->iommu_ops->vfio_stop) {
> iommu->iommu_ops->vfio_stop(section->mr);
> }
> @@ -957,11 +1056,6 @@ static int vfio_connect_container(VFIOGroup *group,
> AddressSpace *as)
> }
> }
>
> - /*
> - * This only considers the host IOMMU's 32-bit window. At
> - * some point we need to add support for the optional 64-bit
> - * window and dynamic windows
> - */
> info.argsz = sizeof(info);
> ret = ioctl(fd, VFIO_IOMMU_SPAPR_TCE_GET_INFO, &info);
> if (ret) {
> @@ -970,11 +1064,30 @@ static int vfio_connect_container(VFIOGroup *group,
> AddressSpace *as)
> goto listener_release_exit;
> }
>
> - /* 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);
> + if (v2) {
> + /*
> + * There is a default window in just created container.
> + * To make region_add/del simpler, we better remove this
> + * window now and let those iommu_listener callbacks
> + * create/remove them when needed.
> + */
> + struct vfio_iommu_spapr_tce_remove remove = {
> + .argsz = sizeof(remove),
> + .start_addr = info.dma32_window_start,
> + };
> + ret = ioctl(fd, VFIO_IOMMU_SPAPR_TCE_REMOVE, &remove);
> + if (ret) {
> + error_report("vfio: VFIO_IOMMU_SPAPR_TCE_REMOVE failed: %m");
> + ret = -errno;
> + goto free_container_exit;
> + }
> + } else {
> + /* 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/trace-events b/trace-events
> index d0d8615..b5419de 100644
> --- a/trace-events
> +++ b/trace-events
> @@ -1739,6 +1739,8 @@ vfio_region_finalize(const char *name, int index)
> "Device %s, region %d"
> vfio_region_mmaps_set_enabled(const char *name, bool enabled) "Region %s
> mmaps enabled: %d"
> vfio_ram_register(uint64_t va, uint64_t size, int ret) "va=%"PRIx64"
> size=%"PRIx64" ret=%d"
> vfio_ram_unregister(uint64_t va, uint64_t size, int ret) "va=%"PRIx64"
> size=%"PRIx64" ret=%d"
> +vfio_spapr_create_window(int ps, uint64_t ws, uint64_t off) "pageshift=0x%x
> winsize=0x%"PRIx64" offset=0x%"PRIx64
> +vfio_spapr_remove_window(uint64_t off) "offset=%"PRIx64
>
> # hw/vfio/platform.c
> vfio_platform_base_device_init(char *name, int groupid) "%s belongs to group
> #%d"
- Re: [Qemu-devel] [PATCH qemu v16 19/19] spapr_pci/spapr_pci_vfio: Support Dynamic DMA Windows (DDW), (continued)
[Qemu-devel] [PATCH qemu v16 14/19] vfio: spapr: Add DMA memory preregistering (SPAPR IOMMU v2), Alexey Kardashevskiy, 2016/05/04
[Qemu-devel] [PATCH qemu v16 18/19] vfio/spapr: Create DMA window dynamically (SPAPR IOMMU v2), Alexey Kardashevskiy, 2016/05/04
- Re: [Qemu-devel] [PATCH qemu v16 18/19] vfio/spapr: Create DMA window dynamically (SPAPR IOMMU v2),
Alex Williamson <=
- Re: [Qemu-devel] [PATCH qemu v16 18/19] vfio/spapr: Create DMA window dynamically (SPAPR IOMMU v2), Alexey Kardashevskiy, 2016/05/16
- Re: [Qemu-devel] [PATCH qemu v16 18/19] vfio/spapr: Create DMA window dynamically (SPAPR IOMMU v2), Alex Williamson, 2016/05/16
- Re: [Qemu-devel] [PATCH qemu v16 18/19] vfio/spapr: Create DMA window dynamically (SPAPR IOMMU v2), David Gibson, 2016/05/26
- Re: [Qemu-devel] [PATCH qemu v16 18/19] vfio/spapr: Create DMA window dynamically (SPAPR IOMMU v2), Alexey Kardashevskiy, 2016/05/26
- Re: [Qemu-devel] [PATCH qemu v16 18/19] vfio/spapr: Create DMA window dynamically (SPAPR IOMMU v2), David Gibson, 2016/05/27
[Qemu-devel] [PATCH qemu v16 01/19] vfio: Delay DMA address space listener release, Alexey Kardashevskiy, 2016/05/04