Two AF_XDP zero-copy fixes for virtio_net.
Patch 1: on arm64, binding a zero-copy socket fails with -ENOMEM and a
"rejecting DMA map of vmalloc memory" warning whenever the device uses
the DMA API (e.g. VIRTIO_F_ACCESS_PLATFORM), because the static TX
header lives in the kernel image, which arm64 maps in the vmalloc area.
Patch 2: freeze frees the rx/tx queues while the sockets stay bound in
the xsk core. The driver state of the pools is leaked, and closing the
socket after resume hits a "Missing register" warning and a NULL
pointer dereference in xp_dma_unmap().
Testing used KASAN kernels with a small /init that binds an
XDP_ZEROCOPY socket to eth0 queue 0, runs one suspend cycle with
pm_test=devices and closes the socket, on virtio-net-pci with
iommu_platform=on,disable-legacy=on:
- x86_64, QEMU/KVM on bare metal and nested inside a KVM guest:
- without the series: WARNING + KASAN null-ptr-deref + oops on close
(patch 1 does not apply to x86, binding works there)
- with both patches: no warnings
- A full x86_64 guest kernel with the series passed virtio-net ping,
a 100MB HTTP download with checksum check and suspend cycles.
Haishuang Yan (2):
virtio_net: Don't DMA map the kernel image for the AF_XDP TX header
virtio_net: Keep AF_XDP zero-copy pools bound across suspend
drivers/net/virtio_net.c | 70 +++++++++++++++++++++++++++++++++++++---
1 file changed, 66 insertions(+), 4 deletions(-)
base-commit: 37dfd0efbfffc20a57e41c2eb349ac49b1ca1ff8
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2.43.0
