Add a chunking loop to vfio_pci_driver_memcpy() so that it breaks up large memcpy requests into max_memcpy_size-sized chunks. This allows callers to request any size without worrying about per-driver limits. The memcpy_start()/memcpy_wait() semantics are unchanged.
Update the test to use 4x max_memcpy_size so it exercises the new chunking path (4 iterations) while keeping execution fast for drivers with small DMA transfer sizes. Signed-off-by: Rubin Du <[email protected]> --- .../selftests/vfio/lib/vfio_pci_driver.c | 18 ++++++++++++++++-- .../selftests/vfio/vfio_pci_driver_test.c | 18 ++++++++++-------- 2 files changed, 26 insertions(+), 10 deletions(-) diff --git a/tools/testing/selftests/vfio/lib/vfio_pci_driver.c b/tools/testing/selftests/vfio/lib/vfio_pci_driver.c index 6827f4a6febe..e6c5b9c703f4 100644 --- a/tools/testing/selftests/vfio/lib/vfio_pci_driver.c +++ b/tools/testing/selftests/vfio/lib/vfio_pci_driver.c @@ -106,7 +106,21 @@ int vfio_pci_driver_memcpy_wait(struct vfio_pci_device *device) int vfio_pci_driver_memcpy(struct vfio_pci_device *device, iova_t src, iova_t dst, u64 size) { - vfio_pci_driver_memcpy_start(device, src, dst, size, 1); + struct vfio_pci_driver *driver = &device->driver; + u64 offset = 0; + + while (offset < size) { + u64 chunk = min(size - offset, driver->max_memcpy_size); + int ret; + + vfio_pci_driver_memcpy_start(device, src + offset, + dst + offset, chunk, 1); + ret = vfio_pci_driver_memcpy_wait(device); + if (ret) + return ret; + + offset += chunk; + } - return vfio_pci_driver_memcpy_wait(device); + return 0; } diff --git a/tools/testing/selftests/vfio/vfio_pci_driver_test.c b/tools/testing/selftests/vfio/vfio_pci_driver_test.c index afa0480ddd9b..44aa90ee113a 100644 --- a/tools/testing/selftests/vfio/vfio_pci_driver_test.c +++ b/tools/testing/selftests/vfio/vfio_pci_driver_test.c @@ -89,12 +89,12 @@ FIXTURE_SETUP(vfio_pci_driver_test) self->msi_fd = self->device->msi_eventfds[driver->msi]; /* - * Use the maximum size supported by the device for memcpy operations, - * slimmed down to fit into the memcpy region (divided by 2 so src and - * dst regions do not overlap). + * Use 4x the driver's max_memcpy_size to exercise the chunking + * logic in vfio_pci_driver_memcpy(). Cap to half the memcpy + * region so src and dst do not overlap. */ - self->size = self->device->driver.max_memcpy_size; - self->size = min(self->size, self->memcpy_region.size / 2); + self->size = min_t(u64, driver->max_memcpy_size * 4, + self->memcpy_region.size / 2); self->src = self->memcpy_region.vaddr; self->dst = self->src + self->size; @@ -211,6 +211,7 @@ TEST_F_TIMEOUT(vfio_pci_driver_test, memcpy_storm, 60) { struct vfio_pci_driver *driver = &self->device->driver; u64 total_size; + u64 size; u64 count; fcntl_set_nonblock(self->msi_fd); @@ -221,13 +222,14 @@ TEST_F_TIMEOUT(vfio_pci_driver_test, memcpy_storm, 60) * will take too long. */ total_size = 250UL * SZ_1G; - count = min(total_size / self->size, driver->max_memcpy_count); + size = min(driver->max_memcpy_size, self->memcpy_region.size / 2); + count = min(total_size / size, driver->max_memcpy_count); - printf("Kicking off %lu memcpys of size 0x%lx\n", count, self->size); + printf("Kicking off %lu memcpys of size 0x%lx\n", count, size); vfio_pci_driver_memcpy_start(self->device, self->src_iova, self->dst_iova, - self->size, count); + size, count); ASSERT_EQ(0, vfio_pci_driver_memcpy_wait(self->device)); ASSERT_NO_MSI(self->msi_fd); -- 2.43.0
