在 2024/10/28 8:25, Daisuke Matsuda (Fujitsu) 写道:
On Sun, Oct 13, 2024 3:16 PM Zhu Yanjun wrote:
在 2024/10/9 9:59, Daisuke Matsuda 写道:
On page invalidation, an MMU notifier callback is invoked to unmap DMA
addresses and update the driver page table(umem_odp->dma_list). It also
sets the corresponding entries in MR xarray to NULL to prevent any access.
The callback is registered when an ODP-enabled MR is created.
Signed-off-by: Daisuke Matsuda <matsuda-daisuke@xxxxxxxxxxx>
---
drivers/infiniband/sw/rxe/Makefile | 2 +
drivers/infiniband/sw/rxe/rxe_odp.c | 57 +++++++++++++++++++++++++++++
2 files changed, 59 insertions(+)
create mode 100644 drivers/infiniband/sw/rxe/rxe_odp.c
diff --git a/drivers/infiniband/sw/rxe/Makefile b/drivers/infiniband/sw/rxe/Makefile
index 5395a581f4bb..93134f1d1d0c 100644
--- a/drivers/infiniband/sw/rxe/Makefile
+++ b/drivers/infiniband/sw/rxe/Makefile
@@ -23,3 +23,5 @@ rdma_rxe-y := \
rxe_task.o \
rxe_net.o \
rxe_hw_counters.o
+
+rdma_rxe-$(CONFIG_INFINIBAND_ON_DEMAND_PAGING) += rxe_odp.o
diff --git a/drivers/infiniband/sw/rxe/rxe_odp.c b/drivers/infiniband/sw/rxe/rxe_odp.c
new file mode 100644
index 000000000000..ea55b79be0c6
--- /dev/null
+++ b/drivers/infiniband/sw/rxe/rxe_odp.c
@@ -0,0 +1,57 @@
+// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
+/*
+ * Copyright (c) 2022-2023 Fujitsu Ltd. All rights reserved.
+ */
+
+#include <linux/hmm.h>
+
+#include <rdma/ib_umem_odp.h>
+
+#include "rxe.h"
+
+static void rxe_mr_unset_xarray(struct rxe_mr *mr, unsigned long start,
+ unsigned long end)
+{
+ unsigned long upper = rxe_mr_iova_to_index(mr, end - 1);
+ unsigned long lower = rxe_mr_iova_to_index(mr, start);
+ void *entry;
+
+ XA_STATE(xas, &mr->page_list, lower);
+
+ /* make elements in xarray NULL */
+ xas_lock(&xas);
+ xas_for_each(&xas, entry, upper)
+ xas_store(&xas, NULL);
+ xas_unlock(&xas);
+}
+
+static bool rxe_ib_invalidate_range(struct mmu_interval_notifier *mni,
+ const struct mmu_notifier_range *range,
+ unsigned long cur_seq)
+{
+ struct ib_umem_odp *umem_odp =
+ container_of(mni, struct ib_umem_odp, notifier);
+ struct rxe_mr *mr = umem_odp->private;
+ unsigned long start, end;
+
+ if (!mmu_notifier_range_blockable(range))
+ return false;
+
+ mutex_lock(&umem_odp->umem_mutex);
guard(mutex)(&umem_odp->umem_mutex);
It seems that the above is more popular.
Thanks for the comment.
I have no objection to your suggestion since the increasing number of
kernel components use "guard(mutex)" syntax these days, but I would rather
suggest making the change to the whole infiniband subsystem at once because
there are multiple mutex lock/unlock pairs to be converted.
If you want to make the such changes to the whole infiniband subsystem,
I am fine with it.
The "guard(mutex)" is used in the following patch.
https://patchwork.kernel.org/project/linux-rdma/patch/20241009210048.4122518-1-bvanassche@xxxxxxx/
Zhu Yanjun
Regards,
Daisuke Matsuda
Zhu Yanjun
+ mmu_interval_set_seq(mni, cur_seq);
+
+ start = max_t(u64, ib_umem_start(umem_odp), range->start);
+ end = min_t(u64, ib_umem_end(umem_odp), range->end);
+
+ rxe_mr_unset_xarray(mr, start, end);
+
+ /* update umem_odp->dma_list */
+ ib_umem_odp_unmap_dma_pages(umem_odp, start, end);
+
+ mutex_unlock(&umem_odp->umem_mutex);
+ return true;
+}
+
+const struct mmu_interval_notifier_ops rxe_mn_ops = {
+ .invalidate = rxe_ib_invalidate_range,
+};
