diff mbox series

[for-next,v6,4/7] RDMA/rxe: Add page invalidation support

Message ID 1566fd3c63e4dac66717731e2c7a80039244e3af.1694153251.git.matsuda-daisuke@fujitsu.com (mailing list archive)
State Superseded
Headers show
Series On-Demand Paging on SoftRoCE | expand

Commit Message

Daisuke Matsuda (Fujitsu) Sept. 8, 2023, 6:26 a.m. UTC 
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@fujitsu.com>
---
 drivers/infiniband/sw/rxe/Makefile  |  2 +
 drivers/infiniband/sw/rxe/rxe_odp.c | 64 +++++++++++++++++++++++++++++
 2 files changed, 66 insertions(+)
 create mode 100644 drivers/infiniband/sw/rxe/rxe_odp.c

Comments

Jason Gunthorpe Sept. 8, 2023, 2:22 p.m. UTC | #1 
On Fri, Sep 08, 2023 at 03:26:45PM +0900, Daisuke Matsuda wrote:
> 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@fujitsu.com>
> ---
>  drivers/infiniband/sw/rxe/Makefile  |  2 +
>  drivers/infiniband/sw/rxe/rxe_odp.c | 64 +++++++++++++++++++++++++++++
>  2 files changed, 66 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..834fb1a84800
> --- /dev/null
> +++ b/drivers/infiniband/sw/rxe/rxe_odp.c
> @@ -0,0 +1,64 @@
> +// 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 lower = rxe_mr_iova_to_index(mr, start);
> +	unsigned long upper = rxe_mr_iova_to_index(mr, end - 1);
> +	void *entry;
> +
> +	XA_STATE(xas, &mr->page_list, lower);
> +
> +	/* make elements in xarray NULL */
> +	xas_lock(&xas);
> +	while (true) {
> +		xas_store(&xas, NULL);
> +
> +		entry = xas_next(&xas);

I think this should just be

   xas_for_each(xas, entry, upper)
         xas_store(&xas, NULL)

> +		if (xas_retry(&xas, entry) || (xas.xa_index <= upper))
> +			continue;

xa_erase doesn't deal with retry entries, why do you think this does?

IIRC retry entries cannot be seen under the spinlock

Jason
Zhu Yanjun Sept. 10, 2023, 8:30 a.m. UTC | #2 
在 2023/9/8 14:26, 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@fujitsu.com>
> ---
>   drivers/infiniband/sw/rxe/Makefile  |  2 +
>   drivers/infiniband/sw/rxe/rxe_odp.c | 64 +++++++++++++++++++++++++++++
>   2 files changed, 66 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..834fb1a84800
> --- /dev/null
> +++ b/drivers/infiniband/sw/rxe/rxe_odp.c
> @@ -0,0 +1,64 @@
> +// 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 lower = rxe_mr_iova_to_index(mr, start);
> +	unsigned long upper = rxe_mr_iova_to_index(mr, end - 1);
> +	void *entry;

Should follow Reverse Christmas Tree to declare variables.

Zhu Yanjun

> +
> +	XA_STATE(xas, &mr->page_list, lower);
> +
> +	/* make elements in xarray NULL */
> +	xas_lock(&xas);
> +	while (true) {
> +		xas_store(&xas, NULL);
> +
> +		entry = xas_next(&xas);
> +		if (xas_retry(&xas, entry) || (xas.xa_index <= upper))
> +			continue;
> +
> +		break;
> +	}
> +	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);
> +	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,
> +};
diff mbox series

Patch

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..834fb1a84800
--- /dev/null
+++ b/drivers/infiniband/sw/rxe/rxe_odp.c
@@ -0,0 +1,64 @@ 
+// 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 lower = rxe_mr_iova_to_index(mr, start);
+	unsigned long upper = rxe_mr_iova_to_index(mr, end - 1);
+	void *entry;
+
+	XA_STATE(xas, &mr->page_list, lower);
+
+	/* make elements in xarray NULL */
+	xas_lock(&xas);
+	while (true) {
+		xas_store(&xas, NULL);
+
+		entry = xas_next(&xas);
+		if (xas_retry(&xas, entry) || (xas.xa_index <= upper))
+			continue;
+
+		break;
+	}
+	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);
+	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,
+};