2023-06-23 07:41:21

by Souradeep Chakrabarti

[permalink] [raw]
Subject: [PATCH V2 net] net: mana: Fix MANA VF unload when host is unresponsive

From: Souradeep Chakrabarti <[email protected]>

This patch addresses the VF unload issue, where mana_dealloc_queues()
gets stuck in infinite while loop, because of host unresponsiveness.
It adds a timeout in the while loop, to fix it.

Also this patch adds a new attribute in mana_context, which gets set when
mana_hwc_send_request() hits a timeout because of host unresponsiveness.
This flag then helps to avoid the timeouts in successive calls.

Signed-off-by: Souradeep Chakrabarti <[email protected]>
---
V1 -> V2:
* Added net branch
* Removed the typecasting to (struct mana_context*) of void pointer
* Repositioned timeout variable in mana_dealloc_queues()
* Repositioned vf_unload_timeout in mana_context struct, to utilise the
6 bytes hole
---
.../net/ethernet/microsoft/mana/gdma_main.c | 4 +++-
.../net/ethernet/microsoft/mana/hw_channel.c | 12 ++++++++++-
drivers/net/ethernet/microsoft/mana/mana_en.c | 21 +++++++++++++++++--
include/net/mana/mana.h | 2 ++
4 files changed, 35 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/microsoft/mana/gdma_main.c b/drivers/net/ethernet/microsoft/mana/gdma_main.c
index 8f3f78b68592..6411f01be0d9 100644
--- a/drivers/net/ethernet/microsoft/mana/gdma_main.c
+++ b/drivers/net/ethernet/microsoft/mana/gdma_main.c
@@ -946,10 +946,12 @@ int mana_gd_deregister_device(struct gdma_dev *gd)
struct gdma_context *gc = gd->gdma_context;
struct gdma_general_resp resp = {};
struct gdma_general_req req = {};
+ struct mana_context *ac;
int err;

if (gd->pdid == INVALID_PDID)
return -EINVAL;
+ ac = gd->driver_data;

mana_gd_init_req_hdr(&req.hdr, GDMA_DEREGISTER_DEVICE, sizeof(req),
sizeof(resp));
@@ -957,7 +959,7 @@ int mana_gd_deregister_device(struct gdma_dev *gd)
req.hdr.dev_id = gd->dev_id;

err = mana_gd_send_request(gc, sizeof(req), &req, sizeof(resp), &resp);
- if (err || resp.hdr.status) {
+ if ((err || resp.hdr.status) && !ac->vf_unload_timeout) {
dev_err(gc->dev, "Failed to deregister device: %d, 0x%x\n",
err, resp.hdr.status);
if (!err)
diff --git a/drivers/net/ethernet/microsoft/mana/hw_channel.c b/drivers/net/ethernet/microsoft/mana/hw_channel.c
index 9d1507eba5b9..492cb2c6e2cb 100644
--- a/drivers/net/ethernet/microsoft/mana/hw_channel.c
+++ b/drivers/net/ethernet/microsoft/mana/hw_channel.c
@@ -1,8 +1,10 @@
// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
/* Copyright (c) 2021, Microsoft Corporation. */

+#include "asm-generic/errno.h"
#include <net/mana/gdma.h>
#include <net/mana/hw_channel.h>
+#include <net/mana/mana.h>

static int mana_hwc_get_msg_index(struct hw_channel_context *hwc, u16 *msg_id)
{
@@ -786,12 +788,19 @@ int mana_hwc_send_request(struct hw_channel_context *hwc, u32 req_len,
struct hwc_wq *txq = hwc->txq;
struct gdma_req_hdr *req_msg;
struct hwc_caller_ctx *ctx;
+ struct mana_context *ac;
u32 dest_vrcq = 0;
u32 dest_vrq = 0;
u16 msg_id;
int err;

mana_hwc_get_msg_index(hwc, &msg_id);
+ ac = hwc->gdma_dev->driver_data;
+ if (ac->vf_unload_timeout) {
+ dev_err(hwc->dev, "HWC: vport is already unloaded.\n");
+ err = -ETIMEDOUT;
+ goto out;
+ }

tx_wr = &txq->msg_buf->reqs[msg_id];

@@ -825,9 +834,10 @@ int mana_hwc_send_request(struct hw_channel_context *hwc, u32 req_len,
goto out;
}

- if (!wait_for_completion_timeout(&ctx->comp_event, 30 * HZ)) {
+ if (!wait_for_completion_timeout(&ctx->comp_event, 5 * HZ)) {
dev_err(hwc->dev, "HWC: Request timed out!\n");
err = -ETIMEDOUT;
+ ac->vf_unload_timeout = true;
goto out;
}

diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
index d907727c7b7a..cb2080b3a00c 100644
--- a/drivers/net/ethernet/microsoft/mana/mana_en.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
@@ -2329,7 +2329,10 @@ static int mana_dealloc_queues(struct net_device *ndev)
{
struct mana_port_context *apc = netdev_priv(ndev);
struct gdma_dev *gd = apc->ac->gdma_dev;
+ unsigned long timeout;
struct mana_txq *txq;
+ struct sk_buff *skb;
+ struct mana_cq *cq;
int i, err;

if (apc->port_is_up)
@@ -2348,13 +2351,26 @@ static int mana_dealloc_queues(struct net_device *ndev)
*
* Drain all the in-flight TX packets
*/
+
+ timeout = jiffies + 120 * HZ;
for (i = 0; i < apc->num_queues; i++) {
txq = &apc->tx_qp[i].txq;
-
- while (atomic_read(&txq->pending_sends) > 0)
+ while (atomic_read(&txq->pending_sends) > 0 &&
+ time_before(jiffies, timeout)) {
usleep_range(1000, 2000);
+ }
}

+ for (i = 0; i < apc->num_queues; i++) {
+ txq = &apc->tx_qp[i].txq;
+ cq = &apc->tx_qp[i].tx_cq;
+ while (atomic_read(&txq->pending_sends)) {
+ skb = skb_dequeue(&txq->pending_skbs);
+ mana_unmap_skb(skb, apc);
+ napi_consume_skb(skb, cq->budget);
+ atomic_sub(1, &txq->pending_sends);
+ }
+ }
/* We're 100% sure the queues can no longer be woken up, because
* we're sure now mana_poll_tx_cq() can't be running.
*/
@@ -2605,6 +2621,7 @@ int mana_probe(struct gdma_dev *gd, bool resuming)
}
}

+ ac->vf_unload_timeout = false;
err = add_adev(gd);
out:
if (err)
diff --git a/include/net/mana/mana.h b/include/net/mana/mana.h
index 9eef19972845..5f5affdca1eb 100644
--- a/include/net/mana/mana.h
+++ b/include/net/mana/mana.h
@@ -358,6 +358,8 @@ struct mana_context {

u16 num_ports;

+ bool vf_unload_timeout;
+
struct mana_eq *eqs;

struct net_device *ports[MAX_PORTS_IN_MANA_DEV];
--
2.34.1



2023-06-23 09:50:46

by Jiri Pirko

[permalink] [raw]
Subject: Re: [PATCH V2 net] net: mana: Fix MANA VF unload when host is unresponsive

Fri, Jun 23, 2023 at 09:29:15AM CEST, [email protected] wrote:
>From: Souradeep Chakrabarti <[email protected]>
>
>This patch addresses the VF unload issue, where mana_dealloc_queues()

double space here ^^

>gets stuck in infinite while loop, because of host unresponsiveness.
>It adds a timeout in the while loop, to fix it.
>
>Also this patch adds a new attribute in mana_context, which gets set when
>mana_hwc_send_request() hits a timeout because of host unresponsiveness.
>This flag then helps to avoid the timeouts in successive calls.

You aparently combine 2 patches together. Please split.


>
>Signed-off-by: Souradeep Chakrabarti <[email protected]>

Please provide a "Fixes" tag with pointer to the commit that introduced
the problem.


>---
>V1 -> V2:
>* Added net branch
>* Removed the typecasting to (struct mana_context*) of void pointer
>* Repositioned timeout variable in mana_dealloc_queues()
>* Repositioned vf_unload_timeout in mana_context struct, to utilise the
> 6 bytes hole
>---
> .../net/ethernet/microsoft/mana/gdma_main.c | 4 +++-
> .../net/ethernet/microsoft/mana/hw_channel.c | 12 ++++++++++-
> drivers/net/ethernet/microsoft/mana/mana_en.c | 21 +++++++++++++++++--
> include/net/mana/mana.h | 2 ++
> 4 files changed, 35 insertions(+), 4 deletions(-)
>
>diff --git a/drivers/net/ethernet/microsoft/mana/gdma_main.c b/drivers/net/ethernet/microsoft/mana/gdma_main.c
>index 8f3f78b68592..6411f01be0d9 100644
>--- a/drivers/net/ethernet/microsoft/mana/gdma_main.c
>+++ b/drivers/net/ethernet/microsoft/mana/gdma_main.c
>@@ -946,10 +946,12 @@ int mana_gd_deregister_device(struct gdma_dev *gd)
> struct gdma_context *gc = gd->gdma_context;
> struct gdma_general_resp resp = {};
> struct gdma_general_req req = {};
>+ struct mana_context *ac;
> int err;
>
> if (gd->pdid == INVALID_PDID)
> return -EINVAL;
>+ ac = gd->driver_data;
>
> mana_gd_init_req_hdr(&req.hdr, GDMA_DEREGISTER_DEVICE, sizeof(req),
> sizeof(resp));
>@@ -957,7 +959,7 @@ int mana_gd_deregister_device(struct gdma_dev *gd)
> req.hdr.dev_id = gd->dev_id;
>
> err = mana_gd_send_request(gc, sizeof(req), &req, sizeof(resp), &resp);
>- if (err || resp.hdr.status) {
>+ if ((err || resp.hdr.status) && !ac->vf_unload_timeout) {
> dev_err(gc->dev, "Failed to deregister device: %d, 0x%x\n",
> err, resp.hdr.status);
> if (!err)
>diff --git a/drivers/net/ethernet/microsoft/mana/hw_channel.c b/drivers/net/ethernet/microsoft/mana/hw_channel.c
>index 9d1507eba5b9..492cb2c6e2cb 100644
>--- a/drivers/net/ethernet/microsoft/mana/hw_channel.c
>+++ b/drivers/net/ethernet/microsoft/mana/hw_channel.c
>@@ -1,8 +1,10 @@
> // SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
> /* Copyright (c) 2021, Microsoft Corporation. */
>
>+#include "asm-generic/errno.h"
> #include <net/mana/gdma.h>
> #include <net/mana/hw_channel.h>
>+#include <net/mana/mana.h>
>
> static int mana_hwc_get_msg_index(struct hw_channel_context *hwc, u16 *msg_id)
> {
>@@ -786,12 +788,19 @@ int mana_hwc_send_request(struct hw_channel_context *hwc, u32 req_len,
> struct hwc_wq *txq = hwc->txq;
> struct gdma_req_hdr *req_msg;
> struct hwc_caller_ctx *ctx;
>+ struct mana_context *ac;
> u32 dest_vrcq = 0;
> u32 dest_vrq = 0;
> u16 msg_id;
> int err;
>
> mana_hwc_get_msg_index(hwc, &msg_id);
>+ ac = hwc->gdma_dev->driver_data;
>+ if (ac->vf_unload_timeout) {
>+ dev_err(hwc->dev, "HWC: vport is already unloaded.\n");
>+ err = -ETIMEDOUT;
>+ goto out;
>+ }
>
> tx_wr = &txq->msg_buf->reqs[msg_id];
>
>@@ -825,9 +834,10 @@ int mana_hwc_send_request(struct hw_channel_context *hwc, u32 req_len,
> goto out;
> }
>
>- if (!wait_for_completion_timeout(&ctx->comp_event, 30 * HZ)) {
>+ if (!wait_for_completion_timeout(&ctx->comp_event, 5 * HZ)) {
> dev_err(hwc->dev, "HWC: Request timed out!\n");
> err = -ETIMEDOUT;
>+ ac->vf_unload_timeout = true;
> goto out;
> }
>
>diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
>index d907727c7b7a..cb2080b3a00c 100644
>--- a/drivers/net/ethernet/microsoft/mana/mana_en.c
>+++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
>@@ -2329,7 +2329,10 @@ static int mana_dealloc_queues(struct net_device *ndev)
> {
> struct mana_port_context *apc = netdev_priv(ndev);
> struct gdma_dev *gd = apc->ac->gdma_dev;
>+ unsigned long timeout;
> struct mana_txq *txq;
>+ struct sk_buff *skb;
>+ struct mana_cq *cq;
> int i, err;
>
> if (apc->port_is_up)
>@@ -2348,13 +2351,26 @@ static int mana_dealloc_queues(struct net_device *ndev)
> *
> * Drain all the in-flight TX packets
> */
>+
>+ timeout = jiffies + 120 * HZ;
> for (i = 0; i < apc->num_queues; i++) {
> txq = &apc->tx_qp[i].txq;
>-
>- while (atomic_read(&txq->pending_sends) > 0)
>+ while (atomic_read(&txq->pending_sends) > 0 &&
>+ time_before(jiffies, timeout)) {
> usleep_range(1000, 2000);
>+ }
> }
>
>+ for (i = 0; i < apc->num_queues; i++) {
>+ txq = &apc->tx_qp[i].txq;
>+ cq = &apc->tx_qp[i].tx_cq;
>+ while (atomic_read(&txq->pending_sends)) {
>+ skb = skb_dequeue(&txq->pending_skbs);
>+ mana_unmap_skb(skb, apc);
>+ napi_consume_skb(skb, cq->budget);
>+ atomic_sub(1, &txq->pending_sends);
>+ }
>+ }
> /* We're 100% sure the queues can no longer be woken up, because
> * we're sure now mana_poll_tx_cq() can't be running.
> */
>@@ -2605,6 +2621,7 @@ int mana_probe(struct gdma_dev *gd, bool resuming)
> }
> }
>
>+ ac->vf_unload_timeout = false;

Pointless init. You have the struct zeroed during allocation.


> err = add_adev(gd);
> out:
> if (err)
>diff --git a/include/net/mana/mana.h b/include/net/mana/mana.h
>index 9eef19972845..5f5affdca1eb 100644
>--- a/include/net/mana/mana.h
>+++ b/include/net/mana/mana.h
>@@ -358,6 +358,8 @@ struct mana_context {
>
> u16 num_ports;
>
>+ bool vf_unload_timeout;
>+
> struct mana_eq *eqs;
>
> struct net_device *ports[MAX_PORTS_IN_MANA_DEV];
>--
>2.34.1
>
>

2023-06-23 18:34:37

by Simon Horman

[permalink] [raw]
Subject: Re: [PATCH V2 net] net: mana: Fix MANA VF unload when host is unresponsive

On Fri, Jun 23, 2023 at 12:29:15AM -0700, souradeep chakrabarti wrote:
> From: Souradeep Chakrabarti <[email protected]>
>
> This patch addresses the VF unload issue, where mana_dealloc_queues()
> gets stuck in infinite while loop, because of host unresponsiveness.
> It adds a timeout in the while loop, to fix it.
>
> Also this patch adds a new attribute in mana_context, which gets set when
> mana_hwc_send_request() hits a timeout because of host unresponsiveness.
> This flag then helps to avoid the timeouts in successive calls.
>
> Signed-off-by: Souradeep Chakrabarti <[email protected]>

...

> diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
> index d907727c7b7a..cb2080b3a00c 100644
> --- a/drivers/net/ethernet/microsoft/mana/mana_en.c
> +++ b/drivers/net/ethernet/microsoft/mana/mana_en.c

...

> @@ -2348,13 +2351,26 @@ static int mana_dealloc_queues(struct net_device *ndev)
> *
> * Drain all the in-flight TX packets
> */
> +
> + timeout = jiffies + 120 * HZ;
> for (i = 0; i < apc->num_queues; i++) {
> txq = &apc->tx_qp[i].txq;
> -
> - while (atomic_read(&txq->pending_sends) > 0)
> + while (atomic_read(&txq->pending_sends) > 0 &&
> + time_before(jiffies, timeout)) {
> usleep_range(1000, 2000);
> + }

Hi Souradeep,

minor feedback from my side, as it seems there will be a new version anyway:
I think the braces - '{' '}' - are unnecessary above.

...

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