From: "Michael S. Tsirkin" <mst@redhat.com> To: linux-kernel@vger.kernel.org Cc: Jens Axboe <axboe@kernel.dk>, "Martin K. Petersen" <martin.petersen@oracle.com>, netdev@vger.kernel.org, virtualization@lists.linux-foundation.org, James Bottomley <James.Bottomley@hansenpartnership.com>, Eric Dumazet <edumazet@google.com>, Andres Freund <andres@anarazel.de>, Greg KH <gregkh@linuxfoundation.org>, Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>, Linus Torvalds <torvalds@linux-foundation.org>, "David S. Miller" <davem@davemloft.net>, Guenter Roeck <linux@roeck-us.net> Subject: [PATCH v2 1/5] virtio_net: Revert "virtio_net: set the default max ring size by find_vqs()" Date: Mon, 15 Aug 2022 17:53:24 -0400 [thread overview] Message-ID: <20220815215251.154451-3-mst@redhat.com> (raw) In-Reply-To: <20220815215251.154451-1-mst@redhat.com> This reverts commit 762faee5a2678559d3dc09d95f8f2c54cd0466a7. This has been reported to trip up guests on GCP (Google Cloud). The reason is that virtio_find_vqs_ctx_size is broken on legacy devices. We can in theory fix virtio_find_vqs_ctx_size but in fact the patch itself has several other issues: - It treats unknown speed as < 10G - It leaves userspace no way to find out the ring size set by hypervisor - It tests speed when link is down - It ignores the virtio spec advice: Both \field{speed} and \field{duplex} can change, thus the driver is expected to re-read these values after receiving a configuration change notification. - It is not clear the performance impact has been tested properly Revert the patch for now. Reported-by: Andres Freund <andres@anarazel.de> Link: https://lore.kernel.org/r/20220814212610.GA3690074%40roeck-us.net Link: https://lore.kernel.org/r/20220815070203.plwjx7b3cyugpdt7%40awork3.anarazel.de Link: https://lore.kernel.org/r/3df6bb82-1951-455d-a768-e9e1513eb667%40www.fastmail.com Link: https://lore.kernel.org/r/FCDC5DDE-3CDD-4B8A-916F-CA7D87B547CE%40anarazel.de Fixes: 762faee5a267 ("virtio_net: set the default max ring size by find_vqs()") Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Cc: Jason Wang <jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Tested-by: Andres Freund <andres@anarazel.de> Tested-by: From: Guenter Roeck <linux@roeck-us.net> --- drivers/net/virtio_net.c | 42 ++++------------------------------------ 1 file changed, 4 insertions(+), 38 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index d934774e9733..ece00b84e3a7 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -3432,29 +3432,6 @@ static unsigned int mergeable_min_buf_len(struct virtnet_info *vi, struct virtqu (unsigned int)GOOD_PACKET_LEN); } -static void virtnet_config_sizes(struct virtnet_info *vi, u32 *sizes) -{ - u32 i, rx_size, tx_size; - - if (vi->speed == SPEED_UNKNOWN || vi->speed < SPEED_10000) { - rx_size = 1024; - tx_size = 1024; - - } else if (vi->speed < SPEED_40000) { - rx_size = 1024 * 4; - tx_size = 1024 * 4; - - } else { - rx_size = 1024 * 8; - tx_size = 1024 * 8; - } - - for (i = 0; i < vi->max_queue_pairs; i++) { - sizes[rxq2vq(i)] = rx_size; - sizes[txq2vq(i)] = tx_size; - } -} - static int virtnet_find_vqs(struct virtnet_info *vi) { vq_callback_t **callbacks; @@ -3462,7 +3439,6 @@ static int virtnet_find_vqs(struct virtnet_info *vi) int ret = -ENOMEM; int i, total_vqs; const char **names; - u32 *sizes; bool *ctx; /* We expect 1 RX virtqueue followed by 1 TX virtqueue, followed by @@ -3490,15 +3466,10 @@ static int virtnet_find_vqs(struct virtnet_info *vi) ctx = NULL; } - sizes = kmalloc_array(total_vqs, sizeof(*sizes), GFP_KERNEL); - if (!sizes) - goto err_sizes; - /* Parameters for control virtqueue, if any */ if (vi->has_cvq) { callbacks[total_vqs - 1] = NULL; names[total_vqs - 1] = "control"; - sizes[total_vqs - 1] = 64; } /* Allocate/initialize parameters for send/receive virtqueues */ @@ -3513,10 +3484,8 @@ static int virtnet_find_vqs(struct virtnet_info *vi) ctx[rxq2vq(i)] = true; } - virtnet_config_sizes(vi, sizes); - - ret = virtio_find_vqs_ctx_size(vi->vdev, total_vqs, vqs, callbacks, - names, sizes, ctx, NULL); + ret = virtio_find_vqs_ctx(vi->vdev, total_vqs, vqs, callbacks, + names, ctx, NULL); if (ret) goto err_find; @@ -3536,8 +3505,6 @@ static int virtnet_find_vqs(struct virtnet_info *vi) err_find: - kfree(sizes); -err_sizes: kfree(ctx); err_ctx: kfree(names); @@ -3897,9 +3864,6 @@ static int virtnet_probe(struct virtio_device *vdev) vi->curr_queue_pairs = num_online_cpus(); vi->max_queue_pairs = max_queue_pairs; - virtnet_init_settings(dev); - virtnet_update_settings(vi); - /* Allocate/initialize the rx/tx queues, and invoke find_vqs */ err = init_vqs(vi); if (err) @@ -3912,6 +3876,8 @@ static int virtnet_probe(struct virtio_device *vdev) netif_set_real_num_tx_queues(dev, vi->curr_queue_pairs); netif_set_real_num_rx_queues(dev, vi->curr_queue_pairs); + virtnet_init_settings(dev); + if (virtio_has_feature(vdev, VIRTIO_NET_F_STANDBY)) { vi->failover = net_failover_create(vi->dev); if (IS_ERR(vi->failover)) { -- MST _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
WARNING: multiple messages have this Message-ID (diff)
From: "Michael S. Tsirkin" <mst@redhat.com> To: linux-kernel@vger.kernel.org Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com>, Jason Wang <jasowang@redhat.com>, "David S. Miller" <davem@davemloft.net>, Eric Dumazet <edumazet@google.com>, Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, Linus Torvalds <torvalds@linux-foundation.org>, Jens Axboe <axboe@kernel.dk>, James Bottomley <James.Bottomley@hansenpartnership.com>, "Martin K. Petersen" <martin.petersen@oracle.com>, Guenter Roeck <linux@roeck-us.net>, Greg KH <gregkh@linuxfoundation.org>, Andres Freund <andres@anarazel.de> Subject: [PATCH v2 1/5] virtio_net: Revert "virtio_net: set the default max ring size by find_vqs()" Date: Mon, 15 Aug 2022 17:53:24 -0400 [thread overview] Message-ID: <20220815215251.154451-3-mst@redhat.com> (raw) In-Reply-To: <20220815215251.154451-1-mst@redhat.com> This reverts commit 762faee5a2678559d3dc09d95f8f2c54cd0466a7. This has been reported to trip up guests on GCP (Google Cloud). The reason is that virtio_find_vqs_ctx_size is broken on legacy devices. We can in theory fix virtio_find_vqs_ctx_size but in fact the patch itself has several other issues: - It treats unknown speed as < 10G - It leaves userspace no way to find out the ring size set by hypervisor - It tests speed when link is down - It ignores the virtio spec advice: Both \field{speed} and \field{duplex} can change, thus the driver is expected to re-read these values after receiving a configuration change notification. - It is not clear the performance impact has been tested properly Revert the patch for now. Reported-by: Andres Freund <andres@anarazel.de> Link: https://lore.kernel.org/r/20220814212610.GA3690074%40roeck-us.net Link: https://lore.kernel.org/r/20220815070203.plwjx7b3cyugpdt7%40awork3.anarazel.de Link: https://lore.kernel.org/r/3df6bb82-1951-455d-a768-e9e1513eb667%40www.fastmail.com Link: https://lore.kernel.org/r/FCDC5DDE-3CDD-4B8A-916F-CA7D87B547CE%40anarazel.de Fixes: 762faee5a267 ("virtio_net: set the default max ring size by find_vqs()") Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Cc: Jason Wang <jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Tested-by: Andres Freund <andres@anarazel.de> Tested-by: From: Guenter Roeck <linux@roeck-us.net> --- drivers/net/virtio_net.c | 42 ++++------------------------------------ 1 file changed, 4 insertions(+), 38 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index d934774e9733..ece00b84e3a7 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -3432,29 +3432,6 @@ static unsigned int mergeable_min_buf_len(struct virtnet_info *vi, struct virtqu (unsigned int)GOOD_PACKET_LEN); } -static void virtnet_config_sizes(struct virtnet_info *vi, u32 *sizes) -{ - u32 i, rx_size, tx_size; - - if (vi->speed == SPEED_UNKNOWN || vi->speed < SPEED_10000) { - rx_size = 1024; - tx_size = 1024; - - } else if (vi->speed < SPEED_40000) { - rx_size = 1024 * 4; - tx_size = 1024 * 4; - - } else { - rx_size = 1024 * 8; - tx_size = 1024 * 8; - } - - for (i = 0; i < vi->max_queue_pairs; i++) { - sizes[rxq2vq(i)] = rx_size; - sizes[txq2vq(i)] = tx_size; - } -} - static int virtnet_find_vqs(struct virtnet_info *vi) { vq_callback_t **callbacks; @@ -3462,7 +3439,6 @@ static int virtnet_find_vqs(struct virtnet_info *vi) int ret = -ENOMEM; int i, total_vqs; const char **names; - u32 *sizes; bool *ctx; /* We expect 1 RX virtqueue followed by 1 TX virtqueue, followed by @@ -3490,15 +3466,10 @@ static int virtnet_find_vqs(struct virtnet_info *vi) ctx = NULL; } - sizes = kmalloc_array(total_vqs, sizeof(*sizes), GFP_KERNEL); - if (!sizes) - goto err_sizes; - /* Parameters for control virtqueue, if any */ if (vi->has_cvq) { callbacks[total_vqs - 1] = NULL; names[total_vqs - 1] = "control"; - sizes[total_vqs - 1] = 64; } /* Allocate/initialize parameters for send/receive virtqueues */ @@ -3513,10 +3484,8 @@ static int virtnet_find_vqs(struct virtnet_info *vi) ctx[rxq2vq(i)] = true; } - virtnet_config_sizes(vi, sizes); - - ret = virtio_find_vqs_ctx_size(vi->vdev, total_vqs, vqs, callbacks, - names, sizes, ctx, NULL); + ret = virtio_find_vqs_ctx(vi->vdev, total_vqs, vqs, callbacks, + names, ctx, NULL); if (ret) goto err_find; @@ -3536,8 +3505,6 @@ static int virtnet_find_vqs(struct virtnet_info *vi) err_find: - kfree(sizes); -err_sizes: kfree(ctx); err_ctx: kfree(names); @@ -3897,9 +3864,6 @@ static int virtnet_probe(struct virtio_device *vdev) vi->curr_queue_pairs = num_online_cpus(); vi->max_queue_pairs = max_queue_pairs; - virtnet_init_settings(dev); - virtnet_update_settings(vi); - /* Allocate/initialize the rx/tx queues, and invoke find_vqs */ err = init_vqs(vi); if (err) @@ -3912,6 +3876,8 @@ static int virtnet_probe(struct virtio_device *vdev) netif_set_real_num_tx_queues(dev, vi->curr_queue_pairs); netif_set_real_num_rx_queues(dev, vi->curr_queue_pairs); + virtnet_init_settings(dev); + if (virtio_has_feature(vdev, VIRTIO_NET_F_STANDBY)) { vi->failover = net_failover_create(vi->dev); if (IS_ERR(vi->failover)) { -- MST
next prev parent reply other threads:[~2022-08-15 21:53 UTC|newest] Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-08-15 21:53 [PATCH v2 0/5] virtio: drop sizing vqs during init Michael S. Tsirkin 2022-08-15 21:53 ` Michael S. Tsirkin 2022-08-15 21:53 ` [PATCH v2 1/1] virtio: kerneldocs fixes and enhancements Michael S. Tsirkin 2022-08-15 21:53 ` Michael S. Tsirkin 2022-08-15 21:56 ` Michael S. Tsirkin 2022-08-15 21:56 ` Michael S. Tsirkin 2022-08-15 21:53 ` Michael S. Tsirkin [this message] 2022-08-15 21:53 ` [PATCH v2 1/5] virtio_net: Revert "virtio_net: set the default max ring size by find_vqs()" Michael S. Tsirkin 2022-08-15 21:53 ` [PATCH v2 1/1] virtio: Revert "virtio: find_vqs() add arg sizes" Michael S. Tsirkin 2022-08-15 21:53 ` Michael S. Tsirkin 2022-08-15 21:53 ` Michael S. Tsirkin 2022-08-15 21:53 ` [PATCH v2 2/5] virtio: Revert "virtio: add helper virtio_find_vqs_ctx_size()" Michael S. Tsirkin 2022-08-15 21:53 ` Michael S. Tsirkin 2022-08-15 21:53 ` [PATCH v2 3/5] virtio-mmio: Revert "virtio_mmio: support the arg sizes of find_vqs()" Michael S. Tsirkin 2022-08-15 21:53 ` Michael S. Tsirkin 2022-08-15 21:53 ` [PATCH v2 4/5] virtio_pci: Revert "virtio_pci: " Michael S. Tsirkin 2022-08-15 21:53 ` Michael S. Tsirkin 2022-08-15 21:53 ` [PATCH v2 5/5] virtio: Revert "virtio: find_vqs() add arg sizes" Michael S. Tsirkin 2022-08-15 21:53 ` Michael S. Tsirkin 2022-08-15 21:53 ` Michael S. Tsirkin
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