From bb34da88524f313681005435f8fd6d905ca81b6a Mon Sep 17 00:00:00 2001

From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>

Date: Thu, 17 Aug 2017 09:45:35 +0200

Subject: [PATCH 2/4] virtio-net: dynamic network offloads configuration

RH-Author: Dr. David Alan Gilbert <dgilbert@redhat.com>

Message-id: <20170817094536.12740-2-dgilbert@redhat.com>

Patchwork-id: 76021

O-Subject: [RHEL-7.5/7.4.z/7.3.z/7.2.z qemu-kvm PATCH v2 1/2] virtio-net: dynamic network offloads configuration

Bugzilla: 1480428

RH-Acked-by: Eduardo Habkost <ehabkost@redhat.com>

RH-Acked-by: Michael S. Tsirkin <mst@redhat.com>

RH-Acked-by: Thomas Huth <thuth@redhat.com>

From: Dmitry Fleytman <dfleytma@redhat.com>

Virtio-net driver currently negotiates network offloads

on startup via features mechanism and have no ability to

disable and re-enable offloads later.

This patch introduced a new control command that allows

to configure device network offloads state dynamically.

The patch also introduces a new feature flag

VIRTIO_NET_F_CTRL_GUEST_OFFLOADS.

Signed-off-by: Dmitry Fleytman <dfleytma@redhat.com>

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

Message-id: 20130520081814.GA8162@redhat.com

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

(cherry picked from commit 644c98587d4ccc09e7592e1688e4e7fa363c5a75)

RHEL7.0 qemu-kvm only: Configure ctrl_guest_offloads off

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>

---

 hw/net/virtio-net.c            | 99 +++++++++++++++++++++++++++++++++++-------

 include/hw/i386/pc.h           |  4 ++

 include/hw/virtio/virtio-net.h | 14 ++++++

 3 files changed, 102 insertions(+), 15 deletions(-)

diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c

index 3fde455..eb2feaf 100644

--- a/hw/net/virtio-net.c

+++ b/hw/net/virtio-net.c

@@ -477,6 +477,34 @@ static uint32_t virtio_net_bad_features(VirtIODevice *vdev)

     return features;

 }

+static void virtio_net_apply_guest_offloads(VirtIONet *n)

+{

+    tap_set_offload(qemu_get_subqueue(n->nic, 0)->peer,

+            !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_CSUM)),

+            !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_TSO4)),

+            !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_TSO6)),

+            !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_ECN)),

+            !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_UFO)));

+}

+

+static uint64_t virtio_net_guest_offloads_by_features(uint32_t features)

+{

+    static const uint64_t guest_offloads_mask =

+        (1ULL << VIRTIO_NET_F_GUEST_CSUM) |

+        (1ULL << VIRTIO_NET_F_GUEST_TSO4) |

+        (1ULL << VIRTIO_NET_F_GUEST_TSO6) |

+        (1ULL << VIRTIO_NET_F_GUEST_ECN)  |

+        (1ULL << VIRTIO_NET_F_GUEST_UFO);

+

+    return guest_offloads_mask & features;

+}

+

+static inline uint64_t virtio_net_supported_guest_offloads(VirtIONet *n)

+{

+    VirtIODevice *vdev = VIRTIO_DEVICE(n);

+    return virtio_net_guest_offloads_by_features(vdev->guest_features);

+}

+

 static void virtio_net_set_features(VirtIODevice *vdev, uint32_t features)

 {

     VirtIONet *n = VIRTIO_NET(vdev);

@@ -487,12 +515,9 @@ static void virtio_net_set_features(VirtIODevice *vdev, uint32_t features)

     virtio_net_set_mrg_rx_bufs(n, !!(features & (1 << VIRTIO_NET_F_MRG_RXBUF)));

     if (n->has_vnet_hdr) {

-        tap_set_offload(qemu_get_subqueue(n->nic, 0)->peer,

-                        (features >> VIRTIO_NET_F_GUEST_CSUM) & 1,

-                        (features >> VIRTIO_NET_F_GUEST_TSO4) & 1,

-                        (features >> VIRTIO_NET_F_GUEST_TSO6) & 1,

-                        (features >> VIRTIO_NET_F_GUEST_ECN)  & 1,

-                        (features >> VIRTIO_NET_F_GUEST_UFO)  & 1);

+        n->curr_guest_offloads =

+            virtio_net_guest_offloads_by_features(features);

+        virtio_net_apply_guest_offloads(n);

     }

     for (i = 0;  i < n->max_queues; i++) {

@@ -547,6 +572,43 @@ static int virtio_net_handle_rx_mode(VirtIONet *n, uint8_t cmd,

     return VIRTIO_NET_OK;

 }

+static int virtio_net_handle_offloads(VirtIONet *n, uint8_t cmd,

+                                     struct iovec *iov, unsigned int iov_cnt)

+{

+    VirtIODevice *vdev = VIRTIO_DEVICE(n);

+    uint64_t offloads;

+    size_t s;

+

+    if (!((1 << VIRTIO_NET_F_CTRL_GUEST_OFFLOADS) & vdev->guest_features)) {

+        return VIRTIO_NET_ERR;

+    }

+

+    s = iov_to_buf(iov, iov_cnt, 0, &offloads, sizeof(offloads));

+    if (s != sizeof(offloads)) {

+        return VIRTIO_NET_ERR;

+    }

+

+    if (cmd == VIRTIO_NET_CTRL_GUEST_OFFLOADS_SET) {

+        uint64_t supported_offloads;

+

+        if (!n->has_vnet_hdr) {

+            return VIRTIO_NET_ERR;

+        }

+

+        supported_offloads = virtio_net_supported_guest_offloads(n);

+        if (offloads & ~supported_offloads) {

+            return VIRTIO_NET_ERR;

+        }

+

+        n->curr_guest_offloads = offloads;

+        virtio_net_apply_guest_offloads(n);

+

+        return VIRTIO_NET_OK;

+    } else {

+        return VIRTIO_NET_ERR;

+    }

+}

+

 static int virtio_net_handle_mac(VirtIONet *n, uint8_t cmd,

                                  struct iovec *iov, unsigned int iov_cnt)

 {

@@ -735,6 +797,8 @@ static void virtio_net_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)

             status = virtio_net_handle_vlan_table(n, ctrl.cmd, iov, iov_cnt);

         } else if (ctrl.class == VIRTIO_NET_CTRL_MQ) {

             status = virtio_net_handle_mq(n, ctrl.cmd, iov, iov_cnt);

+        } else if (ctrl.class == VIRTIO_NET_CTRL_GUEST_OFFLOADS) {

+            status = virtio_net_handle_offloads(n, ctrl.cmd, iov, iov_cnt);

         }

         s = iov_from_buf(elem.in_sg, elem.in_num, 0, &status, sizeof(status));

@@ -1253,6 +1317,10 @@ static void virtio_net_save(QEMUFile *f, void *opaque)

             qemu_put_be32(f, n->vqs[i].tx_waiting);

         }

     }

+

+    if ((1 << VIRTIO_NET_F_CTRL_GUEST_OFFLOADS) & vdev->guest_features) {

+        qemu_put_be64(f, n->curr_guest_offloads);

+    }

 }

 static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)

@@ -1317,15 +1385,6 @@ static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)

             error_report("virtio-net: saved image requires vnet_hdr=on");

             return -1;

         }

-

-        if (n->has_vnet_hdr) {

-            tap_set_offload(qemu_get_queue(n->nic)->peer,

-                    (vdev->guest_features >> VIRTIO_NET_F_GUEST_CSUM) & 1,

-                    (vdev->guest_features >> VIRTIO_NET_F_GUEST_TSO4) & 1,

-                    (vdev->guest_features >> VIRTIO_NET_F_GUEST_TSO6) & 1,

-                    (vdev->guest_features >> VIRTIO_NET_F_GUEST_ECN)  & 1,

-                    (vdev->guest_features >> VIRTIO_NET_F_GUEST_UFO)  & 1);

-        }

     }

     if (version_id >= 9) {

@@ -1364,6 +1423,16 @@ static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)

         }

     }

+    if ((1 << VIRTIO_NET_F_CTRL_GUEST_OFFLOADS) & vdev->guest_features) {

+        n->curr_guest_offloads = qemu_get_be64(f);

+    } else {

+        n->curr_guest_offloads = virtio_net_supported_guest_offloads(n);

+    }

+

+    if (peer_has_vnet_hdr(n)) {

+        virtio_net_apply_guest_offloads(n);

+    }

+

     virtio_net_set_queues(n);

     /* Find the first multicast entry in the saved MAC filter */

diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h

index 3b8f7d8..89bb458 100644

--- a/include/hw/i386/pc.h

+++ b/include/hw/i386/pc.h

@@ -318,6 +318,10 @@ int e820_add_entry(uint64_t, uint64_t, uint32_t);

             .property = "vectors",\

             /* DEV_NVECTORS_UNSPECIFIED as a uint32_t string */\

             .value    = stringify(0xFFFFFFFF),\

+        },{ \

+            .driver   = "virtio-net-pci", \

+            .property = "ctrl_guest_offloads", \

+            .value    = "off", \

         },{\

             .driver   = "e1000",\

             .property = "romfile",\

diff --git a/include/hw/virtio/virtio-net.h b/include/hw/virtio/virtio-net.h

index a02fc50..02fa5c5 100644

--- a/include/hw/virtio/virtio-net.h

+++ b/include/hw/virtio/virtio-net.h

@@ -31,6 +31,8 @@

 /* The feature bitmap for virtio net */

 #define VIRTIO_NET_F_CSUM       0       /* Host handles pkts w/ partial csum */

 #define VIRTIO_NET_F_GUEST_CSUM 1       /* Guest handles pkts w/ partial csum */

+#define VIRTIO_NET_F_CTRL_GUEST_OFFLOADS 2 /* Control channel offload

+                                         * configuration support */

 #define VIRTIO_NET_F_MAC        5       /* Host has given MAC address. */

 #define VIRTIO_NET_F_GSO        6       /* Host handles pkts w/ any GSO type */

 #define VIRTIO_NET_F_GUEST_TSO4 7       /* Guest can handle TSOv4 in. */

@@ -190,6 +192,7 @@ typedef struct VirtIONet {

     size_t config_size;

     char *netclient_name;

     char *netclient_type;

+    uint64_t curr_guest_offloads;

 } VirtIONet;

 #define VIRTIO_NET_CTRL_MAC    1

@@ -229,6 +232,15 @@ struct virtio_net_ctrl_mq {

  #define VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN        1

  #define VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX        0x8000

+/*

+ * Control network offloads

+ *

+ * Dynamic offloads are available with the

+ * VIRTIO_NET_F_CTRL_GUEST_OFFLOADS feature bit.

+ */

+#define VIRTIO_NET_CTRL_GUEST_OFFLOADS   5

+ #define VIRTIO_NET_CTRL_GUEST_OFFLOADS_SET        0

+

 #define DEFINE_VIRTIO_NET_FEATURES(_state, _field) \

         DEFINE_VIRTIO_COMMON_FEATURES(_state, _field), \

         DEFINE_PROP_BIT("any_layout", _state, _field, VIRTIO_F_ANY_LAYOUT, true), \

@@ -250,6 +262,8 @@ struct virtio_net_ctrl_mq {

         DEFINE_PROP_BIT("ctrl_vlan", _state, _field, VIRTIO_NET_F_CTRL_VLAN, true), \

         DEFINE_PROP_BIT("ctrl_rx_extra", _state, _field, VIRTIO_NET_F_CTRL_RX_EXTRA, true), \

         DEFINE_PROP_BIT("ctrl_mac_addr", _state, _field, VIRTIO_NET_F_CTRL_MAC_ADDR, true), \

+        /* RHEL 7.0 qemu-kvm: ctrl_guest_offloads always configured off */ \

+        DEFINE_PROP_BIT("ctrl_guest_offloads", _state, _field, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS, false), \

         DEFINE_PROP_BIT("mq", _state, _field, VIRTIO_NET_F_MQ, false)

 #define DEFINE_VIRTIO_NET_PROPERTIES(_state, _field)                           \

-- 

1.8.3.1