From a3129ae6df9b4aeeeccc051b4566db45fddecd2f Mon Sep 17 00:00:00 2001
From: Michal Privoznik <mprivozn@redhat.com>
Date: Tue, 5 Dec 2023 14:32:48 +0100
Subject: [PATCH] qemuDomainChangeNet: Reflect trustGuestRxFilters change
MIME-Version: 1.0
Content-Type: text/plain; charset=utf8
Content-Transfer-Encoding: 8bit

On device-update, when user requests change of
trustGuestRxFilters we currently do nothing. Nor error out, nor
act on the request. While we can just throw an error,
implementing this is pretty trivial.

Resolves: https://issues.redhat.com/browse/RHEL-735
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
---
 src/qemu/qemu_hotplug.c | 51 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)

diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c
index 4e2fc724c0..75e1d39b60 100644
--- a/src/qemu/qemu_hotplug.c
+++ b/src/qemu/qemu_hotplug.c
@@ -3625,6 +3625,43 @@ qemuDomainChangeNetLinkState(virDomainObj *vm,
     return ret;
 }
 
+static int
+qemuDomainQueryRxFilterDummy(virDomainObj *vm,
+                             virDomainNetDef *dev,
+                             bool trustGuestRxFilters)
+{
+    qemuDomainObjPrivate *priv = vm->privateData;
+
+    VIR_DEBUG("dev: %s, trustGuestRxFilters: %d",
+              NULLSTR(dev->info.alias), trustGuestRxFilters);
+
+    /* Transition from "yes" to "no" is simple, just record the new
+     * setting and processNicRxFilterChangedEvent() will ignore
+     * NIC_RX_FILTER_CHANGED event.
+     * Transition from "no" to "yes" requires issuing query-rx-filter
+     * monitor command to enable the event delivery again.
+     */
+    if (trustGuestRxFilters) {
+        int rc;
+
+        if (!dev->info.alias) {
+            virReportError(VIR_ERR_OPERATION_FAILED, "%s",
+                           _("can't query rx filters: device alias not found"));
+            return -1;
+        }
+
+        qemuDomainObjEnterMonitor(vm);
+        rc = qemuMonitorQueryRxFilter(priv->mon, dev->info.alias, NULL);
+        qemuDomainObjExitMonitor(vm);
+        if (rc < 0)
+            return -1;
+    }
+
+    /* modify the device configuration */
+    dev->trustGuestRxFilters = trustGuestRxFilters;
+    return 0;
+}
+
 static int
 qemuDomainChangeNet(virQEMUDriver *driver,
                     virDomainObj *vm,
@@ -3644,6 +3681,7 @@ qemuDomainChangeNet(virQEMUDriver *driver,
     bool needCoalesceChange = false;
     bool needVlanUpdate = false;
     bool needIsolatedPortChange = false;
+    bool needQueryRxFilter = false;
     int ret = -1;
     int changeidx = -1;
     g_autoptr(virConnect) conn = NULL;
@@ -3999,6 +4037,11 @@ qemuDomainChangeNet(virQEMUDriver *driver,
         needIsolatedPortChange = true;
     }
 
+    if (virDomainNetGetActualTrustGuestRxFilters(olddev) !=
+        virDomainNetGetActualTrustGuestRxFilters(newdev)) {
+        needQueryRxFilter = true;
+    }
+
     if (olddev->linkstate != newdev->linkstate)
         needLinkStateChange = true;
 
@@ -4091,6 +4134,14 @@ qemuDomainChangeNet(virQEMUDriver *driver,
         needReplaceDevDef = true;
     }
 
+    if (needQueryRxFilter) {
+        if (qemuDomainQueryRxFilterDummy(vm, olddev,
+                                         virDomainNetGetActualTrustGuestRxFilters(newdev)) < 0) {
+            goto cleanup;
+        }
+        needReplaceDevDef = true;
+    }
+
     if (needLinkStateChange &&
         qemuDomainChangeNetLinkState(vm, olddev, newdev->linkstate) < 0) {
         goto cleanup;
-- 
2.39.5