libvirt/SOURCES/libvirt-util-probe-stub-driver-from-within-function-that-binds-to-stub-driver.patch

From 2d9c9445b9cc093c870f101eb884ddeac3ae40f7 Mon Sep 17 00:00:00 2001
From: Laine Stump <laine@redhat.com>
Date: Sun, 9 Jul 2023 15:00:26 -0400
Subject: [PATCH] util: probe stub driver from within function that binds to
 stub driver

virPCIProbeStubDriver() and virPCIDeviceBindToStub() both have
very similar code that locally sets a driver name (based on
stubDriverType). These two functions are each also called in just one
place (virPCIDeviceDetach()), with just a small bit of validation code
in between.

To eliminate the "duplicated" code (which is going to be expanded
slightly in upcoming patches to support manually or automatically
picking a VFIO variant driver), this patch modifies
virPCIProbeStubDriver() to take the driver name as an argument
(rather than the virPCIDevice object), and calls it from within
virPCIDeviceBindToStub() (rather than from that function's caller),
using the driverName it has just figured out with the
now-not-duplicated code.

(NB: Since it could be used to probe *any* driver module, the name is
changed to virPCIProbeDriver()).

Signed-off-by: Laine Stump <laine@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
---
 src/util/virpci.c | 33 ++++++++++++---------------------
 1 file changed, 12 insertions(+), 21 deletions(-)

diff --git a/src/util/virpci.c b/src/util/virpci.c
index 253ddccabdd..f1936795da7 100644
--- a/src/util/virpci.c
+++ b/src/util/virpci.c
@@ -1154,28 +1154,19 @@ virPCIDeviceReset(virPCIDevice *dev,
 
 
 static int
-virPCIProbeStubDriver(virPCIStubDriver driver)
+virPCIProbeDriver(const char *driverName)
 {
-    const char *drvname = NULL;
     g_autofree char *drvpath = NULL;
     g_autofree char *errbuf = NULL;
 
-    if (driver == VIR_PCI_STUB_DRIVER_NONE ||
-        !(drvname = virPCIStubDriverTypeToString(driver))) {
-        virReportError(VIR_ERR_INTERNAL_ERROR,
-                       "%s",
-                       _("Attempting to use unknown stub driver"));
-        return -1;
-    }
-
-    drvpath = virPCIDriverDir(drvname);
+    drvpath = virPCIDriverDir(driverName);
 
     /* driver previously loaded, return */
     if (virFileExists(drvpath))
         return 0;
 
-    if ((errbuf = virKModLoad(drvname))) {
-        VIR_WARN("failed to load driver %s: %s", drvname, errbuf);
+    if ((errbuf = virKModLoad(driverName))) {
+        VIR_WARN("failed to load driver %s: %s", driverName, errbuf);
         goto cleanup;
     }
 
@@ -1187,14 +1178,14 @@ virPCIProbeStubDriver(virPCIStubDriver driver)
     /* If we know failure was because of admin config, let's report that;
      * otherwise, report a more generic failure message
      */
-    if (virKModIsProhibited(drvname)) {
+    if (virKModIsProhibited(driverName)) {
         virReportError(VIR_ERR_INTERNAL_ERROR,
-                       _("Failed to load PCI stub module %1$s: administratively prohibited"),
-                       drvname);
+                       _("Failed to load PCI driver module %1$s: administratively prohibited"),
+                       driverName);
     } else {
         virReportError(VIR_ERR_INTERNAL_ERROR,
-                       _("Failed to load PCI stub module %1$s"),
-                       drvname);
+                       _("Failed to load PCI driver module %1$s"),
+                       driverName);
     }
 
     return -1;
@@ -1316,6 +1307,9 @@ virPCIDeviceBindToStub(virPCIDevice *dev)
         return -1;
     }
 
+    if (virPCIProbeDriver(stubDriverName) < 0)
+        return -1;
+
     stubDriverPath = virPCIDriverDir(stubDriverName);
     driverLink = virPCIFile(dev->name, "driver");
 
@@ -1359,9 +1353,6 @@ virPCIDeviceDetach(virPCIDevice *dev,
                    virPCIDeviceList *activeDevs,
                    virPCIDeviceList *inactiveDevs)
 {
-    if (virPCIProbeStubDriver(dev->stubDriverType) < 0)
-        return -1;
-
     if (activeDevs && virPCIDeviceListFind(activeDevs, &dev->address)) {
         virReportError(VIR_ERR_INTERNAL_ERROR,
                        _("Not detaching active device %1$s"), dev->name);