[PATCH] fuzz: map all BARs and enable PCI devices

[Alexander Bulekov]

Prior to this patch, the fuzzer found inputs to map PCI device BARs and
enable the device. While it is nice that the fuzzer can do this, it
added significant overhead, since the fuzzer needs to map all the
BARs (regenerating the memory topology), at the start of each input.
With this patch, we do this once, before fuzzing, mitigating some of
this overhead.

Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
---
 tests/qtest/fuzz/generic_fuzz.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/tests/qtest/fuzz/generic_fuzz.c b/tests/qtest/fuzz/generic_fuzz.c
index 07ad690683..d95093ee53 100644
--- a/tests/qtest/fuzz/generic_fuzz.c
+++ b/tests/qtest/fuzz/generic_fuzz.c
@@ -16,6 +16,7 @@
 
 #include "hw/core/cpu.h"
 #include "tests/qtest/libqos/libqtest.h"
+#include "tests/qtest/libqos/pci-pc.h"
 #include "fuzz.h"
 #include "fork_fuzz.h"
 #include "exec/address-spaces.h"
@@ -762,6 +763,22 @@ static int locate_fuzz_objects(Object *child, void *opaque)
     return 0;
 }
 
+
+static void pci_enum(gpointer pcidev, gpointer bus)
+{
+    PCIDevice *dev = pcidev;
+    QPCIDevice *qdev;
+
+    qdev = qpci_device_find(bus, dev->devfn);
+    g_assert(qdev != NULL);
+    for (int i = 0; i < 6; i++) {
+        if (dev->io_regions[i].size) {
+            qpci_iomap(qdev, i, NULL);
+        }
+    }
+    qpci_device_enable(qdev);
+}
+
 static void generic_pre_fuzz(QTestState *s)
 {
     GHashTableIter iter;
@@ -810,6 +827,12 @@ static void generic_pre_fuzz(QTestState *s)
         exit(1);
     }
 
+    QPCIBus *pcibus;
+
+    pcibus = qpci_new_pc(s, NULL);
+    g_ptr_array_foreach(fuzzable_pci_devices, pci_enum, pcibus);
+    qpci_free_pc(pcibus);
+
     counter_shm_init();
 }
 
-- 
2.28.0