[Qemu-devel] [PATCH RFC 3/3] pci-testdev: add RO pages for ioeventfd

[Michael S. Tsirkin]

This seems hackish - would it be better to create this region
automatically within kvm? Suggestions are welcome.

Signed-off-by: Michael S. Tsirkin <m...@redhat.com>
---
 hw/misc/pci-testdev.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/hw/misc/pci-testdev.c b/hw/misc/pci-testdev.c
index 94141a3..55efc32 100644
--- a/hw/misc/pci-testdev.c
+++ b/hw/misc/pci-testdev.c
@@ -21,6 +21,7 @@
 #include "hw/pci/pci.h"
 #include "qemu/event_notifier.h"
 #include "qemu/osdep.h"
+#include <sys/mman.h>
 
 typedef struct PCITestDevHdr {
     uint8_t test;
@@ -82,11 +83,13 @@ typedef struct PCITestDevState {
     PCIDevice parent_obj;
     /*< public >*/
 
+    MemoryRegion zeromr;
     MemoryRegion mmio;
     MemoryRegion mbar;
     MemoryRegion portio;
     IOTest *tests;
     int current;
+    void *zero;
 } PCITestDevState;
 
 #define TYPE_PCI_TEST_DEV "pci-testdev"
@@ -242,6 +245,11 @@ static void pci_testdev_realize(PCIDevice *pci_dev, Error 
**errp)
     uint8_t *pci_conf;
     char *name;
     int r, i;
+    d->zero = mmap(NULL, IOTEST_MEMSIZE * 2, PROT_READ,
+                         MAP_SHARED | MAP_ANONYMOUS, -1, 0);
+
+    memory_region_init_ram_ptr(&d->zeromr, OBJECT(d), "pci-testdev-zero", 
0x1000, d->zero);
+    memory_region_set_readonly(&d->zeromr, true);
 
     pci_conf = pci_dev->config;
 
@@ -286,6 +294,11 @@ static void pci_testdev_realize(PCIDevice *pci_dev, Error 
**errp)
             test->hasnotifier = false;
             continue;
         }
+
+        if (test->hasnotifier && !test->size) {
+            memory_region_add_subregion_overlap(&d->mbar, 
le32_to_cpu(test->hdr->offset),
+                                                &d->zeromr, 2 /* prio */);
+        }
         r = event_notifier_init(&test->notifier, 0);
         assert(r >= 0);
         test->hasnotifier = true;
-- 
MST