pc: fix regression for 64 bit PCI memory

commit 398489018183d613306ab022653552247d93919f
    pc: limit 64 bit hole to 2G by default
introduced a way for management to control
the window allocated to the 64 bit PCI hole.

This is useful, but existing management tools do not know how to set
this property.  As a result, e.g. specifying a large ivshmem device with
size > 4G is broken by default.  For example this configuration no
longer works:

-device ivshmem,size=4294967296,chardev=cfoo
-chardev socket,path=/tmp/sock,id=cfoo,server,nowait

Fix this by detecting that hole size was not specified
and defaulting to the backwards-compatible value of 1 << 62.

Cc: qemu-stable@nongnu.org
Cc: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 10 insertions, 1 deletions

diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
index f79d4782c1..475ba9ee2d 100644
--- a/include/hw/i386/pc.h
+++ b/include/hw/i386/pc.h
@@ -106,7 +106,16 @@ PcGuestInfo *pc_guest_info_init(ram_addr_t below_4g_mem_size,
 #define PCI_HOST_PROP_PCI_HOLE64_START "pci-hole64-start"
 #define PCI_HOST_PROP_PCI_HOLE64_END   "pci-hole64-end"
 #define PCI_HOST_PROP_PCI_HOLE64_SIZE  "pci-hole64-size"
-#define DEFAULT_PCI_HOLE64_SIZE (1ULL << 31)
+#define DEFAULT_PCI_HOLE64_SIZE (~0x0ULL)
+
+static inline uint64_t pci_host_get_hole64_size(uint64_t pci_hole64_size)
+{
+    if (pci_hole64_size == DEFAULT_PCI_HOLE64_SIZE) {
+        return 1ULL << 62;
+    } else {
+        return pci_hole64_size;
+    }
+}
 
 void pc_init_pci64_hole(PcPciInfo *pci_info, uint64_t pci_hole64_start,
                         uint64_t pci_hole64_size);