[Qemu-devel] [PATCH 27/51] piix: fix 32bit pci hole

[Michael Roth <mdroth@linux.vnet.ibm.com>]

From: Gerd Hoffmann <kraxel@redhat.com>

Make the 32bit pci hole start at end of ram, so all possible address
space is covered.

We used to try and make addresses aligned so they are easier to cover
with MTRRs, but since they are cosmetic on KVM, this is probably not
worth worrying about.
Of course the firmware can use less than that.  Leaving space unused is
no problem, mapping pci bars outside the hole causes problems though.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
(cherry picked from commit ddaaefb4dd427d6d2e41c1cfbe0cd8d8e8d6aad9)

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
---
 hw/i386/pc_piix.c    |    1 +
 hw/pci-host/piix.c   |   11 ++---------
 include/hw/i386/pc.h |    1 +
 3 files changed, 4 insertions(+), 9 deletions(-)

diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index 29b47d4..cc9b273 100644
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -149,6 +149,7 @@ static void pc_init1(QEMUMachineInitArgs *args,
     if (pci_enabled) {
         pci_bus = i440fx_init(&i440fx_state, &piix3_devfn, &isa_bus, gsi,
                               system_memory, system_io, args->ram_size,
+                              below_4g_mem_size,
                               above_4g_mem_size,
                               pci_memory, ram_memory);
     } else {
diff --git a/hw/pci-host/piix.c b/hw/pci-host/piix.c
index 63be7f6..4229d09 100644
--- a/hw/pci-host/piix.c
+++ b/hw/pci-host/piix.c
@@ -311,6 +311,7 @@ PCIBus *i440fx_init(PCII440FXState **pi440fx_state,
                     MemoryRegion *address_space_mem,
                     MemoryRegion *address_space_io,
                     ram_addr_t ram_size,
+                    ram_addr_t below_4g_mem_size,
                     ram_addr_t above_4g_mem_size,
                     MemoryRegion *pci_address_space,
                     MemoryRegion *ram_memory)
@@ -340,15 +341,7 @@ PCIBus *i440fx_init(PCII440FXState **pi440fx_state,
     f->ram_memory = ram_memory;
 
     i440fx = I440FX_PCI_HOST_BRIDGE(dev);
-    /* Set PCI window size the way seabios has always done it. */
-    /* Power of 2 so bios can cover it with a single MTRR */
-    if (ram_size <= 0x80000000) {
-        i440fx->pci_info.w32.begin = 0x80000000;
-    } else if (ram_size <= 0xc0000000) {
-        i440fx->pci_info.w32.begin = 0xc0000000;
-    } else {
-        i440fx->pci_info.w32.begin = 0xe0000000;
-    }
+    i440fx->pci_info.w32.begin = below_4g_mem_size;
 
     /* setup pci memory mapping */
     pc_pci_as_mapping_init(OBJECT(f), f->system_memory,
diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
index 8ea1a98..2a4a094 100644
--- a/include/hw/i386/pc.h
+++ b/include/hw/i386/pc.h
@@ -179,6 +179,7 @@ PCIBus *i440fx_init(PCII440FXState **pi440fx_state, int *piix_devfn,
                     MemoryRegion *address_space_mem,
                     MemoryRegion *address_space_io,
                     ram_addr_t ram_size,
+                    ram_addr_t below_4g_mem_size,
                     ram_addr_t above_4g_mem_size,
                     MemoryRegion *pci_memory,
                     MemoryRegion *ram_memory);
-- 
1.7.9.5