On 05/18/2016 05:14 PM, Michael S. Tsirkin wrote:
On Sun, May 15, 2016 at 10:23:32PM +0300, Marcel Apfelbaum wrote:
Using the firmware assigned MMIO ranges for 64-bit PCI window
leads to zero space for hot-plugging PCI devices over 4G.
PC machines can use the whole CPU addressable range after
the space reserved for memory-hotplug.
Signed-off-by: Marcel Apfelbaum <mar...@redhat.com>
---
hw/pci/pci.c | 16 ++++++++++++++--
1 file changed, 14 insertions(+), 2 deletions(-)
diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index bb605ef..44dd949 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -41,6 +41,7 @@
#include "hw/hotplug.h"
#include "hw/boards.h"
#include "qemu/cutils.h"
+#include "hw/i386/pc.h"
//#define DEBUG_PCI
#ifdef DEBUG_PCI
I don't want pci to depend on PC.
Pls find another way to do this.
Igor has an idea to not call pci_dev_get_w64 and make the computations
in the acpi code. I'll follow this idea.
@@ -2467,8 +2468,19 @@ static void pci_dev_get_w64(PCIBus *b, PCIDevice *dev,
void *opaque)
void pci_bus_get_w64_range(PCIBus *bus, Range *range)
{
- range->begin = range->end = 0;
- pci_for_each_device_under_bus(bus, pci_dev_get_w64, range);
+ Object *machine = qdev_get_machine();
An empty line won't hurt here after the declaration.
+ if (object_dynamic_cast(machine, TYPE_PC_MACHINE)) {
+ PCMachineState *pcms = PC_MACHINE(machine);
An empty line won't hurt here after the declaration.
+ range->begin = pc_machine_get_reserved_memory_end(pcms);
+ if (!range->begin) {
+ range->begin = ROUND_UP(0x100000000ULL + pcms->above_4g_mem_size,
+ 1ULL << 30);
Why 30? what is the logic here?
Will put it inside pci_dev_get_w64 and explain.
+ }
+ range->end = 1ULL << 40; /* 40 bits physical */
This comment does not help. Physical what? And why is 40 bit right?
It refers to how many bits are CPU addressable. (I will add a better comment)
cpu_x86_cpuid from target-i386/cpu.c it always returns 40
so hard-coding it looked like a safe choice.
Thanks,
Marcel
+ } else {
+ range->begin = range->end = 0;
+ pci_for_each_device_under_bus(bus, pci_dev_get_w64, range);
When does this trigger?
Pls add a comment.
+ }
}
static bool pcie_has_upstream_port(PCIDevice *dev)
--
2.4.3
