On Wed, May 18, 2016 at 06:01:15PM +0300, Marcel Apfelbaum wrote: > On 05/18/2016 05:57 PM, Michael S. Tsirkin wrote: > >On Wed, May 18, 2016 at 05:43:37PM +0300, Marcel Apfelbaum wrote: > >>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 > > > >Besides being ugly (we should get this from CPU code, not hard-code it) > >not all guests look at CPUID unfortunately. > >E.g. try win7 32 bit. > > > > I am open to better ideas, can you please advice? > > Thanks, > Marcel
I'm afraid you will have to try a ton of guests and collect data on which window ranges make them crash :( > > > >>>>+ } 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