diff options
| author | Alexey Korolev <akorolex@gmail.com> | 2013-02-22 16:58:44 +1300 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2013-02-27 17:23:22 +0200 |
| commit | 7feb640cf32d86f91f5a624136345eb6a63eab42 (patch) | |
| tree | 42face6a4260bb03af364e356f760d7516139b6a /hw/sysbus.c | |
| parent | 2af234e61d59f39ae16ba882271e7c4fef2c41c1 (diff) | |
Fix guest OS hang when 64bit PCI bar present
This patch addresses the issue fully described here:
http://lists.nongnu.org/archive/html/qemu-devel/2013-02/msg01804.html
Linux kernels prior to 2.6.36 do not disable the PCI device during
enumeration process. Since lower and higher parts of a 64bit BAR
are programmed separately this leads to qemu receiving a request to occupy
a completely wrong address region for a short period of time.
We have found that the boot process screws up completely if kvm-apic range
is overlapped even for a short period of time (it is fine for other
regions though).
This patch raises the priority of the kvm-apic memory region, so it is
never pushed out by PCI devices. The patch is quite safe as it does not
touch memory manager.
Signed-off-by: Alexey Korolev <akorolex@gmail.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'hw/sysbus.c')
| -rw-r--r-- | hw/sysbus.c | 27 |
1 files changed, 23 insertions, 4 deletions
diff --git a/hw/sysbus.c b/hw/sysbus.c index 6d9d1df419..50c7232799 100644 --- a/hw/sysbus.c +++ b/hw/sysbus.c @@ -48,7 +48,8 @@ void sysbus_connect_irq(SysBusDevice *dev, int n, qemu_irq irq) } } -void sysbus_mmio_map(SysBusDevice *dev, int n, hwaddr addr) +static void sysbus_mmio_map_common(SysBusDevice *dev, int n, hwaddr addr, + bool may_overlap, unsigned priority) { assert(n >= 0 && n < dev->num_mmio); @@ -61,11 +62,29 @@ void sysbus_mmio_map(SysBusDevice *dev, int n, hwaddr addr) memory_region_del_subregion(get_system_memory(), dev->mmio[n].memory); } dev->mmio[n].addr = addr; - memory_region_add_subregion(get_system_memory(), - addr, - dev->mmio[n].memory); + if (may_overlap) { + memory_region_add_subregion_overlap(get_system_memory(), + addr, + dev->mmio[n].memory, + priority); + } + else { + memory_region_add_subregion(get_system_memory(), + addr, + dev->mmio[n].memory); + } } +void sysbus_mmio_map(SysBusDevice *dev, int n, hwaddr addr) +{ + sysbus_mmio_map_common(dev, n, addr, false, 0); +} + +void sysbus_mmio_map_overlap(SysBusDevice *dev, int n, hwaddr addr, + unsigned priority) +{ + sysbus_mmio_map_common(dev, n, addr, true, priority); +} /* Request an IRQ source. The actual IRQ object may be populated later. */ void sysbus_init_irq(SysBusDevice *dev, qemu_irq *p) |