Now that the DMA APIs are unified, we move closer and closer to breaking
memory access from the BQL dependency. This series adds an API to
reference/unreference memory regions, which is not really needed only
for BQL-less memory access: the big lock can already be dropped between
address_space_map and the corresponding unmap, and the last patch fixes
potential problems in this area if the DMA destination is hot-unplugged.
Lockless memory access only makes things a bit worse.
Reference counting the region piggybacks on reference counting of a QOM
object, the "owner" of the region. The owner API is designed so that
it will be called as little as possible. Unowned subregions will get a
region if memory_region_set_owner is called after the subregion is added.
This is in general the common case already; often setting the owner can
be delegated to a bus-specific API that already takes a DeviceState
(for example pci_register_bar or sysbus_init_mmio).
As mentioned earlier, I'm not sending a pull request for the previous
part yet. Unplugging a PCI bridge found a reference counting bug in
memory_region_set_owner.
To test this I tried hot-unplug for all PCI devices.
Paolo
v1->v2: fixed reference counting bug in memory_region_set_owner
added sysbus_pass_mmio (patch 6)
moved qemu_ram_addr_from_host_nofail to cputlb.c (patch 15)
Paolo Bonzini (17):
memory: add getter/setter for owner
memory: add ref/unref
memory: add ref/unref calls
exec: add a reference to the region returned by
address_space_translate
pci: set owner for BARs
sysbus: add sysbus_pass_mmio
sysbus: set owner for MMIO regions
acpi: add memory_region_set_owner calls
misc: add memory_region_set_owner calls
isa/portio: allow setting an owner
vga: add memory_region_set_owner calls
pci-assign: add memory_region_set_owner calls
vfio: add memory_region_set_owner calls
exec: check MRU in qemu_ram_addr_from_host
exec: move qemu_ram_addr_from_host_nofail to cputlb.c
memory: return MemoryRegion from qemu_ram_addr_from_host
memory: ref/unref memory across address_space_map/unmap
cputlb.c | 11 +++++
exec.c | 90 +++++++++++++++++++++++------------
hw/acpi/ich9.c | 1 +
hw/acpi/piix4.c | 5 ++
hw/char/serial-pci.c | 1 +
hw/core/loader.c | 1 +
hw/core/sysbus.c | 14 ++++++
hw/cpu/arm11mpcore.c | 2 +-
hw/display/cirrus_vga.c | 19 ++++++--
hw/display/exynos4210_fimd.c | 6 +++
hw/display/framebuffer.c | 12 +++--
hw/display/qxl.c | 6 ++-
hw/display/vga-isa-mm.c | 2 +-
hw/display/vga-isa.c | 4 +-
hw/display/vga-pci.c | 5 +-
hw/display/vga.c | 19 ++++++--
hw/display/vga_int.h | 9 ++--
hw/display/vmware_vga.c | 4 +-
hw/i386/kvm/pci-assign.c | 11 +++++
hw/i386/kvmvapic.c | 1 +
hw/isa/apm.c | 1 +
hw/isa/isa-bus.c | 2 +
hw/misc/pc-testdev.c | 7 +++
hw/misc/vfio.c | 10 ++++
hw/pci/pci.c | 2 +
hw/virtio/dataplane/hostmem.c | 7 +++
hw/virtio/vhost.c | 2 +
hw/virtio/virtio-balloon.c | 1 +
hw/xen/xen_pt.c | 4 ++
include/exec/cpu-common.h | 3 +-
include/exec/ioport.h | 3 ++
include/exec/memory.h | 69 ++++++++++++++++++++++++++-
include/hw/sysbus.h | 1 +
include/hw/virtio/dataplane/hostmem.h | 1 +
ioport.c | 10 ++++
kvm-all.c | 2 +
memory.c | 79 ++++++++++++++++++++++++++++++
target-arm/kvm.c | 2 +
target-i386/kvm.c | 4 +-
target-sparc/mmu_helper.c | 1 +
xen-all.c | 2 +
41 files changed, 372 insertions(+), 64 deletions(-)
--
1.8.1.4
