| Message ID | 20201210142908.169597-1-andre.przywara@arm.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | Unify I/O port and MMIO trap handling | expand |
Hi Andre, On 12/10/20 2:28 PM, Andre Przywara wrote: > At the moment we use two separate code paths to handle exits for > KVM_EXIT_IO (ioport.c) and KVM_EXIT_MMIO (mmio.c), even though they > are semantically very similar. Because the trap handler callback routine > is different, devices need to decide on one conduit or need to provide > different handler functions for both of them. > > This is not only unnecessary code duplication, but makes switching > devices from I/O port to MMIO a tedious task, even though there is no > real difference between the two, especially on ARM and PowerPC. > > For ARM we aim at providing a flexible memory layout, and also have > trouble with the UART and RTC device overlapping with the PCI I/O area, > so it seems indicated to tackle this once and for all. > > The first three patches do some cleanup, to simplify things later. > > Patch 04/21 lays the groundwork, by extending mmio.c to be able to also > register I/O port trap handlers, using the same callback prototype as > we use for MMIO. > > The next 14 patches then convert devices that use the I/O port > interface over to the new joint interface. This requires to rework > the trap handler routine to adhere to the same prototype as the existing > MMIO handlers. For most devices this is done in two steps: a first to > introduce the reworked handler routine, and a second to switch to the new > joint registration routine. For some devices the first step is trivial, > so it's done in one patch. > > Patch 19/21 then retires the old I/O port interface, by removing ioport.c > and friends. > > The final two patches switch the UART and the RTC device over to register > on the MMIO "bus", when running on ARM or arm64. This changes the > addresses to be at 16MB, so they are not in the PCI I/O area anymore. > > Admittedly this goal can be achieved much simpler, by just having the > first three patches, and some more changes and ifdef's in the last two, > but I figured it would be good to clean up the I/O port mess for good. This is a very good idea, I thought more than once as I was working on other things that there really is no reason to differentiate between ioport and mmio emulation. Thanks, Alex > > Please have a look and comment! > > Cheers, > Andre > > Andre Przywara (21): > ioport: Remove ioport__setup_arch() > hw/serial: Use device abstraction for FDT generator function > ioport: Retire .generate_fdt_node functionality > mmio: Extend handling to include ioport emulation > hw/i8042: Clean up data types > hw/i8042: Refactor trap handler > hw/i8042: Switch to new trap handlers > x86/ioport: Refactor trap handlers > x86/ioport: Switch to new trap handlers > hw/rtc: Refactor trap handlers > hw/rtc: Switch to new trap handler > hw/vesa: Switch trap handling to use MMIO handler > hw/serial: Refactor trap handler > hw/serial: Switch to new trap handlers > vfio: Refactor ioport trap handler > vfio: Switch to new ioport trap handlers > virtio: Switch trap handling to use MMIO handler > pci: Switch trap handling to use MMIO handler > Remove ioport specific routines > hw/serial: ARM/arm64: Use MMIO at higher addresses > hw/rtc: ARM/arm64: Use MMIO at higher addresses > > Makefile | 1 - > arm/ioport.c | 5 - > hw/i8042.c | 88 ++++++---------- > hw/rtc.c | 91 ++++++++--------- > hw/serial.c | 166 +++++++++++++++++++----------- > hw/vesa.c | 19 +--- > include/kvm/i8042.h | 1 - > include/kvm/ioport.h | 25 ----- > include/kvm/kvm.h | 42 +++++++- > ioport.c | 235 ------------------------------------------- > mips/kvm.c | 5 - > mmio.c | 59 +++++++++-- > pci.c | 82 +++++---------- > powerpc/ioport.c | 6 -- > vfio/core.c | 50 ++++----- > virtio/pci.c | 42 ++------ > x86/ioport.c | 106 +++++++++---------- > 17 files changed, 385 insertions(+), 638 deletions(-) > delete mode 100644 ioport.c >