Hey all,
This is the third revision of a patch set implementing an accelerator
for the MSHV kernel driver, exposing HyperV to Linux "Dom0" hosts in various
scenarios. Thank you for the feedback so far. Since the last revision we
incorporated feedback from the last review and identified further areas for
performance fixes, notably in the irqfd handling. I'm looking forward to your
comments.
Best regards,
magnus
Changelog:
v2 => v3
- Addressed code review comments (style)
- Reserve GSI 01-23 for IO-APIC pins (this resolved a problem in which MSI
routes would be overwritten with interrupts from legacy devices, breaking
irqfd notification for virtio-blk queues)
- Guard memory slot table with mutex and RCU mechanism (multiple threads
might access the memory slot table, and in the event of an UNMAPPED_GPA
exit we need to query the table for an unmapped region covering that GPA)
- Include memory slot manager in MshvState
- Produce mshv.h kernel header with ./scripts/update-linux-headers.sh from
linux 6.16 (not all UAPI definitions are defined in the upstream kernel,
hence we ship hw/hyper/hvgdk*.h and hw/hyperv/hvhdk*.h headers)
- Added a QMP command query-mshv (a requirement for integration into
higher-level tooling)
- Removed handling of HALT vm exit, since this is not a supported HV
message any more.
- Added 2 maintainers from Microsoft for the respective file hierarchy
- Added mshv as accelerator option in the documentation
RFC (v1) => v2
- Addressed code review comments (style, consilidation).
- Rewrote the logic that handles overlap-in-userspace mappings to use
a static list of slots, inspired by the HVF accelerator code.
- Fixed a bug that wrote corrupt payload in a MSHV_SET_MSI_ROUTING
call, preventing vhost=on to work on tap network devices.
- Removed an erronous truncation of guest addresses to 32bit when
registering ioeventfd's using MSHV_IOEVENTFD. This resulted in
shadowing of low memory when ioevents were registered with
addresses beyond the 4gb barrier and thus unexpected "unmapped gpa"
vm exits in lower mem regions (impacting io performance).
- Fixed problem in which the MSI routing table was committed for KVM
KVM instead of MSHV in virtio-pci bus initialization.
- Added handler for HLT vm exits.
- The above fixes removed a few limitation present in the previous
revision:
- Guest with machine type "pc" are booting (testing is still mostly
performed with q35)
- Tap network devices can be used with vhost=on option.
- Seabios can be used with >2.75G memory and multiple virtio-pci
devices
- I/O performance improvement as extranous MMIO vm exits are avoided
by registering ioevents with a correct address.
Notes:
- A discrete kernel ioctl "set_immediate_exit" (to avoid a race condition
when handling terminiation signals like ctrl-a x) has been tested and
proven to mitigate the problem. Since other consumers of /dev/mshv have
simular requirements as QEMU, we opted to iterate a bit more on the
respective kernel interface.
Magnus Kulke (25):
accel: Add Meson and config support for MSHV accelerator
target/i386/emulate: Allow instruction decoding from stream
target/i386/mshv: Add x86 decoder/emu implementation
hw/intc: Generalize APIC helper names from kvm_* to accel_*
include/hw/hyperv: Add MSHV ABI header definitions
linux-headers/linux: Add mshv.h headers
accel/mshv: Add accelerator skeleton
accel/mshv: Register memory region listeners
accel/mshv: Initialize VM partition
accel/mshv: Add vCPU creation and execution loop
accel/mshv: Add vCPU signal handling
target/i386/mshv: Add CPU create and remove logic
target/i386/mshv: Implement mshv_store_regs()
target/i386/mshv: Implement mshv_get_standard_regs()
target/i386/mshv: Implement mshv_get_special_regs()
target/i386/mshv: Implement mshv_arch_put_registers()
target/i386/mshv: Set local interrupt controller state
target/i386/mshv: Register CPUID entries with MSHV
target/i386/mshv: Register MSRs with MSHV
target/i386/mshv: Integrate x86 instruction decoder/emulator
target/i386/mshv: Write MSRs to the hypervisor
target/i386/mshv: Implement mshv_vcpu_run()
accel/mshv: Handle overlapping mem mappings
docs: Add mshv to documentation
MAINTAINERS: Add maintainers for mshv accelerator
Praveen K Paladugu (1):
qapi/accel: Allow to query mshv capabilities
MAINTAINERS | 15 +
accel/Kconfig | 3 +
accel/accel-irq.c | 106 ++
accel/meson.build | 3 +-
accel/mshv/irq.c | 397 +++++++
accel/mshv/mem.c | 562 ++++++++++
accel/mshv/meson.build | 9 +
accel/mshv/mshv-all.c | 726 +++++++++++++
accel/mshv/msr.c | 373 +++++++
accel/mshv/trace-events | 30 +
accel/mshv/trace.h | 14 +
docs/devel/codebase.rst | 2 +-
hw/core/machine-qmp-cmds.c | 14 +
hw/intc/apic.c | 8 +
hw/intc/ioapic.c | 20 +-
hw/virtio/virtio-pci.c | 21 +-
include/hw/hyperv/hvgdk.h | 19 +
include/hw/hyperv/hvgdk_mini.h | 864 +++++++++++++++
include/hw/hyperv/hvhdk.h | 164 +++
include/hw/hyperv/hvhdk_mini.h | 105 ++
include/system/accel-irq.h | 37 +
include/system/mshv.h | 195 ++++
linux-headers/linux/mshv.h | 291 ++++++
meson.build | 11 +
meson_options.txt | 2 +
qapi/accelerator.json | 29 +
qemu-options.hx | 16 +-
scripts/meson-buildoptions.sh | 3 +
scripts/update-linux-headers.sh | 2 +-
target/i386/cpu.h | 4 +-
target/i386/emulate/meson.build | 7 +-
target/i386/emulate/x86_decode.c | 27 +-
target/i386/emulate/x86_decode.h | 9 +
target/i386/emulate/x86_emu.c | 3 +-
target/i386/emulate/x86_emu.h | 2 +
target/i386/meson.build | 2 +
target/i386/mshv/meson.build | 8 +
target/i386/mshv/mshv-cpu.c | 1674 ++++++++++++++++++++++++++++++
target/i386/mshv/x86.c | 297 ++++++
39 files changed, 6038 insertions(+), 36 deletions(-)
create mode 100644 accel/accel-irq.c
create mode 100644 accel/mshv/irq.c
create mode 100644 accel/mshv/mem.c
create mode 100644 accel/mshv/meson.build
create mode 100644 accel/mshv/mshv-all.c
create mode 100644 accel/mshv/msr.c
create mode 100644 accel/mshv/trace-events
create mode 100644 accel/mshv/trace.h
create mode 100644 include/hw/hyperv/hvgdk.h
create mode 100644 include/hw/hyperv/hvgdk_mini.h
create mode 100644 include/hw/hyperv/hvhdk.h
create mode 100644 include/hw/hyperv/hvhdk_mini.h
create mode 100644 include/system/accel-irq.h
create mode 100644 include/system/mshv.h
create mode 100644 linux-headers/linux/mshv.h
create mode 100644 target/i386/mshv/meson.build
create mode 100644 target/i386/mshv/mshv-cpu.c
create mode 100644 target/i386/mshv/x86.c
--
2.34.1
