qemu/accel/kvm
Gavin Shan fe6bda58e0 kvm: Fix crash due to access uninitialized kvm_state
Runs into core dump on arm64 and the backtrace extracted from the
core dump is shown as below. It's caused by accessing uninitialized
@kvm_state in kvm_flush_coalesced_mmio_buffer() due to commit 176d073029
("hw/arm/virt: Use machine_memory_devices_init()"), where the machine's
memory region is added earlier than before.

    main
    qemu_init
    configure_accelerators
    qemu_opts_foreach
    do_configure_accelerator
    accel_init_machine
    kvm_init
    virt_kvm_type
    virt_set_memmap
    machine_memory_devices_init
    memory_region_add_subregion
    memory_region_add_subregion_common
    memory_region_update_container_subregions
    memory_region_transaction_begin
    qemu_flush_coalesced_mmio_buffer
    kvm_flush_coalesced_mmio_buffer

Fix it by bailing early in kvm_flush_coalesced_mmio_buffer() on the
uninitialized @kvm_state. With this applied, no crash is observed on
arm64.

Fixes: 176d073029 ("hw/arm/virt: Use machine_memory_devices_init()")
Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-id: 20230731125946.2038742-1-gshan@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2023-07-31 14:19:43 +01:00
..
kvm-accel-ops.c gdbstub: move update guest debug to accel ops 2023-03-07 20:44:09 +00:00
kvm-all.c kvm: Fix crash due to access uninitialized kvm_state 2023-07-31 14:19:43 +01:00
kvm-cpus.h gdbstub: Use vaddr type for generic insert/remove_breakpoint() API 2023-02-27 22:29:01 +01:00
meson.build target/i386/kvm: Restrict SEV stubs to x86 architecture 2021-10-13 10:47:49 +02:00
trace-events docs: fix references to docs/devel/tracing.rst 2021-06-02 06:51:09 +02:00
trace.h trace: switch position of headers to what Meson requires 2020-08-21 06:18:24 -04:00