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    target/arm: Check supported KVM features globally (not per vCPU) · 7d20e681
    Philippe Mathieu-Daudé 提交于
    Since commit d70c996d, when enabling the PMU we get:
    
      $ qemu-system-aarch64 -cpu host,pmu=on -M virt,accel=kvm,gic-version=3
      Segmentation fault (core dumped)
    
      Thread 1 "qemu-system-aar" received signal SIGSEGV, Segmentation fault.
      0x0000aaaaaae356d0 in kvm_ioctl (s=0x0, type=44547) at accel/kvm/kvm-all.c:2588
      2588        ret = ioctl(s->fd, type, arg);
      (gdb) bt
      #0  0x0000aaaaaae356d0 in kvm_ioctl (s=0x0, type=44547) at accel/kvm/kvm-all.c:2588
      #1  0x0000aaaaaae31568 in kvm_check_extension (s=0x0, extension=126) at accel/kvm/kvm-all.c:916
      #2  0x0000aaaaaafce254 in kvm_arm_pmu_supported (cpu=0xaaaaac214ab0) at target/arm/kvm.c:213
      #3  0x0000aaaaaafc0f94 in arm_set_pmu (obj=0xaaaaac214ab0, value=true, errp=0xffffffffe438) at target/arm/cpu.c:1111
      #4  0x0000aaaaab5533ac in property_set_bool (obj=0xaaaaac214ab0, v=0xaaaaac223a80, name=0xaaaaac11a970 "pmu", opaque=0xaaaaac222730, errp=0xffffffffe438) at qom/object.c:2170
      #5  0x0000aaaaab5512f0 in object_property_set (obj=0xaaaaac214ab0, v=0xaaaaac223a80, name=0xaaaaac11a970 "pmu", errp=0xffffffffe438) at qom/object.c:1328
      #6  0x0000aaaaab551e10 in object_property_parse (obj=0xaaaaac214ab0, string=0xaaaaac11b4c0 "on", name=0xaaaaac11a970 "pmu", errp=0xffffffffe438) at qom/object.c:1561
      #7  0x0000aaaaab54ee8c in object_apply_global_props (obj=0xaaaaac214ab0, props=0xaaaaac018e20, errp=0xaaaaabd6fd88 <error_fatal>) at qom/object.c:407
      #8  0x0000aaaaab1dd5a4 in qdev_prop_set_globals (dev=0xaaaaac214ab0) at hw/core/qdev-properties.c:1218
      #9  0x0000aaaaab1d9fac in device_post_init (obj=0xaaaaac214ab0) at hw/core/qdev.c:1050
      ...
      #15 0x0000aaaaab54f310 in object_initialize_with_type (obj=0xaaaaac214ab0, size=52208, type=0xaaaaabe237f0) at qom/object.c:512
      #16 0x0000aaaaab54fa24 in object_new_with_type (type=0xaaaaabe237f0) at qom/object.c:687
      #17 0x0000aaaaab54fa80 in object_new (typename=0xaaaaabe23970 "host-arm-cpu") at qom/object.c:702
      #18 0x0000aaaaaaf04a74 in machvirt_init (machine=0xaaaaac0a8550) at hw/arm/virt.c:1770
      #19 0x0000aaaaab1e8720 in machine_run_board_init (machine=0xaaaaac0a8550) at hw/core/machine.c:1138
      #20 0x0000aaaaaaf95394 in qemu_init (argc=5, argv=0xffffffffea58, envp=0xffffffffea88) at softmmu/vl.c:4348
      #21 0x0000aaaaaada3f74 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at softmmu/main.c:48
    
    This is because in frame #2, cpu->kvm_state is still NULL
    (the vCPU is not yet realized).
    
    KVM has a hard requirement of all cores supporting the same
    feature set. We only need to check if the accelerator supports
    a feature, not each vCPU individually.
    
    Fix by removing the 'CPUState *cpu' argument from the
    kvm_arm_<FEATURE>_supported() functions.
    
    Fixes: d70c996d ('Use CPUState::kvm_state in kvm_arm_pmu_supported')
    Reported-by: NHaibo Xu <haibo.xu@linaro.org>
    Reviewed-by: NAndrew Jones <drjones@redhat.com>
    Acked-by: NPaolo Bonzini <pbonzini@redhat.com>
    Signed-off-by: NPhilippe Mathieu-Daudé <philmd@redhat.com>
    Suggested-by: NPaolo Bonzini <pbonzini@redhat.com>
    Signed-off-by: NPhilippe Mathieu-Daudé <philmd@redhat.com>
    Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
    7d20e681
kvm_arm.h 12.4 KB