KVM_CAP_SET_GUEST_DEBUG should be supported for x86 however it's not declared as supported. My wild guess is that userspaces like QEMU are using "#ifdef KVM_CAP_SET_GUEST_DEBUG" to check for the capability instead, but that could be wrong because the compilation host may not be the runtime host. The userspace might still want to keep the old "#ifdef" though to not break the guest debug on old kernels. Signed-off-by: Peter Xu <peterx@xxxxxxxxxx> --- I also think both ppc and s390 may need similar thing, but I didn't touch them yet because of not confident enough to cover all cases. --- arch/x86/kvm/x86.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index c5835f9cb9ad..ac7b0e6f4000 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3385,6 +3385,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) case KVM_CAP_GET_MSR_FEATURES: case KVM_CAP_MSR_PLATFORM_INFO: case KVM_CAP_EXCEPTION_PAYLOAD: + case KVM_CAP_SET_GUEST_DEBUG: r = 1; break; case KVM_CAP_SYNC_REGS: -- 2.26.2
