# # requires: arch=amd64 -threaded # r0 = openat$kvm(0, &AUTO='/dev/kvm\x00', 0x0, 0x0) r1 = ioctl$KVM_CREATE_VM(r0, AUTO, 0x0) r2 = syz_kvm_setup_syzos_vm$x86(r1, &(0x7f0000c00000/0x400000)=nil) # Create a nested VM that performs HLT and INVD. # 1. L2 executes HLT -> exit to L1. # 2. L1 disables HLT exiting via vmwrite to CPU_BASED_VM_EXEC_CONTROL. # 3. L1 resumes L2 (RIP still at HLT). # 4. L2 executes HLT (no exit), which is delivered to L0. # 5. L0 resumes L1, which is still running L2. # 6. L2 executes INVD -> exit to L1. # r3 = syz_kvm_add_vcpu$x86(r2, &AUTO={0x0, &AUTO=[@enable_nested={AUTO, AUTO, 0x0}, @nested_create_vm={AUTO, AUTO, 0x0}, @nested_load_code={AUTO, AUTO, {0x0, "f40f08"}}, @nested_vmlaunch={AUTO, AUTO, 0x0}, @nested_intel_vmwrite_mask={AUTO, AUTO, {0x0, @control32=0x4002, 0x0, 0x80, 0x0}}, @nested_vmresume={AUTO, AUTO, 0x0}], AUTO}) r4 = ioctl$KVM_GET_VCPU_MMAP_SIZE(r0, AUTO) r5 = mmap$KVM_VCPU(&(0x7f0000009000/0x1000)=nil, r4, 0x3, 0x1, r3, 0x0) # L2 VM executes HLT. Exit reason is mapped to 0xe2e20001. # ioctl$KVM_RUN(r3, AUTO, 0x0) syz_kvm_assert_syzos_uexit$x86(r3, r5, 0xe2e20001) # L1 disables HLT exiting and resumes L2. L2 resumes at HLT, and breaks out of KVM_RUN. # 0x05 is KVM_EXIT_HLT. # This confirms that the vmwrite command to disable HLT exiting was successful. # ioctl$KVM_RUN(r3, AUTO, 0x0) syz_kvm_assert_syzos_kvm_exit$x86(r5, 0x5) # After resuming, L2 executes INVD. Exit reason is mapped to 0xe2e20002. # ioctl$KVM_RUN(r3, AUTO, 0x0) syz_kvm_assert_syzos_uexit$x86(r3, r5, 0xe2e20002) # guest_main should finish with guest_uexit(-1). # ioctl$KVM_RUN(r3, AUTO, 0x0) syz_kvm_assert_syzos_uexit$x86(r3, r5, 0xffffffffffffffff)