https://bugzilla.kernel.org/show_bug.cgi?id=216033 Sean Christopherson (seanjc@xxxxxxxxxx) changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |seanjc@xxxxxxxxxx --- Comment #1 from Sean Christopherson (seanjc@xxxxxxxxxx) --- Ugh, KVM is comically wrong. It _deliberately_ avoids checking CR0/CR4 with a comment saying that "most faulting conditions have already been checked by hardware", but the SDM pseudocode makes it very clear that only the (CR0.PE = 0) or (CR4.VMXE = 0) or (RFLAGS.VM = 1) or (IA32_EFER.LMA = 1 and CS.L = 0) checks are performed before the VM-Exit occurs. /* * The Intel VMX Instruction Reference lists a bunch of bits that are * prerequisite to running VMXON, most notably cr4.VMXE must be set to * 1 (see vmx_is_valid_cr4() for when we allow the guest to set this). * Otherwise, we should fail with #UD. But most faulting conditions * have already been checked by hardware, prior to the VM-exit for * VMXON. We do test guest cr4.VMXE because processor CR4 always has * that bit set to 1 in non-root mode. */ if (!kvm_read_cr4_bits(vcpu, X86_CR4_VMXE)) { kvm_queue_exception(vcpu, UD_VECTOR); return 1; } -- You may reply to this email to add a comment. You are receiving this mail because: You are watching the assignee of the bug.
