Assuming this hasn't been abandoned... On Wed, Aug 11, 2021, Maxim Levitsky wrote: > This parameter will be used by VMX and SVM code to force > interception of a set of exceptions, given by a bitmask > for guest debug and/or kvm debug. > > This is based on an idea first shown here: > https://patchwork.kernel.org/project/kvm/patch/20160301192822.GD22677@xxxxxxx/ > > CC: Borislav Petkov <bp@xxxxxxx> > Signed-off-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx> > --- > arch/x86/kvm/x86.c | 3 +++ > arch/x86/kvm/x86.h | 2 ++ > 2 files changed, 5 insertions(+) > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index fdc0c18339fb..092e2fad3c0d 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -184,6 +184,9 @@ module_param(force_emulation_prefix, bool, S_IRUGO); > int __read_mostly pi_inject_timer = -1; > module_param(pi_inject_timer, bint, S_IRUGO | S_IWUSR); > > +uint force_intercept_exceptions_mask; > +module_param(force_intercept_exceptions_mask, uint, S_IRUGO | S_IWUSR); Use octal permissions. This also can't be a simple writable param, at least not without a well-documented disclaimer, as there's no guarantee a vCPU will update its exception bitmap in a timely fashion. An alternative to a module param would be to extend/add a per-VM ioctl(), e.g. maybe KVM_SET_GUEST_DEBUG? The downside of an ioctl() is that it would require userspace enabling :-/
