On Thu, Mar 30, 2023, Oliver Upton wrote: > The 'longmode' field is a bit annoying as it blows an entire __u32 to > represent a boolean value. Since other architectures are looking to add > support for KVM_EXIT_HYPERCALL, now is probably a good time to clean it > up. > > Redefine the field (and the remaining padding) as a set of flags. > Preserve the existing ABI by using bit 0 to indicate if the guest was in > long mode and requiring that the remaining 31 bits must be zero. > > Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx> > Cc: Sean Christopherson <seanjc@xxxxxxxxxx> > Signed-off-by: Oliver Upton <oliver.upton@xxxxxxxxx> > --- Acked-by: Sean Christopherson <seanjc@xxxxxxxxxx> > Documentation/virt/kvm/api.rst | 3 +-- > arch/x86/include/asm/kvm_host.h | 7 +++++++ > arch/x86/include/uapi/asm/kvm.h | 3 +++ > arch/x86/kvm/x86.c | 6 +++++- > include/uapi/linux/kvm.h | 9 +++++++-- > 5 files changed, 23 insertions(+), 5 deletions(-) > > diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst > index 62de0768d6aa..9b01e3d0e757 100644 > --- a/Documentation/virt/kvm/api.rst > +++ b/Documentation/virt/kvm/api.rst > @@ -6218,8 +6218,7 @@ to the byte array. > __u64 nr; > __u64 args[6]; > __u64 ret; > - __u32 longmode; > - __u32 pad; > + __u64 flags; > } hypercall; > > Unused. This was once used for 'hypercall to userspace'. To implement Note to self, this needs to be updated as "hypercall" is longer unused.
