On Fri, Mar 20, 2020 at 11:26:42AM +0100, Laurent Dufour wrote: > The Hcall named H_SVM_* are reserved to the Ultravisor. However, nothing > prevent a malicious VM or SVM to call them. This could lead to weird result > and should be filtered out. > > Checking the Secure bit of the calling MSR ensure that the call is coming > from either the Ultravisor or a SVM. But any system call made from a SVM > are going through the Ultravisor, and the Ultravisor should filter out > these malicious call. This way, only the Ultravisor is able to make such a > Hcall. > > Cc: Bharata B Rao <bharata@xxxxxxxxxxxxx> > Cc: Paul Mackerras <paulus@xxxxxxxxxx> > Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> > Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx> > Signed-off-by: Laurent Dufour <ldufour@xxxxxxxxxxxxx> Reviewed-by: Ram Pai <linuxram@xxxxxxxxxxx> > --- > arch/powerpc/kvm/book3s_hv.c | 32 +++++++++++++++++++++----------- > 1 file changed, 21 insertions(+), 11 deletions(-) >
