On Fri, Mar 31, 2023, Mathias Krause wrote: > Enhance the CR.WP toggling test to do additional tests via the emulator > as these used to trigger bugs when CR0.WP is guest owned. > > Link: https://lore.kernel.org/kvm/ea3a8fbc-2bf8-7442-e498-3e5818384c83@xxxxxxxxxxxxxx/ > Signed-off-by: Mathias Krause <minipli@xxxxxxxxxxxxxx> > --- > x86/access.c | 46 +++++++++++++++++++++++++++++++--------------- > 1 file changed, 31 insertions(+), 15 deletions(-) > > diff --git a/x86/access.c b/x86/access.c > index ae5e7d8e8892..21967434bc18 100644 > --- a/x86/access.c > +++ b/x86/access.c > @@ -1107,27 +1107,43 @@ static int check_write_cr0wp(ac_pt_env_t *pt_env) > * We load CR0.WP with the inverse value of what would be used during > * the access test and toggle EFER.NX to flush and rebuild the current > * MMU context based on that value. > + * > + * This used to trigger a bug in the emulator we try to test via FEP. > */ > + for (;;) { As suggested in patch 2, I'm pretty sure it's easier to use a helper, and have the print statement react to at->flags.
