Re: [PATCH v1 3/4] KVM: selftests: Fix pre_fault_memory_test to run on s390

[Claudio Imbrenda]

On Wed, 20 May 2026 08:27:24 -0700
Sean Christopherson <seanjc@xxxxxxxxxx> wrote:

> On Wed, May 20, 2026, Claudio Imbrenda wrote:
> > Add a missing #include <ucall_common.h> which is needed and otherwise
> > not included on s390.
> > 
> > Fence the assertion  vcpu->run->exit_reason == KVM_EXIT_IO  so that it
> > is only checked on x86. On s390 the UCALL will return with a different
> > code.
> > 
> > Signed-off-by: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx>
> > ---
> >  tools/testing/selftests/kvm/pre_fault_memory_test.c | 7 ++++---
> >  1 file changed, 4 insertions(+), 3 deletions(-)
> > 
> > diff --git a/tools/testing/selftests/kvm/pre_fault_memory_test.c b/tools/testing/selftests/kvm/pre_fault_memory_test.c
> > index fcb57fd034e6..42794892e902 100644
> > --- a/tools/testing/selftests/kvm/pre_fault_memory_test.c
> > +++ b/tools/testing/selftests/kvm/pre_fault_memory_test.c
> > @@ -11,6 +11,7 @@
> >  #include <kvm_util.h>
> >  #include <processor.h>
> >  #include <pthread.h>
> > +#include <ucall_common.h>
> >  
> >  /* Arbitrarily chosen values */
> >  #define TEST_SIZE		(SZ_2M + PAGE_SIZE)
> > @@ -167,7 +168,6 @@ static void __test_pre_fault_memory(unsigned long vm_type, bool private)
> >  		.type = vm_type,
> >  	};
> >  	struct kvm_vcpu *vcpu;
> > -	struct kvm_run *run;
> >  	struct kvm_vm *vm;
> >  	struct ucall uc;
> >  
> > @@ -193,10 +193,11 @@ static void __test_pre_fault_memory(unsigned long vm_type, bool private)
> >  	vcpu_args_set(vcpu, 1, gva);
> >  	vcpu_run(vcpu);
> >  
> > -	run = vcpu->run;
> > -	TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
> > +#ifdef __x86_64__  
> 
> I'd say just delete this assertion entirely.  It's an extra layer of paranoia to
> guard against stale ucall data, but x86's ucall_arch_get_ucall() already has
> sufficient guards.

will do, thanks!

> 
> > +	TEST_ASSERT(vcpu->run->exit_reason == KVM_EXIT_IO,
> >  		    "Wanted KVM_EXIT_IO, got exit reason: %u (%s)",
> >  		    run->exit_reason, exit_reason_str(run->exit_reason));
> > +#endif
> >  
> >  	switch (get_ucall(vcpu, &uc)) {
> >  	case UCALL_ABORT:
> > -- 
> > 2.54.0
> >