x86/xen: Don't register Xen IPIs when they aren't going to be used

In the case where xen_have_vector_callback is false, we still register
the IPI vectors in xen_smp_intr_init() for the secondary CPUs even
though they aren't going to be used. Stop doing that.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Link: https://lore.kernel.org/r/20210106153958.584169-5-dwmw2@infradead.org
Signed-off-by: Juergen Gross <jgross@suse.com>

diff --git a/arch/x86/xen/enlighten_hvm.c b/arch/x86/xen/enlighten_hvm.c
index ec50b74..e68ea5f 100644 (file)
--- a/arch/x86/xen/enlighten_hvm.c
+++ b/arch/x86/xen/enlighten_hvm.c
@@ -164,10 +164,10 @@ static int xen_cpu_up_prepare_hvm(unsigned int cpu)
        else
                per_cpu(xen_vcpu_id, cpu) = cpu;
        rc = xen_vcpu_setup(cpu);
-       if (rc)
+       if (rc || !xen_have_vector_callback)
                return rc;
 
-       if (xen_have_vector_callback && xen_feature(XENFEAT_hvm_safe_pvclock))
+       if (xen_feature(XENFEAT_hvm_safe_pvclock))
                xen_setup_timer(cpu);
 
        rc = xen_smp_intr_init(cpu);