x86/hyper-v: Fix the circular dependency in IPI enlightenment

The IPI hypercalls depend on being able to map the Linux notion of CPU ID
to the hypervisor's notion of the CPU ID. The array hv_vp_index[] provides
this mapping. Code for populating this array depends on the IPI functionality.
Break this circular dependency.

[ tglx: Use a proper define instead of '-1' with a u32 variable as pointed
  	out by Vitaly ]

Fixes: 68bb7bfb7985 ("X86/Hyper-V: Enable IPI enlightenments")
Signed-off-by: K. Y. Srinivasan <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Tested-by: Michael Kelley <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]

1 files changed, 5 insertions, 0 deletions

diff --git a/arch/x86/hyperv/hv_apic.c b/arch/x86/hyperv/hv_apic.c
index f68855499391..402338365651 100644
--- a/arch/x86/hyperv/hv_apic.c
+++ b/arch/x86/hyperv/hv_apic.c
@@ -114,6 +114,8 @@ static bool __send_ipi_mask_ex(const struct cpumask *mask, int vector)
 		ipi_arg->vp_set.format = HV_GENERIC_SET_SPARSE_4K;
 		nr_bank = cpumask_to_vpset(&(ipi_arg->vp_set), mask);
 	}
+	if (nr_bank < 0)
+		goto ipi_mask_ex_done;
 	if (!nr_bank)
 		ipi_arg->vp_set.format = HV_GENERIC_SET_ALL;
 
@@ -158,6 +160,9 @@ static bool __send_ipi_mask(const struct cpumask *mask, int vector)
 
 	for_each_cpu(cur_cpu, mask) {
 		vcpu = hv_cpu_number_to_vp_number(cur_cpu);
+		if (vcpu == VP_INVAL)
+			goto ipi_mask_done;
+
 		/*
 		 * This particular version of the IPI hypercall can
 		 * only target upto 64 CPUs.