KVM: x86: WARN_ONCE if sending a PV IPI returns a fatal error

KVM hypercalls return a negative value error code in case of a fatal
error, e.g. when the hypercall isn't supported or was made with invalid
parameters.  WARN_ONCE on fatal errors when sending PV IPIs as any such
error all but guarantees an SMP system will hang due to a missing IPI.

Fixes: aaffcfd1e8 ("KVM: X86: Implement PV IPIs in linux guest")
Cc: stable@vger.kernel.org
Cc: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Sean Christopherson 2019-01-23 09:22:40 -08:00 committed by Paolo Bonzini
parent 1ed199a41c
commit de81c2f912

View File

@ -457,6 +457,7 @@ static void __send_ipi_mask(const struct cpumask *mask, int vector)
#else
u64 ipi_bitmap = 0;
#endif
long ret;
if (cpumask_empty(mask))
return;
@ -482,8 +483,9 @@ static void __send_ipi_mask(const struct cpumask *mask, int vector)
} else if (apic_id < min + KVM_IPI_CLUSTER_SIZE) {
max = apic_id < max ? max : apic_id;
} else {
kvm_hypercall4(KVM_HC_SEND_IPI, (unsigned long)ipi_bitmap,
ret = kvm_hypercall4(KVM_HC_SEND_IPI, (unsigned long)ipi_bitmap,
(unsigned long)(ipi_bitmap >> BITS_PER_LONG), min, icr);
WARN_ONCE(ret < 0, "KVM: failed to send PV IPI: %ld", ret);
min = max = apic_id;
ipi_bitmap = 0;
}
@ -491,8 +493,9 @@ static void __send_ipi_mask(const struct cpumask *mask, int vector)
}
if (ipi_bitmap) {
kvm_hypercall4(KVM_HC_SEND_IPI, (unsigned long)ipi_bitmap,
ret = kvm_hypercall4(KVM_HC_SEND_IPI, (unsigned long)ipi_bitmap,
(unsigned long)(ipi_bitmap >> BITS_PER_LONG), min, icr);
WARN_ONCE(ret < 0, "KVM: failed to send PV IPI: %ld", ret);
}
local_irq_restore(flags);