4.20-stable review patch. If anyone has any objections, please let me know.
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From: Sean Christopherson sean.j.christopherson@intel.com
commit 1ed199a41c70ad7bfaee8b14f78e791fcf43b278 upstream.
The recognition of the KVM_HC_SEND_IPI hypercall was unintentionally wrapped in "#ifdef CONFIG_X86_64", causing 32-bit KVM hosts to reject any and all PV IPI requests despite advertising the feature. This results in all KVM paravirtualized guests hanging during SMP boot due to IPIs never being delivered.
Fixes: 4180bf1b655a ("KVM: X86: Implement "send IPI" hypercall") 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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/x86/kvm/x86.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -6997,10 +6997,10 @@ int kvm_emulate_hypercall(struct kvm_vcp case KVM_HC_CLOCK_PAIRING: ret = kvm_pv_clock_pairing(vcpu, a0, a1); break; +#endif case KVM_HC_SEND_IPI: ret = kvm_pv_send_ipi(vcpu->kvm, a0, a1, a2, a3, op_64_bit); break; -#endif default: ret = -KVM_ENOSYS; break;