KVM: x86: WARN_ONCE if sending a PV IPI returns a fatal error (de81c2f9) · Commits · 戴 / test

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: ("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>

arch/x86/kernel/kvm.c

+5 −2

Original line number	Diff line number	Diff line
		@@ -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);

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