iommu/vt-d: Make sure IOMMUs are off when intel_iommu=off (161b28aa) · Commits · 戴 / test

When booting into a kexec kernel with intel_iommu=off, and the previous kernel had intel_iommu=on, the IOMMU hardware is still enabled and gets not disabled by the new kernel. This causes the boot to fail because DMA is blocked by the hardware. Disable the IOMMUs when we find it enabled in the kexec kernel and boot with intel_iommu=off. Signed-off-by:

Joerg Roedel <jroedel@suse.de>

drivers/iommu/intel-iommu.c

+17 −1

Original line number	Diff line number	Diff line
		@@ -4730,6 +4730,15 @@ static int intel_iommu_cpu_dead(unsigned int cpu)
		return 0;
		}

		static void intel_disable_iommus(void)
		{
		struct intel_iommu *iommu = NULL;
		struct dmar_drhd_unit *drhd;

		for_each_iommu(iommu, drhd)
		iommu_disable_translation(iommu);
		}

		static inline struct intel_iommu dev_to_intel_iommu(struct device dev)
		{
		return container_of(dev, struct intel_iommu, iommu.dev);
		@@ -4840,8 +4849,15 @@ int __init intel_iommu_init(void)
		goto out_free_dmar;
		}

		if (no_iommu \|\| dmar_disabled)
		if (no_iommu \|\| dmar_disabled) {
		/*
		* Make sure the IOMMUs are switched off, even when we
		* boot into a kexec kernel and the previous kernel left
		* them enabled
		*/
		intel_disable_iommus();
		goto out_free_dmar;
		}

		if (list_empty(&dmar_rmrr_units))
		pr_info("No RMRR found\n");

Admin message