iommu/amd: Treat per-device exclusion ranges as r/w unity-mapped regions (387caf0b) · Commits · 戴 / test

Some buggy BIOSes might define multiple exclusion ranges of the IVMD entries which are associated with the same IOMMU hardware. This leads to the overwritten exclusion range (exclusion_start and exclusion_length members) in set_device_exclusion_range(). Here is a real case: When attaching two Broadcom RAID controllers to a server, the first one reports the failure during booting (the disks connecting to the RAID controller cannot be detected). This patch prevents the issue by treating per-device exclusion ranges as r/w unity-mapped regions. Discussion: * https://lists.linuxfoundation.org/pipermail/iommu/2019-November/040140.html Suggested-by:

Joerg Roedel <joro@8bytes.org> Signed-off-by:

Adrian Huang <ahuang12@lenovo.com> Signed-off-by:

Joerg Roedel <jroedel@suse.de>

drivers/iommu/amd_iommu_init.c

+10 −10

Original line number	Diff line number	Diff line
		@@ -71,6 +71,8 @@
		#define IVHD_FLAG_ISOC_EN_MASK 0x08

		#define IVMD_FLAG_EXCL_RANGE 0x08
		#define IVMD_FLAG_IW 0x04
		#define IVMD_FLAG_IR 0x02
		#define IVMD_FLAG_UNITY_MAP 0x01

		#define ACPI_DEVFLAG_INITPASS 0x01
		@@ -1121,16 +1123,14 @@ static void __init set_device_exclusion_range(u16 devid, struct ivmd_header *m)
		if (!(m->flags & IVMD_FLAG_EXCL_RANGE))
		return;

		if (iommu) {
		/*
		* We only can configure exclusion ranges per IOMMU, not
		* per device. But we can enable the exclusion range per
		* device. This is done here
		* Treat per-device exclusion ranges as r/w unity-mapped regions
		* since some buggy BIOSes might lead to the overwritten exclusion
		* range (exclusion_start and exclusion_length members). This
		* happens when there are multiple exclusion ranges (IVMD entries)
		* defined in ACPI table.
		*/
		set_dev_entry_bit(devid, DEV_ENTRY_EX);
		iommu->exclusion_start = m->range_start;
		iommu->exclusion_length = m->range_length;
		}
		m->flags = (IVMD_FLAG_IW \| IVMD_FLAG_IR \| IVMD_FLAG_UNITY_MAP);
		}

		/*

Admin message