Commit b74aa02d authored Apr 22, 2020 by Suravee Suthikulpanit Committed by Joerg Roedel May 01, 2020

iommu/amd: Fix legacy interrupt remapping for x2APIC-enabled system



Currently, system fails to boot because the legacy interrupt remapping
mode does not enable 128-bit IRTE (GA), which is required for x2APIC
support.

Fix by using AMD_IOMMU_GUEST_IR_LEGACY_GA mode when booting with
kernel option amd_iommu_intr=legacy instead. The initialization
logic will check GASup and automatically fallback to using
AMD_IOMMU_GUEST_IR_LEGACY if GA mode is not supported.

Fixes: 3928aa3f ("iommu/amd: Detect and enable guest vAPIC support")
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Link: https://lore.kernel.org/r/1587562202-14183-1-git-send-email-suravee.suthikulpanit@amd.com


Signed-off-by: Joerg Roedel <jroedel@suse.de>

parent 9dd124b6

drivers/iommu/amd_iommu_init.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -2936,7 +2936,7 @@ static int __init parse_amd_iommu_intr(char *str)
		{
		for (; *str; ++str) {
		if (strncmp(str, "legacy", 6) == 0) {
		amd_iommu_guest_ir = AMD_IOMMU_GUEST_IR_LEGACY;
		amd_iommu_guest_ir = AMD_IOMMU_GUEST_IR_LEGACY_GA;
		break;
		}
		if (strncmp(str, "vapic", 5) == 0) {

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