From: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx> [ Upstream commit b74aa02d7a30ee5e262072a7d6e8deff10b37924 ] 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: 3928aa3f5775 ("iommu/amd: Detect and enable guest vAPIC support") Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx> Link: https://lore.kernel.org/r/1587562202-14183-1-git-send-email-suravee.suthikulpanit@xxxxxxx Signed-off-by: Joerg Roedel <jroedel@xxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/iommu/amd_iommu_init.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c index 4d2920988d607..6c228144b3da5 100644 --- a/drivers/iommu/amd_iommu_init.c +++ b/drivers/iommu/amd_iommu_init.c @@ -2809,7 +2809,7 @@ 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) { -- 2.20.1