From: Suravee Suthikulpanit suravee.suthikulpanit@amd.com
commit b74aa02d7a30ee5e262072a7d6e8deff10b37924 upstream.
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@amd.com Link: https://lore.kernel.org/r/1587562202-14183-1-git-send-email-suravee.suthikul... Signed-off-by: Joerg Roedel jroedel@suse.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/iommu/amd_iommu_init.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/iommu/amd_iommu_init.c +++ b/drivers/iommu/amd_iommu_init.c @@ -2836,7 +2836,7 @@ static int __init parse_amd_iommu_intr(c { 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) {