This is a note to let you know that I've just added the patch titled
iommu/amd: Fix legacy interrupt remapping for x2APIC-enabled system
to the 5.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
iommu-amd-fix-legacy-interrupt-remapping-for-x2apic-.patch
and it can be found in the queue-5.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 72b23458c9a220f600ce561458ff6a644e440862
Author: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx>
Date: Wed Apr 22 08:30:02 2020 -0500
iommu/amd: Fix legacy interrupt remapping for x2APIC-enabled system
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@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: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index 6be3853a5d978..2b9a67ecc6ac4 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -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) {
