Patch "iommu/amd: Fix interrupt remapping when disable guest_mode" has been added to the 4.11-stable tree

This is a note to let you know that I've just added the patch titled

iommu/amd: Fix interrupt remapping when disable guest_mode

to the 4.11-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-interrupt-remapping-when-disable-guest_mode.patch
and it can be found in the queue-4.11 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Suravee Suthikulpanit <[email protected]>
Date: Mon, 26 Jun 2017 04:28:04 -0500
Subject: iommu/amd: Fix interrupt remapping when disable guest_mode

From: Suravee Suthikulpanit <[email protected]>

commit 84a21dbdef0b96d773599c33c2afbb002198d303 upstream.

Pass-through devices to VM guest can get updated IRQ affinity information via irq_set_affinity() when not running in guest mode. Currently, AMD IOMMU driver in GA mode ignores the updated information if the pass-through device is setup to use vAPIC regardless of guest_mode. This could cause invalid interrupt remapping.

Also, the guest_mode bit should be set and cleared only when SVM updates posted-interrupt interrupt remapping information.

---
 drivers/iommu/amd_iommu.c |    6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

@@ -3879,11 +3879,9 @@ static void irte_ga_prepare(void *entry,
 			    u8 vector, u32 dest_apicid, int devid)
 {
 	struct irte_ga *irte = (struct irte_ga *) entry;
-	struct iommu_dev_data *dev_data = search_dev_data(devid);
 
 	irte->lo.val                      = 0;
 	irte->hi.val                      = 0;
-	irte->lo.fields_remap.guest_mode  = dev_data ? dev_data->use_vapic : 0;
 	irte->lo.fields_remap.int_type    = delivery_mode;
 	irte->lo.fields_remap.dm          = dest_mode;
 	irte->hi.fields.vector            = vector;

@@ -3939,10 +3937,10 @@ static void irte_ga_set_affinity(void *e
 	struct irte_ga *irte = (struct irte_ga *) entry;
 	struct iommu_dev_data *dev_data = search_dev_data(devid);
 
-	if (!dev_data || !dev_data->use_vapic) {
+	if (!dev_data || !dev_data->use_vapic ||
+	    !irte->lo.fields_remap.guest_mode) {
 		irte->hi.fields.vector = vector;
 		irte->lo.fields_remap.destination = dest_apicid;
-		irte->lo.fields_remap.guest_mode = 0;
 		modify_irte_ga(devid, index, irte, NULL);
 	}
 }

Patches currently in stable-queue which might be from [email protected] are

queue-4.11/iommu-amd-fix-interrupt-remapping-when-disable-guest_mode.patch