[PATCH 1/2 v2] iommu: amd: Restore IRTE.RemapEn bit after programming IRTE

From: Suravee Suthikulpanit
Date: Thu Sep 03 2020 - 05:36:41 EST


Currently, the RemapEn (valid) bit is accidentally cleared when
programming IRTE w/ guestMode=0. It should be restored to
the prior state.

Reviewed-by: Joao Martins <joao.m.martins@xxxxxxxxxx>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx>
Fixes: b9fc6b56f478 ("iommu/amd: Implements irq_set_vcpu_affinity() hook to setup vapic mode for pass-through devices")
---
drivers/iommu/amd/iommu.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index ba9f3dbc5b94..967f4e96d1eb 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -3850,6 +3850,7 @@ int amd_iommu_deactivate_guest_mode(void *data)
struct amd_ir_data *ir_data = (struct amd_ir_data *)data;
struct irte_ga *entry = (struct irte_ga *) ir_data->entry;
struct irq_cfg *cfg = ir_data->cfg;
+ u64 valid = entry->lo.fields_remap.valid;

if (!AMD_IOMMU_GUEST_IR_VAPIC(amd_iommu_guest_ir) ||
!entry || !entry->lo.fields_vapic.guest_mode)
@@ -3858,6 +3859,7 @@ int amd_iommu_deactivate_guest_mode(void *data)
entry->lo.val = 0;
entry->hi.val = 0;

+ entry->lo.fields_remap.valid = valid;
entry->lo.fields_remap.dm = apic->irq_dest_mode;
entry->lo.fields_remap.int_type = apic->irq_delivery_mode;
entry->hi.fields.vector = cfg->vector;
--
2.17.1