[PATCH 5.8 113/186] iommu/amd: Restore IRTE.RemapEn bit after programming IRTE

From: Greg Kroah-Hartman
Date: Tue Sep 08 2020 - 15:16:21 EST


From: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx>

[ Upstream commit 26e495f341075c09023ba16dee9a7f37a021e745 ]

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

Fixes: b9fc6b56f478 ("iommu/amd: Implements irq_set_vcpu_affinity() hook to setup vapic mode for pass-through devices")
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx>
Reviewed-by: Joao Martins <joao.m.martins@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20200903093822.52012-2-suravee.suthikulpanit@xxxxxxx
Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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 2f22326ee4dfe..d7b037891fb7e 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -3841,6 +3841,7 @@ 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)
@@ -3849,6 +3850,7 @@ 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;
--
2.25.1