[PATCH 5.5 149/151] iommu/amd: Fix IOMMU AVIC not properly update the is_run bit in IRTE

From: Greg Kroah-Hartman
Date: Tue Mar 17 2020 - 07:14:02 EST


From: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx>

commit 730ad0ede130015a773229573559e97ba0943065 upstream.

Commit b9c6ff94e43a ("iommu/amd: Re-factor guest virtual APIC
(de-)activation code") accidentally left out the ir_data pointer when
calling modity_irte_ga(), which causes the function amd_iommu_update_ga()
to return prematurely due to struct amd_ir_data.ref is NULL and
the "is_run" bit of IRTE does not get updated properly.

This results in bad I/O performance since IOMMU AVIC always generate GA Log
entry and notify IOMMU driver and KVM when it receives interrupt from the
PCI pass-through device instead of directly inject interrupt to the vCPU.

Fixes by passing ir_data when calling modify_irte_ga() as done previously.

Fixes: b9c6ff94e43a ("iommu/amd: Re-factor guest virtual APIC (de-)activation code")
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx>
Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

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

--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -3836,7 +3836,7 @@ int amd_iommu_activate_guest_mode(void *
entry->lo.fields_vapic.ga_tag = ir_data->ga_tag;

return modify_irte_ga(ir_data->irq_2_irte.devid,
- ir_data->irq_2_irte.index, entry, NULL);
+ ir_data->irq_2_irte.index, entry, ir_data);
}
EXPORT_SYMBOL(amd_iommu_activate_guest_mode);

@@ -3862,7 +3862,7 @@ int amd_iommu_deactivate_guest_mode(void
APICID_TO_IRTE_DEST_HI(cfg->dest_apicid);

return modify_irte_ga(ir_data->irq_2_irte.devid,
- ir_data->irq_2_irte.index, entry, NULL);
+ ir_data->irq_2_irte.index, entry, ir_data);
}
EXPORT_SYMBOL(amd_iommu_deactivate_guest_mode);