Commit 730ad0ed authored Mar 12, 2020 by Suravee Suthikulpanit Committed by Joerg Roedel Mar 14, 2020

iommu/amd: Fix IOMMU AVIC not properly update the is_run bit in IRTE



Commit b9c6ff94 ("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: b9c6ff94 ("iommu/amd: Re-factor guest virtual APIC (de-)activation code")
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

parent da72a379

drivers/iommu/amd_iommu.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -3826,7 +3826,7 @@ int amd_iommu_activate_guest_mode(void *data)
		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);

		@@ -3852,7 +3852,7 @@ int amd_iommu_deactivate_guest_mode(void *data)
		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);

Admin message