Commit e97685ab authored by Suravee Suthikulpanit's avatar Suravee Suthikulpanit Committed by Joerg Roedel
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iommu/amd: Restore IRTE.RemapEn bit for amd_iommu_activate_guest_mode 



Commit e52d58d5 ("iommu/amd: Use cmpxchg_double() when updating
128-bit IRTE") removed an assumption that modify_irte_ga always set
the valid bit, which requires the callers to set the appropriate value
for the struct irte_ga.valid bit before calling the function.

Similar to the commit 26e495f3 ("iommu/amd: Restore IRTE.RemapEn
bit after programming IRTE"), which is for the function
amd_iommu_deactivate_guest_mode().

The same change is also needed for the amd_iommu_activate_guest_mode().
Otherwise, this could trigger IO_PAGE_FAULT for the VFIO based VMs with
AVIC enabled.

Fixes: e52d58d5 ("iommu/amd: Use cmpxchg_double() when updating 128-bit IRTE")
Reported-by: default avatarMaxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: default avatarSuravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Tested-by: default avatarMaxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: default avatarJoao Martins <joao.m.martins@oracle.com>
Reviewed-by: default avatarMaxim Levitsky <mlevitsk@redhat.com>
Cc: Joao Martins <joao.m.martins@oracle.com>
Link: https://lore.kernel.org/r/20200916111720.43913-1-suravee.suthikulpanit@amd.com


Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 14c4acc5

drivers/iommu/amd/iommu.c

+4 −0
Original line number Diff line number Diff line
@@ -3840,14 +3840,18 @@ int amd_iommu_activate_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;

	u64 valid;



	if (!AMD_IOMMU_GUEST_IR_VAPIC(amd_iommu_guest_ir) ||

	    !entry || entry->lo.fields_vapic.guest_mode)

		return 0;



	valid = entry->lo.fields_vapic.valid;



	entry->lo.val = 0;

	entry->hi.val = 0;



	entry->lo.fields_vapic.valid       = valid;

	entry->lo.fields_vapic.guest_mode  = 1;

	entry->lo.fields_vapic.ga_log_intr = 1;

	entry->hi.fields.ga_root_ptr       = ir_data->ga_root_ptr;