From e97685abd5d711c885053d4949178f7ab9acbaef Mon Sep 17 00:00:00 2001 From: Suravee Suthikulpanit Date: Wed, 16 Sep 2020 11:17:20 +0000 Subject: iommu/amd: Restore IRTE.RemapEn bit for amd_iommu_activate_guest_mode Commit e52d58d54a32 ("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 26e495f34107 ("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: e52d58d54a321 ("iommu/amd: Use cmpxchg_double() when updating 128-bit IRTE") Reported-by: Maxim Levitsky Signed-off-by: Suravee Suthikulpanit Tested-by: Maxim Levitsky Reviewed-by: Joao Martins Reviewed-by: Maxim Levitsky Cc: Joao Martins Link: https://lore.kernel.org/r/20200916111720.43913-1-suravee.suthikulpanit@amd.com Signed-off-by: Joerg Roedel --- drivers/iommu/amd/iommu.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'drivers/iommu') diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c index 8abe1c7ad45b..10e4200d3552 100644 --- a/drivers/iommu/amd/iommu.c +++ b/drivers/iommu/amd/iommu.c @@ -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; -- cgit v1.2.3