From c5b0320bbf79548fbf058a3925a07c8f281beeab Mon Sep 17 00:00:00 2001 From: Alejandro Jimenez Date: Mon, 6 Jan 2025 19:14:13 +0000 Subject: [PATCH] iommu/amd: Preserve default DTE fields when updating Host Page Table Root When updating the page table root field on the DTE, avoid overwriting any bits that are already set. The earlier call to make_clear_dte() writes default values that all DTEs must have set (currently DTE[V]), and those must be preserved. Currently this doesn't cause problems since the page table root update is the first field that is set after make_clear_dte() is called, and DTE_FLAG_V is set again later along with the permission bits (IR/IW). Remove this redundant assignment too. Fixes: fd5dff9de4be ("iommu/amd: Modify set_dte_entry() to use 256-bit DTE helpers") Signed-off-by: Alejandro Jimenez Reviewed-by: Dheeraj Kumar Srivastava Reviewed-by: Vasant Hegde Link: https://lore.kernel.org/r/20250106191413.3107140-1-alejandro.j.jimenez@oracle.com Signed-off-by: Joerg Roedel --- drivers/iommu/amd/iommu.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c index b48a72bd7b23..cd5116d8c3b2 100644 --- a/drivers/iommu/amd/iommu.c +++ b/drivers/iommu/amd/iommu.c @@ -2043,12 +2043,12 @@ static void set_dte_entry(struct amd_iommu *iommu, make_clear_dte(dev_data, dte, &new); if (domain->iop.mode != PAGE_MODE_NONE) - new.data[0] = iommu_virt_to_phys(domain->iop.root); + new.data[0] |= iommu_virt_to_phys(domain->iop.root); new.data[0] |= (domain->iop.mode & DEV_ENTRY_MODE_MASK) << DEV_ENTRY_MODE_SHIFT; - new.data[0] |= DTE_FLAG_IR | DTE_FLAG_IW | DTE_FLAG_V; + new.data[0] |= DTE_FLAG_IR | DTE_FLAG_IW; /* * When SNP is enabled, we can only support TV=1 with non-zero domain ID.