Re: [PATCH 1/1] iommu/amd: Preserve default DTE fields when updating Host Page Table Root

From: Joerg Roedel
Date: Fri Feb 28 2025 - 06:18:30 EST


On Mon, Jan 06, 2025 at 07:14:13PM +0000, Alejandro Jimenez wrote:
> 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 <alejandro.j.jimenez@xxxxxxxxxx>
> ---
> drivers/iommu/amd/iommu.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)

Applied, thanks.