[xen staging-4.20] amd-vi: set the size flag in the IOTLB page invalidation command

[patchbot@xxxxxxx]

commit 4af5ddb42be0a932791fee2a677e471a0d7eb936
Author:     Stefano Stabellini <stefano.stabellini@xxxxxxx>
AuthorDate: Thu Oct 29 13:34:28 2026 +0100
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Thu Oct 29 13:34:28 2026 +0100

    amd-vi: set the size flag in the IOTLB page invalidation command
    
    The S bit of an INVALIDATE_IOTLB_PAGES command selects between the two
    sizes the command can name: cleared, the invalidation covers 4 Kbytes;
    set, it covers the range encoded by the first zero bit of the address,
    counting from bit 12. invalidate_iotlb_pages() builds that encoding
    whenever it is given a non-zero order or the all-pages address, and then
    passes the field's mask where set_field_in_reg_u32() expects the shift.
    The correct mask is 1 and the shift is 0.  When mask (1) is passed for
    both, the value is shifted out of the field it was to occupy and the
    bit is left clear.  i.e. (x << 1) & 1 is always 0.
    
    An endpoint holding translations of its own is therefore told to drop one
    page where it should have dropped a range.  The rest of the range is
    kept in its cache after the page tables backing it have changed.
    
    Pass the shift, as the sibling INVALIDATE_IOMMU_PAGES builder does.
    
    Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxx>
    Reviewed-by: Xenia Ragiadakou <xenia.ragiadakou@xxxxxxx>
    [ Reword commit message. ]
    Signed-off-by: Jason Andryuk <jason.andryuk@xxxxxxx>
    Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
    master commit: 847d34f2329102dc4cd670df239ec41a651b2b48
    master date: 2026-10-27 08:50:22 +0100
---
 xen/drivers/passthrough/amd/iommu_cmd.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/xen/drivers/passthrough/amd/iommu_cmd.c 
b/xen/drivers/passthrough/amd/iommu_cmd.c
index 83c525b84f..8c4ed778d2 100644
--- a/xen/drivers/passthrough/amd/iommu_cmd.c
+++ b/xen/drivers/passthrough/amd/iommu_cmd.c
@@ -212,7 +212,7 @@ static void invalidate_iotlb_pages(struct amd_iommu *iommu,
 
     set_field_in_reg_u32(sflag, 0,
                          IOMMU_INV_IOTLB_PAGES_S_FLAG_MASK,
-                         IOMMU_INV_IOTLB_PAGES_S_FLAG_MASK, &entry);
+                         IOMMU_INV_IOTLB_PAGES_S_FLAG_SHIFT, &entry);
 
     set_field_in_reg_u32((u32)addr_lo >> PAGE_SHIFT, entry,
                          IOMMU_INV_IOTLB_PAGES_ADDR_LOW_MASK,
--
generated by git-patchbot for /home/xen/git/xen.git#staging-4.20