[xen staging] VT-d: correct off-by-1 in fault register range check

[patchbot@xxxxxxx]

commit 08826a044ebfefc429aaecb861dc31051f2bb288
Author:     Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Wed Nov 24 11:12:03 2021 +0100
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Wed Nov 24 11:12:03 2021 +0100

    VT-d: correct off-by-1 in fault register range check
    
    All our present implementation requires is that the range fully fits
    in a single page. No need to exclude the case of the last register
    extending right to the end of that page.
    
    Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
    Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>
---
 xen/drivers/passthrough/vtd/iommu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/xen/drivers/passthrough/vtd/iommu.c 
b/xen/drivers/passthrough/vtd/iommu.c
index dab8590e25..c1bf48cbcb 100644
--- a/xen/drivers/passthrough/vtd/iommu.c
+++ b/xen/drivers/passthrough/vtd/iommu.c
@@ -1273,7 +1273,7 @@ int __init iommu_alloc(struct acpi_drhd_unit *drhd)
     quirk_iommu_caps(iommu);
 
     if ( cap_fault_reg_offset(iommu->cap) +
-         cap_num_fault_regs(iommu->cap) * PRIMARY_FAULT_REG_LEN >= PAGE_SIZE ||
+         cap_num_fault_regs(iommu->cap) * PRIMARY_FAULT_REG_LEN > PAGE_SIZE ||
          ecap_iotlb_offset(iommu->ecap) >= PAGE_SIZE )
     {
         printk(XENLOG_ERR VTDPREFIX "IOMMU: unsupported\n");
--
generated by git-patchbot for /home/xen/git/xen.git#staging