[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [xen stable-4.16] VT-d: refuse to use IOMMU with reserved CAP.ND value
commit b378ee56c7e0bb5eeb35dcc55b3d29e5f50eb566 Author: Jan Beulich <jbeulich@xxxxxxxx> AuthorDate: Tue Jun 7 13:58:16 2022 +0200 Commit: Jan Beulich <jbeulich@xxxxxxxx> CommitDate: Tue Jun 7 13:58:16 2022 +0200 VT-d: refuse to use IOMMU with reserved CAP.ND value The field taking the value 7 (resulting in 18-bit DIDs when using the calculation in cap_ndoms(), when the DID fields are only 16 bits wide) is reserved. Instead of misbehaving in case we would encounter such an IOMMU, refuse to use it. Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx> Reviewed-by: Roger Pau Monné <roger.pau@xxxxxxxxxx> Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx> master commit: a1545fbf45c689aff39ce76a6eaa609d32ef72a7 master date: 2022-04-20 10:54:26 +0200 --- xen/drivers/passthrough/vtd/iommu.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/xen/drivers/passthrough/vtd/iommu.c b/xen/drivers/passthrough/vtd/iommu.c index 93dd8aa643..8975c1de61 100644 --- a/xen/drivers/passthrough/vtd/iommu.c +++ b/xen/drivers/passthrough/vtd/iommu.c @@ -1279,8 +1279,11 @@ int __init iommu_alloc(struct acpi_drhd_unit *drhd) quirk_iommu_caps(iommu); + nr_dom = cap_ndoms(iommu->cap); + if ( cap_fault_reg_offset(iommu->cap) + cap_num_fault_regs(iommu->cap) * PRIMARY_FAULT_REG_LEN >= PAGE_SIZE || + ((nr_dom - 1) >> 16) /* I.e. cap.nd > 6 */ || ecap_iotlb_offset(iommu->ecap) >= PAGE_SIZE ) { printk(XENLOG_ERR VTDPREFIX "IOMMU: unsupported\n"); @@ -1305,7 +1308,6 @@ int __init iommu_alloc(struct acpi_drhd_unit *drhd) vtd_ops.sync_cache = sync_cache; /* allocate domain id bitmap */ - nr_dom = cap_ndoms(iommu->cap); iommu->domid_bitmap = xzalloc_array(unsigned long, BITS_TO_LONGS(nr_dom)); if ( !iommu->domid_bitmap ) return -ENOMEM; -- generated by git-patchbot for /home/xen/git/xen.git#stable-4.16
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