[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [xen staging] VT-d: refuse to use IOMMU with reserved CAP.ND value
commit a1545fbf45c689aff39ce76a6eaa609d32ef72a7 Author: Jan Beulich <jbeulich@xxxxxxxx> AuthorDate: Wed Apr 20 10:54:26 2022 +0200 Commit: Jan Beulich <jbeulich@xxxxxxxx> CommitDate: Wed Apr 20 10:54:26 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> --- xen/drivers/passthrough/vtd/iommu.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/xen/drivers/passthrough/vtd/iommu.c b/xen/drivers/passthrough/vtd/iommu.c index 1e309dedf4..657e805987 100644 --- a/xen/drivers/passthrough/vtd/iommu.c +++ b/xen/drivers/passthrough/vtd/iommu.c @@ -1267,8 +1267,11 @@ 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 */ || (has_register_based_invalidation(iommu) && ecap_iotlb_offset(iommu->ecap) >= PAGE_SIZE) ) { @@ -1294,8 +1297,6 @@ int __init iommu_alloc(struct acpi_drhd_unit *drhd) if ( !ecap_coherent(iommu->ecap) ) iommu_non_coherent = true; - nr_dom = cap_ndoms(iommu->cap); - if ( nr_dom <= DOMID_MASK * 2 + cap_caching_mode(iommu->cap) ) { /* Allocate domain id (bit) maps. */ -- generated by git-patchbot for /home/xen/git/xen.git#staging
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