From a6902a65160aac72a1889a268fd5f3cebb159d8e Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Fri, 8 Apr 2022 15:20:21 +0200 Subject: [PATCH] VT-d: don't needlessly look up DID MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit If get_iommu_domid() in domain_context_unmap_one() fails, we better wouldn't clear the context entry in the first place, as we're then unable to issue the corresponding flush. However, we have no need to look up the DID in the first place: What needs flushing is very specifically the DID that was in the context entry before our clearing of it. Signed-off-by: Jan Beulich Reviewed-by: Roger Pau Monné master commit: 445ab9852d69d8957467f0036098ebec75fec092 master date: 2022-04-07 12:29:03 +0200 --- xen/drivers/passthrough/vtd/iommu.c | 10 ++-------- 1 file changed, 2 insertions(+), 8 deletions(-) diff --git a/xen/drivers/passthrough/vtd/iommu.c b/xen/drivers/passthrough/vtd/iommu.c index 6571b5dde4..4b0d6a873c 100644 --- a/xen/drivers/passthrough/vtd/iommu.c +++ b/xen/drivers/passthrough/vtd/iommu.c @@ -1821,18 +1821,12 @@ int domain_context_unmap_one( return 0; } + iommu_domid = context_domain_id(*context); + context_clear_present(*context); context_clear_entry(*context); iommu_sync_cache(context, sizeof(struct context_entry)); - iommu_domid = get_iommu_did(domid, iommu, !domain->is_dying); - if ( iommu_domid == -1 ) - { - spin_unlock(&iommu->lock); - unmap_vtd_domain_page(context_entries); - return -EINVAL; - } - rc = iommu_flush_context_device(iommu, iommu_domid, PCI_BDF2(bus, devfn), DMA_CCMD_MASK_NOBIT, 0);