From 92e4beecd36e92d7a628738aa35a31e6781bb4cd Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Fri, 8 Apr 2022 15:24:23 +0200 Subject: [PATCH] VT-d: don't needlessly look up DID MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 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 5ca1d02981..6c06baa939 100644 --- a/xen/drivers/passthrough/vtd/iommu.c +++ b/xen/drivers/passthrough/vtd/iommu.c @@ -1852,18 +1852,12 @@ 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); -- 2.39.5