linux-kernel - [PATCH v8 3/7] vfio/type1: bypass unmap/unpin and replay for VFIO_IOVA

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Date:	Thu, 28 Apr 2016 08:28:34 +0000
From:	Eric Auger <eric.auger@...aro.org>
To:	eric.auger@...com, eric.auger@...aro.org, robin.murphy@....com,
	alex.williamson@...hat.com, will.deacon@....com, joro@...tes.org,
	tglx@...utronix.de, jason@...edaemon.net, marc.zyngier@....com,
	christoffer.dall@...aro.org, linux-arm-kernel@...ts.infradead.org
Cc:	patches@...aro.org, linux-kernel@...r.kernel.org,
	Bharat.Bhushan@...escale.com, pranav.sawargaonkar@...il.com,
	p.fedin@...sung.com, iommu@...ts.linux-foundation.org,
	Jean-Philippe.Brucker@....com, julien.grall@....com
Subject: [PATCH v8 3/7] vfio/type1: bypass unmap/unpin and replay for VFIO_IOVA_RESERVED slots

Before allowing the end-user to create VFIO_IOVA_RESERVED dma slots,
let's implement the expected behavior for removal and replay. As opposed
to user dma slots, IOVAs are not systematically bound to PAs and PAs are
not pinned. VFIO just initializes the IOVA "aperture". IOVAs are allocated
outside of the VFIO framework, typically the MSI layer which is
responsible to free and unmap them. The MSI mapping resources are freeed
by the IOMMU driver on domain destruction.

Signed-off-by: Eric Auger <eric.auger@...aro.org>

---

v7 -> v8:
- do no destroy anything anymore, just bypass unmap/unpin and iommu_map
  on replay
---
 drivers/vfio/vfio_iommu_type1.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 2d769d4..94a9916 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -391,7 +391,7 @@ static void vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma)
 	struct vfio_domain *domain, *d;
 	long unlocked = 0;
 
-	if (!dma->size)
+	if (!dma->size || dma->type != VFIO_IOVA_USER)
 		return;
 	/*
 	 * We use the IOMMU to track the physical addresses, otherwise we'd
@@ -727,6 +727,9 @@ static int vfio_iommu_replay(struct vfio_iommu *iommu,
 		dma = rb_entry(n, struct vfio_dma, node);
 		iova = dma->iova;
 
+		if (dma->type == VFIO_IOVA_RESERVED)
+			continue;
+
 		while (iova < dma->iova + dma->size) {
 			phys_addr_t phys = iommu_iova_to_phys(d->domain, iova);
 			size_t size;
-- 
1.9.1