linux-kernel - [RFC PATCH 05/12] vfio/pci: Support get

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20250107142719.179636-6-yilun.xu@linux.intel.com>
Date: Tue,  7 Jan 2025 22:27:12 +0800
From: Xu Yilun <yilun.xu@...ux.intel.com>
To: kvm@...r.kernel.org,
	dri-devel@...ts.freedesktop.org,
	linux-media@...r.kernel.org,
	linaro-mm-sig@...ts.linaro.org,
	sumit.semwal@...aro.org,
	christian.koenig@....com,
	pbonzini@...hat.com,
	seanjc@...gle.com,
	alex.williamson@...hat.com,
	jgg@...dia.com,
	vivek.kasireddy@...el.com,
	dan.j.williams@...el.com,
	aik@....com
Cc: yilun.xu@...el.com,
	yilun.xu@...ux.intel.com,
	linux-coco@...ts.linux.dev,
	linux-kernel@...r.kernel.org,
	lukas@...ner.de,
	yan.y.zhao@...el.com,
	daniel.vetter@...ll.ch,
	leon@...nel.org,
	baolu.lu@...ux.intel.com,
	zhenzhong.duan@...el.com,
	tao1.su@...el.com
Subject: [RFC PATCH 05/12] vfio/pci: Support get_pfn() callback for dma-buf

Implement get_pfn() callback for exported MMIO resources.

Signed-off-by: Xu Yilun <yilun.xu@...ux.intel.com>
---
 drivers/vfio/pci/dma_buf.c | 30 ++++++++++++++++++++++++++++--
 1 file changed, 28 insertions(+), 2 deletions(-)

diff --git a/drivers/vfio/pci/dma_buf.c b/drivers/vfio/pci/dma_buf.c
index 1d5f46744922..ad12cfb85099 100644
--- a/drivers/vfio/pci/dma_buf.c
+++ b/drivers/vfio/pci/dma_buf.c
@@ -33,8 +33,34 @@ static int vfio_pci_dma_buf_pin(struct dma_buf_attachment *attachment)
 static int vfio_pci_dma_buf_get_pfn(struct dma_buf_attachment *attachment,
 				    pgoff_t pgoff, u64 *pfn, int *max_order)
 {
-	/* TODO */
-	return -EOPNOTSUPP;
+	struct vfio_pci_dma_buf *priv = attachment->dmabuf->priv;
+	struct vfio_region_dma_range *dma_ranges = priv->dma_ranges;
+	u64 offset = pgoff << PAGE_SHIFT;
+	int i;
+
+	dma_resv_assert_held(priv->dmabuf->resv);
+
+	if (priv->revoked)
+		return -ENODEV;
+
+	if (offset >= priv->dmabuf->size)
+		return -EINVAL;
+
+	for (i = 0; i < priv->nr_ranges; i++) {
+		if (offset < dma_ranges[i].length)
+			break;
+
+		offset -= dma_ranges[i].length;
+	}
+
+	*pfn = PHYS_PFN(pci_resource_start(priv->vdev->pdev, dma_ranges[i].region_index) +
+			dma_ranges[i].offset + offset);
+
+	/* TODO: large page mapping is yet to be supported */
+	if (max_order)
+		*max_order = 0;
+
+	return 0;
 }
 
 static void vfio_pci_dma_buf_release(struct dma_buf *dmabuf)
-- 
2.25.1