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From:   Tianyu Lan <ltykernel@gmail.com>
To:     kys@microsoft.com, haiyangz@microsoft.com, sthemmin@microsoft.com,
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Cc:     Tianyu Lan <Tianyu.Lan@microsoft.com>,
        iommu@lists.linux-foundation.org, linux-arch@vger.kernel.org,
        linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org,
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Subject: [Resend RFC PATCH V2 08/12] UIO/Hyper-V: Not load UIO HV driver in the isolation VM.
Date:   Wed, 14 Apr 2021 10:49:41 -0400
Message-Id: <20210414144945.3460554-9-ltykernel@gmail.com>
In-Reply-To: <20210414144945.3460554-1-ltykernel@gmail.com>
References: <20210414144945.3460554-1-ltykernel@gmail.com>
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From: Tianyu Lan <Tianyu.Lan@microsoft.com>

UIO HV driver should not load in the isolation VM for security reason.
Return ENOTSUPP in the hv_uio_probe() in the isolation VM.

Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
---
 drivers/uio/uio_hv_generic.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/uio/uio_hv_generic.c b/drivers/uio/uio_hv_generic.c
index 0330ba99730e..678b021d66f8 100644
--- a/drivers/uio/uio_hv_generic.c
+++ b/drivers/uio/uio_hv_generic.c
@@ -29,6 +29,7 @@
 #include <linux/hyperv.h>
 #include <linux/vmalloc.h>
 #include <linux/slab.h>
+#include <asm/mshyperv.h>
 
 #include "../hv/hyperv_vmbus.h"
 
@@ -241,6 +242,10 @@ hv_uio_probe(struct hv_device *dev,
 	void *ring_buffer;
 	int ret;
 
+	/* UIO driver should not be loaded in the isolation VM.*/
+	if (hv_is_isolation_supported())
+		return -ENOTSUPP;
+		
 	/* Communicating with host has to be via shared memory not hypercall */
 	if (!channel->offermsg.monitor_allocated) {
 		dev_err(&dev->device, "vmbus channel requires hypercall\n");
-- 
2.25.1