From 66200bbcde697dea7f48071d325ea4dec6f66b11 Mon Sep 17 00:00:00 2001
From: Michael Kelley <mikelley@microsoft.com>
Date: Tue, 12 Apr 2022 19:49:00 -0700
Subject: Drivers: hv: vmbus: Add VMbus IMC device to unsupported list

Hyper-V may offer an Initial Machine Configuration (IMC) synthetic
device to guest VMs. The device may be used by Windows guests to get
specialization information, such as the hostname.  But the device
is not used in Linux and there is no Linux driver, so it is
unsupported.

Currently, the IMC device GUID is not recognized by the VMbus driver,
which results in an "Unknown GUID" error message during boot. Add
the GUID to the list of known but unsupported devices so that the
error message is not generated. Other than avoiding the error message,
there is no change in guest behavior.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1649818140-100953-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
---
 include/linux/hyperv.h | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

(limited to 'include')

diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index fe2e0179ed51..2d085d951ee4 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -1451,12 +1451,14 @@ void vmbus_free_mmio(resource_size_t start, resource_size_t size);
 			  0x80, 0x2e, 0x27, 0xed, 0xe1, 0x9f)
 
 /*
- * Linux doesn't support the 3 devices: the first two are for
- * Automatic Virtual Machine Activation, and the third is for
- * Remote Desktop Virtualization.
+ * Linux doesn't support these 4 devices: the first two are for
+ * Automatic Virtual Machine Activation, the third is for
+ * Remote Desktop Virtualization, and the fourth is Initial
+ * Machine Configuration (IMC) used only by Windows guests.
  * {f8e65716-3cb3-4a06-9a60-1889c5cccab5}
  * {3375baf4-9e15-4b30-b765-67acb10d607b}
  * {276aacf4-ac15-426c-98dd-7521ad3f01fe}
+ * {c376c1c3-d276-48d2-90a9-c04748072c60}
  */
 
 #define HV_AVMA1_GUID \
@@ -1471,6 +1473,10 @@ void vmbus_free_mmio(resource_size_t start, resource_size_t size);
 	.guid = GUID_INIT(0x276aacf4, 0xac15, 0x426c, 0x98, 0xdd, \
 			  0x75, 0x21, 0xad, 0x3f, 0x01, 0xfe)
 
+#define HV_IMC_GUID \
+	.guid = GUID_INIT(0xc376c1c3, 0xd276, 0x48d2, 0x90, 0xa9, \
+			  0xc0, 0x47, 0x48, 0x07, 0x2c, 0x60)
+
 /*
  * Common header for Hyper-V ICs
  */
-- 
cgit v1.2.3


From b03afa57c65e1e045e02df49777e953742745f4c Mon Sep 17 00:00:00 2001
From: "Andrea Parri (Microsoft)" <parri.andrea@gmail.com>
Date: Tue, 19 Apr 2022 14:23:22 +0200
Subject: Drivers: hv: vmbus: Introduce vmbus_sendpacket_getid()

The function can be used to send a VMbus packet and retrieve the
corresponding transaction ID.  It will be used by hv_pci.

No functional change.

Suggested-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20220419122325.10078-4-parri.andrea@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
---
 drivers/hv/channel.c      | 38 ++++++++++++++++++++++++++++++++------
 drivers/hv/hyperv_vmbus.h |  2 +-
 drivers/hv/ring_buffer.c  | 14 +++++++++++---
 include/linux/hyperv.h    |  7 +++++++
 4 files changed, 51 insertions(+), 10 deletions(-)

(limited to 'include')

diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index 20fc8d50a039..585a8084848b 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -1022,11 +1022,13 @@ void vmbus_close(struct vmbus_channel *channel)
 EXPORT_SYMBOL_GPL(vmbus_close);
 
 /**
- * vmbus_sendpacket() - Send the specified buffer on the given channel
+ * vmbus_sendpacket_getid() - Send the specified buffer on the given channel
  * @channel: Pointer to vmbus_channel structure
  * @buffer: Pointer to the buffer you want to send the data from.
  * @bufferlen: Maximum size of what the buffer holds.
  * @requestid: Identifier of the request
+ * @trans_id: Identifier of the transaction associated to this request, if
+ *            the send is successful; undefined, otherwise.
  * @type: Type of packet that is being sent e.g. negotiate, time
  *	  packet etc.
  * @flags: 0 or VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED
@@ -1036,8 +1038,8 @@ EXPORT_SYMBOL_GPL(vmbus_close);
  *
  * Mainly used by Hyper-V drivers.
  */
-int vmbus_sendpacket(struct vmbus_channel *channel, void *buffer,
-			   u32 bufferlen, u64 requestid,
+int vmbus_sendpacket_getid(struct vmbus_channel *channel, void *buffer,
+			   u32 bufferlen, u64 requestid, u64 *trans_id,
 			   enum vmbus_packet_type type, u32 flags)
 {
 	struct vmpacket_descriptor desc;
@@ -1063,7 +1065,31 @@ int vmbus_sendpacket(struct vmbus_channel *channel, void *buffer,
 	bufferlist[2].iov_base = &aligned_data;
 	bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 
-	return hv_ringbuffer_write(channel, bufferlist, num_vecs, requestid);
+	return hv_ringbuffer_write(channel, bufferlist, num_vecs, requestid, trans_id);
+}
+EXPORT_SYMBOL(vmbus_sendpacket_getid);
+
+/**
+ * vmbus_sendpacket() - Send the specified buffer on the given channel
+ * @channel: Pointer to vmbus_channel structure
+ * @buffer: Pointer to the buffer you want to send the data from.
+ * @bufferlen: Maximum size of what the buffer holds.
+ * @requestid: Identifier of the request
+ * @type: Type of packet that is being sent e.g. negotiate, time
+ *	  packet etc.
+ * @flags: 0 or VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED
+ *
+ * Sends data in @buffer directly to Hyper-V via the vmbus.
+ * This will send the data unparsed to Hyper-V.
+ *
+ * Mainly used by Hyper-V drivers.
+ */
+int vmbus_sendpacket(struct vmbus_channel *channel, void *buffer,
+		     u32 bufferlen, u64 requestid,
+		     enum vmbus_packet_type type, u32 flags)
+{
+	return vmbus_sendpacket_getid(channel, buffer, bufferlen,
+				      requestid, NULL, type, flags);
 }
 EXPORT_SYMBOL(vmbus_sendpacket);
 
@@ -1122,7 +1148,7 @@ int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel,
 	bufferlist[2].iov_base = &aligned_data;
 	bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 
-	return hv_ringbuffer_write(channel, bufferlist, 3, requestid);
+	return hv_ringbuffer_write(channel, bufferlist, 3, requestid, NULL);
 }
 EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer);
 
@@ -1160,7 +1186,7 @@ int vmbus_sendpacket_mpb_desc(struct vmbus_channel *channel,
 	bufferlist[2].iov_base = &aligned_data;
 	bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 
-	return hv_ringbuffer_write(channel, bufferlist, 3, requestid);
+	return hv_ringbuffer_write(channel, bufferlist, 3, requestid, NULL);
 }
 EXPORT_SYMBOL_GPL(vmbus_sendpacket_mpb_desc);
 
diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
index 6b45c22bb717..4f5b824b16cf 100644
--- a/drivers/hv/hyperv_vmbus.h
+++ b/drivers/hv/hyperv_vmbus.h
@@ -181,7 +181,7 @@ void hv_ringbuffer_cleanup(struct hv_ring_buffer_info *ring_info);
 
 int hv_ringbuffer_write(struct vmbus_channel *channel,
 			const struct kvec *kv_list, u32 kv_count,
-			u64 requestid);
+			u64 requestid, u64 *trans_id);
 
 int hv_ringbuffer_read(struct vmbus_channel *channel,
 		       void *buffer, u32 buflen, u32 *buffer_actual_len,
diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c
index 3d215d9dec43..e101b11f95e5 100644
--- a/drivers/hv/ring_buffer.c
+++ b/drivers/hv/ring_buffer.c
@@ -283,7 +283,7 @@ void hv_ringbuffer_cleanup(struct hv_ring_buffer_info *ring_info)
 /* Write to the ring buffer. */
 int hv_ringbuffer_write(struct vmbus_channel *channel,
 			const struct kvec *kv_list, u32 kv_count,
-			u64 requestid)
+			u64 requestid, u64 *trans_id)
 {
 	int i;
 	u32 bytes_avail_towrite;
@@ -294,7 +294,7 @@ int hv_ringbuffer_write(struct vmbus_channel *channel,
 	unsigned long flags;
 	struct hv_ring_buffer_info *outring_info = &channel->outbound;
 	struct vmpacket_descriptor *desc = kv_list[0].iov_base;
-	u64 rqst_id = VMBUS_NO_RQSTOR;
+	u64 __trans_id, rqst_id = VMBUS_NO_RQSTOR;
 
 	if (channel->rescind)
 		return -ENODEV;
@@ -353,7 +353,15 @@ int hv_ringbuffer_write(struct vmbus_channel *channel,
 		}
 	}
 	desc = hv_get_ring_buffer(outring_info) + old_write;
-	desc->trans_id = (rqst_id == VMBUS_NO_RQSTOR) ? requestid : rqst_id;
+	__trans_id = (rqst_id == VMBUS_NO_RQSTOR) ? requestid : rqst_id;
+	/*
+	 * Ensure the compiler doesn't generate code that reads the value of
+	 * the transaction ID from the ring buffer, which is shared with the
+	 * Hyper-V host and subject to being changed at any time.
+	 */
+	WRITE_ONCE(desc->trans_id, __trans_id);
+	if (trans_id)
+		*trans_id = __trans_id;
 
 	/* Set previous packet start */
 	prev_indices = hv_get_ring_bufferindices(outring_info);
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index 2d085d951ee4..7cb8718825ee 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -1161,6 +1161,13 @@ extern int vmbus_open(struct vmbus_channel *channel,
 
 extern void vmbus_close(struct vmbus_channel *channel);
 
+extern int vmbus_sendpacket_getid(struct vmbus_channel *channel,
+				  void *buffer,
+				  u32 bufferLen,
+				  u64 requestid,
+				  u64 *trans_id,
+				  enum vmbus_packet_type type,
+				  u32 flags);
 extern int vmbus_sendpacket(struct vmbus_channel *channel,
 				  void *buffer,
 				  u32 bufferLen,
-- 
cgit v1.2.3


From 0aadb6a7bb811554cf39318b5d18e8ec50dd9f02 Mon Sep 17 00:00:00 2001
From: "Andrea Parri (Microsoft)" <parri.andrea@gmail.com>
Date: Tue, 19 Apr 2022 14:23:23 +0200
Subject: Drivers: hv: vmbus: Introduce vmbus_request_addr_match()

The function can be used to retrieve and clear/remove a transation ID
from a channel requestor, provided the memory address corresponding to
the ID equals a specified address.  The function, and its 'lockless'
variant __vmbus_request_addr_match(), will be used by hv_pci.

Refactor vmbus_request_addr() to reuse the 'newly' introduced code.

No functional change.

Suggested-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20220419122325.10078-5-parri.andrea@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
---
 drivers/hv/channel.c   | 65 ++++++++++++++++++++++++++++++++++++--------------
 include/linux/hyperv.h |  5 ++++
 2 files changed, 52 insertions(+), 18 deletions(-)

(limited to 'include')

diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index 585a8084848b..49f10a603a09 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -1279,17 +1279,11 @@ u64 vmbus_next_request_id(struct vmbus_channel *channel, u64 rqst_addr)
 }
 EXPORT_SYMBOL_GPL(vmbus_next_request_id);
 
-/*
- * vmbus_request_addr - Returns the memory address stored at @trans_id
- * in @rqstor. Uses a spin lock to avoid race conditions.
- * @channel: Pointer to the VMbus channel struct
- * @trans_id: Request id sent back from Hyper-V. Becomes the requestor's
- * next request id.
- */
-u64 vmbus_request_addr(struct vmbus_channel *channel, u64 trans_id)
+/* As in vmbus_request_addr_match() but without the requestor lock */
+u64 __vmbus_request_addr_match(struct vmbus_channel *channel, u64 trans_id,
+			       u64 rqst_addr)
 {
 	struct vmbus_requestor *rqstor = &channel->requestor;
-	unsigned long flags;
 	u64 req_addr;
 
 	/* Check rqstor has been initialized */
@@ -1300,25 +1294,60 @@ u64 vmbus_request_addr(struct vmbus_channel *channel, u64 trans_id)
 	if (!trans_id)
 		return VMBUS_RQST_ERROR;
 
-	spin_lock_irqsave(&rqstor->req_lock, flags);
-
 	/* Data corresponding to trans_id is stored at trans_id - 1 */
 	trans_id--;
 
 	/* Invalid trans_id */
-	if (trans_id >= rqstor->size || !test_bit(trans_id, rqstor->req_bitmap)) {
-		spin_unlock_irqrestore(&rqstor->req_lock, flags);
+	if (trans_id >= rqstor->size || !test_bit(trans_id, rqstor->req_bitmap))
 		return VMBUS_RQST_ERROR;
-	}
 
 	req_addr = rqstor->req_arr[trans_id];
-	rqstor->req_arr[trans_id] = rqstor->next_request_id;
-	rqstor->next_request_id = trans_id;
+	if (rqst_addr == VMBUS_RQST_ADDR_ANY || req_addr == rqst_addr) {
+		rqstor->req_arr[trans_id] = rqstor->next_request_id;
+		rqstor->next_request_id = trans_id;
 
-	/* The already held spin lock provides atomicity */
-	bitmap_clear(rqstor->req_bitmap, trans_id, 1);
+		/* The already held spin lock provides atomicity */
+		bitmap_clear(rqstor->req_bitmap, trans_id, 1);
+	}
+
+	return req_addr;
+}
+EXPORT_SYMBOL_GPL(__vmbus_request_addr_match);
+
+/*
+ * vmbus_request_addr_match - Clears/removes @trans_id from the @channel's
+ * requestor, provided the memory address stored at @trans_id equals @rqst_addr
+ * (or provided @rqst_addr matches the sentinel value VMBUS_RQST_ADDR_ANY).
+ *
+ * Returns the memory address stored at @trans_id, or VMBUS_RQST_ERROR if
+ * @trans_id is not contained in the requestor.
+ *
+ * Acquires and releases the requestor spin lock.
+ */
+u64 vmbus_request_addr_match(struct vmbus_channel *channel, u64 trans_id,
+			     u64 rqst_addr)
+{
+	struct vmbus_requestor *rqstor = &channel->requestor;
+	unsigned long flags;
+	u64 req_addr;
 
+	spin_lock_irqsave(&rqstor->req_lock, flags);
+	req_addr = __vmbus_request_addr_match(channel, trans_id, rqst_addr);
 	spin_unlock_irqrestore(&rqstor->req_lock, flags);
+
 	return req_addr;
 }
+EXPORT_SYMBOL_GPL(vmbus_request_addr_match);
+
+/*
+ * vmbus_request_addr - Returns the memory address stored at @trans_id
+ * in @rqstor. Uses a spin lock to avoid race conditions.
+ * @channel: Pointer to the VMbus channel struct
+ * @trans_id: Request id sent back from Hyper-V. Becomes the requestor's
+ * next request id.
+ */
+u64 vmbus_request_addr(struct vmbus_channel *channel, u64 trans_id)
+{
+	return vmbus_request_addr_match(channel, trans_id, VMBUS_RQST_ADDR_ANY);
+}
 EXPORT_SYMBOL_GPL(vmbus_request_addr);
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index 7cb8718825ee..2e4962a2fbec 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -788,6 +788,7 @@ struct vmbus_requestor {
 
 #define VMBUS_NO_RQSTOR U64_MAX
 #define VMBUS_RQST_ERROR (U64_MAX - 1)
+#define VMBUS_RQST_ADDR_ANY U64_MAX
 /* NetVSC-specific */
 #define VMBUS_RQST_ID_NO_RESPONSE (U64_MAX - 2)
 /* StorVSC-specific */
@@ -1042,6 +1043,10 @@ struct vmbus_channel {
 };
 
 u64 vmbus_next_request_id(struct vmbus_channel *channel, u64 rqst_addr);
+u64 __vmbus_request_addr_match(struct vmbus_channel *channel, u64 trans_id,
+			       u64 rqst_addr);
+u64 vmbus_request_addr_match(struct vmbus_channel *channel, u64 trans_id,
+			     u64 rqst_addr);
 u64 vmbus_request_addr(struct vmbus_channel *channel, u64 trans_id);
 
 static inline bool is_hvsock_channel(const struct vmbus_channel *c)
-- 
cgit v1.2.3


From b91eaf7267cf7aec0a4e087decf7770dfb694d78 Mon Sep 17 00:00:00 2001
From: "Andrea Parri (Microsoft)" <parri.andrea@gmail.com>
Date: Tue, 19 Apr 2022 14:23:24 +0200
Subject: Drivers: hv: vmbus: Introduce {lock,unlock}_requestor()

To abtract the lock and unlock operations on the requestor spin lock.
The helpers will come in handy in hv_pci.

No functional change.

Suggested-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20220419122325.10078-6-parri.andrea@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
---
 drivers/hv/channel.c   | 11 +++++------
 include/linux/hyperv.h | 15 +++++++++++++++
 2 files changed, 20 insertions(+), 6 deletions(-)

(limited to 'include')

diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index 49f10a603a09..56f7e06c673e 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -1252,12 +1252,12 @@ u64 vmbus_next_request_id(struct vmbus_channel *channel, u64 rqst_addr)
 	if (!channel->rqstor_size)
 		return VMBUS_NO_RQSTOR;
 
-	spin_lock_irqsave(&rqstor->req_lock, flags);
+	lock_requestor(channel, flags);
 	current_id = rqstor->next_request_id;
 
 	/* Requestor array is full */
 	if (current_id >= rqstor->size) {
-		spin_unlock_irqrestore(&rqstor->req_lock, flags);
+		unlock_requestor(channel, flags);
 		return VMBUS_RQST_ERROR;
 	}
 
@@ -1267,7 +1267,7 @@ u64 vmbus_next_request_id(struct vmbus_channel *channel, u64 rqst_addr)
 	/* The already held spin lock provides atomicity */
 	bitmap_set(rqstor->req_bitmap, current_id, 1);
 
-	spin_unlock_irqrestore(&rqstor->req_lock, flags);
+	unlock_requestor(channel, flags);
 
 	/*
 	 * Cannot return an ID of 0, which is reserved for an unsolicited
@@ -1327,13 +1327,12 @@ EXPORT_SYMBOL_GPL(__vmbus_request_addr_match);
 u64 vmbus_request_addr_match(struct vmbus_channel *channel, u64 trans_id,
 			     u64 rqst_addr)
 {
-	struct vmbus_requestor *rqstor = &channel->requestor;
 	unsigned long flags;
 	u64 req_addr;
 
-	spin_lock_irqsave(&rqstor->req_lock, flags);
+	lock_requestor(channel, flags);
 	req_addr = __vmbus_request_addr_match(channel, trans_id, rqst_addr);
-	spin_unlock_irqrestore(&rqstor->req_lock, flags);
+	unlock_requestor(channel, flags);
 
 	return req_addr;
 }
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index 2e4962a2fbec..460a716f4748 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -1042,6 +1042,21 @@ struct vmbus_channel {
 	u32 max_pkt_size;
 };
 
+#define lock_requestor(channel, flags)					\
+do {									\
+	struct vmbus_requestor *rqstor = &(channel)->requestor;		\
+									\
+	spin_lock_irqsave(&rqstor->req_lock, flags);			\
+} while (0)
+
+static __always_inline void unlock_requestor(struct vmbus_channel *channel,
+					     unsigned long flags)
+{
+	struct vmbus_requestor *rqstor = &channel->requestor;
+
+	spin_unlock_irqrestore(&rqstor->req_lock, flags);
+}
+
 u64 vmbus_next_request_id(struct vmbus_channel *channel, u64 rqst_addr);
 u64 __vmbus_request_addr_match(struct vmbus_channel *channel, u64 trans_id,
 			       u64 rqst_addr);
-- 
cgit v1.2.3


From dbde6d0c7a5a462a1767a07c28eadd2c3dd08fb2 Mon Sep 17 00:00:00 2001
From: "Andrea Parri (Microsoft)" <parri.andrea@gmail.com>
Date: Thu, 28 Apr 2022 16:51:05 +0200
Subject: hv_sock: Add validation for untrusted Hyper-V values

For additional robustness in the face of Hyper-V errors or malicious
behavior, validate all values that originate from packets that Hyper-V
has sent to the guest in the host-to-guest ring buffer.  Ensure that
invalid values cannot cause data being copied out of the bounds of the
source buffer in hvs_stream_dequeue().

Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://lore.kernel.org/r/20220428145107.7878-4-parri.andrea@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
---
 include/linux/hyperv.h           |  5 +++++
 net/vmw_vsock/hyperv_transport.c | 10 ++++++++--
 2 files changed, 13 insertions(+), 2 deletions(-)

(limited to 'include')

diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index 460a716f4748..a01c9fd0a334 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -1696,6 +1696,11 @@ static inline u32 hv_pkt_datalen(const struct vmpacket_descriptor *desc)
 	return (desc->len8 << 3) - (desc->offset8 << 3);
 }
 
+/* Get packet length associated with descriptor */
+static inline u32 hv_pkt_len(const struct vmpacket_descriptor *desc)
+{
+	return desc->len8 << 3;
+}
 
 struct vmpacket_descriptor *
 hv_pkt_iter_first_raw(struct vmbus_channel *channel);
diff --git a/net/vmw_vsock/hyperv_transport.c b/net/vmw_vsock/hyperv_transport.c
index 8c37d07017fc..fd98229e3db3 100644
--- a/net/vmw_vsock/hyperv_transport.c
+++ b/net/vmw_vsock/hyperv_transport.c
@@ -577,12 +577,18 @@ static bool hvs_dgram_allow(u32 cid, u32 port)
 static int hvs_update_recv_data(struct hvsock *hvs)
 {
 	struct hvs_recv_buf *recv_buf;
-	u32 payload_len;
+	u32 pkt_len, payload_len;
+
+	pkt_len = hv_pkt_len(hvs->recv_desc);
+
+	if (pkt_len < HVS_HEADER_LEN)
+		return -EIO;
 
 	recv_buf = (struct hvs_recv_buf *)(hvs->recv_desc + 1);
 	payload_len = recv_buf->hdr.data_size;
 
-	if (payload_len > HVS_MTU_SIZE)
+	if (payload_len > pkt_len - HVS_HEADER_LEN ||
+	    payload_len > HVS_MTU_SIZE)
 		return -EIO;
 
 	if (payload_len == 0)
-- 
cgit v1.2.3


From da795eb239d9e9496812e22cb582d38a71e0789a Mon Sep 17 00:00:00 2001
From: "Andrea Parri (Microsoft)" <parri.andrea@gmail.com>
Date: Thu, 28 Apr 2022 16:51:06 +0200
Subject: Drivers: hv: vmbus: Accept hv_sock offers in isolated guests

So that isolated guests can communicate with the host via hv_sock
channels.

Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20220428145107.7878-5-parri.andrea@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
---
 drivers/hv/channel_mgmt.c | 8 ++++++--
 include/linux/hyperv.h    | 8 ++++++--
 2 files changed, 12 insertions(+), 4 deletions(-)

(limited to 'include')

diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index 50fea31f019f..0db1b775e013 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -976,13 +976,17 @@ find_primary_channel_by_offer(const struct vmbus_channel_offer_channel *offer)
 	return channel;
 }
 
-static bool vmbus_is_valid_device(const guid_t *guid)
+static bool vmbus_is_valid_offer(const struct vmbus_channel_offer_channel *offer)
 {
+	const guid_t *guid = &offer->offer.if_type;
 	u16 i;
 
 	if (!hv_is_isolation_supported())
 		return true;
 
+	if (is_hvsock_offer(offer))
+		return true;
+
 	for (i = 0; i < ARRAY_SIZE(vmbus_devs); i++) {
 		if (guid_equal(guid, &vmbus_devs[i].guid))
 			return vmbus_devs[i].allowed_in_isolated;
@@ -1004,7 +1008,7 @@ static void vmbus_onoffer(struct vmbus_channel_message_header *hdr)
 
 	trace_vmbus_onoffer(offer);
 
-	if (!vmbus_is_valid_device(&offer->offer.if_type)) {
+	if (!vmbus_is_valid_offer(offer)) {
 		pr_err_ratelimited("Invalid offer %d from the host supporting isolation\n",
 				   offer->child_relid);
 		atomic_dec(&vmbus_connection.offer_in_progress);
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index a01c9fd0a334..b028905d8334 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -1064,10 +1064,14 @@ u64 vmbus_request_addr_match(struct vmbus_channel *channel, u64 trans_id,
 			     u64 rqst_addr);
 u64 vmbus_request_addr(struct vmbus_channel *channel, u64 trans_id);
 
+static inline bool is_hvsock_offer(const struct vmbus_channel_offer_channel *o)
+{
+	return !!(o->offer.chn_flags & VMBUS_CHANNEL_TLNPI_PROVIDER_OFFER);
+}
+
 static inline bool is_hvsock_channel(const struct vmbus_channel *c)
 {
-	return !!(c->offermsg.offer.chn_flags &
-		  VMBUS_CHANNEL_TLNPI_PROVIDER_OFFER);
+	return is_hvsock_offer(&c->offermsg);
 }
 
 static inline bool is_sub_channel(const struct vmbus_channel *c)
-- 
cgit v1.2.3


From 1c9de08f7f952b4101f092802581344033d84429 Mon Sep 17 00:00:00 2001
From: "Andrea Parri (Microsoft)" <parri.andrea@gmail.com>
Date: Thu, 28 Apr 2022 16:51:07 +0200
Subject: Drivers: hv: vmbus: Refactor the ring-buffer iterator functions

With no users of hv_pkt_iter_next_raw() and no "external" users of
hv_pkt_iter_first_raw(), the iterator functions can be refactored
and simplified to remove some indirection/code.

Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20220428145107.7878-6-parri.andrea@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
---
 drivers/hv/ring_buffer.c | 32 +++++++++-----------------------
 include/linux/hyperv.h   | 35 ++++-------------------------------
 2 files changed, 13 insertions(+), 54 deletions(-)

(limited to 'include')

diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c
index e101b11f95e5..59a4aa86d1f3 100644
--- a/drivers/hv/ring_buffer.c
+++ b/drivers/hv/ring_buffer.c
@@ -429,7 +429,7 @@ int hv_ringbuffer_read(struct vmbus_channel *channel,
 	memcpy(buffer, (const char *)desc + offset, packetlen);
 
 	/* Advance ring index to next packet descriptor */
-	__hv_pkt_iter_next(channel, desc, true);
+	__hv_pkt_iter_next(channel, desc);
 
 	/* Notify host of update */
 	hv_pkt_iter_close(channel);
@@ -464,22 +464,6 @@ static u32 hv_pkt_iter_avail(const struct hv_ring_buffer_info *rbi)
 		return (rbi->ring_datasize - priv_read_loc) + write_loc;
 }
 
-/*
- * Get first vmbus packet without copying it out of the ring buffer
- */
-struct vmpacket_descriptor *hv_pkt_iter_first_raw(struct vmbus_channel *channel)
-{
-	struct hv_ring_buffer_info *rbi = &channel->inbound;
-
-	hv_debug_delay_test(channel, MESSAGE_DELAY);
-
-	if (hv_pkt_iter_avail(rbi) < sizeof(struct vmpacket_descriptor))
-		return NULL;
-
-	return (struct vmpacket_descriptor *)(hv_get_ring_buffer(rbi) + rbi->priv_read_index);
-}
-EXPORT_SYMBOL_GPL(hv_pkt_iter_first_raw);
-
 /*
  * Get first vmbus packet from ring buffer after read_index
  *
@@ -491,11 +475,14 @@ struct vmpacket_descriptor *hv_pkt_iter_first(struct vmbus_channel *channel)
 	struct vmpacket_descriptor *desc, *desc_copy;
 	u32 bytes_avail, pkt_len, pkt_offset;
 
-	desc = hv_pkt_iter_first_raw(channel);
-	if (!desc)
+	hv_debug_delay_test(channel, MESSAGE_DELAY);
+
+	bytes_avail = hv_pkt_iter_avail(rbi);
+	if (bytes_avail < sizeof(struct vmpacket_descriptor))
 		return NULL;
+	bytes_avail = min(rbi->pkt_buffer_size, bytes_avail);
 
-	bytes_avail = min(rbi->pkt_buffer_size, hv_pkt_iter_avail(rbi));
+	desc = (struct vmpacket_descriptor *)(hv_get_ring_buffer(rbi) + rbi->priv_read_index);
 
 	/*
 	 * Ensure the compiler does not use references to incoming Hyper-V values (which
@@ -542,8 +529,7 @@ EXPORT_SYMBOL_GPL(hv_pkt_iter_first);
  */
 struct vmpacket_descriptor *
 __hv_pkt_iter_next(struct vmbus_channel *channel,
-		   const struct vmpacket_descriptor *desc,
-		   bool copy)
+		   const struct vmpacket_descriptor *desc)
 {
 	struct hv_ring_buffer_info *rbi = &channel->inbound;
 	u32 packetlen = desc->len8 << 3;
@@ -556,7 +542,7 @@ __hv_pkt_iter_next(struct vmbus_channel *channel,
 		rbi->priv_read_index -= dsize;
 
 	/* more data? */
-	return copy ? hv_pkt_iter_first(channel) : hv_pkt_iter_first_raw(channel);
+	return hv_pkt_iter_first(channel);
 }
 EXPORT_SYMBOL_GPL(__hv_pkt_iter_next);
 
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index b028905d8334..c440c45887c2 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -1706,55 +1706,28 @@ static inline u32 hv_pkt_len(const struct vmpacket_descriptor *desc)
 	return desc->len8 << 3;
 }
 
-struct vmpacket_descriptor *
-hv_pkt_iter_first_raw(struct vmbus_channel *channel);
-
 struct vmpacket_descriptor *
 hv_pkt_iter_first(struct vmbus_channel *channel);
 
 struct vmpacket_descriptor *
 __hv_pkt_iter_next(struct vmbus_channel *channel,
-		   const struct vmpacket_descriptor *pkt,
-		   bool copy);
+		   const struct vmpacket_descriptor *pkt);
 
 void hv_pkt_iter_close(struct vmbus_channel *channel);
 
 static inline struct vmpacket_descriptor *
-hv_pkt_iter_next_pkt(struct vmbus_channel *channel,
-		     const struct vmpacket_descriptor *pkt,
-		     bool copy)
+hv_pkt_iter_next(struct vmbus_channel *channel,
+		 const struct vmpacket_descriptor *pkt)
 {
 	struct vmpacket_descriptor *nxt;
 
-	nxt = __hv_pkt_iter_next(channel, pkt, copy);
+	nxt = __hv_pkt_iter_next(channel, pkt);
 	if (!nxt)
 		hv_pkt_iter_close(channel);
 
 	return nxt;
 }
 
-/*
- * Get next packet descriptor without copying it out of the ring buffer
- * If at end of list, return NULL and update host.
- */
-static inline struct vmpacket_descriptor *
-hv_pkt_iter_next_raw(struct vmbus_channel *channel,
-		     const struct vmpacket_descriptor *pkt)
-{
-	return hv_pkt_iter_next_pkt(channel, pkt, false);
-}
-
-/*
- * Get next packet descriptor from iterator
- * If at end of list, return NULL and update host.
- */
-static inline struct vmpacket_descriptor *
-hv_pkt_iter_next(struct vmbus_channel *channel,
-		 const struct vmpacket_descriptor *pkt)
-{
-	return hv_pkt_iter_next_pkt(channel, pkt, true);
-}
-
 #define foreach_vmbus_pkt(pkt, channel) \
 	for (pkt = hv_pkt_iter_first(channel); pkt; \
 	    pkt = hv_pkt_iter_next(channel, pkt))
-- 
cgit v1.2.3


From a6b94c6b49198266eaf78095a632df7245ef5196 Mon Sep 17 00:00:00 2001
From: Michael Kelley <mikelley@microsoft.com>
Date: Mon, 2 May 2022 09:36:28 -0700
Subject: Drivers: hv: vmbus: Remove support for Hyper-V 2008 and Hyper-V
 2008R2/Win7

The VMbus driver has special case code for running on the first released
versions of Hyper-V: 2008 and 2008 R2/Windows 7. These versions are now
out of support (except for extended security updates) and lack the
performance features needed for effective production usage of Linux
guests.

Simplify the code by removing the negotiation of the VMbus protocol
versions required for these releases of Hyper-V, and by removing the
special case code for handling these VMbus protocol versions.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Link: https://lore.kernel.org/r/1651509391-2058-2-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
---
 drivers/hv/channel_mgmt.c | 29 +++++++++--------------
 drivers/hv/connection.c   |  6 ++---
 drivers/hv/vmbus_drv.c    | 60 ++++++++++-------------------------------------
 include/linux/hyperv.h    | 10 +++++---
 4 files changed, 33 insertions(+), 72 deletions(-)

(limited to 'include')

diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index 0db1b775e013..97d8f5646778 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -714,15 +714,13 @@ static bool hv_cpuself_used(u32 cpu, struct vmbus_channel *chn)
 static int next_numa_node_id;
 
 /*
- * Starting with Win8, we can statically distribute the incoming
- * channel interrupt load by binding a channel to VCPU.
+ * We can statically distribute the incoming channel interrupt load
+ * by binding a channel to VCPU.
  *
- * For pre-win8 hosts or non-performance critical channels we assign the
- * VMBUS_CONNECT_CPU.
- *
- * Starting with win8, performance critical channels will be distributed
- * evenly among all the available NUMA nodes.  Once the node is assigned,
- * we will assign the CPU based on a simple round robin scheme.
+ * For non-performance critical channels we assign the VMBUS_CONNECT_CPU.
+ * Performance critical channels will be distributed evenly among all
+ * the available NUMA nodes.  Once the node is assigned, we will assign
+ * the CPU based on a simple round robin scheme.
  */
 static void init_vp_index(struct vmbus_channel *channel)
 {
@@ -733,13 +731,10 @@ static void init_vp_index(struct vmbus_channel *channel)
 	u32 target_cpu;
 	int numa_node;
 
-	if ((vmbus_proto_version == VERSION_WS2008) ||
-	    (vmbus_proto_version == VERSION_WIN7) || (!perf_chn) ||
+	if (!perf_chn ||
 	    !alloc_cpumask_var(&available_mask, GFP_KERNEL)) {
 		/*
-		 * Prior to win8, all channel interrupts are
-		 * delivered on VMBUS_CONNECT_CPU.
-		 * Also if the channel is not a performance critical
+		 * If the channel is not a performance critical
 		 * channel, bind it to VMBUS_CONNECT_CPU.
 		 * In case alloc_cpumask_var() fails, bind it to
 		 * VMBUS_CONNECT_CPU.
@@ -932,11 +927,9 @@ static void vmbus_setup_channel_state(struct vmbus_channel *channel,
 	 */
 	channel->sig_event = VMBUS_EVENT_CONNECTION_ID;
 
-	if (vmbus_proto_version != VERSION_WS2008) {
-		channel->is_dedicated_interrupt =
-				(offer->is_dedicated_interrupt != 0);
-		channel->sig_event = offer->connection_id;
-	}
+	channel->is_dedicated_interrupt =
+			(offer->is_dedicated_interrupt != 0);
+	channel->sig_event = offer->connection_id;
 
 	memcpy(&channel->offermsg, offer,
 	       sizeof(struct vmbus_channel_offer_channel));
diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
index a3d8be8d6cfb..6218bbf6863a 100644
--- a/drivers/hv/connection.c
+++ b/drivers/hv/connection.c
@@ -47,6 +47,8 @@ EXPORT_SYMBOL_GPL(vmbus_proto_version);
 
 /*
  * Table of VMBus versions listed from newest to oldest.
+ * VERSION_WIN7 and VERSION_WS2008 are no longer supported in
+ * Linux guests and are not listed.
  */
 static __u32 vmbus_versions[] = {
 	VERSION_WIN10_V5_3,
@@ -56,9 +58,7 @@ static __u32 vmbus_versions[] = {
 	VERSION_WIN10_V4_1,
 	VERSION_WIN10,
 	VERSION_WIN8_1,
-	VERSION_WIN8,
-	VERSION_WIN7,
-	VERSION_WS2008
+	VERSION_WIN8
 };
 
 /*
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 14de17087864..9c1b3620775c 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -1263,23 +1263,17 @@ static void vmbus_chan_sched(struct hv_per_cpu_context *hv_cpu)
 	unsigned long *recv_int_page;
 	u32 maxbits, relid;
 
-	if (vmbus_proto_version < VERSION_WIN8) {
-		maxbits = MAX_NUM_CHANNELS_SUPPORTED;
-		recv_int_page = vmbus_connection.recv_int_page;
-	} else {
-		/*
-		 * When the host is win8 and beyond, the event page
-		 * can be directly checked to get the id of the channel
-		 * that has the interrupt pending.
-		 */
-		void *page_addr = hv_cpu->synic_event_page;
-		union hv_synic_event_flags *event
-			= (union hv_synic_event_flags *)page_addr +
-						 VMBUS_MESSAGE_SINT;
+	/*
+	 * The event page can be directly checked to get the id of
+	 * the channel that has the interrupt pending.
+	 */
+	void *page_addr = hv_cpu->synic_event_page;
+	union hv_synic_event_flags *event
+		= (union hv_synic_event_flags *)page_addr +
+					 VMBUS_MESSAGE_SINT;
 
-		maxbits = HV_EVENT_FLAGS_COUNT;
-		recv_int_page = event->flags;
-	}
+	maxbits = HV_EVENT_FLAGS_COUNT;
+	recv_int_page = event->flags;
 
 	if (unlikely(!recv_int_page))
 		return;
@@ -1351,40 +1345,10 @@ static void vmbus_isr(void)
 {
 	struct hv_per_cpu_context *hv_cpu
 		= this_cpu_ptr(hv_context.cpu_context);
-	void *page_addr = hv_cpu->synic_event_page;
+	void *page_addr;
 	struct hv_message *msg;
-	union hv_synic_event_flags *event;
-	bool handled = false;
-
-	if (unlikely(page_addr == NULL))
-		return;
-
-	event = (union hv_synic_event_flags *)page_addr +
-					 VMBUS_MESSAGE_SINT;
-	/*
-	 * Check for events before checking for messages. This is the order
-	 * in which events and messages are checked in Windows guests on
-	 * Hyper-V, and the Windows team suggested we do the same.
-	 */
-
-	if ((vmbus_proto_version == VERSION_WS2008) ||
-		(vmbus_proto_version == VERSION_WIN7)) {
-
-		/* Since we are a child, we only need to check bit 0 */
-		if (sync_test_and_clear_bit(0, event->flags))
-			handled = true;
-	} else {
-		/*
-		 * Our host is win8 or above. The signaling mechanism
-		 * has changed and we can directly look at the event page.
-		 * If bit n is set then we have an interrup on the channel
-		 * whose id is n.
-		 */
-		handled = true;
-	}
 
-	if (handled)
-		vmbus_chan_sched(hv_cpu);
+	vmbus_chan_sched(hv_cpu);
 
 	page_addr = hv_cpu->synic_message_page;
 	msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT;
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index c440c45887c2..a2464295c14a 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -230,15 +230,19 @@ static inline u32 hv_get_avail_to_write_percent(
  * two 16 bit quantities: major_number. minor_number.
  *
  * 0 . 13 (Windows Server 2008)
- * 1 . 1  (Windows 7)
- * 2 . 4  (Windows 8)
- * 3 . 0  (Windows 8 R2)
+ * 1 . 1  (Windows 7, WS2008 R2)
+ * 2 . 4  (Windows 8, WS2012)
+ * 3 . 0  (Windows 8.1, WS2012 R2)
  * 4 . 0  (Windows 10)
  * 4 . 1  (Windows 10 RS3)
  * 5 . 0  (Newer Windows 10)
  * 5 . 1  (Windows 10 RS4)
  * 5 . 2  (Windows Server 2019, RS5)
  * 5 . 3  (Windows Server 2022)
+ *
+ * The WS2008 and WIN7 versions are listed here for
+ * completeness but are no longer supported in the
+ * Linux kernel.
  */
 
 #define VERSION_WS2008  ((0 << 16) | (13))
-- 
cgit v1.2.3