Commit 846da38d authored by Tianyu Lan's avatar Tianyu Lan Committed by Wei Liu
Browse files

net: netvsc: Add Isolation VM support for netvsc driver 



In Isolation VM, all shared memory with host needs to mark visible
to host via hvcall. vmbus_establish_gpadl() has already done it for
netvsc rx/tx ring buffer. The page buffer used by vmbus_sendpacket_
pagebuffer() stills need to be handled. Use DMA API to map/umap
these memory during sending/receiving packet and Hyper-V swiotlb
bounce buffer dma address will be returned. The swiotlb bounce buffer
has been masked to be visible to host during boot up.

rx/tx ring buffer is allocated via vzalloc() and they need to be
mapped into unencrypted address space(above vTOM) before sharing
with host and accessing. Add hv_map/unmap_memory() to map/umap rx
/tx ring buffer.

Signed-off-by: default avatarTianyu Lan <Tianyu.Lan@microsoft.com>
Reviewed-by: default avatarHaiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: default avatarMichael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20211213071407.314309-6-ltykernel@gmail.com


Signed-off-by: default avatarWei Liu <wei.liu@kernel.org>
parent 743b237c

arch/x86/hyperv/ivm.c

+28 −0
Original line number Diff line number Diff line
@@ -287,3 +287,31 @@ int hv_set_mem_host_visibility(unsigned long kbuffer, int pagecount, bool visibl 
	kfree(pfn_array);

	return ret;

}



/*

 * hv_map_memory - map memory to extra space in the AMD SEV-SNP Isolation VM.

 */

void *hv_map_memory(void *addr, unsigned long size)

{

	unsigned long *pfns = kcalloc(size / PAGE_SIZE,

				      sizeof(unsigned long), GFP_KERNEL);

	void *vaddr;

	int i;



	if (!pfns)

		return NULL;



	for (i = 0; i < size / PAGE_SIZE; i++)

		pfns[i] = vmalloc_to_pfn(addr + i * PAGE_SIZE) +

			(ms_hyperv.shared_gpa_boundary >> PAGE_SHIFT);



	vaddr = vmap_pfn(pfns, size / PAGE_SIZE, PAGE_KERNEL_IO);

	kfree(pfns);



	return vaddr;

}



void hv_unmap_memory(void *addr)

{

	vunmap(addr);

}

drivers/hv/hv_common.c

+11 −0
Original line number Diff line number Diff line
@@ -295,3 +295,14 @@ u64 __weak hv_ghcb_hypercall(u64 control, void *input, void *output, u32 input_s 
	return HV_STATUS_INVALID_PARAMETER;

}

EXPORT_SYMBOL_GPL(hv_ghcb_hypercall);



void __weak *hv_map_memory(void *addr, unsigned long size)

{

	return NULL;

}

EXPORT_SYMBOL_GPL(hv_map_memory);



void __weak hv_unmap_memory(void *addr)

{

}

EXPORT_SYMBOL_GPL(hv_unmap_memory);

drivers/net/hyperv/hyperv_net.h

+5 −0
Original line number Diff line number Diff line
@@ -164,6 +164,7 @@ struct hv_netvsc_packet { 
	u32 total_bytes;

	u32 send_buf_index;

	u32 total_data_buflen;

	struct hv_dma_range *dma_range;

};



#define NETVSC_HASH_KEYLEN 40
@@ -1074,6 +1075,7 @@ struct netvsc_device { 


	/* Receive buffer allocated by us but manages by NetVSP */

	void *recv_buf;

	void *recv_original_buf;

	u32 recv_buf_size; /* allocated bytes */

	struct vmbus_gpadl recv_buf_gpadl_handle;

	u32 recv_section_cnt;
@@ -1082,6 +1084,7 @@ struct netvsc_device { 


	/* Send buffer allocated by us */

	void *send_buf;

	void *send_original_buf;

	u32 send_buf_size;

	struct vmbus_gpadl send_buf_gpadl_handle;

	u32 send_section_cnt;
@@ -1731,4 +1734,6 @@ struct rndis_message { 
#define RETRY_US_HI	10000

#define RETRY_MAX	2000	/* >10 sec */



void netvsc_dma_unmap(struct hv_device *hv_dev,

		      struct hv_netvsc_packet *packet);

#endif /* _HYPERV_NET_H */

drivers/net/hyperv/netvsc.c

+133 −3
Original line number Diff line number Diff line
@@ -153,8 +153,21 @@ static void free_netvsc_device(struct rcu_head *head) 
	int i;



	kfree(nvdev->extension);



	if (nvdev->recv_original_buf) {

		hv_unmap_memory(nvdev->recv_buf);

		vfree(nvdev->recv_original_buf);

	} else {

		vfree(nvdev->recv_buf);

	}



	if (nvdev->send_original_buf) {

		hv_unmap_memory(nvdev->send_buf);

		vfree(nvdev->send_original_buf);

	} else {

		vfree(nvdev->send_buf);

	}



	kfree(nvdev->send_section_map);



	for (i = 0; i < VRSS_CHANNEL_MAX; i++) {
@@ -338,6 +351,7 @@ static int netvsc_init_buf(struct hv_device *device, 
	unsigned int buf_size;

	size_t map_words;

	int i, ret = 0;

	void *vaddr;



	/* Get receive buffer area. */

	buf_size = device_info->recv_sections * device_info->recv_section_size;
@@ -373,6 +387,17 @@ static int netvsc_init_buf(struct hv_device *device, 
		goto cleanup;

	}



	if (hv_isolation_type_snp()) {

		vaddr = hv_map_memory(net_device->recv_buf, buf_size);

		if (!vaddr) {

			ret = -ENOMEM;

			goto cleanup;

		}



		net_device->recv_original_buf = net_device->recv_buf;

		net_device->recv_buf = vaddr;

	}



	/* Notify the NetVsp of the gpadl handle */

	init_packet = &net_device->channel_init_pkt;

	memset(init_packet, 0, sizeof(struct nvsp_message));
@@ -476,6 +501,17 @@ static int netvsc_init_buf(struct hv_device *device, 
		goto cleanup;

	}



	if (hv_isolation_type_snp()) {

		vaddr = hv_map_memory(net_device->send_buf, buf_size);

		if (!vaddr) {

			ret = -ENOMEM;

			goto cleanup;

		}



		net_device->send_original_buf = net_device->send_buf;

		net_device->send_buf = vaddr;

	}



	/* Notify the NetVsp of the gpadl handle */

	init_packet = &net_device->channel_init_pkt;

	memset(init_packet, 0, sizeof(struct nvsp_message));
@@ -766,7 +802,7 @@ static void netvsc_send_tx_complete(struct net_device *ndev, 


	/* Notify the layer above us */

	if (likely(skb)) {

		const struct hv_netvsc_packet *packet

		struct hv_netvsc_packet *packet

			= (struct hv_netvsc_packet *)skb->cb;

		u32 send_index = packet->send_buf_index;

		struct netvsc_stats *tx_stats;
@@ -782,6 +818,7 @@ static void netvsc_send_tx_complete(struct net_device *ndev, 
		tx_stats->bytes += packet->total_bytes;

		u64_stats_update_end(&tx_stats->syncp);



		netvsc_dma_unmap(ndev_ctx->device_ctx, packet);

		napi_consume_skb(skb, budget);

	}
@@ -946,6 +983,88 @@ static void netvsc_copy_to_send_buf(struct netvsc_device *net_device, 
		memset(dest, 0, padding);

}



void netvsc_dma_unmap(struct hv_device *hv_dev,

		      struct hv_netvsc_packet *packet)

{

	u32 page_count = packet->cp_partial ?

		packet->page_buf_cnt - packet->rmsg_pgcnt :

		packet->page_buf_cnt;

	int i;



	if (!hv_is_isolation_supported())

		return;



	if (!packet->dma_range)

		return;



	for (i = 0; i < page_count; i++)

		dma_unmap_single(&hv_dev->device, packet->dma_range[i].dma,

				 packet->dma_range[i].mapping_size,

				 DMA_TO_DEVICE);



	kfree(packet->dma_range);

}



/* netvsc_dma_map - Map swiotlb bounce buffer with data page of

 * packet sent by vmbus_sendpacket_pagebuffer() in the Isolation

 * VM.

 *

 * In isolation VM, netvsc send buffer has been marked visible to

 * host and so the data copied to send buffer doesn't need to use

 * bounce buffer. The data pages handled by vmbus_sendpacket_pagebuffer()

 * may not be copied to send buffer and so these pages need to be

 * mapped with swiotlb bounce buffer. netvsc_dma_map() is to do

 * that. The pfns in the struct hv_page_buffer need to be converted

 * to bounce buffer's pfn. The loop here is necessary because the

 * entries in the page buffer array are not necessarily full

 * pages of data.  Each entry in the array has a separate offset and

 * len that may be non-zero, even for entries in the middle of the

 * array.  And the entries are not physically contiguous.  So each

 * entry must be individually mapped rather than as a contiguous unit.

 * So not use dma_map_sg() here.

 */

static int netvsc_dma_map(struct hv_device *hv_dev,

			  struct hv_netvsc_packet *packet,

			  struct hv_page_buffer *pb)

{

	u32 page_count =  packet->cp_partial ?

		packet->page_buf_cnt - packet->rmsg_pgcnt :

		packet->page_buf_cnt;

	dma_addr_t dma;

	int i;



	if (!hv_is_isolation_supported())

		return 0;



	packet->dma_range = kcalloc(page_count,

				    sizeof(*packet->dma_range),

				    GFP_KERNEL);

	if (!packet->dma_range)

		return -ENOMEM;



	for (i = 0; i < page_count; i++) {

		char *src = phys_to_virt((pb[i].pfn << HV_HYP_PAGE_SHIFT)

					 + pb[i].offset);

		u32 len = pb[i].len;



		dma = dma_map_single(&hv_dev->device, src, len,

				     DMA_TO_DEVICE);

		if (dma_mapping_error(&hv_dev->device, dma)) {

			kfree(packet->dma_range);

			return -ENOMEM;

		}



		/* pb[].offset and pb[].len are not changed during dma mapping

		 * and so not reassign.

		 */

		packet->dma_range[i].dma = dma;

		packet->dma_range[i].mapping_size = len;

		pb[i].pfn = dma >> HV_HYP_PAGE_SHIFT;

	}



	return 0;

}



static inline int netvsc_send_pkt(

	struct hv_device *device,

	struct hv_netvsc_packet *packet,
@@ -986,14 +1105,24 @@ static inline int netvsc_send_pkt( 


	trace_nvsp_send_pkt(ndev, out_channel, rpkt);



	packet->dma_range = NULL;

	if (packet->page_buf_cnt) {

		if (packet->cp_partial)

			pb += packet->rmsg_pgcnt;



		ret = netvsc_dma_map(ndev_ctx->device_ctx, packet, pb);

		if (ret) {

			ret = -EAGAIN;

			goto exit;

		}



		ret = vmbus_sendpacket_pagebuffer(out_channel,

						  pb, packet->page_buf_cnt,

						  &nvmsg, sizeof(nvmsg),

						  req_id);



		if (ret)

			netvsc_dma_unmap(ndev_ctx->device_ctx, packet);

	} else {

		ret = vmbus_sendpacket(out_channel,

				       &nvmsg, sizeof(nvmsg),
@@ -1001,6 +1130,7 @@ static inline int netvsc_send_pkt( 
				       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);

	}



exit:

	if (ret == 0) {

		atomic_inc_return(&nvchan->queue_sends);

drivers/net/hyperv/netvsc_drv.c

+1 −0
Original line number Diff line number Diff line
@@ -2512,6 +2512,7 @@ static int netvsc_probe(struct hv_device *dev, 
	net->netdev_ops = &device_ops;

	net->ethtool_ops = &ethtool_ops;

	SET_NETDEV_DEV(net, &dev->device);

	dma_set_min_align_mask(&dev->device, HV_HYP_PAGE_SIZE - 1);



	/* We always need headroom for rndis header */

	net->needed_headroom = RNDIS_AND_PPI_SIZE;