[RFC V2 PATCH 00/12] x86/Hyper-V: Add Hyper-V Isolation VM support

[RFC V2 PATCH 00/12] x86/Hyper-V: Add Hyper-V Isolation VM support

[Tianyu Lan]

From: Tianyu Lan <Tianyu.Lan@microsoft.com>


Hyper-V provides two kinds of Isolation VMs. VBS(Virtualization-based
security) and AMD SEV-SNP unenlightened Isolation VMs. This patchset
is to add support for these Isolation VM support in Linux.

The memory of these vms are encrypted and host can't access guest
memory directly. Hyper-V provides new host visibility hvcall and
the guest needs to call new hvcall to mark memory visible to host
before sharing memory with host. For security, all network/storage
stack memory should not be shared with host and so there is bounce
buffer requests.

Vmbus channel ring buffer already plays bounce buffer role because
all data from/to host needs to copy from/to between the ring buffer
and IO stack memory. So mark vmbus channel ring buffer visible to
host.

There are two exceptions - packets sent by vmbus_sendpacket_
pagebuffer() and vmbus_sendpacket_mpb_desc(). These packets
contains IO stack memory address and host will access these memory.
So add Hyper-V DMA Ops and use DMA API in the netvsc and storvsc
drivers to allocate bounce buffer via swiotlb interface.

For SNP isolation VM, guest needs to access the shared memory via
extra address space which is specified by Hyper-V CPUID HYPERV_CPUID_
ISOLATION_CONFIG. The access physical address of the shared memory
should be bounce buffer memory GPA plus with shared_gpa_boundary
reported by CPUID.

Change since v1:
       * Add DMA API support in the netvsc and storvsc driver.
       * Add Hyper-V DMA ops.
       * Add static branch for the check of isolation type snp.
       * Fix some code style comments.

Tianyu Lan (12):
  x86/HV: Initialize GHCB page in Isolation VM
  x86/HV: Initialize shared memory boundary in Isolation VM
  x86/Hyper-V: Add new hvcall guest address host visibility support
  HV: Add Write/Read MSR registers via ghcb
  HV: Add ghcb hvcall support for SNP VM
  HV/Vmbus: Add SNP support for VMbus channel initiate message
  HV/Vmbus: Initialize VMbus ring buffer for Isolation VM
  UIO/Hyper-V: Not load UIO HV driver in the isolation VM.
  swiotlb: Add bounce buffer remap address setting function
  HV/IOMMU: Add Hyper-V dma ops support
  HV/Netvsc: Add Isolation VM support for netvsc driver
  HV/Storvsc: Add Isolation VM support for storvsc driver

 arch/x86/hyperv/Makefile           |   2 +-
 arch/x86/hyperv/hv_init.c          |  70 +++++--
 arch/x86/hyperv/ivm.c              | 289 +++++++++++++++++++++++++++++
 arch/x86/include/asm/hyperv-tlfs.h |  22 +++
 arch/x86/include/asm/mshyperv.h    |  90 +++++++--
 arch/x86/kernel/cpu/mshyperv.c     |   5 +
 arch/x86/kernel/pci-swiotlb.c      |   3 +-
 drivers/hv/channel.c               |  44 ++++-
 drivers/hv/connection.c            |  68 ++++++-
 drivers/hv/hv.c                    |  73 ++++++--
 drivers/hv/hyperv_vmbus.h          |   3 +
 drivers/hv/ring_buffer.c           |  83 ++++++---
 drivers/hv/vmbus_drv.c             |   3 +
 drivers/iommu/hyperv-iommu.c       | 127 +++++++++++++
 drivers/net/hyperv/hyperv_net.h    |  11 ++
 drivers/net/hyperv/netvsc.c        | 137 +++++++++++++-
 drivers/net/hyperv/rndis_filter.c  |   3 +
 drivers/scsi/storvsc_drv.c         |  67 ++++++-
 drivers/uio/uio_hv_generic.c       |   5 +
 include/asm-generic/hyperv-tlfs.h  |   1 +
 include/asm-generic/mshyperv.h     |  18 +-
 include/linux/hyperv.h             |  12 +-
 include/linux/swiotlb.h            |   5 +
 kernel/dma/swiotlb.c               |  13 +-
 mm/ioremap.c                       |   1 +
 mm/vmalloc.c                       |   1 +
 26 files changed, 1068 insertions(+), 88 deletions(-)
 create mode 100644 arch/x86/hyperv/ivm.c

-- 
2.25.1

[RFC V2 PATCH 11/12] HV/Netvsc: Add Isolation VM support for netvsc driver

[Tianyu Lan]

From: Tianyu Lan <Tianyu.Lan@microsoft.com>

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() still need to handle. Use DMA API to map/umap these
memory during sending/receiving packet and Hyper-V DMA ops callback
will use swiotlb fucntion to allocate bounce buffer and copy data
from/to bounce buffer.

Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
---
 drivers/net/hyperv/hyperv_net.h   |  11 +++
 drivers/net/hyperv/netvsc.c       | 137 ++++++++++++++++++++++++++++--
 drivers/net/hyperv/rndis_filter.c |   3 +
 3 files changed, 144 insertions(+), 7 deletions(-)

diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h
index 2a87cfa27ac0..d85f811238c7 100644
--- a/drivers/net/hyperv/hyperv_net.h
+++ b/drivers/net/hyperv/hyperv_net.h
@@ -130,6 +130,7 @@ struct hv_netvsc_packet {
 	u32 total_bytes;
 	u32 send_buf_index;
 	u32 total_data_buflen;
+	struct dma_range *dma_range;
 };
 
 #define NETVSC_HASH_KEYLEN 40
@@ -1026,6 +1027,7 @@ 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 */
 	u32 recv_buf_gpadl_handle;
 	u32 recv_section_cnt;
@@ -1034,6 +1036,8 @@ struct netvsc_device {
 
 	/* Send buffer allocated by us */
 	void *send_buf;
+	void *send_original_buf;
+	u32 send_buf_size;
 	u32 send_buf_gpadl_handle;
 	u32 send_section_cnt;
 	u32 send_section_size;
@@ -1715,4 +1719,11 @@ struct rndis_message {
 #define TRANSPORT_INFO_IPV6_TCP 0x10
 #define TRANSPORT_INFO_IPV6_UDP 0x20
 
+struct dma_range {
+	dma_addr_t dma;
+	u32 mapping_size;
+};
+
+void netvsc_dma_unmap(struct hv_device *hv_dev,
+		      struct hv_netvsc_packet *packet);
 #endif /* _HYPERV_NET_H */
diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index 2353623259f3..1a5f5be4eeea 100644
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -26,6 +26,7 @@
 
 #include "hyperv_net.h"
 #include "netvsc_trace.h"
+#include "../../hv/hyperv_vmbus.h"
 
 /*
  * Switch the data path from the synthetic interface to the VF
@@ -119,8 +120,21 @@ static void free_netvsc_device(struct rcu_head *head)
 	int i;
 
 	kfree(nvdev->extension);
-	vfree(nvdev->recv_buf);
-	vfree(nvdev->send_buf);
+
+	if (nvdev->recv_original_buf) {
+		iounmap(nvdev->recv_buf);
+		vfree(nvdev->recv_original_buf);
+	} else {
+		vfree(nvdev->recv_buf);
+	}
+
+	if (nvdev->send_original_buf) {
+		iounmap(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++) {
@@ -302,9 +316,12 @@ static int netvsc_init_buf(struct hv_device *device,
 	struct nvsp_1_message_send_receive_buffer_complete *resp;
 	struct net_device *ndev = hv_get_drvdata(device);
 	struct nvsp_message *init_packet;
+	struct vm_struct *area;
+	u64 extra_phys;
 	unsigned int buf_size;
+	unsigned long vaddr;
 	size_t map_words;
-	int ret = 0;
+	int ret = 0, i;
 
 	/* Get receive buffer area. */
 	buf_size = device_info->recv_sections * device_info->recv_section_size;
@@ -340,6 +357,27 @@ static int netvsc_init_buf(struct hv_device *device,
 		goto cleanup;
 	}
 
+	if (hv_isolation_type_snp()) {
+		area = get_vm_area(buf_size, VM_IOREMAP);
+		if (!area)
+			goto cleanup;
+
+		vaddr = (unsigned long)area->addr;
+		for (i = 0; i < buf_size / HV_HYP_PAGE_SIZE; i++) {
+			extra_phys = (virt_to_hvpfn(net_device->recv_buf + i * HV_HYP_PAGE_SIZE)
+				<< HV_HYP_PAGE_SHIFT) + ms_hyperv.shared_gpa_boundary;
+			ret |= ioremap_page_range(vaddr + i * HV_HYP_PAGE_SIZE,
+					   vaddr + (i + 1) * HV_HYP_PAGE_SIZE,
+					   extra_phys, PAGE_KERNEL_IO);
+		}
+
+		if (ret)
+			goto cleanup;
+
+		net_device->recv_original_buf = net_device->recv_buf;
+		net_device->recv_buf = (void *)vaddr;
+	}
+
 	/* Notify the NetVsp of the gpadl handle */
 	init_packet = &net_device->channel_init_pkt;
 	memset(init_packet, 0, sizeof(struct nvsp_message));
@@ -432,6 +470,28 @@ static int netvsc_init_buf(struct hv_device *device,
 		goto cleanup;
 	}
 
+	if (hv_isolation_type_snp()) {
+		area = get_vm_area(buf_size, VM_IOREMAP);
+		if (!area)
+			goto cleanup;
+
+		vaddr = (unsigned long)area->addr;
+
+		for (i = 0; i < buf_size / HV_HYP_PAGE_SIZE; i++) {
+			extra_phys = (virt_to_hvpfn(net_device->send_buf + i * HV_HYP_PAGE_SIZE)
+				<< HV_HYP_PAGE_SHIFT) + ms_hyperv.shared_gpa_boundary;
+			ret |= ioremap_page_range(vaddr + i * HV_HYP_PAGE_SIZE,
+					   vaddr + (i + 1) * HV_HYP_PAGE_SIZE,
+					   extra_phys, PAGE_KERNEL_IO);
+		}
+
+		if (ret)
+			goto cleanup;
+
+		net_device->send_original_buf = net_device->send_buf;
+		net_device->send_buf = (void *)vaddr;
+	}
+
 	/* Notify the NetVsp of the gpadl handle */
 	init_packet = &net_device->channel_init_pkt;
 	memset(init_packet, 0, sizeof(struct nvsp_message));
@@ -722,7 +782,7 @@ 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;
@@ -738,6 +798,7 @@ 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);
 	}
 
@@ -878,6 +939,60 @@ 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 (!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);
+}
+
+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;
+
+	packet->dma_range = kzalloc(sizeof(struct dma_range) * page_count,
+			      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))
+			return -ENOMEM;
+
+		packet->dma_range[i].dma = dma;
+		packet->dma_range[i].mapping_size = len;
+		pb[i].pfn = dma >> HV_HYP_PAGE_SHIFT;
+		pb[i].offset = offset_in_hvpage(dma);
+		pb[i].len = len;
+	}
+
+	return 0;
+}
+
 static inline int netvsc_send_pkt(
 	struct hv_device *device,
 	struct hv_netvsc_packet *packet,
@@ -917,14 +1032,22 @@ 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)
+			return ret;
+
 		ret = vmbus_sendpacket_pagebuffer(out_channel,
-						  pb, packet->page_buf_cnt,
-						  &nvmsg, sizeof(nvmsg),
-						  req_id);
+					  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),
diff --git a/drivers/net/hyperv/rndis_filter.c b/drivers/net/hyperv/rndis_filter.c
index 598713c0d5a8..b19243f5874c 100644
--- a/drivers/net/hyperv/rndis_filter.c
+++ b/drivers/net/hyperv/rndis_filter.c
@@ -263,6 +263,8 @@ static void rndis_filter_receive_response(struct net_device *ndev,
 {
 	struct rndis_device *dev = nvdev->extension;
 	struct rndis_request *request = NULL;
+	struct hv_device *hv_dev = ((struct net_device_context *)
+			netdev_priv(ndev))->device_ctx;
 	bool found = false;
 	unsigned long flags;
 
@@ -327,6 +329,7 @@ static void rndis_filter_receive_response(struct net_device *ndev,
 			}
 		}
 
+		netvsc_dma_unmap(hv_dev, &request->pkt);
 		complete(&request->wait_event);
 	} else {
 		netdev_err(ndev,
-- 
2.25.1

Re: [RFC V2 PATCH 11/12] HV/Netvsc: Add Isolation VM support for netvsc driver

[Leon Romanovsky]

On Tue, Apr 13, 2021 at 11:22:16AM -0400, Tianyu Lan wrote:
> From: Tianyu Lan <Tianyu.Lan@microsoft.com>
> 
> 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() still need to handle. Use DMA API to map/umap these
> memory during sending/receiving packet and Hyper-V DMA ops callback
> will use swiotlb fucntion to allocate bounce buffer and copy data
> from/to bounce buffer.
> 
> Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
> ---
>  drivers/net/hyperv/hyperv_net.h   |  11 +++
>  drivers/net/hyperv/netvsc.c       | 137 ++++++++++++++++++++++++++++--
>  drivers/net/hyperv/rndis_filter.c |   3 +
>  3 files changed, 144 insertions(+), 7 deletions(-)

<...>

> +	packet->dma_range = kzalloc(sizeof(struct dma_range) * page_count,
> +			      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))
> +			return -ENOMEM;

Don't you leak dma_range here?

BTW, It will be easier if you CC all on all patches, so we will be able
to get whole context.

Thanks