[PATCH V4 04/13] hyperv: Mark vmbus ring buffer visible to host in Isolation VM

[Tianyu Lan <ltykernel@xxxxxxxxx>]

From: Tianyu Lan <Tianyu.Lan@xxxxxxxxxxxxx>

Mark vmbus ring buffer visible with set_memory_decrypted() when
establish gpadl handle.

Signed-off-by: Tianyu Lan <Tianyu.Lan@xxxxxxxxxxxxx>
---
Change since v3:
       * Change vmbus_teardown_gpadl() parameter and put gpadl handle,
       buffer and buffer size in the struct vmbus_gpadl.
---
 drivers/hv/channel.c            | 36 ++++++++++++++++++++++++++++-----
 drivers/net/hyperv/hyperv_net.h |  1 +
 drivers/net/hyperv/netvsc.c     | 16 +++++++++++----
 drivers/uio/uio_hv_generic.c    | 14 +++++++++++--
 include/linux/hyperv.h          |  8 +++++++-
 5 files changed, 63 insertions(+), 12 deletions(-)

diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index f3761c73b074..82650beb3af0 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -17,6 +17,7 @@
 #include <linux/hyperv.h>
 #include <linux/uio.h>
 #include <linux/interrupt.h>
+#include <linux/set_memory.h>
 #include <asm/page.h>
 #include <asm/mshyperv.h>
 
@@ -474,6 +475,13 @@ static int __vmbus_establish_gpadl(struct vmbus_channel 
*channel,
        if (ret)
                return ret;
 
+       ret = set_memory_decrypted((unsigned long)kbuffer,
+                                  HVPFN_UP(size));
+       if (ret) {
+               pr_warn("Failed to set host visibility for new GPADL %d.\n", 
ret);
+               return ret;
+       }
+
        init_completion(&msginfo->waitevent);
        msginfo->waiting_channel = channel;
 
@@ -549,6 +557,11 @@ static int __vmbus_establish_gpadl(struct vmbus_channel 
*channel,
        }
 
        kfree(msginfo);
+
+       if (ret)
+               set_memory_encrypted((unsigned long)kbuffer,
+                                    HVPFN_UP(size));
+
        return ret;
 }
 
@@ -639,6 +652,7 @@ static int __vmbus_open(struct vmbus_channel *newchannel,
        struct vmbus_channel_open_channel *open_msg;
        struct vmbus_channel_msginfo *open_info = NULL;
        struct page *page = newchannel->ringbuffer_page;
+       struct vmbus_gpadl gpadl;
        u32 send_pages, recv_pages;
        unsigned long flags;
        int err;
@@ -759,7 +773,10 @@ static int __vmbus_open(struct vmbus_channel *newchannel,
 error_free_info:
        kfree(open_info);
 error_free_gpadl:
-       vmbus_teardown_gpadl(newchannel, newchannel->ringbuffer_gpadlhandle);
+       gpadl.gpadl_handle = newchannel->ringbuffer_gpadlhandle;
+       gpadl.buffer = page_address(newchannel->ringbuffer_page);
+       gpadl.size = (send_pages + recv_pages) << PAGE_SHIFT;
+       vmbus_teardown_gpadl(newchannel, &gpadl);
        newchannel->ringbuffer_gpadlhandle = 0;
 error_clean_ring:
        hv_ringbuffer_cleanup(&newchannel->outbound);
@@ -806,7 +823,7 @@ EXPORT_SYMBOL_GPL(vmbus_open);
 /*
  * vmbus_teardown_gpadl -Teardown the specified GPADL handle
  */
-int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
+int vmbus_teardown_gpadl(struct vmbus_channel *channel, struct vmbus_gpadl 
*gpadl)
 {
        struct vmbus_channel_gpadl_teardown *msg;
        struct vmbus_channel_msginfo *info;
@@ -825,7 +842,7 @@ int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 
gpadl_handle)
 
        msg->header.msgtype = CHANNELMSG_GPADL_TEARDOWN;
        msg->child_relid = channel->offermsg.child_relid;
-       msg->gpadl = gpadl_handle;
+       msg->gpadl = gpadl->gpadl_handle;
 
        spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
        list_add_tail(&info->msglistentry,
@@ -859,6 +876,12 @@ int vmbus_teardown_gpadl(struct vmbus_channel *channel, 
u32 gpadl_handle)
        spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 
        kfree(info);
+
+       ret = set_memory_encrypted((unsigned long)gpadl->buffer,
+                                  HVPFN_UP(gpadl->size));
+       if (ret)
+               pr_warn("Fail to set mem host visibility in GPADL teardown 
%d.\n", ret);
+
        return ret;
 }
 EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl);
@@ -896,6 +919,7 @@ void vmbus_reset_channel_cb(struct vmbus_channel *channel)
 static int vmbus_close_internal(struct vmbus_channel *channel)
 {
        struct vmbus_channel_close_channel *msg;
+       struct vmbus_gpadl gpadl;
        int ret;
 
        vmbus_reset_channel_cb(channel);
@@ -934,8 +958,10 @@ static int vmbus_close_internal(struct vmbus_channel 
*channel)
 
        /* Tear down the gpadl for the channel's ring buffer */
        else if (channel->ringbuffer_gpadlhandle) {
-               ret = vmbus_teardown_gpadl(channel,
-                                          channel->ringbuffer_gpadlhandle);
+               gpadl.gpadl_handle = channel->ringbuffer_gpadlhandle;
+               gpadl.buffer = page_address(channel->ringbuffer_page);
+               gpadl.size = channel->ringbuffer_pagecount;
+               ret = vmbus_teardown_gpadl(channel, &gpadl);
                if (ret) {
                        pr_err("Close failed: teardown gpadl return %d\n", ret);
                        /*
diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h
index bc48855dff10..aa7c9962dbd8 100644
--- a/drivers/net/hyperv/hyperv_net.h
+++ b/drivers/net/hyperv/hyperv_net.h
@@ -1082,6 +1082,7 @@ struct netvsc_device {
 
        /* Send buffer allocated by us */
        void *send_buf;
+       u32 send_buf_size;
        u32 send_buf_gpadl_handle;
        u32 send_section_cnt;
        u32 send_section_size;
diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index 7bd935412853..f19bffff6a63 100644
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -276,11 +276,14 @@ static void netvsc_teardown_recv_gpadl(struct hv_device 
*device,
                                       struct netvsc_device *net_device,
                                       struct net_device *ndev)
 {
+       struct vmbus_gpadl gpadl;
        int ret;
 
        if (net_device->recv_buf_gpadl_handle) {
-               ret = vmbus_teardown_gpadl(device->channel,
-                                          net_device->recv_buf_gpadl_handle);
+               gpadl.gpadl_handle = net_device->recv_buf_gpadl_handle;
+               gpadl.buffer = net_device->recv_buf;
+               gpadl.size = net_device->recv_buf_size;
+               ret = vmbus_teardown_gpadl(device->channel, &gpadl);
 
                /* If we failed here, we might as well return and have a leak
                 * rather than continue and a bugchk
@@ -298,11 +301,15 @@ static void netvsc_teardown_send_gpadl(struct hv_device 
*device,
                                       struct netvsc_device *net_device,
                                       struct net_device *ndev)
 {
+       struct vmbus_gpadl gpadl;
        int ret;
 
        if (net_device->send_buf_gpadl_handle) {
-               ret = vmbus_teardown_gpadl(device->channel,
-                                          net_device->send_buf_gpadl_handle);
+               gpadl.gpadl_handle = net_device->send_buf_gpadl_handle;
+               gpadl.buffer = net_device->send_buf;
+               gpadl.size = net_device->send_buf_size;
+
+               ret = vmbus_teardown_gpadl(device->channel, &gpadl);
 
                /* If we failed here, we might as well return and have a leak
                 * rather than continue and a bugchk
@@ -463,6 +470,7 @@ static int netvsc_init_buf(struct hv_device *device,
                ret = -ENOMEM;
                goto cleanup;
        }
+       net_device->send_buf_size = buf_size;
 
        /* Establish the gpadl handle for this buffer on this
         * channel.  Note: This call uses the vmbus connection rather
diff --git a/drivers/uio/uio_hv_generic.c b/drivers/uio/uio_hv_generic.c
index 652fe2547587..13c5df8dd11d 100644
--- a/drivers/uio/uio_hv_generic.c
+++ b/drivers/uio/uio_hv_generic.c
@@ -179,14 +179,24 @@ hv_uio_new_channel(struct vmbus_channel *new_sc)
 static void
 hv_uio_cleanup(struct hv_device *dev, struct hv_uio_private_data *pdata)
 {
+       struct vmbus_gpadl gpadl;
+
        if (pdata->send_gpadl) {
-               vmbus_teardown_gpadl(dev->channel, pdata->send_gpadl);
+               gpadl.gpadl_handle = pdata->send_gpadl;
+               gpadl.buffer = pdata->send_buf;
+               gpadl.size = SEND_BUFFER_SIZE;
+
+               vmbus_teardown_gpadl(dev->channel, &gpadl);
                pdata->send_gpadl = 0;
                vfree(pdata->send_buf);
        }
 
        if (pdata->recv_gpadl) {
-               vmbus_teardown_gpadl(dev->channel, pdata->recv_gpadl);
+               gpadl.gpadl_handle = pdata->recv_gpadl;
+               gpadl.buffer = pdata->recv_buf;
+               gpadl.size = RECV_BUFFER_SIZE;
+
+               vmbus_teardown_gpadl(dev->channel, &gpadl);
                pdata->recv_gpadl = 0;
                vfree(pdata->recv_buf);
        }
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index ddc8713ce57b..757e09606fd3 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -803,6 +803,12 @@ struct vmbus_device {
 
 #define VMBUS_DEFAULT_MAX_PKT_SIZE 4096
 
+struct vmbus_gpadl {
+       u32 gpadl_handle;
+       u32 size;
+       void *buffer;
+};
+
 struct vmbus_channel {
        struct list_head listentry;
 
@@ -1195,7 +1201,7 @@ extern int vmbus_establish_gpadl(struct vmbus_channel 
*channel,
                                      u32 *gpadl_handle);
 
 extern int vmbus_teardown_gpadl(struct vmbus_channel *channel,
-                                    u32 gpadl_handle);
+                                    struct vmbus_gpadl *gpadl);
 
 void vmbus_reset_channel_cb(struct vmbus_channel *channel);
 
-- 
2.25.1