Drivers: hv: Support confidential VMBus channels

To make use of Confidential VMBus channels, initialize the
co_ring_buffers and co_external_memory fields of the channel
structure.

Advertise support upon negotiating the version and compute
values for those fields and initialize them.

Signed-off-by: Roman Kisel <romank@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>

diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index 6d66cbc9030b230d80f169b7023118f189edfc44..74fed2c073d447033252cf2c9cf4492cd8ee6a5e 100644 (file)
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -1022,6 +1022,7 @@ static void vmbus_onoffer(struct vmbus_channel_message_header *hdr)
        struct vmbus_channel_offer_channel *offer;
        struct vmbus_channel *oldchannel, *newchannel;
        size_t offer_sz;
+       bool co_ring_buffer, co_external_memory;
 
        offer = (struct vmbus_channel_offer_channel *)hdr;
 
@@ -1034,6 +1035,22 @@ static void vmbus_onoffer(struct vmbus_channel_message_header *hdr)
                return;
        }
 
+       co_ring_buffer = is_co_ring_buffer(offer);
+       co_external_memory = is_co_external_memory(offer);
+       if (!co_ring_buffer && co_external_memory) {
+               pr_err("Invalid offer relid=%d: the ring buffer isn't encrypted\n",
+                       offer->child_relid);
+               return;
+       }
+       if (co_ring_buffer || co_external_memory) {
+               if (vmbus_proto_version < VERSION_WIN10_V6_0 || !vmbus_is_confidential()) {
+                       pr_err("Invalid offer relid=%d: no support for confidential VMBus\n",
+                               offer->child_relid);
+                       atomic_dec(&vmbus_connection.offer_in_progress);
+                       return;
+               }
+       }
+
        oldchannel = find_primary_channel_by_offer(offer);
 
        if (oldchannel != NULL) {
@@ -1112,6 +1129,8 @@ static void vmbus_onoffer(struct vmbus_channel_message_header *hdr)
                pr_err("Unable to allocate channel object\n");
                return;
        }
+       newchannel->co_ring_buffer = co_ring_buffer;
+       newchannel->co_external_memory = co_external_memory;
 
        vmbus_setup_channel_state(newchannel, offer);
 

diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
index 1fe3573ae52a4bd8ff258f93a0f9b1c7a5faeea4..5ac9232396f7cdf252f65ee67b716eb3f99d86af 100644 (file)
--- a/drivers/hv/connection.c
+++ b/drivers/hv/connection.c
@@ -105,6 +105,9 @@ int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo, u32 version)
                vmbus_connection.msg_conn_id = VMBUS_MESSAGE_CONNECTION_ID;
        }
 
+       if (vmbus_is_confidential() && version >= VERSION_WIN10_V6_0)
+               msg->feature_flags = VMBUS_FEATURE_FLAG_CONFIDENTIAL_CHANNELS;
+
        /*
         * shared_gpa_boundary is zero in non-SNP VMs, so it's safe to always
         * bitwise OR it