[PATCH hyperv-next v3 13/15] Drivers: hv: Support confidential VMBus channels

[Roman Kisel]

To run a confidential VMBus channels, one has to initialize the
co_ring_buffers and co_external_memory fields of the channel
structure.

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

Signed-off-by: Roman Kisel <rom...@linux.microsoft.com>
---
 drivers/hv/channel_mgmt.c | 19 +++++++++++++++++++
 drivers/hv/connection.c   |  3 +++
 2 files changed, 22 insertions(+)

diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index ca2fe10c110a..33bc29e826bd 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -1021,6 +1021,7 @@ 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;
 
@@ -1033,6 +1034,22 @@ static void vmbus_onoffer(struct 
vmbus_channel_message_header *hdr)
                return;
        }
 
+       co_ring_buffer = is_co_ring_buffer(offer);
+       if (co_ring_buffer) {
+               if (vmbus_proto_version < VERSION_WIN10_V6_0 || 
!vmbus_is_confidential()) {
+                       atomic_dec(&vmbus_connection.offer_in_progress);
+                       return;
+               }
+       }
+
+       co_external_memory = is_co_external_memory(offer);
+       if (is_co_external_memory(offer)) {
+               if (vmbus_proto_version < VERSION_WIN10_V6_0 || 
!vmbus_is_confidential()) {
+                       atomic_dec(&vmbus_connection.offer_in_progress);
+                       return;
+               }
+       }
+
        oldchannel = find_primary_channel_by_offer(offer);
 
        if (oldchannel != NULL) {
@@ -1111,6 +1128,8 @@ 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 be490c598785..eeb472019d69 100644
--- 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
-- 
2.43.0