When the confidential VMBus is available, the guest should post
messages to the paravisor.
Update hv_post_message() to post messages to the paravisor rather than
through GHCB or TD calls.
Signed-off-by: Roman Kisel <romank@xxxxxxxxxxxxxxxxxxx>
Reviewed-by: Tianyu Lan <tiala@xxxxxxxxxxxxx>
Reviewed-by: Michael Kelley <mhklinux@xxxxxxxxxxx>
---
drivers/hv/hv.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index fe97591bc44d..951330ca4ba9 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -76,7 +76,11 @@ int hv_post_message(union hv_connection_id connection_id,
aligned_msg->payload_size = payload_size;
memcpy((void *)aligned_msg->payload, payload, payload_size);
- if (ms_hyperv.paravisor_present) {
+ if (ms_hyperv.paravisor_present && !vmbus_is_confidential()) {
+ /*
+ * If the VMBus isn't confidential, use the CoCo-specific
+ * mechanism to communicate with the hypervisor.
+ */
if (hv_isolation_type_tdx())
status = hv_tdx_hypercall(HVCALL_POST_MESSAGE,
virt_to_phys(aligned_msg), 0);
@@ -90,6 +94,11 @@ int hv_post_message(union hv_connection_id connection_id,
u64 control = HVCALL_POST_MESSAGE;
control |= hv_nested ? HV_HYPERCALL_NESTED : 0;
+ /*
+ * If there is no paravisor, this will go to the hypervisor.
+ * In the Confidential VMBus case, there is the paravisor
+ * to which this will trap.
+ */
status = hv_do_hypercall(control, aligned_msg, NULL);
}
--
2.43.0
