virgl: Add command and flags to initiate debugging on the host (v2)

On the host VREND_DEBUG=guestallow must be set to let the guest override
the debug flags.

v2: Send flag string instead of flags, this avoids the need to keep
    the flags in sync.
v3: Only request host logging if the host actually understands the command

Signed-off-by: Gert Wollny <[email protected]>
Reviewed-by: Erik Faye-Lund <[email protected]>

1 files changed, 8 insertions, 0 deletions

diff --git a/src/gallium/drivers/virgl/virgl_context.c b/src/gallium/drivers/virgl/virgl_context.c
index 4511bf3b2fb..96932c473d8 100644
--- a/src/gallium/drivers/virgl/virgl_context.c
+++ b/src/gallium/drivers/virgl/virgl_context.c
@@ -1164,6 +1164,7 @@ struct pipe_context *virgl_context_create(struct pipe_screen *pscreen,
    struct virgl_context *vctx;
    struct virgl_screen *rs = virgl_screen(pscreen);
    vctx = CALLOC_STRUCT(virgl_context);
+   const char *host_debug_flagstring;
 
    vctx->cbuf = rs->vws->cmd_buf_create(rs->vws);
    if (!vctx->cbuf) {
@@ -1268,6 +1269,13 @@ struct pipe_context *virgl_context_create(struct pipe_screen *pscreen,
    virgl_encoder_create_sub_ctx(vctx, vctx->hw_sub_ctx_id);
 
    virgl_encoder_set_sub_ctx(vctx, vctx->hw_sub_ctx_id);
+
+   if (rs->caps.caps.v2.capability_bits & VIRGL_CAP_GUEST_MAY_INIT_LOG) {
+      host_debug_flagstring = getenv("VIRGL_HOST_DEBUG");
+      if (host_debug_flagstring)
+         virgl_encode_host_debug_flagstring(vctx, host_debug_flagstring);
+   }
+
    return &vctx->base;
 fail:
    return NULL;