From 4be62d311791bf9d318f5139439d170ad5112279 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Marc-Andr=C3=A9=20Lureau?= Date: Mon, 27 Oct 2025 16:47:11 +0400 Subject: [PATCH] ui/vdagent: fix windows agent regression MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Since commit f626116f ("ui/vdagent: factor out clipboard peer registration"), the QEMU clipboard serial is reset whenever the vdagent chardev receives the guest caps. This triggers a CHR_EVENT_CLOSED which is handled by virtio_serial_close() to notify the guest. The "reconnection logic" is there to reset the agent when a client (dbus, spice etc) reconnects, or the agent is restarted. It is required to sync the clipboard serials and to prevent races or loops due to clipboard managers on both ends (but this is not implemented by windows vdagent). The Unix agent has been reconnecting without resending caps, thus working with this approach. However, the Windows agent does not seem to have a way to handle VIRTIO_CONSOLE_PORT_OPEN=0 event and do not receive further data... Let's not trigger this disconnection/reset logic if the agent does not support VD_AGENT_CAP_CLIPBOARD_GRAB_SERIAL. Fixes: f626116f ("ui/vdagent: factor out clipboard peer registration") Signed-off-by: Marc-André Lureau Reported-by: Lucas Kornicki Tested-by: Fiona Ebner Reviewed-by: Fiona Ebner Tested-by: Lucas Kornicki --- ui/vdagent.c | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-) diff --git a/ui/vdagent.c b/ui/vdagent.c index ddb91e75c64..660686c9c0b 100644 --- a/ui/vdagent.c +++ b/ui/vdagent.c @@ -316,6 +316,15 @@ static bool have_selection(VDAgentChardev *vd) return vd->caps & (1 << VD_AGENT_CAP_CLIPBOARD_SELECTION); } +static bool have_clipboard_serial(VDAgentChardev *vd) +{ +#if CHECK_SPICE_PROTOCOL_VERSION(0, 14, 1) + return vd->caps & (1 << VD_AGENT_CAP_CLIPBOARD_GRAB_SERIAL); +#else + return false; +#endif +} + static uint32_t type_qemu_to_vdagent(enum QemuClipboardType type) { switch (type) { @@ -345,8 +354,7 @@ static void vdagent_send_clipboard_grab(VDAgentChardev *vd, return; } -#if CHECK_SPICE_PROTOCOL_VERSION(0, 14, 1) - if (vd->caps & (1 << VD_AGENT_CAP_CLIPBOARD_GRAB_SERIAL)) { + if (have_clipboard_serial(vd)) { if (!info->has_serial) { /* client should win */ info->serial = vd->last_serial[info->selection]++; @@ -356,7 +364,6 @@ static void vdagent_send_clipboard_grab(VDAgentChardev *vd, data++; msg->size += sizeof(uint32_t); } -#endif for (q = 0; q < QEMU_CLIPBOARD_TYPE__COUNT; q++) { type = type_qemu_to_vdagent(q); @@ -464,6 +471,9 @@ static void vdagent_clipboard_reset_serial(VDAgentChardev *vd) { Chardev *chr = CHARDEV(vd); + if (!have_clipboard_serial(vd)) { + return; + } /* reopen the agent connection to reset the serial state */ qemu_chr_be_event(chr, CHR_EVENT_CLOSED); /* OPENED again after the guest disconnected, see set_fe_open */ @@ -518,8 +528,7 @@ static void vdagent_clipboard_recv_grab(VDAgentChardev *vd, uint8_t s, uint32_t trace_vdagent_cb_grab_selection(GET_NAME(sel_name, s)); info = qemu_clipboard_info_new(&vd->cbpeer, s); -#if CHECK_SPICE_PROTOCOL_VERSION(0, 14, 1) - if (vd->caps & (1 << VD_AGENT_CAP_CLIPBOARD_GRAB_SERIAL)) { + if (have_clipboard_serial(vd)) { if (size < sizeof(uint32_t)) { /* this shouldn't happen! */ return; @@ -537,7 +546,6 @@ static void vdagent_clipboard_recv_grab(VDAgentChardev *vd, uint8_t s, uint32_t data += sizeof(uint32_t); size -= sizeof(uint32_t); } -#endif if (size > sizeof(uint32_t) * 10) { /* * spice has 6 types as of 2021. Limiting to 10 entries -- 2.47.3