ui/gtk: add a keyboard fifo to the VTE consoles

Since commit 8eb13bbbac ("ui/gtk: vte: fix sending multiple
characeters") it's very easy to lock up QEMU with the GTK ui.
If you configure a guest with a serial device and the guest
doesn't listen on this device, QEMU will lock up after
entering two characters in the serial console. That's because
current code uses a busy loop for the chardev write retries
and the busy loop doesn't terminate in this case.

To fix this problem add a fifo to the VTE consoles and use the
chr_accept_input() callback function to write the remaining
characters in the queue to the chardev.

The fifo has a size of 4096 bytes, so one can copy and paste
a fairly large URL or file path.

Fixes: 8eb13bbbac ("ui/gtk: vte: fix sending multiple characeters")
Signed-off-by: Volker Rümelin <vr_qemu@t-online.de>
Message-Id: <20210725165039.5242-1-vr_qemu@t-online.de>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
This commit is contained in:
Volker Rümelin 2021-07-25 18:50:39 +02:00 committed by Gerd Hoffmann
parent d4a1210480
commit 584af1f1d9
2 changed files with 37 additions and 9 deletions

View File

@ -25,6 +25,9 @@
#include "ui/egl-helpers.h"
#include "ui/egl-context.h"
#endif
#ifdef CONFIG_VTE
#include "qemu/fifo8.h"
#endif
#define MAX_VCS 10
@ -62,6 +65,7 @@ typedef struct VirtualVteConsole {
GtkWidget *scrollbar;
GtkWidget *terminal;
Chardev *chr;
Fifo8 out_fifo;
bool echo;
} VirtualVteConsole;
#endif

View File

@ -1640,6 +1640,25 @@ static void gd_vc_adjustment_changed(GtkAdjustment *adjustment, void *opaque)
}
}
static void gd_vc_send_chars(VirtualConsole *vc)
{
uint32_t len, avail;
len = qemu_chr_be_can_write(vc->vte.chr);
avail = fifo8_num_used(&vc->vte.out_fifo);
if (len > avail) {
len = avail;
}
while (len > 0) {
const uint8_t *buf;
uint32_t size;
buf = fifo8_pop_buf(&vc->vte.out_fifo, len, &size);
qemu_chr_be_write(vc->vte.chr, (uint8_t *)buf, size);
len -= size;
}
}
static int gd_vc_chr_write(Chardev *chr, const uint8_t *buf, int len)
{
VCChardev *vcd = VC_CHARDEV(chr);
@ -1649,6 +1668,14 @@ static int gd_vc_chr_write(Chardev *chr, const uint8_t *buf, int len)
return len;
}
static void gd_vc_chr_accept_input(Chardev *chr)
{
VCChardev *vcd = VC_CHARDEV(chr);
VirtualConsole *vc = vcd->console;
gd_vc_send_chars(vc);
}
static void gd_vc_chr_set_echo(Chardev *chr, bool echo)
{
VCChardev *vcd = VC_CHARDEV(chr);
@ -1688,6 +1715,7 @@ static void char_gd_vc_class_init(ObjectClass *oc, void *data)
cc->parse = qemu_chr_parse_vc;
cc->open = gd_vc_open;
cc->chr_write = gd_vc_chr_write;
cc->chr_accept_input = gd_vc_chr_accept_input;
cc->chr_set_echo = gd_vc_chr_set_echo;
}
@ -1702,6 +1730,7 @@ static gboolean gd_vc_in(VteTerminal *terminal, gchar *text, guint size,
gpointer user_data)
{
VirtualConsole *vc = user_data;
uint32_t free;
if (vc->vte.echo) {
VteTerminal *term = VTE_TERMINAL(vc->vte.terminal);
@ -1721,16 +1750,10 @@ static gboolean gd_vc_in(VteTerminal *terminal, gchar *text, guint size,
}
}
int remaining = size;
uint8_t* p = (uint8_t *)text;
while (remaining > 0) {
int can_write = qemu_chr_be_can_write(vc->vte.chr);
int written = MIN(remaining, can_write);
qemu_chr_be_write(vc->vte.chr, p, written);
free = fifo8_num_free(&vc->vte.out_fifo);
fifo8_push_all(&vc->vte.out_fifo, (uint8_t *)text, MIN(free, size));
gd_vc_send_chars(vc);
remaining -= written;
p += written;
}
return TRUE;
}
@ -1747,6 +1770,7 @@ static GSList *gd_vc_vte_init(GtkDisplayState *s, VirtualConsole *vc,
vc->s = s;
vc->vte.echo = vcd->echo;
vc->vte.chr = chr;
fifo8_create(&vc->vte.out_fifo, 4096);
vcd->console = vc;
snprintf(buffer, sizeof(buffer), "vc%d", idx);