e9354b5825
1 OBS-URL: https://build.opensuse.org/request/show/483217 OBS-URL: https://build.opensuse.org/package/show/Virtualization/qemu?expand=0&rev=331
72 lines
2.5 KiB
Diff
72 lines
2.5 KiB
Diff
From a1893eb93c3e6a59108e3b2d6db315323b44bb39 Mon Sep 17 00:00:00 2001
|
|
From: Alexander Graf <agraf@suse.de>
|
|
Date: Thu, 1 Apr 2010 17:36:23 +0200
|
|
Subject: [PATCH] Make char muxer more robust wrt small FIFOs
|
|
|
|
Virtio-Console can only process one character at a time. Using it on S390
|
|
gave me strage "lags" where I got the character I pressed before when
|
|
pressing one. So I typed in "abc" and only received "a", then pressed "d"
|
|
but the guest received "b" and so on.
|
|
|
|
While the stdio driver calls a poll function that just processes on its
|
|
queue in case virtio-console can't take multiple characters at once, the
|
|
muxer does not have such callbacks, so it can't empty its queue.
|
|
|
|
To work around that limitation, I introduced a new timer that only gets
|
|
active when the guest can not receive any more characters. In that case
|
|
it polls again after a while to check if the guest is now receiving input.
|
|
|
|
This patch fixes input when using -nographic on s390 for me.
|
|
|
|
[AF: Rebased for v2.7.0-rc2]
|
|
---
|
|
chardev/char-mux.c | 13 +++++++++++++
|
|
chardev/char-mux.h | 3 +++
|
|
2 files changed, 16 insertions(+)
|
|
|
|
diff --git a/chardev/char-mux.c b/chardev/char-mux.c
|
|
index 5547a36..7b80dc8 100644
|
|
--- a/chardev/char-mux.c
|
|
+++ b/chardev/char-mux.c
|
|
@@ -179,6 +179,15 @@ static void mux_chr_accept_input(Chardev *chr)
|
|
be->chr_read(be->opaque,
|
|
&d->buffer[m][d->cons[m]++ & MUX_BUFFER_MASK], 1);
|
|
}
|
|
+
|
|
+#if defined(TARGET_S390X)
|
|
+ /* We're still not able to sync producer and consumer, so let's wait a bit
|
|
+ and try again by then. */
|
|
+ if (d->prod[m] != d->cons[m]) {
|
|
+ qemu_mod_timer(d->accept_timer, qemu_get_clock_ns(vm_clock)
|
|
+ + (int64_t)100000);
|
|
+ }
|
|
+#endif
|
|
}
|
|
|
|
static int mux_chr_can_read(void *opaque)
|
|
@@ -308,6 +317,10 @@ static void qemu_chr_open_mux(Chardev *chr,
|
|
}
|
|
|
|
d->focus = -1;
|
|
+#if defined(TARGET_S390X)
|
|
+ d->accept_timer = qemu_new_timer_ns(vm_clock,
|
|
+ (QEMUTimerCB*)mux_chr_accept_input, chr);
|
|
+#endif
|
|
/* only default to opened state if we've realized the initial
|
|
* set of muxes
|
|
*/
|
|
diff --git a/chardev/char-mux.h b/chardev/char-mux.h
|
|
index 9a2fffc..d5f419c 100644
|
|
--- a/chardev/char-mux.h
|
|
+++ b/chardev/char-mux.h
|
|
@@ -35,6 +35,9 @@ typedef struct MuxChardev {
|
|
Chardev parent;
|
|
CharBackend *backends[MAX_MUX];
|
|
CharBackend chr;
|
|
+#if defined(TARGET_S390X)
|
|
+ QEMUTimer *accept_timer;
|
|
+#endif
|
|
int focus;
|
|
int mux_cnt;
|
|
int term_got_escape;
|