qemu/Make-char-muxer-more-robust-wrt-small-FI.patch
Bruce Rogers 0f796dd004 Accepting request 730437 from Virtualization:Staging
Update to v4.1.0. Also includes other major packaging changes as follows:
There is a new package maintenance workflow - see README.PACKAGING for details.
The sibling packages qemu-linux-user and qemu-testsuite are now created with the Build Service's MultiBuild feature. This also necessitates combining the qemu-linux-user changelog content back into qemu's. Luckily the delta there is quite small. Note that the qemu spec file is now that much busier, but added section markers should help reduce the confusion. Also qemu is being enabled for RISCV host compatibility, so some changes are related to that as well.

OBS-URL: https://build.opensuse.org/request/show/730437
OBS-URL: https://build.opensuse.org/package/show/Virtualization/qemu?expand=0&rev=487
2019-09-12 15:54:03 +00:00

119 lines
4.0 KiB
Diff

From: Alexander Graf <agraf@suse.de>
Date: Thu, 1 Apr 2010 17:36:23 +0200
Subject: 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]
[BR: minor edits to pass qemu's checkpatch script]
Signed-off-by: Bruce Rogers <brogers@suse.com>
---
chardev/char-fe.c | 1 +
chardev/char-mux.c | 16 ++++++++++++++++
chardev/char.c | 1 +
include/chardev/char-mux.h | 3 +++
tests/test-char.c | 1 +
5 files changed, 22 insertions(+)
diff --git a/chardev/char-fe.c b/chardev/char-fe.c
index f3530a90e6364d813097105b6113..f8aa0daf31692810efc7d5ca32eb 100644
--- a/chardev/char-fe.c
+++ b/chardev/char-fe.c
@@ -21,6 +21,7 @@
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
+#define HW_POISON_H /* avoid poison since we patch against rules it "enforces" */
#include "qemu/osdep.h"
#include "qemu/error-report.h"
#include "qapi/error.h"
diff --git a/chardev/char-mux.c b/chardev/char-mux.c
index 200c62a0d08bd779de8efdc95aad..10acb4fce1d3bda0d9f818eeb5ee 100644
--- a/chardev/char-mux.c
+++ b/chardev/char-mux.c
@@ -22,6 +22,7 @@
* THE SOFTWARE.
*/
+#define HW_POISON_H /* avoid poison since we patch against rules it "enforces" */
#include "qemu/osdep.h"
#include "qapi/error.h"
#include "qemu/module.h"
@@ -191,6 +192,17 @@ 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)
@@ -325,6 +337,10 @@ 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.c b/chardev/char.c
index 7b6b2cb12300042c6adf257e188c..d2134d72f60e58f35ee9e7869db4 100644
--- a/chardev/char.c
+++ b/chardev/char.c
@@ -22,6 +22,7 @@
* THE SOFTWARE.
*/
+#define HW_POISON_H /* avoid poison since we patch against rules it "enforces" */
#include "qemu/osdep.h"
#include "qemu/cutils.h"
#include "monitor/monitor.h"
diff --git a/include/chardev/char-mux.h b/include/chardev/char-mux.h
index 572cefd517c8fa9d605cbd10fc21..6e80785bd9c12b85e747fa9f924e 100644
--- a/include/chardev/char-mux.h
+++ b/include/chardev/char-mux.h
@@ -34,6 +34,9 @@ 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;
diff --git a/tests/test-char.c b/tests/test-char.c
index f9440cdcfdb51f98b2f6542e6f21..d1f99632de1acb95ba8e1b4a8584 100644
--- a/tests/test-char.c
+++ b/tests/test-char.c
@@ -1,3 +1,4 @@
+#define HW_POISON_H /* avoid poison since we patch against rules it "enforces" */
#include "qemu/osdep.h"
#include <glib/gstdio.h>