Re: [patch 16/20] XEN-paravirt: Add the Xen virtual console driver.
Pavel Machek wrote: > You have drivers/xen... so maybe arch/i386/xen is easier to type? > arch/i386/paravirt/xen would make some sense, too, but it looks too > deep to me. I think the exact placement of these files needs a bit of work. I don't much care about xen/ vs paravirt/xen vs paravirt-xen/, but placement of headers needs a bit more thought. lhype, er, lguest and vmi are in kernel/, but I think it would be nice to put them near Xen. J - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [patch 16/20] XEN-paravirt: Add the Xen virtual console driver.
Hi! > This provides a bootstrap and ongoing emergency console which is > intended to be available from very early during boot and at all times > thereafter, in contrast with alternatives such as UDP-based syslogd, > or logging in via ssh. The protocol is based on a simple shared-memory > ring buffer. > > Signed-off-by: Ian Pratt <[EMAIL PROTECTED]> > Signed-off-by: Christian Limpach <[EMAIL PROTECTED]> > Signed-off-by: Chris Wright <[EMAIL PROTECTED]> > > --- > arch/i386/kernel/early_printk.c|2 > arch/i386/paravirt-xen/enlighten.c |3 > drivers/Makefile |3 > drivers/xen/Makefile |1 You have drivers/xen... so maybe arch/i386/xen is easier to type? arch/i386/paravirt/xen would make some sense, too, but it looks too deep to me. Pavel -- Thanks for all the (sleeping) penguins. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [patch 16/20] XEN-paravirt: Add the Xen virtual console driver.
Alan wrote: > Andrew: No objection to this tty stuff being merged provided the bugs > noted above (not worried about the sign stuff) are fixed before it goes > on to Linus. > Thanks for the comments. I'll see if I can put together a fixup patch before LCA, but possibly not. J - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [patch 16/20] XEN-paravirt: Add the Xen virtual console driver.
> +#endif
> + tty_insert_flip_char(xencons_tty, buf[i], 0);
Please use the defines like TTY_NORMAL not just 0.
> + if ((xencons_tty->flags & (1 << TTY_DO_WRITE_WAKEUP)) &&
> + (xencons_tty->ldisc.write_wakeup != NULL))
> + (xencons_tty->ldisc.write_wakeup)(xencons_tty);
> + }
You are't allowed to derefence and call ldisc methods without
holding the lock. You can replace that chunk with a call to the helper
function tty_wakeup(tty). Small but real race condition otherwise as you
xencons_tty->ldisc may be changing as you call it.
> +static inline int __xencons_put_char(int ch)
> +{
> + char _ch = (char)ch;
> + if ((wp - wc) == wbuf_size)
> + return 0;
> + wbuf[WBUF_MASK(wp++)] = _ch;
> + return 1;
> +}
A lot of very confusing sign stuff here - you turn an int into a char and
put it into a uchar array
> + for (i = 0; i < count; i++)
> + if (!__xencons_put_char(buf[i]))
> + break;
The int coming from a uchar array
Don't think its wrong - just acutely weird and perhaps could be tidier
> +static void xencons_close(struct tty_struct *tty, struct file *filp)
> +{
> + unsigned long flags;
> +
> + mutex_lock(&tty_mutex);
It would be good in future if you could avoid using tty_mutex and use a
private lock. At the moment vt "borrows" it and there are a couple of
incestuous spots but the plan is to eventually fix them and make it
private to tty_io.
Andrew: No objection to this tty stuff being merged provided the bugs
noted above (not worried about the sign stuff) are fixed before it goes
on to Linus.
Alan
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Please read the FAQ at http://www.tux.org/lkml/
[patch 16/20] XEN-paravirt: Add the Xen virtual console driver.
This provides a bootstrap and ongoing emergency console which is
intended to be available from very early during boot and at all times
thereafter, in contrast with alternatives such as UDP-based syslogd,
or logging in via ssh. The protocol is based on a simple shared-memory
ring buffer.
Signed-off-by: Ian Pratt <[EMAIL PROTECTED]>
Signed-off-by: Christian Limpach <[EMAIL PROTECTED]>
Signed-off-by: Chris Wright <[EMAIL PROTECTED]>
---
arch/i386/kernel/early_printk.c|2
arch/i386/paravirt-xen/enlighten.c |3
drivers/Makefile |3
drivers/xen/Makefile |1
drivers/xen/console/Makefile |2
drivers/xen/console/console.c | 588
drivers/xen/console/xencons_ring.c | 144
include/xen/xencons.h | 14
init/main.c|2
9 files changed, 759 insertions(+)
===
--- a/arch/i386/kernel/early_printk.c
+++ b/arch/i386/kernel/early_printk.c
@@ -1,2 +1,4 @@
+#ifndef CONFIG_XEN
#include "../../x86_64/kernel/early_printk.c"
+#endif
===
--- a/arch/i386/paravirt-xen/enlighten.c
+++ b/arch/i386/paravirt-xen/enlighten.c
@@ -798,6 +798,9 @@ static asmlinkage void __init xen_start_
INITRD_START = xen_start_info->mod_start ?
__pa(xen_start_info->mod_start) : 0;
INITRD_SIZE = xen_start_info->mod_len;
+ /* use Xen console */
+ vgacon_enabled = 0;
+
/* Start the world */
start_kernel();
}
===
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -14,6 +14,9 @@ obj-$(CONFIG_ACPI)+= acpi/
# was used and do nothing if so
obj-$(CONFIG_PNP) += pnp/
obj-$(CONFIG_ARM_AMBA) += amba/
+
+# Xen is the default console when running as a guest
+obj-$(CONFIG_XEN) += xen/
# char/ comes before serial/ etc so that the VT console is the boot-time
# default.
===
--- /dev/null
+++ b/drivers/xen/Makefile
@@ -0,0 +1,1 @@
+obj-y += console/
===
--- /dev/null
+++ b/drivers/xen/console/Makefile
@@ -0,0 +1,2 @@
+
+obj-y := console.o xencons_ring.o
===
--- /dev/null
+++ b/drivers/xen/console/console.c
@@ -0,0 +1,588 @@
+/**
+ * console.c
+ *
+ * Virtual console driver.
+ *
+ * Copyright (c) 2002-2004, K A Fraser.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation; or, when distributed
+ * separately from the Linux kernel or incorporated into other
+ * software packages, subject to the following license:
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this source file (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy, modify,
+ * merge, publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+
+#include
+#include
+#include
+#include
+#include
+#include
+#include "../../../arch/i386/paravirt-xen/events.h"
+#include
+
+MODULE_LICENSE("Dual BSD/GPL");
+
+static int xc_disabled = 0;
+static int xc_num = -1;
+
+/* /dev/xvc0 device number allocated by lanana.org. */
+#define XEN_XVC_MAJOR 204
+#define XEN_XVC_MINOR 191
+
+#ifdef CONFIG_MAGIC_SYSRQ
+static unsigned long sysrq_requested;
+#endif
+
+static int __init xencons_setup(char *str)
+{
+ if (!strcmp(str, "off"))
+ xc_disabled = 1;
+ return 1;
+}
+__setup("xencons=", xencons_setup);
+
+/* The kernel and user-land drivers share a common transmit buffer. */
+static u
