Add Xen console support

Add a Xen console driver so iPXE CLI can be accessed from the Xen PV console (hvc0).

(This applies when iPXE is run as an HVM guest in Xen)

src/arch/x86/drivers/xen/hvm.c

@@ -36,6 +36,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 #include <ipxe/xenstore.h>
 #include <ipxe/xenbus.h>
 #include <ipxe/xengrant.h>
+#include <interface/xen/xencon.h>
 #include "hvm.h"
 
 /** @file
@@ -405,6 +406,69 @@ static void hvm_unmap_xenstore ( struct hvm_device *hvm ) {
 	iounmap ( hvm->xen.store.intf );
 }
 
+/**
+ * Map Xen Console
+ *
+ * @v hvm		HVM device
+ * @ret rc		Return status code
+ */
+static int hvm_map_console ( struct hvm_device *hvm ) {
+	uint64_t console_evtchn=0;
+	uint64_t console_pfn=0;
+	physaddr_t console_phys;
+	int xenrc;
+	int rc;
+
+	/* Get Console event channel */
+	if ( ( xenrc = xen_hvm_get_param ( &hvm->xen, HVM_PARAM_CONSOLE_EVTCHN,
+					   &console_evtchn ) ) != 0 ) {
+		rc = -EXEN ( xenrc );
+		DBGC ( hvm, "HVM could not get Console event channel: %s\n",
+		       strerror ( rc ) );
+		return rc;
+	}
+	hvm->xen.console.port = console_evtchn;
+
+	/* Get Console PFN */
+	if ( ( xenrc = xen_hvm_get_param ( &hvm->xen, HVM_PARAM_CONSOLE_PFN,
+					   &console_pfn ) ) != 0 ) {
+		rc = -EXEN ( xenrc );
+		DBGC ( hvm, "HVM could not get Console PFN: %s\n",
+		       strerror ( rc ) );
+		return rc;
+	}
+	console_phys = ( console_pfn * PAGE_SIZE );
+
+	/* Map Xen Console */
+	hvm->xen.console.intf = pci_ioremap ( hvm->pci, console_phys, PAGE_SIZE );
+	if ( ! hvm->xen.console.intf ) {
+		DBGC ( hvm, "HVM could not map Xen Console at [%08lx,%08lx)\n",
+		       console_phys, ( console_phys + PAGE_SIZE ) );
+		return -ENODEV;
+	}
+	DBGC2 ( hvm,  "HVM mapped Xen Console at [%08lx,%08lx) with event port "
+		"%d\n", console_phys, ( console_phys + PAGE_SIZE ),
+		hvm->xen.console.port );
+
+    xencon_late_init(&hvm->xen);
+
+	return 0;
+}
+
+/**
+ * Unmap Xen Console
+ *
+ * @v hvm		HVM device
+ */
+static void hvm_unmap_console ( struct hvm_device *hvm ) {
+
+    xencon_uninit();
+
+	/* Unmap Xen Console */
+	iounmap ( hvm->xen.console.intf );
+}
+
+
 /**
  * Probe PCI device
  *
@@ -439,6 +503,8 @@ static int hvm_probe ( struct pci_device *pci ) {
 		goto err_map_shared_info;
 	if ( ( rc = hvm_map_grant ( hvm ) ) != 0 )
 		goto err_map_grant;
+	if ( ( rc = hvm_map_console ( hvm ) ) != 0 )
+		goto err_map_console;
 	if ( ( rc = hvm_map_xenstore ( hvm ) ) != 0 )
 		goto err_map_xenstore;
 
@@ -455,6 +521,8 @@ static int hvm_probe ( struct pci_device *pci ) {
 	xenbus_remove ( &hvm->xen, &pci->dev );
  err_xenbus_probe:
 	hvm_unmap_xenstore ( hvm );
+ err_map_console:
+	hvm_unmap_console ( hvm );
  err_map_xenstore:
 	hvm_unmap_grant ( hvm );
  err_map_grant:
@@ -478,6 +546,7 @@ static void hvm_remove ( struct pci_device *pci ) {
 
 	xenbus_remove ( &hvm->xen, &pci->dev );
 	hvm_unmap_xenstore ( hvm );
+	hvm_unmap_console ( hvm );
 	hvm_unmap_grant ( hvm );
 	hvm_unmap_shared_info ( hvm );
 	hvm_unmap_hypercall ( hvm );

src/config/config.c

@@ -78,6 +78,9 @@ REQUIRE_OBJECT ( vmconsole );
 #ifdef CONSOLE_DEBUGCON
 REQUIRE_OBJECT ( debugcon );
 #endif
+#ifdef CONSOLE_XENCON
+REQUIRE_OBJECT ( xencon );
+#endif
 
 /*
  * Drag in all requested network protocols

src/config/console.h

@@ -41,6 +41,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 //#define	CONSOLE_VMWARE		/* VMware logfile console */
 //#define	CONSOLE_DEBUGCON	/* Bochs/QEMU/KVM debug port console */
 //#define	CONSOLE_INT13		/* INT13 disk log console */
+//#define	CONSOLE_XENCON		/* XEN Console */
 
 /*
  * Very obscure console types

src/config/defaults/linux.h

@@ -10,6 +10,7 @@
 FILE_LICENCE ( GPL2_OR_LATER );
 
 #define CONSOLE_LINUX
+#define CONSOLE_XENCON
 #define TIMER_LINUX
 #define UACCESS_LINUX
 #define UMALLOC_LINUX

src/include/ipxe/xen.h

@@ -16,6 +16,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 #include <ipxe/bitops.h>
 #include <ipxe/uaccess.h>
 #include <xen/xen.h>
+#include <xen/console.h>
 #include <xen/event_channel.h>
 
 /* Memory barrier macros used by ring.h */
@@ -47,6 +48,16 @@ struct xen_store {
 	evtchn_port_t port;
 };
 
+/** A Xen Console */
+struct xencons_info {
+
+    /** Event Channel */
+	evtchn_port_t port;
+
+    /* Console interface */
+    volatile struct xencons_interface *intf;
+};
+
 /** A Xen hypervisor */
 struct xen_hypervisor {
 	/** Hypercall table */
@@ -57,6 +68,8 @@ struct xen_hypervisor {
 	struct xen_grant grant;
 	/** XenStore */
 	struct xen_store store;
+    /** Console */
+    struct xencons_info console;
 };
 
 /**

src/include/xen/console.h

@@ -0,0 +1,51 @@
+/******************************************************************************
+ * console.h
+ * 
+ * Console I/O interface for Xen guest OSes.
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (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.
+ *
+ * Copyright (c) 2005, Keir Fraser
+ */
+
+#ifndef __XEN_PUBLIC_IO_CONSOLE_H__
+#define __XEN_PUBLIC_IO_CONSOLE_H__
+
+typedef uint32_t XENCONS_RING_IDX;
+
+#define MASK_XENCONS_IDX(idx, ring) ((idx) & (sizeof(ring)-1))
+
+struct xencons_interface {
+    char in[1024];
+    char out[2048];
+    XENCONS_RING_IDX in_cons, in_prod;
+    XENCONS_RING_IDX out_cons, out_prod;
+};
+
+#endif /* __XEN_PUBLIC_IO_CONSOLE_H__ */
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */

src/interface/xen/xencon.c

@@ -0,0 +1,149 @@
+/*
+ * Copyright (C)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+/** @file
+ *
+ * Xen console
+ *
+ */
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <ipxe/io.h>
+#include <ipxe/console.h>
+#include <ipxe/init.h>
+#include <ipxe/xen.h>
+#include <ipxe/xenevent.h>
+#include <config/console.h>
+#include <interface/xen/xencon.h>
+
+/* Set default console usage if applicable */
+#if ! ( defined ( CONSOLE_XENCON ) && CONSOLE_EXPLICIT ( CONSOLE_XENCON ) )
+#undef CONSOLE_XENCON
+#define CONSOLE_XENCON ( CONSOLE_USAGE_ALL & ~CONSOLE_USAGE_DEBUG)
+#endif
+
+static struct xen_hypervisor *g_xen = NULL;
+
+static inline void notify_daemon(struct xencons_info *cons)
+{
+	struct evtchn_send event = { .port = cons->port };
+	xenevent_send(g_xen, &event);
+}
+
+
+/**
+ * Print a character to debug port console
+ *
+ * @v character		Character to be printed
+ */
+static void xencon_putchar ( int character ) {
+
+	XENCONS_RING_IDX cons, prod;
+	volatile struct xencons_interface *intf = g_xen->console.intf;
+
+
+	prod = intf->out_prod;
+	do
+	{
+		cons = intf->out_cons;
+	}while(MASK_XENCONS_IDX(prod-cons+1, intf->out) == 0);
+
+	intf->out[MASK_XENCONS_IDX(prod++, intf->out)] = character;
+
+	wmb();			/* write ring before updating pointer */
+	intf->out_prod = prod;
+
+	notify_daemon(&g_xen->console);
+}
+
+/**
+ * Get character from console
+ *
+ * @ret character	Character read from console
+ */
+static int xencon_getchar ( void ) {
+	XENCONS_RING_IDX cons, prod;
+	volatile struct xencons_interface *intf = g_xen->console.intf;
+	uint8_t data;
+
+	cons = intf->in_cons;
+
+	/* Wait for data to be ready */
+	do {
+		prod = intf->in_prod;
+	} while(cons == prod);
+
+	/* Receive data */
+	data = intf->in[MASK_XENCONS_IDX(cons++, intf->in)];
+
+	intf->in_cons = cons;
+
+	/* convert DEL to backspace */
+	if ( data == 0x7f )
+		data = 0x08;
+
+	return data;
+}
+
+/**
+ * Check for character ready to read from console
+ *
+ * @ret True		Character available to read
+ * @ret False		No character available to read
+ */
+static int xencon_iskey ( void ) {
+	volatile struct xencons_interface *intf = g_xen->console.intf;
+	return intf->in_cons != intf->in_prod;
+}
+
+/** Xen port console driver */
+struct console_driver xencon_console __console_driver = {
+	.putchar = xencon_putchar,
+	.getchar = xencon_getchar,
+	.iskey = xencon_iskey,
+	.usage = CONSOLE_XENCON,
+	.disabled = CONSOLE_DISABLED,
+};
+
+/*
+ * Initialize xen console
+ */
+void xencon_late_init(struct xen_hypervisor *xen)
+{
+	g_xen = xen;
+	xencon_console.disabled = 0;
+}
+
+/*
+ * Shutdown xen console
+ */
+void xencon_uninit(void)
+{
+	xencon_console.disabled = CONSOLE_DISABLED;
+	g_xen = NULL;
+}
+
+

src/interface/xen/xencon.h

@@ -0,0 +1,14 @@
+#ifndef _XENCON_H
+#define _XENCON_H
+
+/** @file
+ *
+ * Xen Console driver
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+void xencon_late_init(struct xen_hypervisor *xen);
+void xencon_uninit(void);
+#endif