Stefano Stabellini
2012-Jan-27 18:30 UTC
[PATCH v2 0/2] Xen (PV and HVM) multiple PV consoles
Hi all,
this small patch series (sent before a few times) achieves two goals:
- make PV consoles work for PV on HVM guests;
- implement support for multiple PV consoles for PV and PV on HVM guests.
Changes in v2:
- nicer safety check in patch #1;
- kzalloc instead of kmalloc;
- removed the spin_lock in vtermno_to_xencons, use
list_for_each_entry_safe.
It has been tested with pv and hvm guests, with console=ttyS0,
console=hvc0, and earlyprintk=xen, with and without
serial=''pty'' in the
VM config file.
Stefano Stabellini (2):
hvc_xen: support PV on HVM consoles
hvc_xen: implement multiconsole support
drivers/tty/hvc/hvc_xen.c | 455 ++++++++++++++++++++++++++++++++----
include/xen/interface/hvm/params.h | 6 +-
2 files changed, 420 insertions(+), 41 deletions(-)
A branch with these patches based on 3.2 is available here:
git://xenbits.xen.org/people/sstabellini/linux-pvhvm.git 3.2-multiconsole-2
Cheers,
Stefano
Stefano Stabellini
2012-Jan-27 18:31 UTC
[PATCH v2 1/2] hvc_xen: support PV on HVM consoles
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
---
drivers/tty/hvc/hvc_xen.c | 84 +++++++++++++++++++++++++++++-------
include/xen/interface/hvm/params.h | 6 ++-
2 files changed, 73 insertions(+), 17 deletions(-)
diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c
index 52fdf60..d5000aa 100644
--- a/drivers/tty/hvc/hvc_xen.c
+++ b/drivers/tty/hvc/hvc_xen.c
@@ -24,9 +24,12 @@
#include <linux/init.h>
#include <linux/types.h>
+#include <asm/io.h>
#include <asm/xen/hypervisor.h>
#include <xen/xen.h>
+#include <xen/interface/xen.h>
+#include <xen/hvm.h>
#include <xen/page.h>
#include <xen/events.h>
#include <xen/interface/io/console.h>
@@ -42,9 +45,13 @@ static int xencons_irq;
/* ------------------------------------------------------------------ */
static unsigned long console_pfn = ~0ul;
+static unsigned int console_evtchn = ~0ul;
+static struct xencons_interface *xencons_if = NULL;
static inline struct xencons_interface *xencons_interface(void)
{
+ if (xencons_if != NULL)
+ return xencons_if;
if (console_pfn == ~0ul)
return mfn_to_virt(xen_start_info->console.domU.mfn);
else
@@ -54,7 +61,10 @@ static inline struct xencons_interface
*xencons_interface(void)
static inline void notify_daemon(void)
{
/* Use evtchn: this is called early, before irq is set up. */
- notify_remote_via_evtchn(xen_start_info->console.domU.evtchn);
+ if (console_evtchn == ~0ul)
+ notify_remote_via_evtchn(xen_start_info->console.domU.evtchn);
+ else
+ notify_remote_via_evtchn(console_evtchn);
}
static int __write_console(const char *data, int len)
@@ -157,28 +167,63 @@ static struct hv_ops dom0_hvc_ops = {
.notifier_hangup = notifier_hangup_irq,
};
+static int xen_hvm_console_init(void)
+{
+ int r;
+ uint64_t v = 0;
+ unsigned long mfn;
+
+ if (!xen_hvm_domain())
+ return -ENODEV;
+
+ if (xencons_if != NULL)
+ return -EBUSY;
+
+ r = hvm_get_parameter(HVM_PARAM_CONSOLE_EVTCHN, &v);
+ if (r < 0)
+ return -ENODEV;
+ console_evtchn = v;
+ hvm_get_parameter(HVM_PARAM_CONSOLE_PFN, &v);
+ if (r < 0)
+ return -ENODEV;
+ mfn = v;
+ xencons_if = ioremap(mfn << PAGE_SHIFT, PAGE_SIZE);
+ if (xencons_if == NULL)
+ return -ENODEV;
+
+ return 0;
+}
+
static int __init xen_hvc_init(void)
{
struct hvc_struct *hp;
struct hv_ops *ops;
+ int r;
- if (!xen_pv_domain())
+ if (!xen_domain())
return -ENODEV;
if (xen_initial_domain()) {
ops = &dom0_hvc_ops;
xencons_irq = bind_virq_to_irq(VIRQ_CONSOLE, 0);
} else {
- if (!xen_start_info->console.domU.evtchn)
- return -ENODEV;
-
ops = &domU_hvc_ops;
- xencons_irq = bind_evtchn_to_irq(xen_start_info->console.domU.evtchn);
+ if (xen_pv_domain()) {
+ if (!xen_start_info->console.domU.evtchn)
+ return -ENODEV;
+ console_pfn = mfn_to_pfn(xen_start_info->console.domU.mfn);
+ console_evtchn = xen_start_info->console.domU.evtchn;
+ } else {
+ r = xen_hvm_console_init();
+ if (r < 0)
+ return r;
+ }
+ xencons_irq = bind_evtchn_to_irq(console_evtchn);
+ if (xencons_irq < 0)
+ xencons_irq = 0; /* NO_IRQ */
+ else
+ irq_set_noprobe(xencons_irq);
}
- if (xencons_irq < 0)
- xencons_irq = 0; /* NO_IRQ */
- else
- irq_set_noprobe(xencons_irq);
hp = hvc_alloc(HVC_COOKIE, xencons_irq, ops, 256);
if (IS_ERR(hp))
@@ -186,15 +231,13 @@ static int __init xen_hvc_init(void)
hvc = hp;
- console_pfn = mfn_to_pfn(xen_start_info->console.domU.mfn);
-
return 0;
}
void xen_console_resume(void)
{
if (xencons_irq)
- rebind_evtchn_irq(xen_start_info->console.domU.evtchn, xencons_irq);
+ rebind_evtchn_irq(console_evtchn, xencons_irq);
}
static void __exit xen_hvc_fini(void)
@@ -205,16 +248,22 @@ static void __exit xen_hvc_fini(void)
static int xen_cons_init(void)
{
- struct hv_ops *ops;
+ const struct hv_ops *ops;
- if (!xen_pv_domain())
+ if (!xen_domain())
return 0;
if (xen_initial_domain())
ops = &dom0_hvc_ops;
- else
+ else {
ops = &domU_hvc_ops;
+ if (xen_pv_domain())
+ console_evtchn = xen_start_info->console.domU.evtchn;
+ else
+ xen_hvm_console_init();
+ }
+
hvc_instantiate(HVC_COOKIE, 0, ops);
return 0;
}
@@ -230,6 +279,9 @@ static void xenboot_write_console(struct console *console,
const char *string,
unsigned int linelen, off = 0;
const char *pos;
+ if (!xen_pv_domain())
+ return;
+
dom0_write_console(0, string, len);
if (xen_initial_domain())
diff --git a/include/xen/interface/hvm/params.h
b/include/xen/interface/hvm/params.h
index 1888d8c..1b4f923 100644
--- a/include/xen/interface/hvm/params.h
+++ b/include/xen/interface/hvm/params.h
@@ -90,6 +90,10 @@
/* Boolean: Enable aligning all periodic vpts to reduce interrupts */
#define HVM_PARAM_VPT_ALIGN 16
-#define HVM_NR_PARAMS 17
+/* Console debug shared memory ring and event channel */
+#define HVM_PARAM_CONSOLE_PFN 17
+#define HVM_PARAM_CONSOLE_EVTCHN 18
+
+#define HVM_NR_PARAMS 19
#endif /* __XEN_PUBLIC_HVM_PARAMS_H__ */
--
1.7.2.5
Stefano Stabellini
2012-Jan-27 18:31 UTC
[PATCH v2 2/2] hvc_xen: implement multiconsole support
This patch implements support for multiple consoles:
consoles other than the first one are setup using the traditional xenbus
and grant-table based mechanism.
We use a list to keep track of the allocated consoles, we don''t
expect too many of them anyway.
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
---
drivers/tty/hvc/hvc_xen.c | 439 +++++++++++++++++++++++++++++++++++++++------
1 files changed, 381 insertions(+), 58 deletions(-)
diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c
index d5000aa..8209293 100644
--- a/drivers/tty/hvc/hvc_xen.c
+++ b/drivers/tty/hvc/hvc_xen.c
@@ -23,6 +23,7 @@
#include <linux/err.h>
#include <linux/init.h>
#include <linux/types.h>
+#include <linux/list.h>
#include <asm/io.h>
#include <asm/xen/hypervisor.h>
@@ -30,47 +31,67 @@
#include <xen/xen.h>
#include <xen/interface/xen.h>
#include <xen/hvm.h>
+#include <xen/grant_table.h>
#include <xen/page.h>
#include <xen/events.h>
#include <xen/interface/io/console.h>
#include <xen/hvc-console.h>
+#include <xen/xenbus.h>
#include "hvc_console.h"
#define HVC_COOKIE 0x58656e /* "Xen" in hex */
-static struct hvc_struct *hvc;
-static int xencons_irq;
+struct xencons_info {
+ struct list_head list;
+ struct xenbus_device *xbdev;
+ struct xencons_interface *intf;
+ unsigned int evtchn;
+ struct hvc_struct *hvc;
+ int irq;
+ int vtermno;
+ grant_ref_t gntref;
+};
+
+static LIST_HEAD(xenconsoles);
+static DEFINE_SPINLOCK(xencons_lock);
+static struct xenbus_driver xencons_driver;
/* ------------------------------------------------------------------ */
-static unsigned long console_pfn = ~0ul;
-static unsigned int console_evtchn = ~0ul;
-static struct xencons_interface *xencons_if = NULL;
+static struct xencons_info *vtermno_to_xencons(int vtermno)
+{
+ struct xencons_info *entry, *n, *ret = NULL;
+
+ if (list_empty(&xenconsoles))
+ return NULL;
-static inline struct xencons_interface *xencons_interface(void)
+ list_for_each_entry_safe(entry, n, &xenconsoles, list) {
+ if (entry->vtermno == vtermno) {
+ ret = entry;
+ break;
+ }
+ }
+
+ return ret;
+}
+
+static inline int xenbus_devid_to_vtermno(int devid)
{
- if (xencons_if != NULL)
- return xencons_if;
- if (console_pfn == ~0ul)
- return mfn_to_virt(xen_start_info->console.domU.mfn);
- else
- return __va(console_pfn << PAGE_SHIFT);
+ return devid + HVC_COOKIE;
}
-static inline void notify_daemon(void)
+static inline void notify_daemon(struct xencons_info *cons)
{
/* Use evtchn: this is called early, before irq is set up. */
- if (console_evtchn == ~0ul)
- notify_remote_via_evtchn(xen_start_info->console.domU.evtchn);
- else
- notify_remote_via_evtchn(console_evtchn);
+ notify_remote_via_evtchn(cons->evtchn);
}
-static int __write_console(const char *data, int len)
+static int __write_console(struct xencons_info *xencons,
+ const char *data, int len)
{
- struct xencons_interface *intf = xencons_interface();
XENCONS_RING_IDX cons, prod;
+ struct xencons_interface *intf = xencons->intf;
int sent = 0;
cons = intf->out_cons;
@@ -85,13 +106,16 @@ static int __write_console(const char *data, int len)
intf->out_prod = prod;
if (sent)
- notify_daemon();
+ notify_daemon(xencons);
return sent;
}
static int domU_write_console(uint32_t vtermno, const char *data, int len)
{
int ret = len;
+ struct xencons_info *cons = vtermno_to_xencons(vtermno);
+ if (cons == NULL)
+ return -EINVAL;
/*
* Make sure the whole buffer is emitted, polling if
@@ -100,7 +124,7 @@ static int domU_write_console(uint32_t vtermno, const char
*data, int len)
* kernel is crippled.
*/
while (len) {
- int sent = __write_console(data, len);
+ int sent = __write_console(cons, data, len);
data += sent;
len -= sent;
@@ -114,9 +138,13 @@ static int domU_write_console(uint32_t vtermno, const char
*data, int len)
static int domU_read_console(uint32_t vtermno, char *buf, int len)
{
- struct xencons_interface *intf = xencons_interface();
+ struct xencons_interface *intf;
XENCONS_RING_IDX cons, prod;
int recv = 0;
+ struct xencons_info *xencons = vtermno_to_xencons(vtermno);
+ if (xencons == NULL)
+ return -EINVAL;
+ intf = xencons->intf;
cons = intf->in_cons;
prod = intf->in_prod;
@@ -129,7 +157,7 @@ static int domU_read_console(uint32_t vtermno, char *buf,
int len)
mb(); /* read ring before consuming */
intf->in_cons = cons;
- notify_daemon();
+ notify_daemon(xencons);
return recv;
}
@@ -172,78 +200,360 @@ static int xen_hvm_console_init(void)
int r;
uint64_t v = 0;
unsigned long mfn;
+ struct xencons_info *info;
if (!xen_hvm_domain())
return -ENODEV;
- if (xencons_if != NULL)
- return -EBUSY;
+ info = vtermno_to_xencons(HVC_COOKIE);
+ if (!info) {
+ info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL | __GFP_ZERO);
+ if (!info)
+ return -ENOMEM;
+ }
+
+ /* already configured */
+ if (info->intf != NULL)
+ return 0;
r = hvm_get_parameter(HVM_PARAM_CONSOLE_EVTCHN, &v);
- if (r < 0)
+ if (r < 0) {
+ kfree(info);
return -ENODEV;
- console_evtchn = v;
+ }
+ info->evtchn = v;
hvm_get_parameter(HVM_PARAM_CONSOLE_PFN, &v);
- if (r < 0)
+ if (r < 0) {
+ kfree(info);
return -ENODEV;
+ }
mfn = v;
- xencons_if = ioremap(mfn << PAGE_SHIFT, PAGE_SIZE);
- if (xencons_if == NULL)
+ info->intf = ioremap(mfn << PAGE_SHIFT, PAGE_SIZE);
+ if (info->intf == NULL) {
+ kfree(info);
+ return -ENODEV;
+ }
+ info->vtermno = HVC_COOKIE;
+
+ spin_lock(&xencons_lock);
+ list_add_tail(&info->list, &xenconsoles);
+ spin_unlock(&xencons_lock);
+
+ return 0;
+}
+
+static int xen_pv_console_init(void)
+{
+ struct xencons_info *info;
+
+ if (!xen_pv_domain())
return -ENODEV;
+ if (!xen_start_info->console.domU.evtchn)
+ return -ENODEV;
+
+ info = vtermno_to_xencons(HVC_COOKIE);
+ if (!info) {
+ info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL | __GFP_ZERO);
+ if (!info)
+ return -ENOMEM;
+ }
+
+ /* already configured */
+ if (info->intf != NULL)
+ return 0;
+
+ info->evtchn = xen_start_info->console.domU.evtchn;
+ info->intf = mfn_to_virt(xen_start_info->console.domU.mfn);
+ info->vtermno = HVC_COOKIE;
+
+ spin_lock(&xencons_lock);
+ list_add_tail(&info->list, &xenconsoles);
+ spin_unlock(&xencons_lock);
+
+ return 0;
+}
+
+static int xen_initial_domain_console_init(void)
+{
+ struct xencons_info *info;
+
+ if (!xen_initial_domain())
+ return -ENODEV;
+
+ info = vtermno_to_xencons(HVC_COOKIE);
+ if (!info) {
+ info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL | __GFP_ZERO);
+ if (!info)
+ return -ENOMEM;
+ }
+
+ info->irq = bind_virq_to_irq(VIRQ_CONSOLE, 0);
+ info->vtermno = HVC_COOKIE;
+
+ spin_lock(&xencons_lock);
+ list_add_tail(&info->list, &xenconsoles);
+ spin_unlock(&xencons_lock);
+
return 0;
}
static int __init xen_hvc_init(void)
{
- struct hvc_struct *hp;
- struct hv_ops *ops;
int r;
+ struct xencons_info *info;
+ const struct hv_ops *ops;
if (!xen_domain())
return -ENODEV;
if (xen_initial_domain()) {
ops = &dom0_hvc_ops;
- xencons_irq = bind_virq_to_irq(VIRQ_CONSOLE, 0);
+ r = xen_initial_domain_console_init();
+ if (r < 0)
+ return r;
+ info = vtermno_to_xencons(HVC_COOKIE);
} else {
ops = &domU_hvc_ops;
- if (xen_pv_domain()) {
- if (!xen_start_info->console.domU.evtchn)
- return -ENODEV;
- console_pfn = mfn_to_pfn(xen_start_info->console.domU.mfn);
- console_evtchn = xen_start_info->console.domU.evtchn;
- } else {
+ if (xen_hvm_domain())
r = xen_hvm_console_init();
- if (r < 0)
- return r;
- }
- xencons_irq = bind_evtchn_to_irq(console_evtchn);
- if (xencons_irq < 0)
- xencons_irq = 0; /* NO_IRQ */
else
- irq_set_noprobe(xencons_irq);
+ r = xen_pv_console_init();
+ if (r < 0)
+ return r;
+
+ info = vtermno_to_xencons(HVC_COOKIE);
+ info->irq = bind_evtchn_to_irq(info->evtchn);
+ }
+ if (info->irq < 0)
+ info->irq = 0; /* NO_IRQ */
+ else
+ irq_set_noprobe(info->irq);
+
+ info->hvc = hvc_alloc(HVC_COOKIE, info->irq, ops, 256);
+ if (IS_ERR(info->hvc)) {
+ r = PTR_ERR(info->hvc);
+ spin_lock(&xencons_lock);
+ list_del(&info->list);
+ spin_unlock(&xencons_lock);
+ if (info->irq)
+ unbind_from_irqhandler(info->irq, NULL);
+ kfree(info);
+ return r;
}
- hp = hvc_alloc(HVC_COOKIE, xencons_irq, ops, 256);
- if (IS_ERR(hp))
- return PTR_ERR(hp);
+ return xenbus_register_frontend(&xencons_driver);
+}
- hvc = hp;
+void xen_console_resume(void)
+{
+ struct xencons_info *info = vtermno_to_xencons(HVC_COOKIE);
+ if (info != NULL && info->irq)
+ rebind_evtchn_irq(info->evtchn, info->irq);
+}
+static void xencons_disconnect_backend(struct xencons_info *info)
+{
+ if (info->irq > 0)
+ unbind_from_irqhandler(info->irq, NULL);
+ info->irq = 0;
+ if (info->evtchn > 0)
+ xenbus_free_evtchn(info->xbdev, info->evtchn);
+ info->evtchn = 0;
+ if (info->gntref > 0)
+ gnttab_free_grant_references(info->gntref);
+ info->gntref = 0;
+ if (info->hvc != NULL)
+ hvc_remove(info->hvc);
+ info->hvc = NULL;
+}
+
+static void xencons_free(struct xencons_info *info)
+{
+ xencons_disconnect_backend(info);
+ free_page((unsigned long)info->intf);
+ info->intf = NULL;
+ info->vtermno = 0;
+ kfree(info);
+}
+
+static int xencons_remove(struct xenbus_device *dev)
+{
+ struct xencons_info *info = dev_get_drvdata(&dev->dev);
+
+ spin_lock(&xencons_lock);
+ list_del(&info->list);
+ spin_unlock(&xencons_lock);
+ xencons_free(info);
return 0;
}
-void xen_console_resume(void)
+static int xencons_connect_backend(struct xenbus_device *dev,
+ struct xencons_info *info)
+{
+ int ret, evtchn, devid, ref, irq;
+ struct xenbus_transaction xbt;
+ grant_ref_t gref_head;
+ unsigned long mfn;
+
+ ret = xenbus_alloc_evtchn(dev, &evtchn);
+ if (ret)
+ return ret;
+ info->evtchn = evtchn;
+ irq = bind_evtchn_to_irq(evtchn);
+ if (irq < 0)
+ return irq;
+ info->irq = irq;
+ devid = dev->nodename[strlen(dev->nodename) - 1] -
''0'';
+ info->hvc = hvc_alloc(xenbus_devid_to_vtermno(devid),
+ irq, &domU_hvc_ops, 256);
+ if (IS_ERR(info->hvc))
+ return PTR_ERR(info->hvc);
+ if (xen_pv_domain())
+ mfn = virt_to_mfn(info->intf);
+ else
+ mfn = __pa(info->intf) >> PAGE_SHIFT;
+ ret = gnttab_alloc_grant_references(1, &gref_head);
+ if (ret < 0)
+ return ret;
+ info->gntref = gref_head;
+ ref = gnttab_claim_grant_reference(&gref_head);
+ if (ref < 0)
+ return ref;
+ gnttab_grant_foreign_access_ref(ref, info->xbdev->otherend_id,
+ mfn, 0);
+
+ again:
+ ret = xenbus_transaction_start(&xbt);
+ if (ret) {
+ xenbus_dev_fatal(dev, ret, "starting transaction");
+ return ret;
+ }
+ ret = xenbus_printf(xbt, dev->nodename, "ring-ref",
"%d", ref);
+ if (ret)
+ goto error_xenbus;
+ ret = xenbus_printf(xbt, dev->nodename, "port", "%u",
+ evtchn);
+ if (ret)
+ goto error_xenbus;
+ ret = xenbus_printf(xbt, dev->nodename, "type",
"ioemu");
+ if (ret)
+ goto error_xenbus;
+ ret = xenbus_transaction_end(xbt, 0);
+ if (ret) {
+ if (ret == -EAGAIN)
+ goto again;
+ xenbus_dev_fatal(dev, ret, "completing transaction");
+ return ret;
+ }
+
+ xenbus_switch_state(dev, XenbusStateInitialised);
+ return 0;
+
+ error_xenbus:
+ xenbus_transaction_end(xbt, 1);
+ xenbus_dev_fatal(dev, ret, "writing xenstore");
+ return ret;
+}
+
+static int __devinit xencons_probe(struct xenbus_device *dev,
+ const struct xenbus_device_id *id)
{
- if (xencons_irq)
- rebind_evtchn_irq(console_evtchn, xencons_irq);
+ int ret, devid;
+ struct xencons_info *info;
+
+ devid = dev->nodename[strlen(dev->nodename) - 1] -
''0'';
+ if (devid == 0)
+ return -ENODEV;
+
+ info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL | __GFP_ZERO);
+ if (!info)
+ goto error_nomem;
+ dev_set_drvdata(&dev->dev, info);
+ info->xbdev = dev;
+ info->vtermno = xenbus_devid_to_vtermno(devid);
+ info->intf = (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
+ if (!info->intf)
+ goto error_nomem;
+
+ ret = xencons_connect_backend(dev, info);
+ if (ret < 0)
+ goto error;
+ spin_lock(&xencons_lock);
+ list_add_tail(&info->list, &xenconsoles);
+ spin_unlock(&xencons_lock);
+
+ return 0;
+
+ error_nomem:
+ ret = -ENOMEM;
+ xenbus_dev_fatal(dev, ret, "allocating device memory");
+ error:
+ xencons_free(info);
+ return ret;
+}
+
+static int xencons_resume(struct xenbus_device *dev)
+{
+ struct xencons_info *info = dev_get_drvdata(&dev->dev);
+
+ xencons_disconnect_backend(info);
+ memset(info->intf, 0, PAGE_SIZE);
+ return xencons_connect_backend(dev, info);
}
+static void xencons_backend_changed(struct xenbus_device *dev,
+ enum xenbus_state backend_state)
+{
+ switch (backend_state) {
+ case XenbusStateReconfiguring:
+ case XenbusStateReconfigured:
+ case XenbusStateInitialising:
+ case XenbusStateInitialised:
+ case XenbusStateUnknown:
+ case XenbusStateClosed:
+ break;
+
+ case XenbusStateInitWait:
+ break;
+
+ case XenbusStateConnected:
+ xenbus_switch_state(dev, XenbusStateConnected);
+ break;
+
+ case XenbusStateClosing:
+ xenbus_frontend_closed(dev);
+ break;
+ }
+}
+
+static const struct xenbus_device_id xencons_ids[] = {
+ { "console" },
+ { "" }
+};
+
+
static void __exit xen_hvc_fini(void)
{
- if (hvc)
- hvc_remove(hvc);
+ struct xencons_info *entry, *next;
+
+ if (list_empty(&xenconsoles))
+ return;
+
+ spin_lock(&xencons_lock);
+ list_for_each_entry_safe(entry, next, &xenconsoles, list) {
+ list_del(&entry->list);
+ if (entry->xbdev)
+ xencons_remove(entry->xbdev);
+ else {
+ if (entry->irq > 0)
+ unbind_from_irqhandler(entry->irq, NULL);
+ if (entry->hvc);
+ hvc_remove(entry->hvc);
+ kfree(entry);
+ }
+ }
+ spin_unlock(&xencons_lock);
}
static int xen_cons_init(void)
@@ -256,18 +566,31 @@ static int xen_cons_init(void)
if (xen_initial_domain())
ops = &dom0_hvc_ops;
else {
+ int r;
ops = &domU_hvc_ops;
- if (xen_pv_domain())
- console_evtchn = xen_start_info->console.domU.evtchn;
+ if (xen_hvm_domain())
+ r = xen_hvm_console_init();
else
- xen_hvm_console_init();
+ r = xen_pv_console_init();
+ if (r < 0)
+ return r;
}
hvc_instantiate(HVC_COOKIE, 0, ops);
return 0;
}
+static struct xenbus_driver xencons_driver = {
+ .name = "xenconsole",
+ .owner = THIS_MODULE,
+ .ids = xencons_ids,
+ .probe = xencons_probe,
+ .remove = xencons_remove,
+ .resume = xencons_resume,
+ .otherend_changed = xencons_backend_changed,
+};
+
module_init(xen_hvc_init);
module_exit(xen_hvc_fini);
console_initcall(xen_cons_init);
--
1.7.2.5
Konrad Rzeszutek Wilk
2012-Jan-27 18:45 UTC
Re: [PATCH v2 2/2] hvc_xen: implement multiconsole support
> +static void xencons_disconnect_backend(struct xencons_info *info) > +{ > + if (info->irq > 0) > + unbind_from_irqhandler(info->irq, NULL); > + info->irq = 0; > + if (info->evtchn > 0) > + xenbus_free_evtchn(info->xbdev, info->evtchn); > + info->evtchn = 0; > + if (info->gntref > 0) > + gnttab_free_grant_references(info->gntref); > + info->gntref = 0; > + if (info->hvc != NULL) > + hvc_remove(info->hvc); > + info->hvc = NULL; > +} > + > +static void xencons_free(struct xencons_info *info) > +{ > + xencons_disconnect_backend(info); > + free_page((unsigned long)info->intf); > + info->intf = NULL; > + info->vtermno = 0; > + kfree(info); > +} > + > +static int xencons_remove(struct xenbus_device *dev) > +{ > + struct xencons_info *info = dev_get_drvdata(&dev->dev); > +I would say put xencons_disconnect_backend(info) here, that way it calls hvc_remove first, and then this would delete an "not-called" anymore structure.> + spin_lock(&xencons_lock); > + list_del(&info->list); > + spin_unlock(&xencons_lock); > + xencons_free(info);> return 0; > } >.. snip..> + > +static const struct xenbus_device_id xencons_ids[] = { > + { "console" }, > + { "" } > +}; > + > + > static void __exit xen_hvc_fini(void) > { > - if (hvc) > - hvc_remove(hvc); > + struct xencons_info *entry, *next; > + > + if (list_empty(&xenconsoles)) > + return; > + > + spin_lock(&xencons_lock);Take that spin-lock out.> + list_for_each_entry_safe(entry, next, &xenconsoles, list) { > + list_del(&entry->list); > + if (entry->xbdev) > + xencons_remove(entry->xbdev);This guy deletes itself from the list..> + else { > + if (entry->irq > 0) > + unbind_from_irqhandler(entry->irq, NULL); > + if (entry->hvc); > + hvc_remove(entry->hvc); > + kfree(entry);..but this one does not. You could make xencons_remove just remove itself from the list and nothing else. Then rename it to ''xencons_remove_itself'' perhaps? After that, introduce a new function ''xencons_delete'' that would call xecons_disconnect_backend, xencons_remove_itself, and xencons_free?> + } > + } > + spin_unlock(&xencons_lock); > } > > static int xen_cons_init(void) > @@ -256,18 +566,31 @@ static int xen_cons_init(void) > if (xen_initial_domain()) > ops = &dom0_hvc_ops; > else { > + int r; > ops = &domU_hvc_ops; > > - if (xen_pv_domain()) > - console_evtchn = xen_start_info->console.domU.evtchn; > + if (xen_hvm_domain()) > + r = xen_hvm_console_init(); > else > - xen_hvm_console_init(); > + r = xen_pv_console_init(); > + if (r < 0) > + return r; > } > > hvc_instantiate(HVC_COOKIE, 0, ops); > return 0; > } > > +static struct xenbus_driver xencons_driver = {This needs to be wrapped in the new macro that Jan prepared. DEFINE_XENBUS_DRIVER (73db144b58a32fc39733db6a7e1fe582072ad26a)> + .name = "xenconsole", > + .owner = THIS_MODULE, > + .ids = xencons_ids, > + .probe = xencons_probe, > + .remove = xencons_remove, > + .resume = xencons_resume, > + .otherend_changed = xencons_backend_changed, > +}; > + > module_init(xen_hvc_init); > module_exit(xen_hvc_fini); > console_initcall(xen_cons_init); > -- > 1.7.2.5
Konrad Rzeszutek Wilk
2012-Jan-27 18:45 UTC
Re: [PATCH v2 1/2] hvc_xen: support PV on HVM consoles
On Fri, Jan 27, 2012 at 06:31:36PM +0000, Stefano Stabellini wrote:> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>applied.> --- > drivers/tty/hvc/hvc_xen.c | 84 +++++++++++++++++++++++++++++------- > include/xen/interface/hvm/params.h | 6 ++- > 2 files changed, 73 insertions(+), 17 deletions(-) > > diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c > index 52fdf60..d5000aa 100644 > --- a/drivers/tty/hvc/hvc_xen.c > +++ b/drivers/tty/hvc/hvc_xen.c > @@ -24,9 +24,12 @@ > #include <linux/init.h> > #include <linux/types.h> > > +#include <asm/io.h> > #include <asm/xen/hypervisor.h> > > #include <xen/xen.h> > +#include <xen/interface/xen.h> > +#include <xen/hvm.h> > #include <xen/page.h> > #include <xen/events.h> > #include <xen/interface/io/console.h> > @@ -42,9 +45,13 @@ static int xencons_irq; > /* ------------------------------------------------------------------ */ > > static unsigned long console_pfn = ~0ul; > +static unsigned int console_evtchn = ~0ul; > +static struct xencons_interface *xencons_if = NULL; > > static inline struct xencons_interface *xencons_interface(void) > { > + if (xencons_if != NULL) > + return xencons_if; > if (console_pfn == ~0ul) > return mfn_to_virt(xen_start_info->console.domU.mfn); > else > @@ -54,7 +61,10 @@ static inline struct xencons_interface *xencons_interface(void) > static inline void notify_daemon(void) > { > /* Use evtchn: this is called early, before irq is set up. */ > - notify_remote_via_evtchn(xen_start_info->console.domU.evtchn); > + if (console_evtchn == ~0ul) > + notify_remote_via_evtchn(xen_start_info->console.domU.evtchn); > + else > + notify_remote_via_evtchn(console_evtchn); > } > > static int __write_console(const char *data, int len) > @@ -157,28 +167,63 @@ static struct hv_ops dom0_hvc_ops = { > .notifier_hangup = notifier_hangup_irq, > }; > > +static int xen_hvm_console_init(void) > +{ > + int r; > + uint64_t v = 0; > + unsigned long mfn; > + > + if (!xen_hvm_domain()) > + return -ENODEV; > + > + if (xencons_if != NULL) > + return -EBUSY; > + > + r = hvm_get_parameter(HVM_PARAM_CONSOLE_EVTCHN, &v); > + if (r < 0) > + return -ENODEV; > + console_evtchn = v; > + hvm_get_parameter(HVM_PARAM_CONSOLE_PFN, &v); > + if (r < 0) > + return -ENODEV; > + mfn = v; > + xencons_if = ioremap(mfn << PAGE_SHIFT, PAGE_SIZE); > + if (xencons_if == NULL) > + return -ENODEV; > + > + return 0; > +} > + > static int __init xen_hvc_init(void) > { > struct hvc_struct *hp; > struct hv_ops *ops; > + int r; > > - if (!xen_pv_domain()) > + if (!xen_domain()) > return -ENODEV; > > if (xen_initial_domain()) { > ops = &dom0_hvc_ops; > xencons_irq = bind_virq_to_irq(VIRQ_CONSOLE, 0); > } else { > - if (!xen_start_info->console.domU.evtchn) > - return -ENODEV; > - > ops = &domU_hvc_ops; > - xencons_irq = bind_evtchn_to_irq(xen_start_info->console.domU.evtchn); > + if (xen_pv_domain()) { > + if (!xen_start_info->console.domU.evtchn) > + return -ENODEV; > + console_pfn = mfn_to_pfn(xen_start_info->console.domU.mfn); > + console_evtchn = xen_start_info->console.domU.evtchn; > + } else { > + r = xen_hvm_console_init(); > + if (r < 0) > + return r; > + } > + xencons_irq = bind_evtchn_to_irq(console_evtchn); > + if (xencons_irq < 0) > + xencons_irq = 0; /* NO_IRQ */ > + else > + irq_set_noprobe(xencons_irq); > } > - if (xencons_irq < 0) > - xencons_irq = 0; /* NO_IRQ */ > - else > - irq_set_noprobe(xencons_irq); > > hp = hvc_alloc(HVC_COOKIE, xencons_irq, ops, 256); > if (IS_ERR(hp)) > @@ -186,15 +231,13 @@ static int __init xen_hvc_init(void) > > hvc = hp; > > - console_pfn = mfn_to_pfn(xen_start_info->console.domU.mfn); > - > return 0; > } > > void xen_console_resume(void) > { > if (xencons_irq) > - rebind_evtchn_irq(xen_start_info->console.domU.evtchn, xencons_irq); > + rebind_evtchn_irq(console_evtchn, xencons_irq); > } > > static void __exit xen_hvc_fini(void) > @@ -205,16 +248,22 @@ static void __exit xen_hvc_fini(void) > > static int xen_cons_init(void) > { > - struct hv_ops *ops; > + const struct hv_ops *ops; > > - if (!xen_pv_domain()) > + if (!xen_domain()) > return 0; > > if (xen_initial_domain()) > ops = &dom0_hvc_ops; > - else > + else { > ops = &domU_hvc_ops; > > + if (xen_pv_domain()) > + console_evtchn = xen_start_info->console.domU.evtchn; > + else > + xen_hvm_console_init(); > + } > + > hvc_instantiate(HVC_COOKIE, 0, ops); > return 0; > } > @@ -230,6 +279,9 @@ static void xenboot_write_console(struct console *console, const char *string, > unsigned int linelen, off = 0; > const char *pos; > > + if (!xen_pv_domain()) > + return; > + > dom0_write_console(0, string, len); > > if (xen_initial_domain()) > diff --git a/include/xen/interface/hvm/params.h b/include/xen/interface/hvm/params.h > index 1888d8c..1b4f923 100644 > --- a/include/xen/interface/hvm/params.h > +++ b/include/xen/interface/hvm/params.h > @@ -90,6 +90,10 @@ > /* Boolean: Enable aligning all periodic vpts to reduce interrupts */ > #define HVM_PARAM_VPT_ALIGN 16 > > -#define HVM_NR_PARAMS 17 > +/* Console debug shared memory ring and event channel */ > +#define HVM_PARAM_CONSOLE_PFN 17 > +#define HVM_PARAM_CONSOLE_EVTCHN 18 > + > +#define HVM_NR_PARAMS 19 > > #endif /* __XEN_PUBLIC_HVM_PARAMS_H__ */ > -- > 1.7.2.5 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/
Stefano Stabellini
2012-Jan-30 15:33 UTC
Re: [PATCH v2 2/2] hvc_xen: implement multiconsole support
On Fri, 27 Jan 2012, Konrad Rzeszutek Wilk wrote:> > +static void xencons_disconnect_backend(struct xencons_info *info) > > +{ > > + if (info->irq > 0) > > + unbind_from_irqhandler(info->irq, NULL); > > + info->irq = 0; > > + if (info->evtchn > 0) > > + xenbus_free_evtchn(info->xbdev, info->evtchn); > > + info->evtchn = 0; > > + if (info->gntref > 0) > > + gnttab_free_grant_references(info->gntref); > > + info->gntref = 0; > > + if (info->hvc != NULL) > > + hvc_remove(info->hvc); > > + info->hvc = NULL; > > +} > > + > > +static void xencons_free(struct xencons_info *info) > > +{ > > + xencons_disconnect_backend(info); > > + free_page((unsigned long)info->intf); > > + info->intf = NULL; > > + info->vtermno = 0; > > + kfree(info); > > +} > > + > > +static int xencons_remove(struct xenbus_device *dev) > > +{ > > + struct xencons_info *info = dev_get_drvdata(&dev->dev); > > + > > I would say put > xencons_disconnect_backend(info) > > here, that way it calls hvc_remove first, and then this would > delete an "not-called" anymore structure. > > > + spin_lock(&xencons_lock); > > + list_del(&info->list); > > + spin_unlock(&xencons_lock); > > + xencons_free(info); > > > return 0; > > } > > > > .. snip.. > > + > > +static const struct xenbus_device_id xencons_ids[] = { > > + { "console" }, > > + { "" } > > +}; > > + > > + > > static void __exit xen_hvc_fini(void) > > { > > - if (hvc) > > - hvc_remove(hvc); > > + struct xencons_info *entry, *next; > > + > > + if (list_empty(&xenconsoles)) > > + return; > > + > > + spin_lock(&xencons_lock); > > Take that spin-lock out. > > > + list_for_each_entry_safe(entry, next, &xenconsoles, list) { > > + list_del(&entry->list); > > + if (entry->xbdev) > > + xencons_remove(entry->xbdev); > > This guy deletes itself from the list.. > > + else { > > + if (entry->irq > 0) > > + unbind_from_irqhandler(entry->irq, NULL); > > + if (entry->hvc); > > + hvc_remove(entry->hvc); > > + kfree(entry); > > ..but this one does not. You could make xencons_remove just remove > itself from the list and nothing else. Then rename it to ''xencons_remove_itself'' perhaps? > > After that, introduce a new function ''xencons_delete'' that would call > xecons_disconnect_backend, xencons_remove_itself, and xencons_free?Thanks for spotting the deadlock and the useful suggestions. I have reworked the shutdown path a bit, making sure that we don''t take any locks twice and that we call hvc_remove before list_del (see next version of the patch, to be posted soon).> > > > +static struct xenbus_driver xencons_driver = { > > This needs to be wrapped in the new macro that Jan prepared. > DEFINE_XENBUS_DRIVER (73db144b58a32fc39733db6a7e1fe582072ad26a)OK