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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH v3] hvc_xen: implement multiconsole support
On Mon, Jan 30, 2012 at 04:02:31PM +0000, Stefano Stabellini wrote:
> 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.
>
So looks good. applied to #testing. How do I test "multiple" consoles?
>
> Changes in v3:
>
> - call hvc_remove before removing the console from xenconsoles;
> - do not lock xencons_lock twice in the destruction path;
> - use the DEFINE_XENBUS_DRIVER macro.
>
>
> Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
> ---
> drivers/tty/hvc/hvc_xen.c | 435
> +++++++++++++++++++++++++++++++++++++++------
> 1 files changed, 377 insertions(+), 58 deletions(-)
>
> diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c
> index d5000aa..26090c7 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 +200,359 @@ 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)
> +{
> + free_page((unsigned long)info->intf);
> + info->intf = NULL;
> + info->vtermno = 0;
> + kfree(info);
> +}
> +
> +static int xen_console_remove(struct xencons_info *info)
> +{
> + xencons_disconnect_backend(info);
> + spin_lock(&xencons_lock);
> + list_del(&info->list);
> + spin_unlock(&xencons_lock);
> + if (info->xbdev != NULL)
> + xencons_free(info);
> + else {
> + if (xen_hvm_domain())
> + iounmap(info->intf);
> + kfree(info);
> + }
> return 0;
> }
>
> -void xen_console_resume(void)
> +static int xencons_remove(struct xenbus_device *dev)
> +{
> + return xen_console_remove(dev_get_drvdata(&dev->dev));
> +}
> +
> +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)
> +{
> + 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_disconnect_backend(info);
> + xencons_free(info);
> + return ret;
> +}
> +
> +static int xencons_resume(struct xenbus_device *dev)
> {
> - if (xencons_irq)
> - rebind_evtchn_irq(console_evtchn, xencons_irq);
> + 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;
> +
> + list_for_each_entry_safe(entry, next, &xenconsoles, list) {
> + xen_console_remove(entry);
> + }
> }
>
> static int xen_cons_init(void)
> @@ -256,18 +565,28 @@ 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 DEFINE_XENBUS_DRIVER(xencons, "xenconsole",
> + .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
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@xxxxxxxxxxxxxxxxxxx
> http://lists.xensource.com/xen-devel
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