Mailing List Archive

From: Alex Zeffertt <alex.zeffertt@eu.citrix.com>

Changes the minios evtchn implementation to use a list instead of an array.
This allows it to grow as necessary to support any number of ports.
Unfortunately, it's still limited by NR_EVS in events.c.

Signed-off-by: Diego Ongaro <diego.ongaro@citrix.com>
Signed-off-by: Alex Zeffertt <alex.zeffertt@eu.citrix.com>
Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
---
extras/mini-os/include/lib.h | 16 +++---
tools/libxc/xc_minios.c | 139 ++++++++++++++++++++++--------------------
2 files changed, 81 insertions(+), 74 deletions(-)

diff --git a/extras/mini-os/include/lib.h b/extras/mini-os/include/lib.h
index bd3eeaf..12070c3 100644
--- a/extras/mini-os/include/lib.h
+++ b/extras/mini-os/include/lib.h
@@ -53,6 +53,7 @@
#include <xen/xen.h>
#include <xen/event_channel.h>
#include "gntmap.h"
+#include "list.h"

#ifdef HAVE_LIBC
#include <stdio.h>
@@ -143,7 +144,12 @@ enum fd_type {
FTYPE_SAVEFILE,
};

-#define MAX_EVTCHN_PORTS 16
+struct evtchn_port_info {
+ struct minios_list_head list;
+ evtchn_port_t port;
+ unsigned long pending;
+ int bound;
+};

extern struct file {
enum fd_type type;
@@ -158,13 +164,7 @@ extern struct file {
off_t offset;
} file;
struct {
- /* To each event channel FD is associated a series of ports which
- * wakes select for this FD. */
- struct {
- evtchn_port_t port;
- unsigned long pending;
- int bound;
- } ports[MAX_EVTCHN_PORTS];
+ struct minios_list_head ports;
} evtchn;
struct gntmap gntmap;
struct {
diff --git a/tools/libxc/xc_minios.c b/tools/libxc/xc_minios.c
index 8bbfd18..29cce63 100644
--- a/tools/libxc/xc_minios.c
+++ b/tools/libxc/xc_minios.c
@@ -210,15 +210,34 @@ static struct xc_osdep_ops minios_privcmd_ops = {
},
};

+
+/* XXX Note: This is not threadsafe */
+static struct evtchn_port_info* port_alloc(int fd) {
+ struct evtchn_port_info *port_info;
+ port_info = malloc(sizeof(struct evtchn_port_info));
+ if (port_info == NULL)
+ return NULL;
+ port_info->pending = 0;
+ port_info->port = -1;
+ port_info->bound = 0;
+
+ minios_list_add(&port_info->list, &files[fd].evtchn.ports);
+ return port_info;
+}
+
+static void port_dealloc(struct evtchn_port_info *port_info) {
+ if (port_info->bound)
+ unbind_evtchn(port_info->port);
+ minios_list_del(&port_info->list);
+ free(port_info);
+}
+
static xc_osdep_handle minios_evtchn_open(xc_evtchn *xce)
{
- int fd = alloc_fd(FTYPE_EVTCHN), i;
+ int fd = alloc_fd(FTYPE_EVTCHN);
if ( fd == -1 )
return XC_OSDEP_OPEN_ERROR;
- for (i = 0; i < MAX_EVTCHN_PORTS; i++) {
- files[fd].evtchn.ports[i].port = -1;
- files[fd].evtchn.ports[i].bound = 0;
- }
+ MINIOS_INIT_LIST_HEAD(&files[fd].evtchn.ports);
printf("evtchn_open() -> %d\n", fd);
return (xc_osdep_handle)fd;
}
@@ -231,10 +250,10 @@ static int minios_evtchn_close(xc_evtchn *xce, xc_osdep_handle h)

void minios_evtchn_close_fd(int fd)
{
- int i;
- for (i = 0; i < MAX_EVTCHN_PORTS; i++)
- if (files[fd].evtchn.ports[i].bound)
- unbind_evtchn(files[fd].evtchn.ports[i].port);
+ struct evtchn_port_info *port_info, *tmp;
+ minios_list_for_each_entry_safe(port_info, tmp, &files[fd].evtchn.ports, list)
+ port_dealloc(port_info);
+
files[fd].type = FTYPE_NONE;
}

@@ -256,35 +275,21 @@ static int minios_evtchn_notify(xc_evtchn *xce, xc_osdep_handle h, evtchn_port_t
return ret;
}

-/* XXX Note: This is not threadsafe */
-static int port_alloc(int fd) {
- int i;
- for (i= 0; i < MAX_EVTCHN_PORTS; i++)
- if (files[fd].evtchn.ports[i].port == -1)
- break;
- if (i == MAX_EVTCHN_PORTS) {
- printf("Too many ports in xc handle\n");
- errno = EMFILE;
- return -1;
- }
- files[fd].evtchn.ports[i].pending = 0;
- return i;
-}
-
static void evtchn_handler(evtchn_port_t port, struct pt_regs *regs, void *data)
{
int fd = (int)(intptr_t)data;
- int i;
+ struct evtchn_port_info *port_info;
assert(files[fd].type == FTYPE_EVTCHN);
mask_evtchn(port);
- for (i= 0; i < MAX_EVTCHN_PORTS; i++)
- if (files[fd].evtchn.ports[i].port == port)
- break;
- if (i == MAX_EVTCHN_PORTS) {
- printk("Unknown port for handle %d\n", fd);
- return;
+ minios_list_for_each_entry(port_info, &files[fd].evtchn.ports, list) {
+ if (port_info->port == port)
+ goto found;
}
- files[fd].evtchn.ports[i].pending = 1;
+ printk("Unknown port for handle %d\n", fd);
+ return;
+
+ found:
+ port_info->pending = 1;
files[fd].read = 1;
wake_up(&event_queue);
}
@@ -292,12 +297,13 @@ static void evtchn_handler(evtchn_port_t port, struct pt_regs *regs, void *data)
static evtchn_port_or_error_t minios_evtchn_bind_unbound_port(xc_evtchn *xce, xc_osdep_handle h, int domid)
{
int fd = (int)h;
- int ret, i;
+ struct evtchn_port_info *port_info;
+ int ret;
evtchn_port_t port;

assert(get_current() == main_thread);
- i = port_alloc(fd);
- if (i == -1)
+ port_info = port_alloc(fd);
+ if (port_info == NULL)
return -1;

printf("xc_evtchn_bind_unbound_port(%d)", domid);
@@ -305,11 +311,12 @@ static evtchn_port_or_error_t minios_evtchn_bind_unbound_port(xc_evtchn *xce, xc
printf(" = %d\n", ret);

if (ret < 0) {
+ port_dealloc(port_info);
errno = -ret;
return -1;
}
- files[fd].evtchn.ports[i].bound = 1;
- files[fd].evtchn.ports[i].port = port;
+ port_info->bound = 1;
+ port_info->port = port;
unmask_evtchn(port);
return port;
}
@@ -318,12 +325,13 @@ static evtchn_port_or_error_t minios_evtchn_bind_interdomain(xc_evtchn *xce, xc_
evtchn_port_t remote_port)
{
int fd = (int)h;
+ struct evtchn_port_info *port_info;
evtchn_port_t local_port;
- int ret, i;
+ int ret;

assert(get_current() == main_thread);
- i = port_alloc(fd);
- if (i == -1)
+ port_info = port_alloc(fd);
+ if (port_info == NULL)
return -1;

printf("xc_evtchn_bind_interdomain(%d, %"PRId32")", domid, remote_port);
@@ -331,11 +339,12 @@ static evtchn_port_or_error_t minios_evtchn_bind_interdomain(xc_evtchn *xce, xc_
printf(" = %d\n", ret);

if (ret < 0) {
+ port_dealloc(port_info);
errno = -ret;
return -1;
}
- files[fd].evtchn.ports[i].bound = 1;
- files[fd].evtchn.ports[i].port = local_port;
+ port_info->bound = 1;
+ port_info->port = local_port;
unmask_evtchn(local_port);
return local_port;
}
@@ -343,42 +352,40 @@ static evtchn_port_or_error_t minios_evtchn_bind_interdomain(xc_evtchn *xce, xc_
static int minios_evtchn_unbind(xc_evtchn *xce, xc_osdep_handle h, evtchn_port_t port)
{
int fd = (int)h;
- int i;
- for (i = 0; i < MAX_EVTCHN_PORTS; i++)
- if (files[fd].evtchn.ports[i].port == port) {
- files[fd].evtchn.ports[i].port = -1;
- break;
- }
- if (i == MAX_EVTCHN_PORTS) {
- printf("Warning: couldn't find port %"PRId32" for xc handle %x\n", port, fd);
- errno = -EINVAL;
- return -1;
+ struct evtchn_port_info *port_info;
+
+ minios_list_for_each_entry(port_info, &files[fd].evtchn.ports, list) {
+ if (port_info->port == port) {
+ port_dealloc(port_info);
+ return 0;
+ }
}
- files[fd].evtchn.ports[i].bound = 0;
- unbind_evtchn(port);
- return 0;
+ printf("Warning: couldn't find port %"PRId32" for xc handle %x\n", port, fd);
+ errno = -EINVAL;
+ return -1;
}

static evtchn_port_or_error_t minios_evtchn_bind_virq(xc_evtchn *xce, xc_osdep_handle h, unsigned int virq)
{
int fd = (int)h;
+ struct evtchn_port_info *port_info;
evtchn_port_t port;
- int i;

assert(get_current() == main_thread);
- i = port_alloc(fd);
- if (i == -1)
+ port_info = port_alloc(fd);
+ if (port_info == NULL)
return -1;

printf("xc_evtchn_bind_virq(%d)", virq);
port = bind_virq(virq, evtchn_handler, (void*)(intptr_t)fd);

if (port < 0) {
+ port_dealloc(port_info);
errno = -port;
return -1;
}
- files[fd].evtchn.ports[i].bound = 1;
- files[fd].evtchn.ports[i].port = port;
+ port_info->bound = 1;
+ port_info->port = port;
unmask_evtchn(port);
return port;
}
@@ -386,18 +393,18 @@ static evtchn_port_or_error_t minios_evtchn_bind_virq(xc_evtchn *xce, xc_osdep_h
static evtchn_port_or_error_t minios_evtchn_pending(xc_evtchn *xce, xc_osdep_handle h)
{
int fd = (int)h;
- int i;
+ struct evtchn_port_info *port_info;
unsigned long flags;
evtchn_port_t ret = -1;

local_irq_save(flags);
files[fd].read = 0;
- for (i = 0; i < MAX_EVTCHN_PORTS; i++) {
- evtchn_port_t port = files[fd].evtchn.ports[i].port;
- if (port != -1 && files[fd].evtchn.ports[i].pending) {
+
+ minios_list_for_each_entry(port_info, &files[fd].evtchn.ports, list) {
+ if (port_info->port != -1 && port_info->pending) {
if (ret == -1) {
- ret = port;
- files[fd].evtchn.ports[i].pending = 0;
+ ret = port_info->port;
+ port_info->pending = 0;
} else {
files[fd].read = 1;
break;
--
1.7.7.5


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