[3/6] tools/console: use xenforeigmemory to map console ring

Commit Message

Roger Pau Monné Sept. 17, 2021, 3:46 p.m. UTC

This patch replaces the usage of xc_map_foreign_range with
xenforeignmemory_map from the stable xenforeignmemory library. Note
there are still other uses of libxc functions which prevents removing
the dependency.

No functional change intended.

Signed-off-by: Roger Pau Monné <[e-mail]>
---
 tools/console/Makefile    |  4 ++--
 tools/console/daemon/io.c | 25 ++++++++++++++++++++-----
 2 files changed, 22 insertions(+), 7 deletions(-)

Comments

Ian Jackson Sept. 20, 2021, 10:32 a.m. UTC | #1

Roger Pau Monne writes ("[PATCH 3/6] tools/console: use xenforeigmemory to map console ring"):
> This patch replaces the usage of xc_map_foreign_range with
> xenforeignmemory_map from the stable xenforeignmemory library. Note
> there are still other uses of libxc functions which prevents removing
> the dependency.
> 
> No functional change intended.

Reviewed-by: Ian Jackson <[e-mail]>

Patch

diff --git a/tools/console/Makefile b/tools/console/Makefile
index 84796eac8f..3f4cddab03 100644
--- a/tools/console/Makefile
+++ b/tools/console/Makefile
@@ -29,9 +29,9 @@  clean:
 distclean: clean
 
 daemon/main.o: daemon/_paths.h
-daemon/io.o: CFLAGS += $(CFLAGS_libxenevtchn) $(CFLAGS_libxengnttab) $(CONSOLE_CFLAGS-y)
+daemon/io.o: CFLAGS += $(CFLAGS_libxenevtchn) $(CFLAGS_libxengnttab) $(CFLAGS_libxenforeignmemory) $(CONSOLE_CFLAGS-y)
 xenconsoled: $(patsubst %.c,%.o,$(wildcard daemon/*.c))
-	$(CC) $(LDFLAGS) $^ -o $@ $(LDLIBS) $(LDLIBS_libxenevtchn) $(LDLIBS_libxengnttab) $(LDLIBS_xenconsoled) $(APPEND_LDFLAGS)
+	$(CC) $(LDFLAGS) $^ -o $@ $(LDLIBS) $(LDLIBS_libxenevtchn) $(LDLIBS_libxengnttab) $(LDLIBS_libxenforeignmemory) $(LDLIBS_xenconsoled) $(APPEND_LDFLAGS)
 
 client/main.o: client/_paths.h
 xenconsole: $(patsubst %.c,%.o,$(wildcard client/*.c))
diff --git a/tools/console/daemon/io.c b/tools/console/daemon/io.c
index 200b575d76..682c1f4008 100644
--- a/tools/console/daemon/io.c
+++ b/tools/console/daemon/io.c
@@ -22,6 +22,7 @@ 
 #include "utils.h"
 #include "io.h"
 #include <xenevtchn.h>
+#include <xenforeignmemory.h>
 #include <xengnttab.h>
 #include <xenstore.h>
 #include <xen/io/console.h>
@@ -73,6 +74,7 @@  static int log_time_guest_needts = 1;
 static int log_hv_fd = -1;
 
 static xengnttab_handle *xgt_handle = NULL;
+static xenforeignmemory_handle *xfm_handle;
 
 static struct pollfd  *fds;
 static unsigned int current_array_size;
@@ -675,7 +677,7 @@  static void console_unmap_interface(struct console *con)
 	if (xgt_handle && con->ring_ref == -1)
 		xengnttab_unmap(xgt_handle, con->interface, 1);
 	else
-		munmap(con->interface, XC_PAGE_SIZE);
+		xenforeignmemory_unmap(xfm_handle, con->interface, 1);
 	con->interface = NULL;
 	con->ring_ref = -1;
 }
@@ -722,11 +724,12 @@  static int console_create_ring(struct console *con)
 		con->ring_ref = -1;
 	}
 	if (!con->interface) {
+		xen_pfn_t pfn = ring_ref;
+
 		/* Fall back to xc_map_foreign_range */
-		con->interface = xc_map_foreign_range(
-			xc, dom->domid, XC_PAGE_SIZE,
-			PROT_READ|PROT_WRITE,
-			(unsigned long)ring_ref);
+		con->interface = xenforeignmemory_map(
+			xfm_handle, dom->domid,	PROT_READ|PROT_WRITE, 1,
+			&pfn, NULL);
 		if (con->interface == NULL) {
 			err = EINVAL;
 			goto out;
@@ -1341,6 +1344,14 @@  void handle_io(void)
 		      errno, strerror(errno));
 	}
 
+	xfm_handle = xenforeignmemory_open(NULL, 0);
+	if (xfm_handle == NULL) {
+		dolog(LOG_ERR,
+		      "Failed to open xen foreign memory handle: %d (%s)",
+		      errno, strerror(errno));
+		goto out;
+	}
+
 	enum_domains();
 
 	for (;;) {
@@ -1462,6 +1473,10 @@  void handle_io(void)
 		xengnttab_close(xgt_handle);
 		xgt_handle = NULL;
 	}
+	if (xfm_handle != NULL) {
+		xenforeignmemory_close(xfm_handle);
+		xfm_handle = NULL;
+	}
 	log_hv_evtchn = -1;
 }