ioemu: Add tapdisk-ioemu tool

Currently, tap:ioemu can only be used for domains which have a device
model running. This isn't the case for all domains. The most important
of the missing domains is Dom0 which needs acces e.g. to extract the
kernel from the domain's image.

tapdisk-ioemu is a tool compiled from ioemu source plus a small
wrapper which handles tap:ioemu access for domains without device
model (currently Dom0). You must start tapdisk-ioemu manually before
trying to attach a tap:ioemu disk to Dom0 at the moment. A patch to
blktapctrl will follow to automatically start tapdisk-ioemu when
needed.

Signed-off-by: Kevin Wolf <kwolf@suse.de>
Signed-off-by: Keir Fraser <keir.fraser@citrix.com>

diff --git a/.hgignore b/.hgignore
index 7c7d4a9d86b73015fa4a33556fed3f916e9e68d1..e75acbf8aed1e91a29ee0fe46339a304ed617f87 100644 (file)
--- a/.hgignore
+++ b/.hgignore
@@ -150,6 +150,7 @@
 ^tools/ioemu/qemu-tech\.html$
 ^tools/ioemu/qemu\.1$
 ^tools/ioemu/qemu\.pod$
+^tools/ioemu/tapdisk-ioemu$
 ^tools/libxc/ia64/asm/.*\.h$
 ^tools/libxc/ia64/acpi/.*\.h$
 ^tools/libxc/ia64/acpi/platform/.*\.h$

diff --git a/tools/ioemu/Makefile b/tools/ioemu/Makefile
index 76f6f9af9904243a736620e22f754ccdca457c27..053d214bd4ceed6df3b733027aba657f4b7d8e7a 100644 (file)
--- a/tools/ioemu/Makefile
+++ b/tools/ioemu/Makefile
@@ -35,7 +35,7 @@ endif
 endif
 endif
 
-TOOLS=
+TOOLS=tapdisk-ioemu
 
 all: $(TOOLS) $(DOCS) recurse-all
 
@@ -44,6 +44,13 @@ subdir-%:
 
 recurse-all: $(patsubst %,subdir-%, $(TARGET_DIRS))
 
+tapdisk-ioemu: CPPFLAGS += -I$(XEN_ROOT)/tools/libxc
+tapdisk-ioemu: CPPFLAGS += -I$(XEN_ROOT)/tools/blktap/lib
+tapdisk-ioemu: CPPFLAGS += -I$(XEN_ROOT)/tools/xenstore
+tapdisk-ioemu: CPPFLAGS += -I$(XEN_ROOT)/tools/include
+tapdisk-ioemu: tapdisk-ioemu.c cutils.c block.c block-raw.c block-cow.c block-qcow.c aes.c block-vmdk.c block-cloop.c block-dmg.c block-bochs.c block-vpc.c block-vvfat.c block-qcow2.c hw/xen_blktap.c osdep.c
+       $(CC) -DQEMU_TOOL $(CFLAGS) $(CPPFLAGS) $(BASE_CFLAGS) $(LDFLAGS) $(BASE_LDFLAGS) -o $@ $^ -lz $(LIBS)
+
 qemu-img$(EXESUF): qemu-img.c cutils.c block.c block-raw.c block-cow.c block-qcow.c aes.c block-vmdk.c block-cloop.c block-dmg.c block-bochs.c block-vpc.c block-vvfat.c block-qcow2.c
        $(CC) -DQEMU_TOOL $(CFLAGS) $(CPPFLAGS) $(BASE_CFLAGS) $(LDFLAGS) $(BASE_LDFLAGS) -o $@ $^ -lz $(LIBS)
 
@@ -80,7 +87,7 @@ endif
 
 install: all $(if $(BUILD_DOCS),install-doc)
        mkdir -p "$(DESTDIR)$(bindir)"
-#      $(INSTALL) -m 755 -s $(TOOLS) "$(DESTDIR)$(bindir)"
+       $(INSTALL) -m 755 -s $(TOOLS) "$(DESTDIR)$(prefix)/sbin"
 #      mkdir -p "$(DESTDIR)$(datadir)"
 #      for x in bios.bin vgabios.bin vgabios-cirrus.bin ppc_rom.bin \
 #              video.x openbios-sparc32 linux_boot.bin pxe-ne2k_pci.bin \

diff --git a/tools/ioemu/osdep.c b/tools/ioemu/osdep.c
index a25d03fe586edd374c5fc74b158d7be91d8b97b1..774959b65ff95773f11db6fbf81ddac03c9e29f0 100644 (file)
--- a/tools/ioemu/osdep.c
+++ b/tools/ioemu/osdep.c
@@ -32,7 +32,6 @@
 #include <sys/statvfs.h>
 #endif
 
-#include "cpu.h"
 #if defined(USE_KQEMU)
 #include "vl.h"
 #endif

diff --git a/tools/ioemu/tapdisk-ioemu.c b/tools/ioemu/tapdisk-ioemu.c
new file mode 100644 (file)
index 0000000..a28fabe
--- /dev/null
+++ b/tools/ioemu/tapdisk-ioemu.c
@@ -0,0 +1,141 @@
+#include <stdlib.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdint.h>
+#include <signal.h>
+
+#include <assert.h>
+
+extern int init_blktap(void);
+extern void qemu_aio_init(void);
+extern void qemu_aio_poll(void);
+extern void bdrv_init(void);
+
+extern void *qemu_mallocz(size_t size);
+extern void qemu_free(void *ptr);
+
+int domid = 0;
+FILE* logfile;
+
+void term_printf(const char *fmt, ...)
+{
+    va_list ap;
+    va_start(ap, fmt);
+    vprintf(fmt, ap);
+    va_end(ap);
+}
+
+void term_print_filename(const char *filename)
+{
+    term_printf(filename);
+}
+
+
+typedef void IOReadHandler(void *opaque, const uint8_t *buf, int size);
+typedef int IOCanRWHandler(void *opaque);
+typedef void IOHandler(void *opaque);
+
+typedef struct IOHandlerRecord {
+    int fd;
+    IOCanRWHandler *fd_read_poll;
+    IOHandler *fd_read;
+    IOHandler *fd_write;
+    int deleted;
+    void *opaque;
+    /* temporary data */
+    struct pollfd *ufd;
+    struct IOHandlerRecord *next;
+} IOHandlerRecord;
+
+static IOHandlerRecord *first_io_handler;
+
+int qemu_set_fd_handler2(int fd, 
+                         IOCanRWHandler *fd_read_poll, 
+                         IOHandler *fd_read, 
+                         IOHandler *fd_write, 
+                         void *opaque)
+{
+    IOHandlerRecord *ioh;
+
+    /* This is a stripped down version of fd handling */
+    assert(fd_read_poll == NULL);
+    assert(fd_write == NULL);
+
+    for(ioh = first_io_handler; ioh != NULL; ioh = ioh->next)
+        if (ioh->fd == fd)
+            goto found;
+    
+    if (!fd_read && !fd_write)
+        return 0;
+        
+    ioh = qemu_mallocz(sizeof(IOHandlerRecord));
+    if (!ioh)
+        return -1;
+    ioh->next = first_io_handler;
+    first_io_handler = ioh;
+
+found:
+    if (!fd_read && !fd_write) {
+        ioh->deleted = 1;
+    } else {
+        ioh->fd = fd;
+        ioh->fd_read = fd_read;
+        ioh->opaque = opaque;
+        ioh->deleted = 0;
+    }
+
+    return 0;
+}
+
+int main(void) 
+{
+    IOHandlerRecord *ioh, **pioh;
+    int max_fd;
+    fd_set rfds;
+    struct timeval tv;
+
+    logfile = stderr;
+    
+    bdrv_init();
+    qemu_aio_init();
+    init_blktap();
+   
+    /* 
+     * Main loop: Pass events to the corrsponding handlers and check for
+     * completed aio operations.
+     */
+    while (1) {
+        qemu_aio_poll();
+
+        max_fd = -1;
+        FD_ZERO(&rfds);
+        for(ioh = first_io_handler; ioh != NULL; ioh = ioh->next)
+            if (!ioh->deleted) {
+                FD_SET(ioh->fd, &rfds);
+                max_fd = max_fd > ioh->fd ? max_fd : ioh->fd;
+            }
+
+        tv.tv_sec = 0;
+        tv.tv_usec = 10000;
+        if (select(max_fd + 1, &rfds, NULL, NULL, &tv) <= 0)
+            continue;
+            
+        /* Call handlers */
+        for(ioh = first_io_handler; ioh != NULL; ioh = ioh->next)
+            if (FD_ISSET(ioh->fd, &rfds))
+                ioh->fd_read(ioh->opaque);
+
+        /* Remove deleted IO handlers */
+        pioh = &first_io_handler;
+        while (*pioh) {
+            ioh = *pioh;
+            if (ioh->deleted) {
+                *pioh = ioh->next;
+                qemu_free(ioh);
+            } else 
+                pioh = &ioh->next;
+        }
+    }
+    return 0;
+}

diff --git a/tools/ioemu/vl.h b/tools/ioemu/vl.h
index f3ad84bbd162d38662cf6bc8d92905ad8e118e75..7ccd256a3119c23a65c7322b7a068420ecc47e75 100644 (file)
--- a/tools/ioemu/vl.h
+++ b/tools/ioemu/vl.h
@@ -159,7 +159,7 @@ extern void *shared_vram;
 extern FILE *logfile;
 
 
-#if defined(__i386__) || defined(__x86_64__)
+#if (defined(__i386__) || defined(__x86_64__)) && !defined(QEMU_TOOL)
 #define MAPCACHE
 uint8_t *qemu_map_cache(target_phys_addr_t phys_addr);
 void     qemu_invalidate_map_cache(void);
@@ -1553,7 +1553,9 @@ extern long time_offset;
 void timeoffset_get(void);
 
 /* xen_platform.c */
+#ifndef QEMU_TOOL
 void pci_xen_platform_init(PCIBus *bus);
+#endif
 
 
 void kqemu_record_dump(void);