Re: [Qemu-devel] [PATCH v3] s390: use FILE instead of QEMUFile for creating text file

[Eric Blake]

On 01/18/2016 04:05 AM, Daniel P. Berrange wrote:
> The s390 skeys monitor command needs to write out a plain text
> file. Currently it is using the QEMUFile class for this, but
> work is ongoing to refactor QEMUFile and eliminate much code
> related to it. The only feature qemu_fopen() gives over fopen()
> is support for QEMU FD passing, but this can be achieved with
> qemu_open() + fdopen() too. Switching to regular stdio FILE
> APIs avoids the need to sprintf via an intermediate buffer
> which slightly simplifies the code.
> 
> Signed-off-by: Daniel P. Berrange 
> ---
>  hw/s390x/s390-skeys.c | 26 ++
>  1 file changed, 14 insertions(+), 12 deletions(-)
> 

Reviewed-by: Eric Blake 

-- 
Eric Blake   eblake redhat com+1-919-301-3266
Libvirt virtualization library http://libvirt.org



signature.asc
Description: OpenPGP digital signature

[Qemu-devel] [PATCH v3] s390: use FILE instead of QEMUFile for creating text file

[Daniel P. Berrange]

The s390 skeys monitor command needs to write out a plain text
file. Currently it is using the QEMUFile class for this, but
work is ongoing to refactor QEMUFile and eliminate much code
related to it. The only feature qemu_fopen() gives over fopen()
is support for QEMU FD passing, but this can be achieved with
qemu_open() + fdopen() too. Switching to regular stdio FILE
APIs avoids the need to sprintf via an intermediate buffer
which slightly simplifies the code.

Signed-off-by: Daniel P. Berrange 
---
 hw/s390x/s390-skeys.c | 26 ++
 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/hw/s390x/s390-skeys.c b/hw/s390x/s390-skeys.c
index f2b732e..e4c3b07 100644
--- a/hw/s390x/s390-skeys.c
+++ b/hw/s390x/s390-skeys.c
@@ -45,15 +45,11 @@ void s390_skeys_init(void)
 qdev_init_nofail(DEVICE(obj));
 }
 
-static void write_keys(QEMUFile *f, uint8_t *keys, uint64_t startgfn,
+static void write_keys(FILE *f, uint8_t *keys, uint64_t startgfn,
uint64_t count, Error **errp)
 {
 uint64_t curpage = startgfn;
 uint64_t maxpage = curpage + count - 1;
-const char *fmt = "page=%03" PRIx64 ": key(%d) => ACC=%X, FP=%d, REF=%d,"
-  " ch=%d, reserved=%d\n";
-char buf[128];
-int len;
 
 for (; curpage <= maxpage; curpage++) {
 uint8_t acc = (*keys & 0xF0) >> 4;
@@ -62,10 +58,9 @@ static void write_keys(QEMUFile *f, uint8_t *keys, uint64_t 
startgfn,
 int ch = (*keys & 0x02);
 int res = (*keys & 0x01);
 
-len = snprintf(buf, sizeof(buf), fmt, curpage,
-   *keys, acc, fp, ref, ch, res);
-assert(len < sizeof(buf));
-qemu_put_buffer(f, (uint8_t *)buf, len);
+fprintf(f, "page=%03" PRIx64 ": key(%d) => ACC=%X, FP=%d, REF=%d,"
+" ch=%d, reserved=%d\n",
+curpage, *keys, acc, fp, ref, ch, res);
 keys++;
 }
 }
@@ -114,7 +109,8 @@ void qmp_dump_skeys(const char *filename, Error **errp)
 vaddr cur_gfn = 0;
 uint8_t *buf;
 int ret;
-QEMUFile *f;
+int fd;
+FILE *f;
 
 /* Quick check to see if guest is using storage keys*/
 if (!skeyclass->skeys_enabled(ss)) {
@@ -123,9 +119,15 @@ void qmp_dump_skeys(const char *filename, Error **errp)
 return;
 }
 
-f = qemu_fopen(filename, "wb");
+fd = qemu_open(filename, O_WRONLY|O_CREAT|O_TRUNC, 0600);
+if (fd < 0) {
+error_setg_file_open(errp, errno, filename);
+return;
+}
+f = fdopen(fd, "wb");
 if (!f) {
 error_setg_file_open(errp, errno, filename);
+close(fd);
 return;
 }
 
@@ -160,7 +162,7 @@ out_free:
 error_propagate(errp, lerr);
 g_free(buf);
 out:
-qemu_fclose(f);
+fclose(f);
 }
 
 static void qemu_s390_skeys_init(Object *obj)
-- 
2.5.0