[pve-devel] [PATCH qemu] vma: add throttling options to drive mapping fifo protocol

[Wolfgang Bumiller]

Signed-off-by: Wolfgang Bumiller <w.bumiller at proxmox.com>
---
 vma.c | 82 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 73 insertions(+), 9 deletions(-)

diff --git a/vma.c b/vma.c
index 04915427c8..91ae14cdc3 100644
--- a/vma.c
+++ b/vma.c
@@ -18,7 +18,9 @@
 #include "qemu-common.h"
 #include "qemu/error-report.h"
 #include "qemu/main-loop.h"
+#include "qemu/cutils.h"
 #include "qapi/qmp/qstring.h"
+#include "qapi/qmp/qint.h"
 #include "sysemu/char.h" /* qstring_from_str */
 #include "sysemu/block-backend.h"
 
@@ -133,9 +135,39 @@ typedef struct RestoreMap {
     char *devname;
     char *path;
     char *format;
+    uint64_t throttling_bps;
+    char *throttling_group;
     bool write_zero;
 } RestoreMap;
 
+static bool try_parse_option(char **line, const char *optname, char **out, const char *inbuf) {
+    size_t optlen = strlen(optname);
+    if (strncmp(*line, optname, optlen) != 0 || (*line)[optlen] != '=') {
+        return false;
+    }
+    if (*out) {
+        g_error("read map failed - duplicate value for option '%s'", optname);
+    }
+    char *value = (*line) + optlen + 1; /* including a '=' */
+    char *colon = strchr(value, ':');
+    if (!colon) {
+        g_error("read map failed - option '%s' not terminated ('%s')",
+                optname, inbuf);
+    }
+    *line = colon+1;
+    *out = g_strndup(value, colon - value);
+    return true;
+}
+
+static uint64_t verify_u64(const char *text) {
+    uint64_t value;
+    const char *endptr = NULL;
+    if (qemu_strtou64(text, &endptr, 0, &value) != 0 || !endptr || *endptr) {
+        g_error("read map failed - not a number: %s", text);
+    }
+    return value;
+}
+
 static int extract_content(int argc, char **argv)
 {
     int c, ret = 0;
@@ -209,6 +241,9 @@ static int extract_content(int argc, char **argv)
         while (1) {
             char inbuf[8192];
             char *line = fgets(inbuf, sizeof(inbuf), map);
+            char *format = NULL;
+            char *bps = NULL;
+            char *group = NULL;
             if (!line || line[0] == '\0' || !strcmp(line, "done\n")) {
                 break;
             }
@@ -220,15 +255,19 @@ static int extract_content(int argc, char **argv)
                 }
             }
 
-            char *format = NULL;
-            if (strncmp(line, "format=", sizeof("format=")-1) == 0) {
-                format = line + sizeof("format=")-1;
-                char *colon = strchr(format, ':');
-                if (!colon) {
-                    g_error("read map failed - found only a format ('%s')", inbuf);
+            while (1) {
+                if (!try_parse_option(&line, "format", &format, inbuf) &&
+                    !try_parse_option(&line, "throttling.bps", &bps, inbuf) &&
+                    !try_parse_option(&line, "throttling.group", &group, inbuf))
+                {
+                    break;
                 }
-                format = g_strndup(format, colon - format);
-                line = colon+1;
+            }
+
+            uint64_t bps_value = 0;
+            if (bps) {
+                bps_value = verify_u64(bps);
+                g_free(bps);
             }
 
             const char *path;
@@ -254,6 +293,8 @@ static int extract_content(int argc, char **argv)
             map->devname = g_strdup(devname);
             map->path = g_strdup(path);
             map->format = format;
+            map->throttling_bps = bps_value;
+            map->throttling_group = group;
             map->write_zero = write_zero;
 
             g_hash_table_insert(devmap, map->devname, map);
@@ -281,6 +322,8 @@ static int extract_content(int argc, char **argv)
         } else if (di) {
             char *devfn = NULL;
             const char *format = NULL;
+            uint64_t throttling_bps = 0;
+            const char *throttling_group = NULL;
             int flags = BDRV_O_RDWR | BDRV_O_NO_FLUSH;
             bool write_zero = true;
 
@@ -292,6 +335,8 @@ static int extract_content(int argc, char **argv)
                 }
                 devfn = map->path;
                 format = map->format;
+                throttling_bps = map->throttling_bps;
+                throttling_group = map->throttling_group;
                 write_zero = map->write_zero;
             } else {
                 devfn = g_strdup_printf("%s/tmp-disk-%s.raw",
@@ -328,12 +373,31 @@ static int extract_content(int argc, char **argv)
 		qdict_put(options, "driver", qstring_from_str("raw"));
 	    }
 
-
 	    if (errp || !(blk = blk_new_open(devfn, NULL, options, flags, &errp))) {
                 g_error("can't open file %s - %s", devfn,
                         error_get_pretty(errp));
             }
 
+            if (throttling_group) {
+                blk_io_limits_enable(blk, throttling_group);
+            }
+
+            if (throttling_bps) {
+                if (!throttling_group) {
+                    blk_io_limits_enable(blk, devfn);
+                }
+
+                ThrottleConfig cfg;
+                throttle_config_init(&cfg);
+                cfg.buckets[THROTTLE_BPS_WRITE].avg = throttling_bps;
+                Error *err = NULL;
+                if (!throttle_is_valid(&cfg, &err)) {
+                    error_report_err(err);
+                    g_error("failed to apply throttling");
+                }
+                blk_set_io_limits(blk, &cfg);
+            }
+
             if (vma_reader_register_bs(vmar, i, blk, write_zero, &errp) < 0) {
                 g_error("%s", error_get_pretty(errp));
             }
-- 
2.11.0