[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Xen-devel] [RFC PATCH] tools/libxl : add struct and parsing utils for the 'static_shm' xl config entry



Add a new struct libxl_static_shm in the libxl IDL for the proposed new xl
config entry 'static_shm' (see [1]), which allow the user to set up shared
memory areas among several VMs for communication.

Add related parsing code to the libxl/libxlu_* family and xl/xl_parse.c

[1]: [RFC v3]Proposal to allow setting up shared memory areas between VMs from 
xl config file,
     https://lists.xenproject.org/archives/html/xen-devel/2017-07/msg01741.html

Signed-off-by: Zhongze Liu <blackskygg@xxxxxxxxx>
---
Cc: Wei Liu <wei.liu2@xxxxxxxxxx>
Cc: Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
Cc: Stefano Stabellini <sstabellini@xxxxxxxxxx>
Cc: Julien Grall <julien.grall@xxxxxxx>
Cc: xen-devel@xxxxxxxxxxxxx
---
 tools/libxl/Makefile        |   2 +-
 tools/libxl/libxl.h         |  10 ++
 tools/libxl/libxl_types.idl |  52 +++++++++
 tools/libxl/libxlu_sshm.c   | 274 ++++++++++++++++++++++++++++++++++++++++++++
 tools/libxl/libxlutil.h     |   6 +
 tools/xl/xl_parse.c         |  24 +++-
 6 files changed, 366 insertions(+), 2 deletions(-)
 create mode 100644 tools/libxl/libxlu_sshm.c

diff --git a/tools/libxl/Makefile b/tools/libxl/Makefile
index 2ffb78f5c4..b7effb188b 100644
--- a/tools/libxl/Makefile
+++ b/tools/libxl/Makefile
@@ -175,7 +175,7 @@ AUTOINCS= libxlu_cfg_y.h libxlu_cfg_l.h _libxl_list.h 
_paths.h \
 AUTOSRCS= libxlu_cfg_y.c libxlu_cfg_l.c
 AUTOSRCS += _libxl_save_msgs_callout.c _libxl_save_msgs_helper.c
 LIBXLU_OBJS = libxlu_cfg_y.o libxlu_cfg_l.o libxlu_cfg.o \
-       libxlu_disk_l.o libxlu_disk.o libxlu_vif.o libxlu_pci.o
+       libxlu_disk_l.o libxlu_disk.o libxlu_vif.o libxlu_pci.o libxlu_sshm.o
 $(LIBXLU_OBJS): CFLAGS += $(CFLAGS_libxenctrl) # For xentoollog.h
 
 $(TEST_PROG_OBJS) _libxl.api-for-check: CFLAGS += $(CFLAGS_libxentoollog)
diff --git a/tools/libxl/libxl.h b/tools/libxl/libxl.h
index 7cf0f31f68..cf3cbe1ba1 100644
--- a/tools/libxl/libxl.h
+++ b/tools/libxl/libxl.h
@@ -2228,6 +2228,16 @@ int libxl_fd_set_nonblock(libxl_ctx *ctx, int fd, int 
nonblock);
 int libxl_qemu_monitor_command(libxl_ctx *ctx, uint32_t domid,
                                const char *command_line, char **output);
 
+
+/* Functions to stattically set up shared memory regions between two  domains
+ * for shm-based communication. */
+
+#define LIBXL_SSHM_RANGE_UNKNOWN UINT64_MAX
+
+/* TODO: int libxl_sshm_add(libxl_ctx *ctx, uint32_t domid,
+ *                          libxl_static_shm *sshm);
+ */
+
 #include <libxl_event.h>
 
 #endif /* LIBXL_H */
diff --git a/tools/libxl/libxl_types.idl b/tools/libxl/libxl_types.idl
index 8a9849c643..8c68b45add 100644
--- a/tools/libxl/libxl_types.idl
+++ b/tools/libxl/libxl_types.idl
@@ -779,6 +779,57 @@ libxl_device_channel = Struct("device_channel", [
            ])),
 ])
 
+# static shared memory cacheability attributes
+libxl_sshm_cacheattr = Enumeration("sshm_cacheattr", [
+    (-1, "UNKNOWN"),
+    (0, "UC"),
+    (1, "WC"),          #x86 only
+    (4, "WT"),
+    (5, "WP"),          #x86 only
+    (6, "WB"),
+    (7, "SUC"),         #x86 only
+    (8, "BUFFERABLE"),  #ARM only
+    (9, "WA"),          #ARM only
+    ], init_val = "LIBXL_SSHM_CACHEATTR_UNKNOWN")
+
+# static shared memory shareability attributes
+libxl_sshm_shareattr = Enumeration("sshm_shareattr", [
+    (-1, "UNKNOWN"),
+    (0, "NON"),
+    (2, "OUTER"),
+    (3, "INNER"),
+    ], init_val = "LIBXL_SSHM_SHAREATTR_UNKNOWN")
+
+libxl_sshm_prot = Enumeration("sshm_prot", [
+    (-1, "UNKNOWN"),
+    (0, "N"),
+    (1, "R"),
+    (2, "W"),
+    (4, "X"),
+    (3, "RW"),
+    (5, "RX"),
+    (6, "WX"),
+    (7, "RWX"),
+    ], init_val = "LIBXL_SSHM_PROT_UNKNOWN")
+
+libxl_sshm_role = Enumeration("sshm_role", [
+    (-1, "UNKNOWN"),
+    (0, "MASTER"),
+    (1, "SLAVE"),
+    ], init_val = "LIBXL_SSHM_ROLE_UNKNOWN")
+
+libxl_static_shm = Struct("static_shm", [
+    ("id", string),
+    ("begin", uint64, {'init_val': 'LIBXL_SSHM_RANGE_UNKNOWN'}),
+    ("end", uint64, {'init_val': 'LIBXL_SSHM_RANGE_UNKNOWN'}),
+    ("prot", libxl_sshm_prot),
+    ("arm_shareattr", libxl_sshm_shareattr),
+    ("arm_inner_cacheattr", libxl_sshm_cacheattr),
+    ("arm_outer_cacheattr", libxl_sshm_cacheattr),
+    ("x86_cacheattr", libxl_sshm_cacheattr),
+    ("role", libxl_sshm_role),
+])
+
 libxl_domain_config = Struct("domain_config", [
     ("c_info", libxl_domain_create_info),
     ("b_info", libxl_domain_build_info),
@@ -797,6 +848,7 @@ libxl_domain_config = Struct("domain_config", [
     ("channels", Array(libxl_device_channel, "num_channels")),
     ("usbctrls", Array(libxl_device_usbctrl, "num_usbctrls")),
     ("usbdevs", Array(libxl_device_usbdev, "num_usbdevs")),
+    ("sshms", Array(libxl_static_shm, "num_sshms")),
 
     ("on_poweroff", libxl_action_on_shutdown),
     ("on_reboot", libxl_action_on_shutdown),
diff --git a/tools/libxl/libxlu_sshm.c b/tools/libxl/libxlu_sshm.c
new file mode 100644
index 0000000000..fcd65af4d9
--- /dev/null
+++ b/tools/libxl/libxlu_sshm.c
@@ -0,0 +1,274 @@
+#include "libxl_osdeps.h" /* must come before any other headers */
+#include "libxlu_internal.h"
+
+#include <ctype.h>
+
+#define PARAM_RE(EXPR) "^\\s*" EXPR "\\s*(,|$)"
+#define KEY_RE         "([_a-zA-Z0-9]+)"
+#define VAL_RE         "([^ \t\n,]+)"
+#define EQU_RE         PARAM_RE(KEY_RE "\\s*=\\s*" VAL_RE)
+
+#define MASK_4K        ((uint64_t)0xfff)
+#define MAX_ID_LEN     128
+#define CACHEATTR_ARM  0
+#define CACHEATTR_X86  1
+
+#define INVAL_ERR(msg, curr_str)  do {              \
+        xlu__sshm_err(cfg, msg, curr_str);          \
+        rc = EINVAL;                                \
+        goto out;                                   \
+    } while(0)
+
+/* set a member in libxl_static_shm and report an error if it's respecified,
+ * @curr_str indicates the head of the remaining string. */
+#define SET_VAL(var, name, type, value, curr_str)  do {                 \
+        if ((var) != LIBXL_SSHM_##type##_UNKNOWN && (var) != value) {   \
+            INVAL_ERR("\"" name "\" respecified", curr_str);            \
+        }                                                               \
+        (var) = value;                                                  \
+    } while(0)
+
+
+static void xlu__sshm_err(XLU_Config *cfg, const char *msg,
+                          const char *curr_str) {
+    fprintf(cfg->report,
+            "%s: config parsing error in shared_memory: %s at '%s'\n",
+            cfg->config_source, msg, curr_str);
+}
+
+static int parse_prot(XLU_Config *cfg, char *str, libxl_sshm_prot *prot)
+{
+    int rc;
+    libxl_sshm_prot new_prot;
+
+    if (!strcmp(str, "r") || !strcmp(str, "ro")) {
+        new_prot = LIBXL_SSHM_PROT_R;
+    } else if (!strcmp(str, "w") || !strcmp(str, "wo")) {
+        new_prot = LIBXL_SSHM_PROT_W;
+    } else if (!strcmp(str, "x") || !strcmp(str, "xo")) {
+        new_prot = LIBXL_SSHM_PROT_X;
+    } else if (!strcmp(str, "rw")) {
+        new_prot = LIBXL_SSHM_PROT_RW;
+    } else if (!strcmp(str, "rx")) {
+        new_prot = LIBXL_SSHM_PROT_RX;
+    } else if (!strcmp(str, "wx")) {
+        new_prot = LIBXL_SSHM_PROT_WX;
+    } else if (!strcmp(str, "rwx")) {
+        new_prot = LIBXL_SSHM_PROT_RWX;
+    } else if (!strcmp(str, "n")) {
+        new_prot = LIBXL_SSHM_PROT_N;
+    } else {
+        INVAL_ERR("invalid permission flags", str);
+    }
+
+    SET_VAL(*prot, "permission flags", PROT, new_prot, str);
+
+    rc = 0;
+
+ out:
+    return rc;
+}
+
+static int parse_cacheattr(XLU_Config *cfg, char *str, int arch,
+                           libxl_sshm_cacheattr *cattr)
+{
+    int rc;
+    libxl_sshm_cacheattr new_cattr;
+
+    if (!strcmp(str, "uc")) {
+        new_cattr = LIBXL_SSHM_CACHEATTR_UC;
+    } else if (!strcmp(str, "wc")) {
+        if (CACHEATTR_X86 != arch) {
+            INVAL_ERR("invalid cacheability attribute", str);
+        }
+        new_cattr = LIBXL_SSHM_CACHEATTR_WC;
+    } else if (!strcmp(str, "wt")) {
+        new_cattr = LIBXL_SSHM_CACHEATTR_WT;
+    } else if (!strcmp(str, "wp")) {
+        if (CACHEATTR_X86 != arch) {
+            INVAL_ERR("invalid cacheability attribute", str);
+        }
+        new_cattr = LIBXL_SSHM_CACHEATTR_WP;
+    } else if (!strcmp(str, "wb")) {
+        new_cattr = LIBXL_SSHM_CACHEATTR_WB;
+    } else if (!strcmp(str, "suc")) {
+        if (CACHEATTR_X86 != arch) {
+            INVAL_ERR("invalid cacheability attribute", str);
+        }
+        new_cattr = LIBXL_SSHM_CACHEATTR_SUC;
+    } else if (!strcmp(str, "bufferable")) {
+        if (CACHEATTR_ARM != arch) {
+            INVAL_ERR("invalid cacheability attribute", str);
+        }
+        new_cattr = LIBXL_SSHM_CACHEATTR_BUFFERABLE;
+    } else if (!strcmp(str, "wa")) {
+        if (CACHEATTR_ARM != arch) {
+            INVAL_ERR("invalid cacheability attribute", str);
+        }
+        new_cattr = LIBXL_SSHM_CACHEATTR_WA;
+    } else {
+        INVAL_ERR("invalid cacheability attribute", str);
+    }
+
+    SET_VAL(*cattr, "cacheability attributes", CACHEATTR, new_cattr, str);
+    rc = 0;
+
+ out:
+    return rc;
+}
+
+static int parse_shareattr(XLU_Config *cfg, char *str,
+                           libxl_sshm_shareattr *sattr)
+{
+    int rc;
+    libxl_sshm_shareattr new_sattr;
+
+    if (!strcmp(str, "non")) {
+        new_sattr = LIBXL_SSHM_SHAREATTR_NON;
+    } else if (!strcmp(str, "outer")) {
+        new_sattr = LIBXL_SSHM_SHAREATTR_OUTER;
+    } else if (!strcmp(str, "inner")) {
+        new_sattr = LIBXL_SSHM_SHAREATTR_INNER;
+    } else {
+        INVAL_ERR("invalid arm shareability attribute", str);
+    }
+
+    SET_VAL(*sattr, "arm shareability attributes", SHAREATTR, new_sattr, str);
+    rc = 0;
+
+ out:
+    return rc;
+}
+
+/* handle key = value pairs */
+static int handle_equ(XLU_Config *cfg, char *key, char *val,
+                      libxl_static_shm *sshm)
+{
+    int rc;
+
+    if (!strcmp(key, "id")) {
+        if (strlen(val) > MAX_ID_LEN) { INVAL_ERR("id too long", val); }
+        if (sshm->id && !strcmp(sshm->id, val)) {
+            INVAL_ERR("id respecified", val);
+        }
+
+        if (NULL == (sshm->id = strdup(val))) {
+            fprintf(stderr, "sshm parser out of memory\n");
+            rc = ENOMEM;
+            goto out;
+        }
+    } else if (!strcmp(key, "role")) {
+        libxl_sshm_role new_role;
+
+        if (!strcmp("master", val)) {
+            new_role = LIBXL_SSHM_ROLE_MASTER;
+        } else if (!strcmp("slave", val)) {
+            new_role = LIBXL_SSHM_ROLE_SLAVE;
+        } else {
+            INVAL_ERR("invalid role", val);
+        }
+
+        SET_VAL(sshm->role, "role", ROLE, new_role, val);
+
+    } else if (!strcmp(key, "begin") || !strcmp(key, "end")) {
+        char *endptr;
+        int base = 10;
+        uint64_t new_bound;
+
+        /* could be in hex form */
+        if ('0' == val[0] && 'x' == val[1]) { base = 16; }
+        new_bound = strtoull(val, &endptr, base);
+        if (ERANGE == errno || *endptr) {
+            INVAL_ERR("invalid begin/end", val);
+        }
+        if (new_bound & MASK_4K) {
+            INVAL_ERR("begin/end is not a multiple of 4K", val);
+        }
+
+        /* begin or end */
+        if ('b' == key[0]) {
+            SET_VAL(sshm->begin, "beginning address", RANGE, new_bound, val);
+        } else {
+            SET_VAL(sshm->end, "ending address", RANGE, new_bound, val);
+        }
+    } else if (!strcmp(key, "prot")) {
+        rc = parse_prot(cfg, val, &sshm->prot);
+        if (rc) { goto out; }
+    } else if (!strcmp(key, "arm_inner_cacheattr")) {
+        rc = parse_cacheattr(cfg, val, CACHEATTR_ARM,
+                             &sshm->arm_inner_cacheattr);
+        if (rc) { goto out; }
+    } else if (!strcmp(key, "arm_outer_cacheattr")) {
+        rc = parse_cacheattr(cfg, val, CACHEATTR_ARM,
+                             &sshm->arm_outer_cacheattr);
+        if (rc) { goto out; }
+    } else if (!strcmp(key, "x86_cacheattr")) {
+        rc = parse_cacheattr(cfg, val, CACHEATTR_X86,
+                             &sshm->x86_cacheattr);
+        if (rc) { goto out; }
+    } else if (!strcmp(key, "arm_shareattr")) {
+        rc = parse_shareattr(cfg, val, &sshm->arm_shareattr);
+        if (rc) { goto out; }
+    } else {
+        INVAL_ERR("invalid option", key);
+    }
+
+    rc = 0;
+
+ out:
+    return rc;
+}
+
+int xlu_sshm_parse(XLU_Config *cfg, const char *spec,
+                   libxl_static_shm *sshm)
+{
+    int rc;
+    regex_t equ_rec;
+    char *buf2 = NULL, *ptr = NULL;
+    regmatch_t pmatch[3];
+
+    rc = regcomp(&equ_rec, EQU_RE, REG_EXTENDED);
+    if (rc) {
+        fprintf(stderr, "sshm parser failed to initialize\n");
+        goto out;
+    }
+
+    if (NULL == (buf2 = ptr = strdup(spec))) {
+        fprintf(stderr, "sshm parser out of memory\n");
+        rc = ENOMEM;
+        goto out;
+    }
+
+    while (true) {
+        if (!*ptr) { break; }
+        if (regexec(&equ_rec, ptr, 3, pmatch, 0)) {
+            INVAL_ERR("unrecognized token", ptr);
+        }
+
+        ptr[pmatch[1].rm_eo] = '\0';
+        ptr[pmatch[2].rm_eo] = '\0';
+        rc = handle_equ(cfg, ptr + pmatch[1].rm_so,
+                        ptr + pmatch[2].rm_so, sshm);
+        if (rc) { goto out; }
+
+        ptr += pmatch[0].rm_eo;
+    }
+
+    if (*ptr) { INVAL_ERR("invalid syntax", ptr); }
+
+    rc = 0;
+
+ out:
+    if (buf2) { free(buf2); }
+    regfree(&equ_rec);
+    return rc;
+}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
+
diff --git a/tools/libxl/libxlutil.h b/tools/libxl/libxlutil.h
index e81b644c01..ee39cb5bdc 100644
--- a/tools/libxl/libxlutil.h
+++ b/tools/libxl/libxlutil.h
@@ -118,6 +118,12 @@ int xlu_rdm_parse(XLU_Config *cfg, libxl_rdm_reserve *rdm, 
const char *str);
 int xlu_vif_parse_rate(XLU_Config *cfg, const char *rate,
                        libxl_device_nic *nic);
 
+/*
+ * static shared memory specification parsing
+ */
+int xlu_sshm_parse(XLU_Config *cfg, const char *spec,
+                   libxl_static_shm *sshm);
+
 #endif /* LIBXLUTIL_H */
 
 /*
diff --git a/tools/xl/xl_parse.c b/tools/xl/xl_parse.c
index 5c2bf17222..82d955b8b9 100644
--- a/tools/xl/xl_parse.c
+++ b/tools/xl/xl_parse.c
@@ -813,7 +813,7 @@ void parse_config_data(const char *config_source,
     long l, vcpus = 0;
     XLU_Config *config;
     XLU_ConfigList *cpus, *vbds, *nics, *pcis, *cvfbs, *cpuids, *vtpms,
-                   *usbctrls, *usbdevs, *p9devs;
+                   *usbctrls, *usbdevs, *p9devs, *sshms;
     XLU_ConfigList *channels, *ioports, *irqs, *iomem, *viridian, *dtdevs,
                    *mca_caps;
     int num_ioports, num_irqs, num_iomem, num_cpus, num_viridian, num_mca_caps;
@@ -1392,6 +1392,28 @@ void parse_config_data(const char *config_source,
         }
     }
 
+    if (!xlu_cfg_get_list (config, "static_shm", &sshms, 0, 0)) {
+        d_config->num_sshms = 0;
+        d_config->sshms = NULL;
+        while ((buf = xlu_cfg_get_listitem (sshms, d_config->num_sshms)) != 
NULL) {
+            libxl_static_shm *sshm;
+            char *buf2 = strdup(buf);
+            int ret;
+
+            sshm = ARRAY_EXTEND_INIT_NODEVID(d_config->sshms,
+                                             d_config->num_sshms,
+                                             libxl_static_shm_init);
+            ret = xlu_sshm_parse(config, buf2, sshm);
+            if (ret) {
+                fprintf(stderr,
+                        "xl: Invalid argument for static_shm: %s", buf2);
+                exit(EXIT_FAILURE);
+            }
+
+            free(buf2);
+        }
+    }
+
     if (!xlu_cfg_get_list(config, "p9", &p9devs, 0, 0)) {
         libxl_device_p9 *p9;
         char *security_model = NULL;
-- 
2.13.3


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
https://lists.xen.org/xen-devel

 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.