diff mbox

[RFC,XEN,v2,13/15] tools/libxl: add support to map host pmem device to guests

Message ID 20170320000949.24675-14-haozhong.zhang@intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Haozhong Zhang March 20, 2017, 12:09 a.m. UTC
We can map host pmem devices or files on pmem devices to guests. This
patch adds support to map pmem devices. The implementation relies on
the Linux pmem driver (CONFIG_ACPI_NFIT, CONFIG_LIBNVDIMM, CONFIG_BLK_DEV_PMEM),
so it functions only when libxl is compiled for Linux right now.

Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com>
---
Cc: Ian Jackson <ian.jackson@eu.citrix.com>
Cc: Wei Liu <wei.liu2@citrix.com>
---
 tools/libxl/Makefile       |   4 +
 tools/libxl/libxl_nvdimm.c | 182 +++++++++++++++++++++++++++++++++++++++++++++
 tools/libxl/libxl_nvdimm.h |  42 +++++++++++
 3 files changed, 228 insertions(+)
 create mode 100644 tools/libxl/libxl_nvdimm.c
 create mode 100644 tools/libxl/libxl_nvdimm.h
diff mbox

Patch

diff --git a/tools/libxl/Makefile b/tools/libxl/Makefile
index a3e5e9909f..6bfc78972f 100644
--- a/tools/libxl/Makefile
+++ b/tools/libxl/Makefile
@@ -115,6 +115,10 @@  endif
 endif
 endif
 
+ifeq ($(CONFIG_Linux), y)
+LIBXL_OBJS-y += libxl_nvdimm.o
+endif
+
 ifeq ($(FLEX),)
 %.c %.h:: %.l
 	$(warning Flex is needed to rebuild some libxl parsers and \
diff --git a/tools/libxl/libxl_nvdimm.c b/tools/libxl/libxl_nvdimm.c
new file mode 100644
index 0000000000..1b3c83f2ca
--- /dev/null
+++ b/tools/libxl/libxl_nvdimm.c
@@ -0,0 +1,182 @@ 
+/*
+ * tools/libxl/libxl_nvdimm.c
+ *
+ * Copyright (C) 2017,  Intel Corporation
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License, version 2.1, as published by the Free Software Foundation.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <errno.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include "libxl_internal.h"
+#include "libxl_arch.h"
+#include "libxl_nvdimm.h"
+
+#include <xenctrl.h>
+
+#define BLK_DEVICE_ROOT "/sys/dev/block"
+
+static int nvdimm_sysfs_read(libxl__gc *gc,
+                             unsigned int major, unsigned int minor,
+                             const char *name, void **data_r)
+{
+    char *path = libxl__sprintf(gc, BLK_DEVICE_ROOT"/%u:%u/device/%s",
+                                major, minor, name);
+    return libxl__read_sysfs_file_contents(gc, path, data_r, NULL);
+}
+
+static int nvdimm_get_spa(libxl__gc *gc, unsigned int major, unsigned int minor,
+                          uint64_t *spa_r)
+{
+    void *data;
+    int ret = nvdimm_sysfs_read(gc, major, minor, "resource", &data);
+
+    if ( ret )
+        return ret;
+
+    *spa_r = strtoll(data, NULL, 0);
+    return 0;
+}
+
+static int nvdimm_get_size(libxl__gc *gc, unsigned int major, unsigned int minor,
+                           uint64_t *size_r)
+{
+    void *data;
+    int ret = nvdimm_sysfs_read(gc, major, minor, "size", &data);
+
+    if ( ret )
+        return ret;
+
+    *size_r = strtoll(data, NULL, 0);
+
+    return 0;
+}
+
+static int add_pages(libxl__gc *gc, uint32_t domid,
+                     xen_pfn_t mfn, xen_pfn_t gpfn, unsigned long nr_mfns)
+{
+    unsigned int nr;
+    int ret = 0;
+
+    while ( nr_mfns )
+    {
+        nr = min(nr_mfns, (unsigned long) UINT_MAX);
+
+        ret = xc_domain_populate_pmemmap(CTX->xch, domid, mfn, gpfn, nr);
+        if ( ret )
+        {
+            LOG(ERROR, "failed to map pmem pages, "
+                "mfn 0x%" PRIx64", gpfn 0x%" PRIx64 ", nr_mfns %u, err %d",
+                mfn, gpfn, nr, ret);
+            break;
+        }
+
+        nr_mfns -= nr;
+        mfn += nr;
+        gpfn += nr;
+    }
+
+    return ret;
+}
+
+int libxl_nvdimm_add_device(libxl__gc *gc,
+                            uint32_t domid, const char *path,
+                            uint64_t guest_spa, uint64_t guest_size)
+{
+    int fd;
+    struct stat st;
+    unsigned int major, minor;
+    uint64_t host_spa, host_size;
+    xen_pfn_t mfn, gpfn;
+    unsigned long nr_gpfns;
+    int ret;
+
+    if ( (guest_spa & ~XC_PAGE_MASK) || (guest_size & ~XC_PAGE_MASK) )
+        return -EINVAL;
+
+    fd = open(path, O_RDONLY);
+    if ( fd < 0 )
+    {
+        LOG(ERROR, "failed to open file %s (err: %d)", path, errno);
+        return -EIO;
+    }
+
+    ret = fstat(fd, &st);
+    if ( ret )
+    {
+        LOG(ERROR, "failed to get status of file %s (err: %d)",
+            path, errno);
+        goto out;
+    }
+
+    switch ( st.st_mode & S_IFMT )
+    {
+    case S_IFBLK:
+        major = major(st.st_rdev);
+        minor = minor(st.st_rdev);
+        break;
+
+    default:
+        LOG(ERROR, "only support block device now");
+        ret = -EINVAL;
+        goto out;
+    }
+
+    ret = nvdimm_get_spa(gc, major, minor, &host_spa);
+    if ( ret )
+    {
+        LOG(ERROR, "failed to get SPA of device %u:%u", major, minor);
+        goto out;
+    }
+    else if ( host_spa & ~XC_PAGE_MASK )
+    {
+        ret = -EINVAL;
+        goto out;
+    }
+
+    ret = nvdimm_get_size(gc, major, minor, &host_size);
+    if ( ret )
+    {
+        LOG(ERROR, "failed to get size of device %u:%u", major, minor);
+        goto out;
+    }
+    else if ( guest_size > host_size )
+    {
+        LOG(ERROR, "vNVDIMM size %" PRIu64 " expires NVDIMM size %" PRIu64,
+            guest_size, host_size);
+        ret = -EINVAL;
+        goto out;
+    }
+
+    mfn = host_spa >> XC_PAGE_SHIFT;
+    gpfn = guest_spa >> XC_PAGE_SHIFT;
+    nr_gpfns = guest_size >> XC_PAGE_SHIFT;
+    ret = add_pages(gc, domid, mfn, gpfn, nr_gpfns);
+
+ out:
+    close(fd);
+    return ret;
+}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
diff --git a/tools/libxl/libxl_nvdimm.h b/tools/libxl/libxl_nvdimm.h
new file mode 100644
index 0000000000..e95be99c67
--- /dev/null
+++ b/tools/libxl/libxl_nvdimm.h
@@ -0,0 +1,42 @@ 
+/*
+ * tools/libxl/libxl_nvdimm.h
+ *
+ * Copyright (C) 2017,  Intel Corporation
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License, version 2.1, as published by the Free Software Foundation.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef LIBXL_NVDIMM_H
+#define LIBXL_NVDIMM_H
+
+#include <stdint.h>
+#include "libxl_internal.h"
+
+#if defined(__linux__)
+
+int libxl_nvdimm_add_device(libxl__gc *gc,
+                            uint32_t domid, const char *path,
+                            uint64_t spa, uint64_t length);
+
+#else
+
+static inline int libxl_nvdimm_add_device(libxl__gc *gc,
+                                          uint32_t domid, const char *path,
+                                          uint64_t spa, uint64_t length)
+{
+    return -ENOSYS;
+}
+
+#endif /* __linux__ */
+
+#endif /* !LIBXL_NVDIMM_H */