[Qemu-devel] [PATCH v4 2/5] Add Error **errp for xen_host_pci_device_get()

[Cao jin <caoj.fnst@cn.fujitsu.com>]

To catch the error msg. Also modify the caller

Signed-off-by: Cao jin <caoj.fnst@cn.fujitsu.com>
---
 hw/xen/xen-host-pci-device.c | 134 ++++++++++++++++++++++---------------------
 hw/xen/xen-host-pci-device.h |   5 +-
 hw/xen/xen_pt.c              |  13 +++--
 3 files changed, 81 insertions(+), 71 deletions(-)

diff --git a/hw/xen/xen-host-pci-device.c b/hw/xen/xen-host-pci-device.c
index 351b61a..b8ec016 100644
--- a/hw/xen/xen-host-pci-device.c
+++ b/hw/xen/xen-host-pci-device.c
@@ -31,8 +31,8 @@
 #define IORESOURCE_PREFETCH     0x00001000      /* No side effects */
 #define IORESOURCE_MEM_64       0x00100000
 
-static int xen_host_pci_sysfs_path(const XenHostPCIDevice *d,
-                                   const char *name, char *buf, ssize_t size)
+static void xen_host_pci_sysfs_path(const XenHostPCIDevice *d,
+                                    const char *name, char *buf, ssize_t size)
 {
     int rc;
 
@@ -40,16 +40,16 @@ static int xen_host_pci_sysfs_path(const XenHostPCIDevice *d,
                   d->domain, d->bus, d->dev, d->func, name);
 
     if (rc >= size || rc < 0) {
-        /* The output is truncated, or some other error was encountered */
-        return -ENODEV;
+        /* The output is truncated, or some other error was encountered.
+         * Assert here since user can do nothing in case of failure */
+        assert(0);
     }
-    return 0;
 }
 
 
 /* This size should be enough to read the first 7 lines of a resource file */
 #define XEN_HOST_PCI_RESOURCE_BUFFER_SIZE 400
-static int xen_host_pci_get_resource(XenHostPCIDevice *d)
+static void xen_host_pci_get_resource(XenHostPCIDevice *d, Error **errp)
 {
     int i, rc, fd;
     char path[PATH_MAX];
@@ -58,25 +58,22 @@ static int xen_host_pci_get_resource(XenHostPCIDevice *d)
     char *endptr, *s;
     uint8_t type;
 
-    rc = xen_host_pci_sysfs_path(d, "resource", path, sizeof (path));
-    if (rc) {
-        return rc;
-    }
+    xen_host_pci_sysfs_path(d, "resource", path, sizeof(path));
+
     fd = open(path, O_RDONLY);
     if (fd == -1) {
-        XEN_HOST_PCI_LOG("Error: Can't open %s: %s\n", path, strerror(errno));
-        return -errno;
+        error_setg_file_open(errp, errno, path);
+        return;
     }
 
     do {
-        rc = read(fd, &buf, sizeof (buf) - 1);
+        rc = read(fd, &buf, sizeof(buf) - 1);
         if (rc < 0 && errno != EINTR) {
-            rc = -errno;
+            error_setg_errno(errp, errno, "read err");
             goto out;
         }
     } while (rc < 0);
     buf[rc] = 0;
-    rc = 0;
 
     s = buf;
     for (i = 0; i < PCI_NUM_REGIONS; i++) {
@@ -129,20 +126,19 @@ static int xen_host_pci_get_resource(XenHostPCIDevice *d)
             d->rom.bus_flags = flags & IORESOURCE_BITS;
         }
     }
+
     if (i != PCI_NUM_REGIONS) {
-        /* Invalid format or input to short */
-        rc = -ENODEV;
+        error_setg(errp, "Invalid format or input too short: %s", buf);
     }
 
 out:
     close(fd);
-    return rc;
 }
 
 /* This size should be enough to read a long from a file */
 #define XEN_HOST_PCI_GET_VALUE_BUFFER_SIZE 22
-static int xen_host_pci_get_value(XenHostPCIDevice *d, const char *name,
-                                  unsigned int *pvalue, int base)
+static void xen_host_pci_get_value(XenHostPCIDevice *d, const char *name,
+                                   unsigned int *pvalue, int base, Error **errp)
 {
     char path[PATH_MAX];
     char buf[XEN_HOST_PCI_GET_VALUE_BUFFER_SIZE];
@@ -150,44 +146,50 @@ static int xen_host_pci_get_value(XenHostPCIDevice *d, const char *name,
     unsigned long value;
     const char *endptr;
 
-    rc = xen_host_pci_sysfs_path(d, name, path, sizeof (path));
-    if (rc) {
-        return rc;
-    }
+    xen_host_pci_sysfs_path(d, name, path, sizeof(path));
+
     fd = open(path, O_RDONLY);
     if (fd == -1) {
-        XEN_HOST_PCI_LOG("Error: Can't open %s: %s\n", path, strerror(errno));
-        return -errno;
+        error_setg_file_open(errp, errno, path);
+        return;
     }
+
     do {
-        rc = read(fd, &buf, sizeof (buf) - 1);
+        rc = read(fd, &buf, sizeof(buf) - 1);
         if (rc < 0 && errno != EINTR) {
-            rc = -errno;
+            error_setg_errno(errp, errno, "read err");
             goto out;
         }
     } while (rc < 0);
+
     buf[rc] = 0;
     rc = qemu_strtoul(buf, &endptr, base, &value);
     if (!rc) {
         *pvalue = value;
+    } else if (rc == -EINVAL) {
+        error_setg(errp, "strtoul: Invalid argument");
+    } else {
+        error_setg_errno(errp, errno, "strtoul err");
     }
+
 out:
     close(fd);
-    return rc;
 }
 
-static inline int xen_host_pci_get_hex_value(XenHostPCIDevice *d,
+static inline void xen_host_pci_get_hex_value(XenHostPCIDevice *d,
                                              const char *name,
-                                             unsigned int *pvalue)
+                                             unsigned int *pvalue,
+                                             Error **errp)
 {
-    return xen_host_pci_get_value(d, name, pvalue, 16);
+    xen_host_pci_get_value(d, name, pvalue, 16, errp);
 }
 
-static inline int xen_host_pci_get_dec_value(XenHostPCIDevice *d,
+static inline void xen_host_pci_get_dec_value(XenHostPCIDevice *d,
                                              const char *name,
-                                             unsigned int *pvalue)
+                                             unsigned int *pvalue,
+                                             Error **errp)
 {
-    return xen_host_pci_get_value(d, name, pvalue, 10);
+    xen_host_pci_get_value(d, name, pvalue, 10, errp);
 }
 
 static bool xen_host_pci_dev_is_virtfn(XenHostPCIDevice *d)
@@ -195,26 +197,21 @@ static bool xen_host_pci_dev_is_virtfn(XenHostPCIDevice *d)
     char path[PATH_MAX];
     struct stat buf;
 
-    if (xen_host_pci_sysfs_path(d, "physfn", path, sizeof (path))) {
-        return false;
-    }
+    xen_host_pci_sysfs_path(d, "physfn", path, sizeof(path));
+
     return !stat(path, &buf);
 }
 
-static int xen_host_pci_config_open(XenHostPCIDevice *d)
+static void xen_host_pci_config_open(XenHostPCIDevice *d, Error **errp)
 {
     char path[PATH_MAX];
-    int rc;
 
-    rc = xen_host_pci_sysfs_path(d, "config", path, sizeof (path));
-    if (rc) {
-        return rc;
-    }
+    xen_host_pci_sysfs_path(d, "config", path, sizeof(path));
+
     d->config_fd = open(path, O_RDWR);
-    if (d->config_fd < 0) {
-        return -errno;
+    if (d->config_fd == -1) {
+        error_setg_file_open(errp, errno, path);
     }
-    return 0;
 }
 
 static int xen_host_pci_config_read(XenHostPCIDevice *d,
@@ -336,11 +333,12 @@ int xen_host_pci_find_ext_cap_offset(XenHostPCIDevice *d, uint32_t cap)
     return -1;
 }
 
-int xen_host_pci_device_get(XenHostPCIDevice *d, uint16_t domain,
-                            uint8_t bus, uint8_t dev, uint8_t func)
+void xen_host_pci_device_get(XenHostPCIDevice *d, uint16_t domain,
+                            uint8_t bus, uint8_t dev, uint8_t func,
+                            Error **errp)
 {
     unsigned int v;
-    int rc = 0;
+    Error *err = NULL;
 
     d->config_fd = -1;
     d->domain = domain;
@@ -348,43 +346,51 @@ int xen_host_pci_device_get(XenHostPCIDevice *d, uint16_t domain,
     d->dev = dev;
     d->func = func;
 
-    rc = xen_host_pci_config_open(d);
-    if (rc) {
+    xen_host_pci_config_open(d, &err);
+    if (err) {
         goto error;
     }
-    rc = xen_host_pci_get_resource(d);
-    if (rc) {
+
+    xen_host_pci_get_resource(d, &err);
+    if (err) {
         goto error;
     }
-    rc = xen_host_pci_get_hex_value(d, "vendor", &v);
-    if (rc) {
+
+    xen_host_pci_get_hex_value(d, "vendor", &v, &err);
+    if (err) {
         goto error;
     }
     d->vendor_id = v;
-    rc = xen_host_pci_get_hex_value(d, "device", &v);
-    if (rc) {
+
+    xen_host_pci_get_hex_value(d, "device", &v, &err);
+    if (err) {
         goto error;
     }
     d->device_id = v;
-    rc = xen_host_pci_get_dec_value(d, "irq", &v);
-    if (rc) {
+
+    xen_host_pci_get_dec_value(d, "irq", &v, &err);
+    if (err) {
         goto error;
     }
     d->irq = v;
-    rc = xen_host_pci_get_hex_value(d, "class", &v);
-    if (rc) {
+
+    xen_host_pci_get_hex_value(d, "class", &v, &err);
+    if (err) {
         goto error;
     }
     d->class_code = v;
+
     d->is_virtfn = xen_host_pci_dev_is_virtfn(d);
 
-    return 0;
+    return;
+
 error:
+    error_propagate(errp, err);
+
     if (d->config_fd >= 0) {
         close(d->config_fd);
         d->config_fd = -1;
     }
-    return rc;
 }
 
 bool xen_host_pci_device_closed(XenHostPCIDevice *d)
diff --git a/hw/xen/xen-host-pci-device.h b/hw/xen/xen-host-pci-device.h
index 3d44e04..42b9138 100644
--- a/hw/xen/xen-host-pci-device.h
+++ b/hw/xen/xen-host-pci-device.h
@@ -36,8 +36,9 @@ typedef struct XenHostPCIDevice {
     int config_fd;
 } XenHostPCIDevice;
 
-int xen_host_pci_device_get(XenHostPCIDevice *d, uint16_t domain,
-                            uint8_t bus, uint8_t dev, uint8_t func);
+void xen_host_pci_device_get(XenHostPCIDevice *d, uint16_t domain,
+                            uint8_t bus, uint8_t dev, uint8_t func,
+                            Error **errp);
 void xen_host_pci_device_put(XenHostPCIDevice *pci_dev);
 bool xen_host_pci_device_closed(XenHostPCIDevice *d);
 
diff --git a/hw/xen/xen_pt.c b/hw/xen/xen_pt.c
index aa96288..53b5bca 100644
--- a/hw/xen/xen_pt.c
+++ b/hw/xen/xen_pt.c
@@ -767,6 +767,7 @@ static int xen_pt_initfn(PCIDevice *d)
     uint8_t machine_irq = 0, scratch;
     uint16_t cmd = 0;
     int pirq = XEN_PT_UNASSIGNED_PIRQ;
+    Error *err = NULL;
 
     /* register real device */
     XEN_PT_LOG(d, "Assigning real physical device %02x:%02x.%d"
@@ -774,11 +775,13 @@ static int xen_pt_initfn(PCIDevice *d)
                s->hostaddr.bus, s->hostaddr.slot, s->hostaddr.function,
                s->dev.devfn);
 
-    rc = xen_host_pci_device_get(&s->real_device,
-                                 s->hostaddr.domain, s->hostaddr.bus,
-                                 s->hostaddr.slot, s->hostaddr.function);
-    if (rc) {
-        XEN_PT_ERR(d, "Failed to \"open\" the real pci device. rc: %i\n", rc);
+    xen_host_pci_device_get(&s->real_device,
+                            s->hostaddr.domain, s->hostaddr.bus,
+                            s->hostaddr.slot, s->hostaddr.function,
+                            &err);
+    if (err) {
+        error_append_hint(&err, "Failed to \"open\" the real pci device");
+        error_report_err(err);
         return -1;
     }
 
-- 
2.1.0