[Qemu-devel] [PATCH v3 1/4] Add Error **errp for xen_host_pci_device_get()

[Cao jin]

To catch the error msg. Also modify the caller

Signed-off-by: Cao jin <address@hidden>
---
 hw/xen/xen-host-pci-device.c | 106 +++++++++++++++++++++++++------------------
 hw/xen/xen-host-pci-device.h |   5 +-
 hw/xen/xen_pt.c              |  12 +++--
 3 files changed, 71 insertions(+), 52 deletions(-)

diff --git a/hw/xen/xen-host-pci-device.c b/hw/xen/xen-host-pci-device.c
index 7d8a023..952cae0 100644
--- a/hw/xen/xen-host-pci-device.c
+++ b/hw/xen/xen-host-pci-device.c
@@ -49,7 +49,7 @@ static int xen_host_pci_sysfs_path(const XenHostPCIDevice *d,
 
 /* 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];
@@ -60,23 +60,24 @@ static int xen_host_pci_get_resource(XenHostPCIDevice *d)
 
     rc = xen_host_pci_sysfs_path(d, "resource", path, sizeof (path));
     if (rc) {
-        return rc;
+        error_setg_errno(errp, errno, "snprintf err");
+        return;
     }
+
     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_errno(errp, errno, "open %s err", path);
+        return;
     }
 
     do {
         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 +130,20 @@ 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 to 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];
@@ -152,47 +153,52 @@ static int xen_host_pci_get_value(XenHostPCIDevice *d, 
const char *name,
 
     rc = xen_host_pci_sysfs_path(d, name, path, sizeof (path));
     if (rc) {
-        return rc;
+        error_setg_errno(errp, errno, "snprintf err");
+        return;
     }
+
     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_errno(errp, errno, "open %s err", path);
+        return;
     }
+
     do {
         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;
     value = strtol(buf, &endptr, base);
     if (endptr == buf || *endptr != '\n') {
-        rc = -1;
+        error_setg(errp, "format invalid: %s", buf);
     } else if ((value == LONG_MIN || value == LONG_MAX) && errno == ERANGE) {
-        rc = -errno;
+        error_setg_errno(errp, errno, "strtol err");
     } else {
-        rc = 0;
         *pvalue = value;
     }
+
 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)
@@ -206,20 +212,21 @@ static bool xen_host_pci_dev_is_virtfn(XenHostPCIDevice 
*d)
     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;
+        error_setg_errno(errp, errno, "snprintf err");
+        return;
     }
+
     d->config_fd = open(path, O_RDWR);
     if (d->config_fd < 0) {
-        return -errno;
+        error_setg_errno(errp, errno, "open %s err", path);
     }
-    return 0;
 }
 
 static int xen_host_pci_config_read(XenHostPCIDevice *d,
@@ -341,11 +348,12 @@ 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 *local_err = NULL;
 
     d->config_fd = -1;
     d->domain = domain;
@@ -353,43 +361,51 @@ 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, &local_err);
+    if (local_err) {
         goto error;
     }
-    rc = xen_host_pci_get_resource(d);
-    if (rc) {
+
+    xen_host_pci_get_resource(d, &local_err);
+    if (local_err) {
         goto error;
     }
-    rc = xen_host_pci_get_hex_value(d, "vendor", &v);
-    if (rc) {
+
+    xen_host_pci_get_hex_value(d, "vendor", &v, &local_err);
+    if (local_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, &local_err);
+    if (local_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, &local_err);
+    if (local_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, &local_err);
+    if (local_err) {
         goto error;
     }
     d->class_code = v;
+
     d->is_virtfn = xen_host_pci_dev_is_virtfn(d);
 
-    return 0;
+    return;
+
 error:
+    error_propagate(errp, local_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..1bd4109 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 *local_err = NULL;
 
     /* register real device */
     XEN_PT_LOG(d, "Assigning real physical device %02x:%02x.%d"
@@ -774,11 +775,12 @@ 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,
+                            &local_err);
+    if (local_err) {
+        XEN_PT_ERR(d, "Failed to \"open\" the real pci device.\n");
         return -1;
     }
 
-- 
2.1.0