error: Use error_setg_file_open() for simplicity and consistency

Replace

    error_setg_errno(errp, errno, MSG, FNAME);

by

    error_setg_file_open(errp, errno, FNAME);

where MSG is "Could not open '%s'" or similar.

Also replace equivalent uses of error_setg().

A few messages lose prefixes ("net dump: ", "SEV: ", __func__ ": ").
We could put them back with error_prepend().  Not worth the bother.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dave@treblig.org>
Message-ID: <20251121121438.1249498-11-armbru@redhat.com>
[Conflict with commit 26b4a6ffe7 (monitor/hmp: Merge
hmp-cmds-target.c within hmp-cmds.c) resolved]

hw/9pfs/9p-local.c

@@ -1456,7 +1456,7 @@ static int local_init(FsContext *ctx, Error **errp)
 
     data->mountfd = open(ctx->fs_root, O_DIRECTORY | O_RDONLY);
     if (data->mountfd == -1) {
-        error_setg_errno(errp, errno, "failed to open '%s'", ctx->fs_root);
+        error_setg_file_open(errp, errno, ctx->fs_root);
         goto err;
     }
 

hw/acpi/core.c

@@ -277,7 +277,7 @@ void acpi_table_add(const QemuOpts *opts, Error **errp)
         int fd = open(*cur, O_RDONLY | O_BINARY);
 
         if (fd < 0) {
-            error_setg(errp, "can't open file %s: %s", *cur, strerror(errno));
+            error_setg_file_open(errp, errno, *cur);
             goto out;
         }
 

hw/core/loader.c

@@ -380,7 +380,7 @@ bool load_elf_hdr(const char *filename, void *hdr, bool *is64, Error **errp)
 
     fd = open(filename, O_RDONLY | O_BINARY);
     if (fd < 0) {
-        error_setg_errno(errp, errno, "Failed to open file: %s", filename);
+        error_setg_file_open(errp, errno, filename);
         return false;
     }
     if (read(fd, hdr, EI_NIDENT) != EI_NIDENT) {

hw/pci-host/xen_igd_pt.c

@@ -55,7 +55,7 @@ static void host_pci_config_read(int pos, int len, uint32_t *val, Error **errp)
 
     config_fd = open(path, O_RDWR);
     if (config_fd < 0) {
-        error_setg_errno(errp, errno, "Failed to open: %s", path);
+        error_setg_file_open(errp, errno, path);
         goto out;
     }
 

monitor/hmp-cmds.c

@@ -740,7 +740,7 @@ static uint64_t vtop(void *ptr, Error **errp)
 
     fd = open("/proc/self/pagemap", O_RDONLY);
     if (fd == -1) {
-        error_setg_errno(errp, errno, "Cannot open /proc/self/pagemap");
+        error_setg_file_open(errp, errno, "/proc/self/pagemap");
         return -1;
     }
 

net/dump.c

@@ -111,7 +111,7 @@ static int net_dump_state_init(DumpState *s, const char *filename,
 
     fd = open(filename, O_CREAT | O_TRUNC | O_WRONLY | O_BINARY, 0644);
     if (fd < 0) {
-        error_setg_errno(errp, errno, "net dump: can't open %s", filename);
+        error_setg_file_open(errp, errno, filename);
         return -1;
     }
 

net/tap-bsd.c

@@ -68,7 +68,7 @@ int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
         }
     }
     if (fd < 0) {
-        error_setg_errno(errp, errno, "could not open %s", dname);
+        error_setg_file_open(errp, errno, dname);
         return -1;
     }
 
@@ -118,7 +118,7 @@ static int tap_open_clone(char *ifname, int ifname_size, Error **errp)
 
     fd = RETRY_ON_EINTR(open(PATH_NET_TAP, O_RDWR));
     if (fd < 0) {
-        error_setg_errno(errp, errno, "could not open %s", PATH_NET_TAP);
+        error_setg_file_open(errp, errno, PATH_NET_TAP);
         return -1;
     }
 
@@ -166,7 +166,7 @@ int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
         snprintf(dname, sizeof dname, "/dev/%s", ifname);
         fd = RETRY_ON_EINTR(open(dname, O_RDWR));
         if (fd < 0 && errno != ENOENT) {
-            error_setg_errno(errp, errno, "could not open %s", dname);
+            error_setg_file_open(errp, errno, dname);
             return -1;
         }
     }

net/tap-linux.c

@@ -57,7 +57,7 @@ int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
     if (fd < 0) {
         fd = RETRY_ON_EINTR(open(PATH_NET_TUN, O_RDWR));
         if (fd < 0) {
-            error_setg_errno(errp, errno, "could not open %s", PATH_NET_TUN);
+            error_setg_file_open(errp, errno, PATH_NET_TUN);
             return -1;
         }
     }

target/i386/sev.c

@@ -892,8 +892,7 @@ static SevCapability *sev_get_capabilities(Error **errp)
 
     fd = open(sev_device, O_RDWR);
     if (fd < 0) {
-        error_setg_errno(errp, errno, "SEV: Failed to open %s",
-                         sev_device);
+        error_setg_file_open(errp, errno, sev_device);
         g_free(sev_device);
         return NULL;
     }
@@ -1820,8 +1819,7 @@ static int sev_common_kvm_init(ConfidentialGuestSupport *cgs, Error **errp)
     devname = object_property_get_str(OBJECT(sev_common), "sev-device", NULL);
     sev_common->sev_fd = open(devname, O_RDWR);
     if (sev_common->sev_fd < 0) {
-        error_setg(errp, "%s: Failed to open %s '%s'", __func__,
-                   devname, strerror(errno));
+        error_setg_file_open(errp, errno, devname);
         g_free(devname);
         return -1;
     }

util/vfio-helpers.c

@@ -309,7 +309,7 @@ static int qemu_vfio_init_pci(QEMUVFIOState *s, const char *device,
     s->container = open("/dev/vfio/vfio", O_RDWR);
 
     if (s->container == -1) {
-        error_setg_errno(errp, errno, "Failed to open /dev/vfio/vfio");
+        error_setg_file_open(errp, errno, "/dev/vfio/vfio");
         return -errno;
     }
     if (ioctl(s->container, VFIO_GET_API_VERSION) != VFIO_API_VERSION) {
@@ -333,8 +333,7 @@ static int qemu_vfio_init_pci(QEMUVFIOState *s, const char *device,
 
     s->group = open(group_file, O_RDWR);
     if (s->group == -1) {
-        error_setg_errno(errp, errno, "Failed to open VFIO group file: %s",
-                         group_file);
+        error_setg_file_open(errp, errno, group_file);
         g_free(group_file);
         ret = -errno;
         goto fail_container;