libvmm: constify vm_get_name()

Allows callers of vm_get_name() to retrieve the vm name without having
to allocate a buffer.

While in the vicinity, do minor cleanup in vm_snapshot_basic_metadata().

Reviewed by:	jhb
Differential Revision:	https://reviews.freebsd.org/D34290
This commit is contained in:
Robert Wing 2022-03-17 21:26:54 -08:00
parent ee0ebaa420
commit 3efc45f34e
3 changed files with 8 additions and 31 deletions

View file

@ -496,14 +496,11 @@ vm_rev_map_gpa(struct vmctx *ctx, void *addr)
return ((vm_paddr_t)-1);
}
/* TODO: maximum size for vmname */
int
vm_get_name(struct vmctx *ctx, char *buf, size_t max_len)
const char *
vm_get_name(struct vmctx *ctx)
{
if (strlcpy(buf, ctx->name, max_len) >= max_len)
return (EINVAL);
return (0);
return (ctx->name);
}
size_t

View file

@ -133,7 +133,7 @@ uint32_t vm_get_lowmem_limit(struct vmctx *ctx);
void vm_set_lowmem_limit(struct vmctx *ctx, uint32_t limit);
void vm_set_memflags(struct vmctx *ctx, int flags);
int vm_get_memflags(struct vmctx *ctx);
int vm_get_name(struct vmctx *ctx, char *buffer, size_t max_len);
const char *vm_get_name(struct vmctx *ctx);
size_t vm_get_lowmem_size(struct vmctx *ctx);
size_t vm_get_highmem_size(struct vmctx *ctx);
int vm_set_desc(struct vmctx *ctx, int vcpu, int reg,

View file

@ -1123,28 +1123,15 @@ vm_snapshot_kern_structs(struct vmctx *ctx, int data_fd, xo_handle_t *xop)
static int
vm_snapshot_basic_metadata(struct vmctx *ctx, xo_handle_t *xop, size_t memsz)
{
int error;
int memflags;
char vmname_buf[MAX_VMNAME];
memset(vmname_buf, 0, MAX_VMNAME);
error = vm_get_name(ctx, vmname_buf, MAX_VMNAME - 1);
if (error != 0) {
perror("Failed to get VM name");
goto err;
}
memflags = vm_get_memflags(ctx);
xo_open_container_h(xop, JSON_BASIC_METADATA_KEY);
xo_emit_h(xop, "{:" JSON_NCPUS_KEY "/%ld}\n", guest_ncpus);
xo_emit_h(xop, "{:" JSON_VMNAME_KEY "/%s}\n", vmname_buf);
xo_emit_h(xop, "{:" JSON_VMNAME_KEY "/%s}\n", vm_get_name(ctx));
xo_emit_h(xop, "{:" JSON_MEMSIZE_KEY "/%lu}\n", memsz);
xo_emit_h(xop, "{:" JSON_MEMFLAGS_KEY "/%d}\n", memflags);
xo_emit_h(xop, "{:" JSON_MEMFLAGS_KEY "/%d}\n", vm_get_memflags(ctx));
xo_close_container_h(xop, JSON_BASIC_METADATA_KEY);
err:
return (error);
return (0);
}
static int
@ -1518,7 +1505,6 @@ init_checkpoint_thread(struct vmctx *ctx)
struct sockaddr_un addr;
int socket_fd;
pthread_t checkpoint_pthread;
char vmname_buf[MAX_VMNAME];
int err;
memset(&addr, 0, sizeof(addr));
@ -1532,14 +1518,8 @@ init_checkpoint_thread(struct vmctx *ctx)
addr.sun_family = AF_UNIX;
err = vm_get_name(ctx, vmname_buf, MAX_VMNAME - 1);
if (err != 0) {
perror("Failed to get VM name");
goto fail;
}
snprintf(addr.sun_path, sizeof(addr.sun_path), "%s%s",
BHYVE_RUN_DIR, vmname_buf);
BHYVE_RUN_DIR, vm_get_name(ctx));
addr.sun_len = SUN_LEN(&addr);
unlink(addr.sun_path);