记录一下 acrn guest 内存分配原理
dm 的-m参数会调用 vm_setup_memory，将要为user vm 分配的内存大小记录下来，同时调用
hugetlb_setup_memory从 sos 大页中分出对应内存
int hugetlb_setup_memory(struct vmctx *ctx)
{
int level;
size_t lowmem, fbmem, biosmem, highmem;
bool has_gap;
int fd;
unsigned int seal_flag = F_SEAL_GROW | F_SEAL_SHRINK | F_SEAL_SEAL;
size_t mem_size_level;
mem_idx = 0;
memset(&mmap_mem_regions, 0, sizeof(mmap_mem_regions));
if (ctx->lowmem == 0) {
pr_err("vm requests 0 memory");
goto err;
}
/* In course of reboot sequence, the memfd is closed. So it
* needs to recreate the memfd if it is closed.
*/
for (level = HUGETLB_LV1; level < HUGETLB_LV_MAX; level++) {
if (hugetlb_priv[level].fd > 0)
continue;
fd = memfd_create("acrn_memfd", hugetlb_priv[level].flags);
if (fd == -1) {
pr_err("Fail to create memfd for %d.\n",
level);
break;
}
hugetlb_priv[level].fd = fd;
}
if (ALIGN_CHECK(ctx->lowmem, hugetlb_priv[HUGETLB_LV1].pg_size) ||
ALIGN_CHECK(ctx->highmem, hugetlb_priv[HUGETLB_LV1].pg_size) ||
ALIGN_CHECK(ctx->biosmem, hugetlb_priv[HUGETLB_LV1].pg_size) ||
ALIGN_CHECK(ctx->fbmem, hugetlb_priv[HUGETLB_LV1].pg_size)) {
pr_err("Memory size is not aligned to 2M.\n");
goto err;
}
/* all memory should be at least aligned with
* hugetlb_priv[HUGETLB_LV1].pg_size */
ctx->lowmem =
ALIGN_DOWN(ctx->lowmem, hugetlb_priv[HUGETLB_LV1].pg_size);
ctx->fbmem =
ALIGN_DOWN(ctx->fbmem, hugetlb_priv[HUGETLB_LV1].pg_size);
ctx->biosmem =
ALIGN_DOWN(ctx->biosmem, hugetlb_priv[HUGETLB_LV1].pg_size);
ctx->highmem =
ALIGN_DOWN(ctx->highmem, hugetlb_priv[HUGETLB_LV1].pg_size);
total_size = ctx->highmem_gpa_base + ctx->highmem;
/* check & set hugetlb level memory size for lowmem/biosmem/highmem */
lowmem = ctx->lowmem;
fbmem = ctx->fbmem;
biosmem = ctx->biosmem;
highmem = ctx->highmem;
for (level = hugetlb_lv_max - 1; level >= HUGETLB_LV1; level--) {
if (hugetlb_priv[level].fd < 0) {
hugetlb_priv[level].lowmem = 0;
hugetlb_priv[level].highmem = 0;
hugetlb_priv[level].biosmem = 0;
hugetlb_priv[level].fbmem = 0;
continue;
}
hugetlb_priv[level].lowmem =
ALIGN_DOWN(lowmem, hugetlb_priv[level].pg_size);
hugetlb_priv[level].fbmem =
ALIGN_DOWN(fbmem, hugetlb_priv[level].pg_size);
hugetlb_priv[level].biosmem =
ALIGN_DOWN(biosmem, hugetlb_priv[level].pg_size);
hugetlb_priv[level].highmem =
ALIGN_DOWN(highmem, hugetlb_priv[level].pg_size);
if (level > HUGETLB_LV1) {
hugetlb_priv[level-1].lowmem = lowmem =
lowmem - hugetlb_priv[level].lowmem;
hugetlb_priv[level-1].fbmem = fbmem =
fbmem - hugetlb_priv[l
