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page walk during copy_from_vm/copy_to_vm

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there are data transfer between guest(GPA) & hv(HPA), especially for
hypercall from guest.

guest should make sure these GPAs are address continous, but hv cannot
assure HPAs which mapped to these GPAs are address continous, for example,
after enable hugetlb, a contious GPA range could come from two different
2M pages.

this patch is handling such case by doing gpa page walking during
copy_from_vm & copy_to_vm.

Signed-off-by: Jason Chen CJ <jason.cj.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
This commit is contained in:
Jason Chen CJ
2018-05-21 22:26:52 +08:00
committed by lijinxia
parent 58c109e8de
commit 2ff7bf826e
5 changed files with 76 additions and 51 deletions
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31
hypervisor/arch/x86/ept.c
View File

@@ -137,46 +137,37 @@ void destroy_ept(struct vm *vm)
free_ept_mem(HPA2HVA(vm->arch_vm.sworld_eptp));
}
uint64_t gpa2hpa_check(struct vm *vm, uint64_t gpa,
uint64_t size, int *found, bool assert)
uint64_t _gpa2hpa(struct vm *vm, uint64_t gpa, uint32_t *size)
{
uint64_t hpa = 0;
int _found = 0;
uint32_t pg_size = 0;
struct entry_params entry;
struct map_params map_params;
map_params.page_table_type = PTT_EPT;
map_params.pml4_base = HPA2HVA(vm->arch_vm.nworld_eptp);
map_params.pml4_inverted = HPA2HVA(vm->arch_vm.m2p);
obtain_last_page_table_entry(&map_params, &entry,
(void *)gpa, true);
if (entry.entry_present == PT_PRESENT
/* if cross several pages, now not handle it,
* only print error info
*/
&& ((gpa % entry.page_size) + size) <= entry.page_size) {
_found = 1;
obtain_last_page_table_entry(&map_params, &entry, (void *)gpa, true);
if (entry.entry_present == PT_PRESENT) {
hpa = ((entry.entry_val & (~(entry.page_size - 1)))
| (gpa & (entry.page_size - 1)));
}
if (found != NULL)
*found = _found;
if (_found == 0 && assert) {
pg_size = entry.page_size;
pr_dbg("GPA2HPA: 0x%llx->0x%llx", gpa, hpa);
} else {
pr_err("VM %d GPA2HPA: failed for gpa 0x%llx",
vm->attr.boot_idx, gpa);
ASSERT(_found != 0, "GPA2HPA not found");
}
pr_dbg("GPA2HPA: 0x%llx->0x%llx", gpa, hpa);
if (size)
*size = pg_size;
return hpa;
}
/* using return value 0 as failure, make sure guest will not use hpa 0 */
uint64_t gpa2hpa(struct vm *vm, uint64_t gpa)
{
return gpa2hpa_check(vm, gpa, 0, NULL, true);
return _gpa2hpa(vm, gpa, NULL);
}
uint64_t hpa2gpa(struct vm *vm, uint64_t hpa)

62
hypervisor/arch/x86/guest/guest.c
View File

@@ -120,6 +120,68 @@ inline bool vm_lapic_disabled(struct vm *vm)
return true;
}
/* Caller(Guest) should make sure gpa is continuous.
* - gpa from hypercall input which from kernel stack is gpa continous, not
* support kernel stack from vmap
* - some other gpa from hypercall parameters, VHM should make sure it's
* continous
*/
int copy_from_vm(struct vm *vm, void *h_ptr, uint64_t gpa, uint32_t size)
{
uint64_t hpa;
uint32_t off_in_pg, len, pg_size;
void *g_ptr;
do {
hpa = _gpa2hpa(vm, gpa, &pg_size);
if (pg_size == 0) {
ASSERT(0, "copy_from_vm: GPA2HPA not found");
return -EINVAL;
}
off_in_pg = gpa & (pg_size - 1);
if (size > pg_size - off_in_pg)
len = pg_size - off_in_pg;
else
len = size;
g_ptr = HPA2HVA(hpa);
memcpy_s(h_ptr, len, g_ptr, len);
gpa += len;
size -= len;
} while (size > 0);
return 0;
}
int copy_to_vm(struct vm *vm, void *h_ptr, uint64_t gpa, uint32_t size)
{
uint64_t hpa;
uint32_t off_in_pg, len, pg_size;
void *g_ptr;
do {
hpa = _gpa2hpa(vm, gpa, &pg_size);
if (pg_size == 0) {
ASSERT(0, "copy_to_vm: GPA2HPA not found");
return -EINVAL;
}
off_in_pg = gpa & (pg_size - 1);
if (size > pg_size - off_in_pg)
len = pg_size - off_in_pg;
else
len = size;
g_ptr = HPA2HVA(hpa);
memcpy_s(g_ptr, len, h_ptr, len);
gpa += len;
size -= len;
} while (size > 0);
return 0;
}
uint64_t gva2gpa(struct vm *vm, uint64_t cr3, uint64_t gva)
{
int level, index, shift;