/*
* Function: fill_in_frames()
*
* Description:
* Allocate some number of frames and put them into the frame cache
* queue.
*/
static inline void
fill_in_frames(void) {
int i, max_nframe, nframe;
uintptr_t paddr;
/*
* Generate a suitable number not so big that triggers
* release_frames() when calling frame_enqueue().
*/
max_nframe = FRAME_CACHE_SIZE - 1 - frame_cache_used();
if (vg_random) {
/* A random number between 1 and current capacity of frame cache queue */
nframe = random() % max_nframe + 1;
} else {
/* Minimum of a constant and current capacity of frame cache queue */
nframe = max_nframe < MAX_FRAMES_PER_OP ? max_nframe : MAX_FRAMES_PER_OP;
}
for (i = 0; i < nframe; ++i) {
paddr = provideSVAMemory(X86_PAGE_SIZE);
frame_enqueue(paddr);
}
}
/*
* Function: ghostMalloc()
*
* Description:
* Allocate ghost memory.
*/
unsigned char *
ghostMalloc (intptr_t size) {
/* Physical address of allocated secure memory pointer */
uintptr_t sp;
/* Virtual address assigned to secure memory by SVA */
unsigned char * vaddrStart = 0;
/* The address of the PML4e page table */
pml4e_t pml4e = 0;
/*
* Get the current interrupt context; the arguments will be in it.
*/
struct CPUState * cpup = getCPUState();
struct SVAThread * threadp = cpup->currentThread;
/*
* Determine if this is the first secure memory allocation.
*/
unsigned char firstSecAlloc = (threadp->secmemSize == 0);
/*
* Determine where this ghost memory will be allocated and update the size
* of the ghost memory.
*/
unsigned char * vaddr = vaddrStart = getNextSecureAddress (threadp, size);
/*
* Get a page of memory from the operating system. Note that the OS provides
* the physical address of the allocated memory.
*/
for (intptr_t remaining = size; remaining > 0; remaining -= X86_PAGE_SIZE) {
if ((sp = provideSVAMemory (X86_PAGE_SIZE)) != 0) {
/* Physical address of the allocated page */
uintptr_t paddr = sp;
/*
* Map the memory into a part of the address space reserved for secure
* memory.
*/
pml4e = mapSecurePage (vaddr, paddr);
/*
* If this is the first piece of secure memory that we've allocated,
* record the address of the top-level page table that maps in the secure
* memory region. The context switching intrinsics will want to know
* where this entry is so that it can quickly enable and disable it on
* context switches.
*/
if (firstSecAlloc) {
threadp->secmemPML4e = pml4e;
}
/*
* Move to the next virtual address.
*/
vaddr += X86_PAGE_SIZE;
} else {
panic ("SVA: Kernel secure memory allocation failed!\n");
}
}
/* Return a pointer to the allocated ghost memory */
return vaddrStart;
}
void
sva_ghost_fault (uintptr_t vaddr) {
uint64_t tsc_tmp;
if(tsc_read_enable_sva)
tsc_tmp = sva_read_tsc();
kernel_to_usersva_pcid();
/* Old interrupt flags */
uintptr_t rflags;
/*
* Disable interrupts.
*/
rflags = sva_enter_critical();
/* Physical address of allocated secure memory pointer */
uintptr_t sp;
/* The address of the PML4e page table */
pml4e_t pml4e;
/*
* Get the current interrupt context; the arguments will be in it.
*/
struct CPUState * cpup = getCPUState();
struct SVAThread * threadp = cpup->currentThread;
/*
* Determine if this is the first secure memory allocation.
*/
unsigned char firstSecAlloc = (threadp->secmemSize == 0);
/*
* Get a page of memory from the operating system. Note that the OS provides
* the physical address of the allocated memory.
*/
if ((sp = provideSVAMemory (X86_PAGE_SIZE)) != 0) {
/* Physical address of the allocated page */
uintptr_t paddr = (uintptr_t) sp;
/*
* Map the memory into a part of the address space reserved for secure
* memory.
*/
pml4e = mapSecurePage (vaddr, paddr);
/*
* If this is the first piece of secure memory that we've allocated,
* record the address of the top-level page table that maps in the secure
* memory region. The context switching intrinsics will want to know
* where this entry is so that it can quickly enable and disable it on
* context switches.
*/
if (firstSecAlloc) {
threadp->secmemPML4e = pml4e;
}
} else {
panic ("SVA: Kernel secure memory allocation failed!\n");
}
/*
* Zero out the ghost memory contents.
*/
memset (vaddr, 0, X86_PAGE_SIZE);
/* Re-enable interrupts if necessary */
sva_exit_critical (rflags);
usersva_to_kernel_pcid();
record_tsc(sva_ghost_fault_api, ((uint64_t) sva_read_tsc() - tsc_tmp));
return;
}
