예제 #1
0
파일: mmu.c 프로젝트: 0x00evil/linux
/*
 * Unmapping vs dcache management:
 *
 * If a guest maps certain memory pages as uncached, all writes will
 * bypass the data cache and go directly to RAM.  However, the CPUs
 * can still speculate reads (not writes) and fill cache lines with
 * data.
 *
 * Those cache lines will be *clean* cache lines though, so a
 * clean+invalidate operation is equivalent to an invalidate
 * operation, because no cache lines are marked dirty.
 *
 * Those clean cache lines could be filled prior to an uncached write
 * by the guest, and the cache coherent IO subsystem would therefore
 * end up writing old data to disk.
 *
 * This is why right after unmapping a page/section and invalidating
 * the corresponding TLBs, we call kvm_flush_dcache_p*() to make sure
 * the IO subsystem will never hit in the cache.
 */
static void unmap_ptes(struct kvm *kvm, pmd_t *pmd,
		       phys_addr_t addr, phys_addr_t end)
{
	phys_addr_t start_addr = addr;
	pte_t *pte, *start_pte;

	start_pte = pte = pte_offset_kernel(pmd, addr);
	do {
		if (!pte_none(*pte)) {
			pte_t old_pte = *pte;

			kvm_set_pte(pte, __pte(0));
			kvm_tlb_flush_vmid_ipa(kvm, addr);

			/* No need to invalidate the cache for device mappings */
			if ((pte_val(old_pte) & PAGE_S2_DEVICE) != PAGE_S2_DEVICE)
				kvm_flush_dcache_pte(old_pte);

			put_page(virt_to_page(pte));
		}
	} while (pte++, addr += PAGE_SIZE, addr != end);

	if (kvm_pte_table_empty(kvm, start_pte))
		clear_pmd_entry(kvm, pmd, start_addr);
}
예제 #2
0
static int stage2_set_pte(struct kvm *kvm, struct kvm_mmu_memory_cache *cache,
			  phys_addr_t addr, const pte_t *new_pte, bool iomap)
{
	pmd_t *pmd;
	pte_t *pte, old_pte;

	/* Create stage-2 page table mapping - Levels 0 and 1 */
	pmd = stage2_get_pmd(kvm, cache, addr);
	if (!pmd) {
		/*
		 * Ignore calls from kvm_set_spte_hva for unallocated
		 * address ranges.
		 */
		return 0;
	}

	/* Create stage-2 page mappings - Level 2 */
	if (pmd_none(*pmd)) {
		if (!cache)
			return 0; /* ignore calls from kvm_set_spte_hva */
		pte = mmu_memory_cache_alloc(cache);
		kvm_clean_pte(pte);
		pmd_populate_kernel(NULL, pmd, pte);
		get_page(virt_to_page(pmd));
	}

	pte = pte_offset_kernel(pmd, addr);

	if (iomap && pte_present(*pte))
		return -EFAULT;

	/* Create 2nd stage page table mapping - Level 3 */
	old_pte = *pte;
	if (pte_present(old_pte)) {
		/* Skip page table update if there is no change */
		if (pte_val(old_pte) == pte_val(*new_pte))
			return 0;

		kvm_set_pte(pte, __pte(0));
		kvm_tlb_flush_vmid_ipa(kvm, addr);
	} else {
		get_page(virt_to_page(pte));
	}

	kvm_set_pte(pte, *new_pte);
	return 0;
}
예제 #3
0
파일: mmu.c 프로젝트: ManCheol/kernel
static void clear_pte_entry(struct kvm *kvm, pte_t *pte, phys_addr_t addr)
{
	if (pte_present(*pte)) {
		kvm_set_pte(pte, __pte(0));
		put_page(virt_to_page(pte));
		kvm_tlb_flush_vmid_ipa(kvm, addr);
	}
}
예제 #4
0
파일: mmu.c 프로젝트: 0x00evil/linux
static int stage2_set_pte(struct kvm *kvm, struct kvm_mmu_memory_cache *cache,
			  phys_addr_t addr, const pte_t *new_pte,
			  unsigned long flags)
{
	pmd_t *pmd;
	pte_t *pte, old_pte;
	bool iomap = flags & KVM_S2PTE_FLAG_IS_IOMAP;
	bool logging_active = flags & KVM_S2_FLAG_LOGGING_ACTIVE;

	VM_BUG_ON(logging_active && !cache);

	/* Create stage-2 page table mapping - Levels 0 and 1 */
	pmd = stage2_get_pmd(kvm, cache, addr);
	if (!pmd) {
		/*
		 * Ignore calls from kvm_set_spte_hva for unallocated
		 * address ranges.
		 */
		return 0;
	}

	/*
	 * While dirty page logging - dissolve huge PMD, then continue on to
	 * allocate page.
	 */
	if (logging_active)
		stage2_dissolve_pmd(kvm, addr, pmd);

	/* Create stage-2 page mappings - Level 2 */
	if (pmd_none(*pmd)) {
		if (!cache)
			return 0; /* ignore calls from kvm_set_spte_hva */
		pte = mmu_memory_cache_alloc(cache);
		kvm_clean_pte(pte);
		pmd_populate_kernel(NULL, pmd, pte);
		get_page(virt_to_page(pmd));
	}

	pte = pte_offset_kernel(pmd, addr);

	if (iomap && pte_present(*pte))
		return -EFAULT;

	/* Create 2nd stage page table mapping - Level 3 */
	old_pte = *pte;
	kvm_set_pte(pte, *new_pte);
	if (pte_present(old_pte))
		kvm_tlb_flush_vmid_ipa(kvm, addr);
	else
		get_page(virt_to_page(pte));

	return 0;
}
예제 #5
0
파일: mmu.c 프로젝트: ManCheol/kernel
static void create_hyp_pte_mappings(pmd_t *pmd, unsigned long start,
				    unsigned long end, unsigned long pfn,
				    pgprot_t prot)
{
	pte_t *pte;
	unsigned long addr;

	addr = start;
	do {
		pte = pte_offset_kernel(pmd, addr);
		kvm_set_pte(pte, pfn_pte(pfn, prot));
		get_page(virt_to_page(pte));
		kvm_flush_dcache_to_poc(pte, sizeof(*pte));
		pfn++;
	} while (addr += PAGE_SIZE, addr != end);
}
예제 #6
0
파일: mmu.c 프로젝트: ManCheol/kernel
static int stage2_set_pte(struct kvm *kvm, struct kvm_mmu_memory_cache *cache,
			  phys_addr_t addr, const pte_t *new_pte, bool iomap)
{
	pgd_t *pgd;
	pud_t *pud;
	pmd_t *pmd;
	pte_t *pte, old_pte;

	/* Create 2nd stage page table mapping - Level 1 */
	pgd = kvm->arch.pgd + pgd_index(addr);
	pud = pud_offset(pgd, addr);
	if (pud_none(*pud)) {
		if (!cache)
			return 0; /* ignore calls from kvm_set_spte_hva */
		pmd = mmu_memory_cache_alloc(cache);
		pud_populate(NULL, pud, pmd);
		get_page(virt_to_page(pud));
	}

	pmd = pmd_offset(pud, addr);

	/* Create 2nd stage page table mapping - Level 2 */
	if (pmd_none(*pmd)) {
		if (!cache)
			return 0; /* ignore calls from kvm_set_spte_hva */
		pte = mmu_memory_cache_alloc(cache);
		kvm_clean_pte(pte);
		pmd_populate_kernel(NULL, pmd, pte);
		get_page(virt_to_page(pmd));
	}

	pte = pte_offset_kernel(pmd, addr);

	if (iomap && pte_present(*pte))
		return -EFAULT;

	/* Create 2nd stage page table mapping - Level 3 */
	old_pte = *pte;
	kvm_set_pte(pte, *new_pte);
	if (pte_present(old_pte))
		kvm_tlb_flush_vmid_ipa(kvm, addr);
	else
		get_page(virt_to_page(pte));

	return 0;
}
예제 #7
0
static void unmap_ptes(struct kvm *kvm, pmd_t *pmd,
		       phys_addr_t addr, phys_addr_t end)
{
	phys_addr_t start_addr = addr;
	pte_t *pte, *start_pte;

	start_pte = pte = pte_offset_kernel(pmd, addr);
	do {
		if (!pte_none(*pte)) {
			kvm_set_pte(pte, __pte(0));
			put_page(virt_to_page(pte));
			kvm_tlb_flush_vmid_ipa(kvm, addr);
		}
	} while (pte++, addr += PAGE_SIZE, addr != end);

	if (kvm_pte_table_empty(kvm, start_pte))
		clear_pmd_entry(kvm, pmd, start_addr);
}