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-rw-r--r--virt/kvm/arm/mmu.c390
1 files changed, 294 insertions, 96 deletions
diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c
index 5eca48bdb1a6..3053bf2584f8 100644
--- a/virt/kvm/arm/mmu.c
+++ b/virt/kvm/arm/mmu.c
@@ -115,6 +115,25 @@ static void stage2_dissolve_pmd(struct kvm *kvm, phys_addr_t addr, pmd_t *pmd)
put_page(virt_to_page(pmd));
}
+/**
+ * stage2_dissolve_pud() - clear and flush huge PUD entry
+ * @kvm: pointer to kvm structure.
+ * @addr: IPA
+ * @pud: pud pointer for IPA
+ *
+ * Function clears a PUD entry, flushes addr 1st and 2nd stage TLBs. Marks all
+ * pages in the range dirty.
+ */
+static void stage2_dissolve_pud(struct kvm *kvm, phys_addr_t addr, pud_t *pudp)
+{
+ if (!stage2_pud_huge(kvm, *pudp))
+ return;
+
+ stage2_pud_clear(kvm, pudp);
+ kvm_tlb_flush_vmid_ipa(kvm, addr);
+ put_page(virt_to_page(pudp));
+}
+
static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache,
int min, int max)
{
@@ -607,7 +626,7 @@ static void create_hyp_pte_mappings(pmd_t *pmd, unsigned long start,
addr = start;
do {
pte = pte_offset_kernel(pmd, addr);
- kvm_set_pte(pte, pfn_pte(pfn, prot));
+ kvm_set_pte(pte, kvm_pfn_pte(pfn, prot));
get_page(virt_to_page(pte));
pfn++;
} while (addr += PAGE_SIZE, addr != end);
@@ -1022,7 +1041,7 @@ static pmd_t *stage2_get_pmd(struct kvm *kvm, struct kvm_mmu_memory_cache *cache
pmd_t *pmd;
pud = stage2_get_pud(kvm, cache, addr);
- if (!pud)
+ if (!pud || stage2_pud_huge(kvm, *pud))
return NULL;
if (stage2_pud_none(kvm, *pud)) {
@@ -1083,29 +1102,103 @@ static int stage2_set_pmd_huge(struct kvm *kvm, struct kvm_mmu_memory_cache
return 0;
}
-static bool stage2_is_exec(struct kvm *kvm, phys_addr_t addr)
+static int stage2_set_pud_huge(struct kvm *kvm, struct kvm_mmu_memory_cache *cache,
+ phys_addr_t addr, const pud_t *new_pudp)
+{
+ pud_t *pudp, old_pud;
+
+ pudp = stage2_get_pud(kvm, cache, addr);
+ VM_BUG_ON(!pudp);
+
+ old_pud = *pudp;
+
+ /*
+ * A large number of vcpus faulting on the same stage 2 entry,
+ * can lead to a refault due to the
+ * stage2_pud_clear()/tlb_flush(). Skip updating the page
+ * tables if there is no change.
+ */
+ if (pud_val(old_pud) == pud_val(*new_pudp))
+ return 0;
+
+ if (stage2_pud_present(kvm, old_pud)) {
+ stage2_pud_clear(kvm, pudp);
+ kvm_tlb_flush_vmid_ipa(kvm, addr);
+ } else {
+ get_page(virt_to_page(pudp));
+ }
+
+ kvm_set_pud(pudp, *new_pudp);
+ return 0;
+}
+
+/*
+ * stage2_get_leaf_entry - walk the stage2 VM page tables and return
+ * true if a valid and present leaf-entry is found. A pointer to the
+ * leaf-entry is returned in the appropriate level variable - pudpp,
+ * pmdpp, ptepp.
+ */
+static bool stage2_get_leaf_entry(struct kvm *kvm, phys_addr_t addr,
+ pud_t **pudpp, pmd_t **pmdpp, pte_t **ptepp)
{
+ pud_t *pudp;
pmd_t *pmdp;
pte_t *ptep;
- pmdp = stage2_get_pmd(kvm, NULL, addr);
+ *pudpp = NULL;
+ *pmdpp = NULL;
+ *ptepp = NULL;
+
+ pudp = stage2_get_pud(kvm, NULL, addr);
+ if (!pudp || stage2_pud_none(kvm, *pudp) || !stage2_pud_present(kvm, *pudp))
+ return false;
+
+ if (stage2_pud_huge(kvm, *pudp)) {
+ *pudpp = pudp;
+ return true;
+ }
+
+ pmdp = stage2_pmd_offset(kvm, pudp, addr);
if (!pmdp || pmd_none(*pmdp) || !pmd_present(*pmdp))
return false;
- if (pmd_thp_or_huge(*pmdp))
- return kvm_s2pmd_exec(pmdp);
+ if (pmd_thp_or_huge(*pmdp)) {
+ *pmdpp = pmdp;
+ return true;
+ }
ptep = pte_offset_kernel(pmdp, addr);
if (!ptep || pte_none(*ptep) || !pte_present(*ptep))
return false;
- return kvm_s2pte_exec(ptep);
+ *ptepp = ptep;
+ return true;
+}
+
+static bool stage2_is_exec(struct kvm *kvm, phys_addr_t addr)
+{
+ pud_t *pudp;
+ pmd_t *pmdp;
+ pte_t *ptep;
+ bool found;
+
+ found = stage2_get_leaf_entry(kvm, addr, &pudp, &pmdp, &ptep);
+ if (!found)
+ return false;
+
+ if (pudp)
+ return kvm_s2pud_exec(pudp);
+ else if (pmdp)
+ return kvm_s2pmd_exec(pmdp);
+ else
+ return kvm_s2pte_exec(ptep);
}
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)
{
+ pud_t *pud;
pmd_t *pmd;
pte_t *pte, old_pte;
bool iomap = flags & KVM_S2PTE_FLAG_IS_IOMAP;
@@ -1114,7 +1207,31 @@ static int stage2_set_pte(struct kvm *kvm, struct kvm_mmu_memory_cache *cache,
VM_BUG_ON(logging_active && !cache);
/* Create stage-2 page table mapping - Levels 0 and 1 */
- pmd = stage2_get_pmd(kvm, cache, addr);
+ pud = stage2_get_pud(kvm, cache, addr);
+ if (!pud) {
+ /*
+ * Ignore calls from kvm_set_spte_hva for unallocated
+ * address ranges.
+ */
+ return 0;
+ }
+
+ /*
+ * While dirty page logging - dissolve huge PUD, then continue
+ * on to allocate page.
+ */
+ if (logging_active)
+ stage2_dissolve_pud(kvm, addr, pud);
+
+ if (stage2_pud_none(kvm, *pud)) {
+ if (!cache)
+ return 0; /* ignore calls from kvm_set_spte_hva */
+ pmd = mmu_memory_cache_alloc(cache);
+ stage2_pud_populate(kvm, pud, pmd);
+ get_page(virt_to_page(pud));
+ }
+
+ pmd = stage2_pmd_offset(kvm, pud, addr);
if (!pmd) {
/*
* Ignore calls from kvm_set_spte_hva for unallocated
@@ -1182,6 +1299,11 @@ static int stage2_pmdp_test_and_clear_young(pmd_t *pmd)
return stage2_ptep_test_and_clear_young((pte_t *)pmd);
}
+static int stage2_pudp_test_and_clear_young(pud_t *pud)
+{
+ return stage2_ptep_test_and_clear_young((pte_t *)pud);
+}
+
/**
* kvm_phys_addr_ioremap - map a device range to guest IPA
*
@@ -1202,7 +1324,7 @@ int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa,
pfn = __phys_to_pfn(pa);
for (addr = guest_ipa; addr < end; addr += PAGE_SIZE) {
- pte_t pte = pfn_pte(pfn, PAGE_S2_DEVICE);
+ pte_t pte = kvm_pfn_pte(pfn, PAGE_S2_DEVICE);
if (writable)
pte = kvm_s2pte_mkwrite(pte);
@@ -1234,7 +1356,7 @@ static bool transparent_hugepage_adjust(kvm_pfn_t *pfnp, phys_addr_t *ipap)
struct page *page = pfn_to_page(pfn);
/*
- * PageTransCompoungMap() returns true for THP and
+ * PageTransCompoundMap() returns true for THP and
* hugetlbfs. Make sure the adjustment is done only for THP
* pages.
*/
@@ -1347,9 +1469,12 @@ static void stage2_wp_puds(struct kvm *kvm, pgd_t *pgd,
do {
next = stage2_pud_addr_end(kvm, addr, end);
if (!stage2_pud_none(kvm, *pud)) {
- /* TODO:PUD not supported, revisit later if supported */
- BUG_ON(stage2_pud_huge(kvm, *pud));
- stage2_wp_pmds(kvm, pud, addr, next);
+ if (stage2_pud_huge(kvm, *pud)) {
+ if (!kvm_s2pud_readonly(pud))
+ kvm_set_s2pud_readonly(pud);
+ } else {
+ stage2_wp_pmds(kvm, pud, addr, next);
+ }
}
} while (pud++, addr = next, addr != end);
}
@@ -1392,7 +1517,7 @@ static void stage2_wp_range(struct kvm *kvm, phys_addr_t addr, phys_addr_t end)
*
* Called to start logging dirty pages after memory region
* KVM_MEM_LOG_DIRTY_PAGES operation is called. After this function returns
- * all present PMD and PTEs are write protected in the memory region.
+ * all present PUD, PMD and PTEs are write protected in the memory region.
* Afterwards read of dirty page log can be called.
*
* Acquires kvm_mmu_lock. Called with kvm->slots_lock mutex acquired,
@@ -1470,12 +1595,70 @@ static void kvm_send_hwpoison_signal(unsigned long address,
send_sig_mceerr(BUS_MCEERR_AR, (void __user *)address, lsb, current);
}
+static bool fault_supports_stage2_pmd_mappings(struct kvm_memory_slot *memslot,
+ unsigned long hva)
+{
+ gpa_t gpa_start, gpa_end;
+ hva_t uaddr_start, uaddr_end;
+ size_t size;
+
+ size = memslot->npages * PAGE_SIZE;
+
+ gpa_start = memslot->base_gfn << PAGE_SHIFT;
+ gpa_end = gpa_start + size;
+
+ uaddr_start = memslot->userspace_addr;
+ uaddr_end = uaddr_start + size;
+
+ /*
+ * Pages belonging to memslots that don't have the same alignment
+ * within a PMD for userspace and IPA cannot be mapped with stage-2
+ * PMD entries, because we'll end up mapping the wrong pages.
+ *
+ * Consider a layout like the following:
+ *
+ * memslot->userspace_addr:
+ * +-----+--------------------+--------------------+---+
+ * |abcde|fgh Stage-1 PMD | Stage-1 PMD tv|xyz|
+ * +-----+--------------------+--------------------+---+
+ *
+ * memslot->base_gfn << PAGE_SIZE:
+ * +---+--------------------+--------------------+-----+
+ * |abc|def Stage-2 PMD | Stage-2 PMD |tvxyz|
+ * +---+--------------------+--------------------+-----+
+ *
+ * If we create those stage-2 PMDs, we'll end up with this incorrect
+ * mapping:
+ * d -> f
+ * e -> g
+ * f -> h
+ */
+ if ((gpa_start & ~S2_PMD_MASK) != (uaddr_start & ~S2_PMD_MASK))
+ return false;
+
+ /*
+ * Next, let's make sure we're not trying to map anything not covered
+ * by the memslot. This means we have to prohibit PMD size mappings
+ * for the beginning and end of a non-PMD aligned and non-PMD sized
+ * memory slot (illustrated by the head and tail parts of the
+ * userspace view above containing pages 'abcde' and 'xyz',
+ * respectively).
+ *
+ * Note that it doesn't matter if we do the check using the
+ * userspace_addr or the base_gfn, as both are equally aligned (per
+ * the check above) and equally sized.
+ */
+ return (hva & S2_PMD_MASK) >= uaddr_start &&
+ (hva & S2_PMD_MASK) + S2_PMD_SIZE <= uaddr_end;
+}
+
static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
struct kvm_memory_slot *memslot, unsigned long hva,
unsigned long fault_status)
{
int ret;
- bool write_fault, exec_fault, writable, hugetlb = false, force_pte = false;
+ bool write_fault, writable, force_pte = false;
+ bool exec_fault, needs_exec;
unsigned long mmu_seq;
gfn_t gfn = fault_ipa >> PAGE_SHIFT;
struct kvm *kvm = vcpu->kvm;
@@ -1484,7 +1667,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
kvm_pfn_t pfn;
pgprot_t mem_type = PAGE_S2;
bool logging_active = memslot_is_logging(memslot);
- unsigned long flags = 0;
+ unsigned long vma_pagesize, flags = 0;
write_fault = kvm_is_write_fault(vcpu);
exec_fault = kvm_vcpu_trap_is_iabt(vcpu);
@@ -1495,6 +1678,12 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
return -EFAULT;
}
+ if (!fault_supports_stage2_pmd_mappings(memslot, hva))
+ force_pte = true;
+
+ if (logging_active)
+ force_pte = true;
+
/* Let's check if we will get back a huge page backed by hugetlbfs */
down_read(&current->mm->mmap_sem);
vma = find_vma_intersection(current->mm, hva, hva + 1);
@@ -1504,22 +1693,15 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
return -EFAULT;
}
- if (vma_kernel_pagesize(vma) == PMD_SIZE && !logging_active) {
- hugetlb = true;
- gfn = (fault_ipa & PMD_MASK) >> PAGE_SHIFT;
- } else {
- /*
- * Pages belonging to memslots that don't have the same
- * alignment for userspace and IPA cannot be mapped using
- * block descriptors even if the pages belong to a THP for
- * the process, because the stage-2 block descriptor will
- * cover more than a single THP and we loose atomicity for
- * unmapping, updates, and splits of the THP or other pages
- * in the stage-2 block range.
- */
- if ((memslot->userspace_addr & ~PMD_MASK) !=
- ((memslot->base_gfn << PAGE_SHIFT) & ~PMD_MASK))
- force_pte = true;
+ vma_pagesize = vma_kernel_pagesize(vma);
+ /*
+ * PUD level may not exist for a VM but PMD is guaranteed to
+ * exist.
+ */
+ if ((vma_pagesize == PMD_SIZE ||
+ (vma_pagesize == PUD_SIZE && kvm_stage2_has_pud(kvm))) &&
+ !force_pte) {
+ gfn = (fault_ipa & huge_page_mask(hstate_vma(vma))) >> PAGE_SHIFT;
}
up_read(&current->mm->mmap_sem);
@@ -1558,7 +1740,6 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
* should not be mapped with huge pages (it introduces churn
* and performance degradation), so force a pte mapping.
*/
- force_pte = true;
flags |= KVM_S2_FLAG_LOGGING_ACTIVE;
/*
@@ -1573,50 +1754,69 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
if (mmu_notifier_retry(kvm, mmu_seq))
goto out_unlock;
- if (!hugetlb && !force_pte)
- hugetlb = transparent_hugepage_adjust(&pfn, &fault_ipa);
+ if (vma_pagesize == PAGE_SIZE && !force_pte) {
+ /*
+ * Only PMD_SIZE transparent hugepages(THP) are
+ * currently supported. This code will need to be
+ * updated to support other THP sizes.
+ */
+ if (transparent_hugepage_adjust(&pfn, &fault_ipa))
+ vma_pagesize = PMD_SIZE;
+ }
- if (hugetlb) {
- pmd_t new_pmd = pfn_pmd(pfn, mem_type);
- new_pmd = pmd_mkhuge(new_pmd);
- if (writable) {
- new_pmd = kvm_s2pmd_mkwrite(new_pmd);
- kvm_set_pfn_dirty(pfn);
- }
+ if (writable)
+ kvm_set_pfn_dirty(pfn);
- if (fault_status != FSC_PERM)
- clean_dcache_guest_page(pfn, PMD_SIZE);
+ if (fault_status != FSC_PERM)
+ clean_dcache_guest_page(pfn, vma_pagesize);
- if (exec_fault) {
+ if (exec_fault)
+ invalidate_icache_guest_page(pfn, vma_pagesize);
+
+ /*
+ * If we took an execution fault we have made the
+ * icache/dcache coherent above and should now let the s2
+ * mapping be executable.
+ *
+ * Write faults (!exec_fault && FSC_PERM) are orthogonal to
+ * execute permissions, and we preserve whatever we have.
+ */
+ needs_exec = exec_fault ||
+ (fault_status == FSC_PERM && stage2_is_exec(kvm, fault_ipa));
+
+ if (vma_pagesize == PUD_SIZE) {
+ pud_t new_pud = kvm_pfn_pud(pfn, mem_type);
+
+ new_pud = kvm_pud_mkhuge(new_pud);
+ if (writable)
+ new_pud = kvm_s2pud_mkwrite(new_pud);
+
+ if (needs_exec)
+ new_pud = kvm_s2pud_mkexec(new_pud);
+
+ ret = stage2_set_pud_huge(kvm, memcache, fault_ipa, &new_pud);
+ } else if (vma_pagesize == PMD_SIZE) {
+ pmd_t new_pmd = kvm_pfn_pmd(pfn, mem_type);
+
+ new_pmd = kvm_pmd_mkhuge(new_pmd);
+
+ if (writable)
+ new_pmd = kvm_s2pmd_mkwrite(new_pmd);
+
+ if (needs_exec)
new_pmd = kvm_s2pmd_mkexec(new_pmd);
- invalidate_icache_guest_page(pfn, PMD_SIZE);
- } else if (fault_status == FSC_PERM) {
- /* Preserve execute if XN was already cleared */
- if (stage2_is_exec(kvm, fault_ipa))
- new_pmd = kvm_s2pmd_mkexec(new_pmd);
- }
ret = stage2_set_pmd_huge(kvm, memcache, fault_ipa, &new_pmd);
} else {
- pte_t new_pte = pfn_pte(pfn, mem_type);
+ pte_t new_pte = kvm_pfn_pte(pfn, mem_type);
if (writable) {
new_pte = kvm_s2pte_mkwrite(new_pte);
- kvm_set_pfn_dirty(pfn);
mark_page_dirty(kvm, gfn);
}
- if (fault_status != FSC_PERM)
- clean_dcache_guest_page(pfn, PAGE_SIZE);
-
- if (exec_fault) {
+ if (needs_exec)
new_pte = kvm_s2pte_mkexec(new_pte);
- invalidate_icache_guest_page(pfn, PAGE_SIZE);
- } else if (fault_status == FSC_PERM) {
- /* Preserve execute if XN was already cleared */
- if (stage2_is_exec(kvm, fault_ipa))
- new_pte = kvm_s2pte_mkexec(new_pte);
- }
ret = stage2_set_pte(kvm, memcache, fault_ipa, &new_pte, flags);
}
@@ -1637,6 +1837,7 @@ out_unlock:
*/
static void handle_access_fault(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa)
{
+ pud_t *pud;
pmd_t *pmd;
pte_t *pte;
kvm_pfn_t pfn;
@@ -1646,24 +1847,23 @@ static void handle_access_fault(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa)
spin_lock(&vcpu->kvm->mmu_lock);
- pmd = stage2_get_pmd(vcpu->kvm, NULL, fault_ipa);
- if (!pmd || pmd_none(*pmd)) /* Nothing there */
+ if (!stage2_get_leaf_entry(vcpu->kvm, fault_ipa, &pud, &pmd, &pte))
goto out;
- if (pmd_thp_or_huge(*pmd)) { /* THP, HugeTLB */
+ if (pud) { /* HugeTLB */
+ *pud = kvm_s2pud_mkyoung(*pud);
+ pfn = kvm_pud_pfn(*pud);
+ pfn_valid = true;
+ } else if (pmd) { /* THP, HugeTLB */
*pmd = pmd_mkyoung(*pmd);
pfn = pmd_pfn(*pmd);
pfn_valid = true;
- goto out;
+ } else {
+ *pte = pte_mkyoung(*pte); /* Just a page... */
+ pfn = pte_pfn(*pte);
+ pfn_valid = true;
}
- pte = pte_offset_kernel(pmd, fault_ipa);
- if (pte_none(*pte)) /* Nothing there either */
- goto out;
-
- *pte = pte_mkyoung(*pte); /* Just a page... */
- pfn = pte_pfn(*pte);
- pfn_valid = true;
out:
spin_unlock(&vcpu->kvm->mmu_lock);
if (pfn_valid)
@@ -1849,14 +2049,14 @@ static int kvm_set_spte_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *data
}
-void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte)
+int kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte)
{
unsigned long end = hva + PAGE_SIZE;
kvm_pfn_t pfn = pte_pfn(pte);
pte_t stage2_pte;
if (!kvm->arch.pgd)
- return;
+ return 0;
trace_kvm_set_spte_hva(hva);
@@ -1865,48 +2065,46 @@ void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte)
* just like a translation fault and clean the cache to the PoC.
*/
clean_dcache_guest_page(pfn, PAGE_SIZE);
- stage2_pte = pfn_pte(pfn, PAGE_S2);
+ stage2_pte = kvm_pfn_pte(pfn, PAGE_S2);
handle_hva_to_gpa(kvm, hva, end, &kvm_set_spte_handler, &stage2_pte);
+
+ return 0;
}
static int kvm_age_hva_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *data)
{
+ pud_t *pud;
pmd_t *pmd;
pte_t *pte;
- WARN_ON(size != PAGE_SIZE && size != PMD_SIZE);
- pmd = stage2_get_pmd(kvm, NULL, gpa);
- if (!pmd || pmd_none(*pmd)) /* Nothing there */
+ WARN_ON(size != PAGE_SIZE && size != PMD_SIZE && size != PUD_SIZE);
+ if (!stage2_get_leaf_entry(kvm, gpa, &pud, &pmd, &pte))
return 0;
- if (pmd_thp_or_huge(*pmd)) /* THP, HugeTLB */
+ if (pud)
+ return stage2_pudp_test_and_clear_young(pud);
+ else if (pmd)
return stage2_pmdp_test_and_clear_young(pmd);
-
- pte = pte_offset_kernel(pmd, gpa);
- if (pte_none(*pte))
- return 0;
-
- return stage2_ptep_test_and_clear_young(pte);
+ else
+ return stage2_ptep_test_and_clear_young(pte);
}
static int kvm_test_age_hva_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *data)
{
+ pud_t *pud;
pmd_t *pmd;
pte_t *pte;
- WARN_ON(size != PAGE_SIZE && size != PMD_SIZE);
- pmd = stage2_get_pmd(kvm, NULL, gpa);
- if (!pmd || pmd_none(*pmd)) /* Nothing there */
+ WARN_ON(size != PAGE_SIZE && size != PMD_SIZE && size != PUD_SIZE);
+ if (!stage2_get_leaf_entry(kvm, gpa, &pud, &pmd, &pte))
return 0;
- if (pmd_thp_or_huge(*pmd)) /* THP, HugeTLB */
+ if (pud)
+ return kvm_s2pud_young(*pud);
+ else if (pmd)
return pmd_young(*pmd);
-
- pte = pte_offset_kernel(pmd, gpa);
- if (!pte_none(*pte)) /* Just a page... */
+ else
return pte_young(*pte);
-
- return 0;
}
int kvm_age_hva(struct kvm *kvm, unsigned long start, unsigned long end)