Commit 92f94f1e authored by Xiao Guangrong's avatar Xiao Guangrong Committed by Paolo Bonzini

KVM: MMU: rename has_wrprotected_page to mmu_gfn_lpage_is_disallowed

kvm_lpage_info->write_count is used to detect if the large page mapping
for the gfn on the specified level is allowed, rename it to disallow_lpage
to reflect its purpose, also we rename has_wrprotected_page() to
mmu_gfn_lpage_is_disallowed() to make the code more clearer

Later we will extend this mechanism for page tracking: if the gfn is
tracked then large mapping for that gfn on any level is not allowed.
The new name is more straightforward
Reviewed-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarXiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 4d99ba89
......@@ -391,11 +391,11 @@ To instantiate a large spte, four constraints must be satisfied:
write-protected pages
- the guest page must be wholly contained by a single memory slot
To check the last two conditions, the mmu maintains a ->write_count set of
To check the last two conditions, the mmu maintains a ->disallow_lpage set of
arrays for each memory slot and large page size. Every write protected page
causes its write_count to be incremented, thus preventing instantiation of
causes its disallow_lpage to be incremented, thus preventing instantiation of
a large spte. The frames at the end of an unaligned memory slot have
artificially inflated ->write_counts so they can never be instantiated.
artificially inflated ->disallow_lpages so they can never be instantiated.
Zapping all pages (page generation count)
=========================================
......
......@@ -644,7 +644,7 @@ struct kvm_vcpu_arch {
};
struct kvm_lpage_info {
int write_count;
int disallow_lpage;
};
struct kvm_arch_memory_slot {
......
......@@ -789,7 +789,7 @@ static void account_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp)
slot = __gfn_to_memslot(slots, gfn);
for (i = PT_DIRECTORY_LEVEL; i <= PT_MAX_HUGEPAGE_LEVEL; ++i) {
linfo = lpage_info_slot(gfn, slot, i);
linfo->write_count += 1;
linfo->disallow_lpage += 1;
}
kvm->arch.indirect_shadow_pages++;
}
......@@ -807,31 +807,32 @@ static void unaccount_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp)
slot = __gfn_to_memslot(slots, gfn);
for (i = PT_DIRECTORY_LEVEL; i <= PT_MAX_HUGEPAGE_LEVEL; ++i) {
linfo = lpage_info_slot(gfn, slot, i);
linfo->write_count -= 1;
WARN_ON(linfo->write_count < 0);
linfo->disallow_lpage -= 1;
WARN_ON(linfo->disallow_lpage < 0);
}
kvm->arch.indirect_shadow_pages--;
}
static int __has_wrprotected_page(gfn_t gfn, int level,
struct kvm_memory_slot *slot)
static bool __mmu_gfn_lpage_is_disallowed(gfn_t gfn, int level,
struct kvm_memory_slot *slot)
{
struct kvm_lpage_info *linfo;
if (slot) {
linfo = lpage_info_slot(gfn, slot, level);
return linfo->write_count;
return !!linfo->disallow_lpage;
}
return 1;
return true;
}
static int has_wrprotected_page(struct kvm_vcpu *vcpu, gfn_t gfn, int level)
static bool mmu_gfn_lpage_is_disallowed(struct kvm_vcpu *vcpu, gfn_t gfn,
int level)
{
struct kvm_memory_slot *slot;
slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
return __has_wrprotected_page(gfn, level, slot);
return __mmu_gfn_lpage_is_disallowed(gfn, level, slot);
}
static int host_mapping_level(struct kvm *kvm, gfn_t gfn)
......@@ -897,7 +898,7 @@ static int mapping_level(struct kvm_vcpu *vcpu, gfn_t large_gfn,
max_level = min(kvm_x86_ops->get_lpage_level(), host_level);
for (level = PT_DIRECTORY_LEVEL; level <= max_level; ++level)
if (__has_wrprotected_page(large_gfn, level, slot))
if (__mmu_gfn_lpage_is_disallowed(large_gfn, level, slot))
break;
return level - 1;
......@@ -2503,7 +2504,7 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
* be fixed if guest refault.
*/
if (level > PT_PAGE_TABLE_LEVEL &&
has_wrprotected_page(vcpu, gfn, level))
mmu_gfn_lpage_is_disallowed(vcpu, gfn, level))
goto done;
spte |= PT_WRITABLE_MASK | SPTE_MMU_WRITEABLE;
......@@ -2768,7 +2769,7 @@ static void transparent_hugepage_adjust(struct kvm_vcpu *vcpu,
if (!is_error_noslot_pfn(pfn) && !kvm_is_reserved_pfn(pfn) &&
level == PT_PAGE_TABLE_LEVEL &&
PageTransCompound(pfn_to_page(pfn)) &&
!has_wrprotected_page(vcpu, gfn, PT_DIRECTORY_LEVEL)) {
!mmu_gfn_lpage_is_disallowed(vcpu, gfn, PT_DIRECTORY_LEVEL)) {
unsigned long mask;
/*
* mmu_notifier_retry was successful and we hold the
......
......@@ -7879,6 +7879,7 @@ int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot,
int i;
for (i = 0; i < KVM_NR_PAGE_SIZES; ++i) {
struct kvm_lpage_info *linfo;
unsigned long ugfn;
int lpages;
int level = i + 1;
......@@ -7893,15 +7894,16 @@ int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot,
if (i == 0)
continue;
slot->arch.lpage_info[i - 1] = kvm_kvzalloc(lpages *
sizeof(*slot->arch.lpage_info[i - 1]));
if (!slot->arch.lpage_info[i - 1])
linfo = kvm_kvzalloc(lpages * sizeof(*linfo));
if (!linfo)
goto out_free;
slot->arch.lpage_info[i - 1] = linfo;
if (slot->base_gfn & (KVM_PAGES_PER_HPAGE(level) - 1))
slot->arch.lpage_info[i - 1][0].write_count = 1;
linfo[0].disallow_lpage = 1;
if ((slot->base_gfn + npages) & (KVM_PAGES_PER_HPAGE(level) - 1))
slot->arch.lpage_info[i - 1][lpages - 1].write_count = 1;
linfo[lpages - 1].disallow_lpage = 1;
ugfn = slot->userspace_addr >> PAGE_SHIFT;
/*
* If the gfn and userspace address are not aligned wrt each
......@@ -7913,7 +7915,7 @@ int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot,
unsigned long j;
for (j = 0; j < lpages; ++j)
slot->arch.lpage_info[i - 1][j].write_count = 1;
linfo[j].disallow_lpage = 1;
}
}
......
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