Commit 3da0dd43 authored by Izik Eidus's avatar Izik Eidus Committed by Avi Kivity
Browse files

KVM: add support for change_pte mmu notifiers



this is needed for kvm if it want ksm to directly map pages into its
shadow page tables.

[marcelo: cast pfn assignment to u64]
Signed-off-by: default avatarIzik Eidus <ieidus@redhat.com>
Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
parent 1403283a
......@@ -796,6 +796,7 @@ asmlinkage void kvm_handle_fault_on_reboot(void);
#define KVM_ARCH_WANT_MMU_NOTIFIER
int kvm_unmap_hva(struct kvm *kvm, unsigned long hva);
int kvm_age_hva(struct kvm *kvm, unsigned long hva);
void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte);
int cpuid_maxphyaddr(struct kvm_vcpu *vcpu);
int kvm_cpu_has_interrupt(struct kvm_vcpu *vcpu);
int kvm_arch_interrupt_allowed(struct kvm_vcpu *vcpu);
......
......@@ -748,7 +748,7 @@ static int rmap_write_protect(struct kvm *kvm, u64 gfn)
return write_protected;
}
static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp)
static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp, u64 data)
{
u64 *spte;
int need_tlb_flush = 0;
......@@ -763,8 +763,45 @@ static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp)
return need_tlb_flush;
}
static int kvm_handle_hva(struct kvm *kvm, unsigned long hva,
int (*handler)(struct kvm *kvm, unsigned long *rmapp))
static int kvm_set_pte_rmapp(struct kvm *kvm, unsigned long *rmapp, u64 data)
{
int need_flush = 0;
u64 *spte, new_spte;
pte_t *ptep = (pte_t *)data;
pfn_t new_pfn;
WARN_ON(pte_huge(*ptep));
new_pfn = pte_pfn(*ptep);
spte = rmap_next(kvm, rmapp, NULL);
while (spte) {
BUG_ON(!is_shadow_present_pte(*spte));
rmap_printk("kvm_set_pte_rmapp: spte %p %llx\n", spte, *spte);
need_flush = 1;
if (pte_write(*ptep)) {
rmap_remove(kvm, spte);
__set_spte(spte, shadow_trap_nonpresent_pte);
spte = rmap_next(kvm, rmapp, NULL);
} else {
new_spte = *spte &~ (PT64_BASE_ADDR_MASK);
new_spte |= (u64)new_pfn << PAGE_SHIFT;
new_spte &= ~PT_WRITABLE_MASK;
new_spte &= ~SPTE_HOST_WRITEABLE;
if (is_writeble_pte(*spte))
kvm_set_pfn_dirty(spte_to_pfn(*spte));
__set_spte(spte, new_spte);
spte = rmap_next(kvm, rmapp, spte);
}
}
if (need_flush)
kvm_flush_remote_tlbs(kvm);
return 0;
}
static int kvm_handle_hva(struct kvm *kvm, unsigned long hva, u64 data,
int (*handler)(struct kvm *kvm, unsigned long *rmapp,
u64 data))
{
int i, j;
int retval = 0;
......@@ -786,13 +823,15 @@ static int kvm_handle_hva(struct kvm *kvm, unsigned long hva,
if (hva >= start && hva < end) {
gfn_t gfn_offset = (hva - start) >> PAGE_SHIFT;
retval |= handler(kvm, &memslot->rmap[gfn_offset]);
retval |= handler(kvm, &memslot->rmap[gfn_offset],
data);
for (j = 0; j < KVM_NR_PAGE_SIZES - 1; ++j) {
int idx = gfn_offset;
idx /= KVM_PAGES_PER_HPAGE(PT_DIRECTORY_LEVEL + j);
retval |= handler(kvm,
&memslot->lpage_info[j][idx].rmap_pde);
&memslot->lpage_info[j][idx].rmap_pde,
data);
}
}
}
......@@ -802,10 +841,15 @@ static int kvm_handle_hva(struct kvm *kvm, unsigned long hva,
int kvm_unmap_hva(struct kvm *kvm, unsigned long hva)
{
return kvm_handle_hva(kvm, hva, kvm_unmap_rmapp);
return kvm_handle_hva(kvm, hva, 0, kvm_unmap_rmapp);
}
void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte)
{
kvm_handle_hva(kvm, hva, (u64)&pte, kvm_set_pte_rmapp);
}
static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp)
static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp, u64 data)
{
u64 *spte;
int young = 0;
......@@ -841,13 +885,13 @@ static void rmap_recycle(struct kvm_vcpu *vcpu, u64 *spte, gfn_t gfn)
gfn = unalias_gfn(vcpu->kvm, gfn);
rmapp = gfn_to_rmap(vcpu->kvm, gfn, sp->role.level);
kvm_unmap_rmapp(vcpu->kvm, rmapp);
kvm_unmap_rmapp(vcpu->kvm, rmapp, 0);
kvm_flush_remote_tlbs(vcpu->kvm);
}
int kvm_age_hva(struct kvm *kvm, unsigned long hva)
{
return kvm_handle_hva(kvm, hva, kvm_age_rmapp);
return kvm_handle_hva(kvm, hva, 0, kvm_age_rmapp);
}
#ifdef MMU_DEBUG
......
......@@ -850,6 +850,19 @@ static void kvm_mmu_notifier_invalidate_page(struct mmu_notifier *mn,
}
static void kvm_mmu_notifier_change_pte(struct mmu_notifier *mn,
struct mm_struct *mm,
unsigned long address,
pte_t pte)
{
struct kvm *kvm = mmu_notifier_to_kvm(mn);
spin_lock(&kvm->mmu_lock);
kvm->mmu_notifier_seq++;
kvm_set_spte_hva(kvm, address, pte);
spin_unlock(&kvm->mmu_lock);
}
static void kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
struct mm_struct *mm,
unsigned long start,
......@@ -929,6 +942,7 @@ static const struct mmu_notifier_ops kvm_mmu_notifier_ops = {
.invalidate_range_start = kvm_mmu_notifier_invalidate_range_start,
.invalidate_range_end = kvm_mmu_notifier_invalidate_range_end,
.clear_flush_young = kvm_mmu_notifier_clear_flush_young,
.change_pte = kvm_mmu_notifier_change_pte,
.release = kvm_mmu_notifier_release,
};
#endif /* CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER */
......
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