| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Tue, 31 Mar 2009 03:00:04 +0300
From: Izik Eidus <ieidus@...hat.com>
To: unlisted-recipients:; (no To-header on input)
Cc: linux-kernel@...r.kernel.org, kvm@...r.kernel.org,
linux-mm@...ck.org, avi@...hat.com, aarcange@...hat.com,
chrisw@...hat.com, riel@...hat.com, jeremy@...p.org,
mtosatti@...hat.com, hugh@...itas.com, corbet@....net,
yaniv@...hat.com, dmonakhov@...nvz.org,
Izik Eidus <ieidus@...hat.com>
Subject: [PATCH 3/3] 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.
Signed-off-by: Izik Eidus <ieidus@...hat.com>
---
arch/x86/include/asm/kvm_host.h | 1 +
arch/x86/kvm/mmu.c | 68 +++++++++++++++++++++++++++++++++++----
virt/kvm/kvm_main.c | 14 ++++++++
3 files changed, 76 insertions(+), 7 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 8351c4d..9062729 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -791,5 +791,6 @@ 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);
#endif /* _ASM_X86_KVM_HOST_H */
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 6b4d795..f8816dd 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -257,6 +257,11 @@ static pfn_t spte_to_pfn(u64 pte)
return (pte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT;
}
+static pte_t ptep_val(pte_t *ptep)
+{
+ return *ptep;
+}
+
static gfn_t pse36_gfn_delta(u32 gpte)
{
int shift = 32 - PT32_DIR_PSE36_SHIFT - PAGE_SHIFT;
@@ -678,7 +683,8 @@ 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,
+ unsigned long data)
{
u64 *spte;
int need_tlb_flush = 0;
@@ -693,8 +699,48 @@ static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp)
return need_tlb_flush;
}
+static int kvm_set_pte_rmapp(struct kvm *kvm, unsigned long *rmapp,
+ unsigned long data)
+{
+ int need_flush = 0;
+ u64 *spte, new_spte;
+ pte_t *ptep = (pte_t *)data;
+ pfn_t new_pfn;
+
+ new_pfn = pte_pfn(ptep_val(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_val(ptep))) {
+ rmap_remove(kvm, spte);
+ set_shadow_pte(spte, shadow_trap_nonpresent_pte);
+ spte = rmap_next(kvm, rmapp, NULL);
+ } else {
+ new_spte = *spte &~ (PT64_BASE_ADDR_MASK);
+ new_spte |= new_pfn << PAGE_SHIFT;
+
+ if (!pte_write(ptep_val(ptep))) {
+ new_spte &= ~PT_WRITABLE_MASK;
+ new_spte &= ~SPTE_HOST_WRITEABLE;
+ if (is_writeble_pte(*spte))
+ kvm_set_pfn_dirty(spte_to_pfn(*spte));
+ }
+ set_shadow_pte(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,
- int (*handler)(struct kvm *kvm, unsigned long *rmapp))
+ unsigned long data,
+ int (*handler)(struct kvm *kvm, unsigned long *rmapp,
+ unsigned long data))
{
int i;
int retval = 0;
@@ -715,11 +761,13 @@ static int kvm_handle_hva(struct kvm *kvm, unsigned long hva,
end = start + (memslot->npages << PAGE_SHIFT);
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);
retval |= handler(kvm,
&memslot->lpage_info[
gfn_offset /
- KVM_PAGES_PER_HPAGE].rmap_pde);
+ KVM_PAGES_PER_HPAGE].rmap_pde,
+ data);
}
}
@@ -728,10 +776,16 @@ 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, (unsigned long)&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,
+ unsigned long data)
{
u64 *spte;
int young = 0;
@@ -757,7 +811,7 @@ static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp)
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
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 8aa3b95..3d340e9 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -846,6 +846,19 @@ 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,
@@ -925,6 +938,7 @@ 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 */
--
1.5.6.5
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists