lkml.org 
[lkml]   [2009]   [Sep]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[patch 20/71] KVM: x86: check for cr3 validity in mmu_alloc_roots

2.6.30-stable review patch. If anyone has any objections, please let us know.

------------------
From: Marcelo Tosatti <mtosatti@redhat.com>

(cherry picked from commit 8986ecc0ef58c96eec48d8502c048f3ab67fd8e2)

Verify the cr3 address stored in vcpu->arch.cr3 points to an existant
memslot. If not, inject a triple fault.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
arch/x86/kvm/mmu.c | 27 +++++++++++++++++++++++----
arch/x86/kvm/x86.c | 1 +
2 files changed, 24 insertions(+), 4 deletions(-)

--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1942,7 +1942,19 @@ static void mmu_free_roots(struct kvm_vc
vcpu->arch.mmu.root_hpa = INVALID_PAGE;
}

-static void mmu_alloc_roots(struct kvm_vcpu *vcpu)
+static int mmu_check_root(struct kvm_vcpu *vcpu, gfn_t root_gfn)
+{
+ int ret = 0;
+
+ if (!kvm_is_visible_gfn(vcpu->kvm, root_gfn)) {
+ set_bit(KVM_REQ_TRIPLE_FAULT, &vcpu->requests);
+ ret = 1;
+ }
+
+ return ret;
+}
+
+static int mmu_alloc_roots(struct kvm_vcpu *vcpu)
{
int i;
gfn_t root_gfn;
@@ -1957,13 +1969,15 @@ static void mmu_alloc_roots(struct kvm_v
ASSERT(!VALID_PAGE(root));
if (tdp_enabled)
direct = 1;
+ if (mmu_check_root(vcpu, root_gfn))
+ return 1;
sp = kvm_mmu_get_page(vcpu, root_gfn, 0,
PT64_ROOT_LEVEL, direct,
ACC_ALL, NULL);
root = __pa(sp->spt);
++sp->root_count;
vcpu->arch.mmu.root_hpa = root;
- return;
+ return 0;
}
direct = !is_paging(vcpu);
if (tdp_enabled)
@@ -1980,6 +1994,8 @@ static void mmu_alloc_roots(struct kvm_v
root_gfn = vcpu->arch.pdptrs[i] >> PAGE_SHIFT;
} else if (vcpu->arch.mmu.root_level == 0)
root_gfn = 0;
+ if (mmu_check_root(vcpu, root_gfn))
+ return 1;
sp = kvm_mmu_get_page(vcpu, root_gfn, i << 30,
PT32_ROOT_LEVEL, direct,
ACC_ALL, NULL);
@@ -1988,6 +2004,7 @@ static void mmu_alloc_roots(struct kvm_v
vcpu->arch.mmu.pae_root[i] = root | PT_PRESENT_MASK;
}
vcpu->arch.mmu.root_hpa = __pa(vcpu->arch.mmu.pae_root);
+ return 0;
}

static void mmu_sync_roots(struct kvm_vcpu *vcpu)
@@ -2006,7 +2023,7 @@ static void mmu_sync_roots(struct kvm_vc
for (i = 0; i < 4; ++i) {
hpa_t root = vcpu->arch.mmu.pae_root[i];

- if (root) {
+ if (root && VALID_PAGE(root)) {
root &= PT64_BASE_ADDR_MASK;
sp = page_header(root);
mmu_sync_children(vcpu, sp);
@@ -2290,9 +2307,11 @@ int kvm_mmu_load(struct kvm_vcpu *vcpu)
goto out;
spin_lock(&vcpu->kvm->mmu_lock);
kvm_mmu_free_some_pages(vcpu);
- mmu_alloc_roots(vcpu);
+ r = mmu_alloc_roots(vcpu);
mmu_sync_roots(vcpu);
spin_unlock(&vcpu->kvm->mmu_lock);
+ if (r)
+ goto out;
kvm_x86_ops->set_cr3(vcpu, vcpu->arch.mmu.root_hpa);
kvm_mmu_flush_tlb(vcpu);
out:
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4433,6 +4433,7 @@ int kvm_arch_set_memory_region(struct kv
void kvm_arch_flush_shadow(struct kvm *kvm)
{
kvm_mmu_zap_all(kvm);
+ kvm_reload_remote_mmus(kvm);
}

int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu)



\
 
 \ /
  Last update: 2009-09-05 02:27    [W:0.288 / U:6.524 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site