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authorJoerg Roedel <joerg.roedel@amd.com>2010-09-10 19:30:53 +0400
committerAvi Kivity <avi@redhat.com>2010-10-24 12:52:38 +0400
commit3d06b8bfd44ec421c386241f7c5af66c8200cbf4 (patch)
tree3b9c13bbc974a711db264d60384e869c94f8a6cd
parent2329d46d213d0721dafae18db29f54b196f11468 (diff)
downloadlinux-3d06b8bfd44ec421c386241f7c5af66c8200cbf4.tar.xz
KVM: MMU: Introduce kvm_read_nested_guest_page()
This patch introduces the kvm_read_guest_page_x86 function which reads from the physical memory of the guest. If the guest is running in guest-mode itself with nested paging enabled it will read from the guest's guest physical memory instead. The patch also changes changes the code to use this function where it is necessary. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Avi Kivity <avi@redhat.com>
-rw-r--r--arch/x86/kvm/x86.c19
1 files changed, 16 insertions, 3 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index a2efb70f4cc8..46843ed36dc1 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -392,6 +392,13 @@ int kvm_read_guest_page_mmu(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
}
EXPORT_SYMBOL_GPL(kvm_read_guest_page_mmu);
+int kvm_read_nested_guest_page(struct kvm_vcpu *vcpu, gfn_t gfn,
+ void *data, int offset, int len, u32 access)
+{
+ return kvm_read_guest_page_mmu(vcpu, vcpu->arch.walk_mmu, gfn,
+ data, offset, len, access);
+}
+
/*
* Load the pae pdptrs. Return true is they are all valid.
*/
@@ -403,8 +410,9 @@ int load_pdptrs(struct kvm_vcpu *vcpu, unsigned long cr3)
int ret;
u64 pdpte[ARRAY_SIZE(vcpu->arch.pdptrs)];
- ret = kvm_read_guest_page(vcpu->kvm, pdpt_gfn, pdpte,
- offset * sizeof(u64), sizeof(pdpte));
+ ret = kvm_read_nested_guest_page(vcpu, pdpt_gfn, pdpte,
+ offset * sizeof(u64), sizeof(pdpte),
+ PFERR_USER_MASK|PFERR_WRITE_MASK);
if (ret < 0) {
ret = 0;
goto out;
@@ -433,6 +441,8 @@ static bool pdptrs_changed(struct kvm_vcpu *vcpu)
{
u64 pdpte[ARRAY_SIZE(vcpu->arch.pdptrs)];
bool changed = true;
+ int offset;
+ gfn_t gfn;
int r;
if (is_long_mode(vcpu) || !is_pae(vcpu))
@@ -442,7 +452,10 @@ static bool pdptrs_changed(struct kvm_vcpu *vcpu)
(unsigned long *)&vcpu->arch.regs_avail))
return true;
- r = kvm_read_guest(vcpu->kvm, vcpu->arch.cr3 & ~31u, pdpte, sizeof(pdpte));
+ gfn = (vcpu->arch.cr3 & ~31u) >> PAGE_SHIFT;
+ offset = (vcpu->arch.cr3 & ~31u) & (PAGE_SIZE - 1);
+ r = kvm_read_nested_guest_page(vcpu, gfn, pdpte, offset, sizeof(pdpte),
+ PFERR_USER_MASK | PFERR_WRITE_MASK);
if (r < 0)
goto out;
changed = memcmp(pdpte, vcpu->arch.pdptrs, sizeof(pdpte)) != 0;