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authorLadi Prosek <lprosek@redhat.com>2017-04-04 14:18:53 +0200
committerRadim Krčmář <rkrcmar@redhat.com>2017-04-04 16:24:43 +0200
commit1fb883bb827ee8efc1cc9ea0154f953f8a219d38 (patch)
tree1b6c50f1db4bc8dd4bebc42bc1b3751ff292dbcc
parentab007cc94ff9d82f5a8db8363b3becbd946e58cf (diff)
downloadlwn-1fb883bb827ee8efc1cc9ea0154f953f8a219d38.tar.gz
lwn-1fb883bb827ee8efc1cc9ea0154f953f8a219d38.zip
KVM: nVMX: initialize PML fields in vmcs02
L2 was running with uninitialized PML fields which led to incomplete dirty bitmap logging. This manifested as all kinds of subtle erratic behavior of the nested guest. Fixes: 843e4330573c ("KVM: VMX: Add PML support in VMX") Signed-off-by: Ladi Prosek <lprosek@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
-rw-r--r--arch/x86/kvm/vmx.c12
1 files changed, 12 insertions, 0 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 605183291069..259e9b28ccf8 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -10270,6 +10270,18 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
}
+ if (enable_pml) {
+ /*
+ * Conceptually we want to copy the PML address and index from
+ * vmcs01 here, and then back to vmcs01 on nested vmexit. But,
+ * since we always flush the log on each vmexit, this happens
+ * to be equivalent to simply resetting the fields in vmcs02.
+ */
+ ASSERT(vmx->pml_pg);
+ vmcs_write64(PML_ADDRESS, page_to_phys(vmx->pml_pg));
+ vmcs_write16(GUEST_PML_INDEX, PML_ENTITY_NUM - 1);
+ }
+
if (nested_cpu_has_ept(vmcs12)) {
kvm_mmu_unload(vcpu);
nested_ept_init_mmu_context(vcpu);