Il 19/05/2013 06:52, Jun Nakajima ha scritto: > From: Nadav Har'El <[email protected]> > > The existing code for handling cr3 and related VMCS fields during nested > exit and entry wasn't correct in all cases: > > If L2 is allowed to control cr3 (and this is indeed the case in nested EPT), > during nested exit we must copy the modified cr3 from vmcs02 to vmcs12, and > we forgot to do so. This patch adds this copy. > > If L0 isn't controlling cr3 when running L2 (i.e., L0 is using EPT), and > whoever does control cr3 (L1 or L2) is using PAE, the processor might have > saved PDPTEs and we should also save them in vmcs12 (and restore later). > > Signed-off-by: Nadav Har'El <[email protected]> > Signed-off-by: Jun Nakajima <[email protected]> > Signed-off-by: Xinhao Xu <[email protected]> > --- > arch/x86/kvm/vmx.c | 30 ++++++++++++++++++++++++++++++ > 1 file changed, 30 insertions(+) > > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index a88432f..b79efd4 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -7608,6 +7608,17 @@ static void prepare_vmcs02(struct kvm_vcpu *vcpu, > struct vmcs12 *vmcs12) > kvm_set_cr3(vcpu, vmcs12->guest_cr3); > kvm_mmu_reset_context(vcpu); > > + /* > + * Additionally, except when L0 is using shadow page tables, L1 or > + * L2 control guest_cr3 for L2, so they may also have saved PDPTEs > + */ > + if (enable_ept) { > + vmcs_write64(GUEST_PDPTR0, vmcs12->guest_pdptr0); > + vmcs_write64(GUEST_PDPTR1, vmcs12->guest_pdptr1); > + vmcs_write64(GUEST_PDPTR2, vmcs12->guest_pdptr2); > + vmcs_write64(GUEST_PDPTR3, vmcs12->guest_pdptr3); > + } > + > kvm_register_write(vcpu, VCPU_REGS_RSP, vmcs12->guest_rsp); > kvm_register_write(vcpu, VCPU_REGS_RIP, vmcs12->guest_rip); > } > @@ -7930,6 +7941,25 @@ static void prepare_vmcs12(struct kvm_vcpu *vcpu, > struct vmcs12 *vmcs12) > vmcs12->guest_pending_dbg_exceptions = > vmcs_readl(GUEST_PENDING_DBG_EXCEPTIONS); > > + /* > + * In some cases (usually, nested EPT), L2 is allowed to change its > + * own CR3 without exiting. If it has changed it, we must keep it. > + * Of course, if L0 is using shadow page tables, GUEST_CR3 was defined > + * by L0, not L1 or L2, so we mustn't unconditionally copy it to vmcs12. > + */ > + if (enable_ept) > + vmcs12->guest_cr3 = vmcs_read64(GUEST_CR3); > + /* > + * Additionally, except when L0 is using shadow page tables, L1 or > + * L2 control guest_cr3 for L2, so save their PDPTEs > + */ > + if (enable_ept) { > + vmcs12->guest_pdptr0 = vmcs_read64(GUEST_PDPTR0); > + vmcs12->guest_pdptr1 = vmcs_read64(GUEST_PDPTR1); > + vmcs12->guest_pdptr2 = vmcs_read64(GUEST_PDPTR2); > + vmcs12->guest_pdptr3 = vmcs_read64(GUEST_PDPTR3); > + } > + > vmcs12->vm_entry_controls = > (vmcs12->vm_entry_controls & ~VM_ENTRY_IA32E_MODE) | > (vmcs_read32(VM_ENTRY_CONTROLS) & VM_ENTRY_IA32E_MODE); >
Reviewed-by: Paolo Bonzini <[email protected]> -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
