KVM: VMX: Simplify pdptr and cr3 management
Instead of reading the PDPTRs from memory after every exit (which is slow
and wrong, as the PDPTRs are stored on the cpu), sync the PDPTRs from
memory to the VMCS before entry, and from the VMCS to memory after exit.
Do the same for cr3.
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index ea0e1d5..752465f 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -1547,10 +1547,6 @@
static void ept_load_pdptrs(struct kvm_vcpu *vcpu)
{
if (is_paging(vcpu) && is_pae(vcpu) && !is_long_mode(vcpu)) {
- if (!load_pdptrs(vcpu, vcpu->arch.cr3)) {
- printk(KERN_ERR "EPT: Fail to load pdptrs!\n");
- return;
- }
vmcs_write64(GUEST_PDPTR0, vcpu->arch.pdptrs[0]);
vmcs_write64(GUEST_PDPTR1, vcpu->arch.pdptrs[1]);
vmcs_write64(GUEST_PDPTR2, vcpu->arch.pdptrs[2]);
@@ -1558,6 +1554,16 @@
}
}
+static void ept_save_pdptrs(struct kvm_vcpu *vcpu)
+{
+ if (is_paging(vcpu) && is_pae(vcpu) && !is_long_mode(vcpu)) {
+ vcpu->arch.pdptrs[0] = vmcs_read64(GUEST_PDPTR0);
+ vcpu->arch.pdptrs[1] = vmcs_read64(GUEST_PDPTR1);
+ vcpu->arch.pdptrs[2] = vmcs_read64(GUEST_PDPTR2);
+ vcpu->arch.pdptrs[3] = vmcs_read64(GUEST_PDPTR3);
+ }
+}
+
static void vmx_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4);
static void ept_update_paging_mode_cr0(unsigned long *hw_cr0,
@@ -1651,7 +1657,6 @@
if (enable_ept) {
eptp = construct_eptp(cr3);
vmcs_write64(EPT_POINTER, eptp);
- ept_load_pdptrs(vcpu);
guest_cr3 = is_paging(vcpu) ? vcpu->arch.cr3 :
VMX_EPT_IDENTITY_PAGETABLE_ADDR;
}
@@ -3252,7 +3257,7 @@
* to sync with guest real CR3. */
if (enable_ept && is_paging(vcpu)) {
vcpu->arch.cr3 = vmcs_readl(GUEST_CR3);
- ept_load_pdptrs(vcpu);
+ ept_save_pdptrs(vcpu);
}
if (unlikely(vmx->fail)) {
@@ -3437,6 +3442,10 @@
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
+ if (enable_ept && is_paging(vcpu)) {
+ vmcs_writel(GUEST_CR3, vcpu->arch.cr3);
+ ept_load_pdptrs(vcpu);
+ }
/* Record the guest's net vcpu time for enforced NMI injections. */
if (unlikely(!cpu_has_virtual_nmis() && vmx->soft_vnmi_blocked))
vmx->entry_time = ktime_get();