diff options
Diffstat (limited to 'drivers/kvm/x86.c')
| -rw-r--r-- | drivers/kvm/x86.c | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/drivers/kvm/x86.c b/drivers/kvm/x86.c index ac09f381f47..15e1203faef 100644 --- a/drivers/kvm/x86.c +++ b/drivers/kvm/x86.c @@ -166,6 +166,26 @@ out: return ret; } +static bool pdptrs_changed(struct kvm_vcpu *vcpu) +{ + u64 pdpte[ARRAY_SIZE(vcpu->pdptrs)]; + bool changed = true; + int r; + + if (is_long_mode(vcpu) || !is_pae(vcpu)) + return false; + + mutex_lock(&vcpu->kvm->lock); + r = kvm_read_guest(vcpu->kvm, vcpu->cr3 & ~31u, pdpte, sizeof(pdpte)); + if (r < 0) + goto out; + changed = memcmp(pdpte, vcpu->pdptrs, sizeof(pdpte)) != 0; +out: + mutex_unlock(&vcpu->kvm->lock); + + return changed; +} + void set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0) { if (cr0 & CR0_RESERVED_BITS) { @@ -271,6 +291,11 @@ EXPORT_SYMBOL_GPL(set_cr4); void set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3) { + if (cr3 == vcpu->cr3 && !pdptrs_changed(vcpu)) { + kvm_mmu_flush_tlb(vcpu); + return; + } + if (is_long_mode(vcpu)) { if (cr3 & CR3_L_MODE_RESERVED_BITS) { printk(KERN_DEBUG "set_cr3: #GP, reserved bits\n"); |