KVM: MMU: hypercall based pte updates and TLB flushes
Hypercall based pte updates are faster than faults, and also allow use
of the lazy MMU mode to batch operations.
Don't report the feature if two dimensional paging is enabled.
[avi:
- one mmu_op hypercall instead of one per op
- allow 64-bit gpa on hypercall
- don't pass host errors (-ENOMEM) to guest]
[akpm: warning fix on i386]
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 03ba402..63afca1 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -832,6 +832,9 @@
case KVM_CAP_NR_MEMSLOTS:
r = KVM_MEMORY_SLOTS;
break;
+ case KVM_CAP_PV_MMU:
+ r = !tdp_enabled;
+ break;
default:
r = 0;
break;
@@ -2452,9 +2455,19 @@
}
EXPORT_SYMBOL_GPL(kvm_emulate_halt);
+static inline gpa_t hc_gpa(struct kvm_vcpu *vcpu, unsigned long a0,
+ unsigned long a1)
+{
+ if (is_long_mode(vcpu))
+ return a0;
+ else
+ return a0 | ((gpa_t)a1 << 32);
+}
+
int kvm_emulate_hypercall(struct kvm_vcpu *vcpu)
{
unsigned long nr, a0, a1, a2, a3, ret;
+ int r = 1;
kvm_x86_ops->cache_regs(vcpu);
@@ -2476,6 +2489,9 @@
case KVM_HC_VAPIC_POLL_IRQ:
ret = 0;
break;
+ case KVM_HC_MMU_OP:
+ r = kvm_pv_mmu_op(vcpu, a0, hc_gpa(vcpu, a1, a2), &ret);
+ break;
default:
ret = -KVM_ENOSYS;
break;
@@ -2483,7 +2499,7 @@
vcpu->arch.regs[VCPU_REGS_RAX] = ret;
kvm_x86_ops->decache_regs(vcpu);
++vcpu->stat.hypercalls;
- return 0;
+ return r;
}
EXPORT_SYMBOL_GPL(kvm_emulate_hypercall);