[RFC PATCH v2 06/31] KVM: arm64: Invalidate virtual EL2 TLB entries when needed

[Jintack Lim]

From: Christoffer Dall <christoffer.d...@linaro.org>

Sometimes when we are invalidating the TLB for a certain S2 MMU
context, this context can also have EL2 context associated with it and
we have to invalidate this too.

Signed-off-by: Christoffer Dall <christoffer.d...@linaro.org>
Signed-off-by: Jintack Lim <jintack....@linaro.org>
---
 virt/kvm/arm/arm.c |  5 +++++
 virt/kvm/arm/mmu.c | 23 ++++++++++++++++++++++-
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
index 41e0654..63dd897 100644
--- a/virt/kvm/arm/arm.c
+++ b/virt/kvm/arm/arm.c
@@ -362,6 +362,11 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
                u64 vttbr = kvm_get_vttbr(&mmu->vmid, mmu);
 
                kvm_call_hyp(__kvm_tlb_flush_local_vmid, vttbr);
+
+               if (mmu->el2_vmid.vmid) {
+                       vttbr = kvm_get_vttbr(&mmu->el2_vmid, mmu);
+                       kvm_call_hyp(__kvm_tlb_flush_local_vmid, vttbr);
+               }
                *last_ran = vcpu->vcpu_id;
        }
 
diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c
index 0edcf23..184cdc9 100644
--- a/virt/kvm/arm/mmu.c
+++ b/virt/kvm/arm/mmu.c
@@ -64,7 +64,21 @@ void kvm_flush_remote_tlbs(struct kvm *kvm)
        struct kvm_s2_mmu *mmu = &kvm->arch.mmu;
        u64 vttbr = kvm_get_vttbr(&mmu->vmid, mmu);
 
-       kvm_call_hyp(__kvm_tlb_flush_vmid, vttbr);
+       if (!mmu->el2_vmid.vmid) {
+               /*
+                * For a normal (i.e. non-nested) guest, flush entries for the
+                * given VMID *
+                */
+               kvm_call_hyp(__kvm_tlb_flush_vmid, vttbr);
+       } else {
+               /*
+                * When supporting nested virtualization, we can have multiple
+                * VMIDs in play for each VCPU in the VM, so it's really not
+                * worth it to try to quiesce the system and flush all the
+                * VMIDs that may be in use, instead just nuke the whole thing.
+                */
+               kvm_call_hyp(__kvm_flush_vm_context);
+       }
 }
 
 static void kvm_tlb_flush_vmid_ipa(struct kvm_s2_mmu *mmu, phys_addr_t ipa)
@@ -72,6 +86,13 @@ static void kvm_tlb_flush_vmid_ipa(struct kvm_s2_mmu *mmu, 
phys_addr_t ipa)
        u64 vttbr = kvm_get_vttbr(&mmu->vmid, mmu);
 
        kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, vttbr, ipa);
+
+       if (!mmu->el2_vmid.vmid) {
+               /* Nothing to do more for a non-nested guest */
+               return;
+       }
+       vttbr = kvm_get_vttbr(&mmu->el2_vmid, mmu);
+       kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, vttbr, ipa);
 }
 
 /*
-- 
1.9.1