[RFC PATCH v2 26/31] KVM: arm64: Emulate TLBI ALLE1(IS)

[Jintack Lim <jintack.lim@linaro.org>]

TLBI ALLE1(IS) instruction invalidates all EL1&0 regime stage 1 and 2
TLB entries (on all PEs in the same Inner Shareable domain). To emulate
these instructions, we first need to clear all the mappings in the
shadow page tables since executing those instructions implies the change
of mappings in the stage 2 page tables maintained by the guest
hypervisor.  We then need to invalidate all EL1&0 regime stage 1 and 2
TLB entries of all VMIDs, which are assigned by the host hypervisor, for
this VM.

Signed-off-by: Jintack Lim <jintack.lim@linaro.org>
---
 arch/arm64/kvm/sys_regs.c | 29 +++++++++++++++++++++++++++--
 1 file changed, 27 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index a1ae8fb..5a82de9 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1795,6 +1795,31 @@ static bool handle_vae2(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
 	return true;
 }
 
+static bool handle_alle1is(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
+			   const struct sys_reg_desc *r)
+{
+	struct kvm_s2_mmu *mmu = &vcpu->kvm->arch.mmu;
+	u64 vttbr = kvm_get_vttbr(&mmu->vmid, mmu);
+
+	if (vcpu->kvm->arch.mmu.vmid.vmid_gen) {
+		/*
+		 * Invalidate the stage 1 and 2 TLB entries for the host OS
+		 * in a VM only if there is one.
+		 */
+		kvm_call_hyp(__kvm_tlb_flush_vmid, vttbr);
+	}
+
+	spin_lock(&vcpu->kvm->mmu_lock);
+	/*
+	 * Clear all mappings in the shadow page tables and invalidate the stage
+	 * 1 and 2 TLB entries via kvm_tlb_flush_vmid_ipa().
+	 */
+	kvm_nested_s2_clear(vcpu->kvm);
+	spin_unlock(&vcpu->kvm->mmu_lock);
+
+	return true;
+}
+
 /*
  * AT instruction emulation
  *
@@ -1880,14 +1905,14 @@ static bool handle_vae2(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
 	SYS_INSN_TO_DESC(TLBI_IPAS2LE1IS, NULL, NULL),
 	SYS_INSN_TO_DESC(TLBI_ALLE2IS, handle_alle2is, NULL),
 	SYS_INSN_TO_DESC(TLBI_VAE2IS, handle_vae2, NULL),
-	SYS_INSN_TO_DESC(TLBI_ALLE1IS, NULL, NULL),
+	SYS_INSN_TO_DESC(TLBI_ALLE1IS, handle_alle1is, NULL),
 	SYS_INSN_TO_DESC(TLBI_VALE2IS, handle_vae2, NULL),
 	SYS_INSN_TO_DESC(TLBI_VMALLS12E1IS, NULL, NULL),
 	SYS_INSN_TO_DESC(TLBI_IPAS2E1, NULL, NULL),
 	SYS_INSN_TO_DESC(TLBI_IPAS2LE1, NULL, NULL),
 	SYS_INSN_TO_DESC(TLBI_ALLE2, handle_alle2, NULL),
 	SYS_INSN_TO_DESC(TLBI_VAE2, handle_vae2, NULL),
-	SYS_INSN_TO_DESC(TLBI_ALLE1, NULL, NULL),
+	SYS_INSN_TO_DESC(TLBI_ALLE1, handle_alle1is, NULL),
 	SYS_INSN_TO_DESC(TLBI_VALE2, handle_vae2, NULL),
 	SYS_INSN_TO_DESC(TLBI_VMALLS12E1, NULL, NULL),
 };
-- 
1.9.1