[PATCH 08/16] KVM: arm64: nv: Handle TLBI VMALLS12E1{,IS} operations

[Marc Zyngier]

Emulating TLBI VMALLS12E1* results in tearing down all the shadow
S2 PTs that match the current VMID, since our shadow S2s are just
some form of SW-managed TLBs. That teardown itself results in a
full TLB invalidation for both S1 and S2.

This can result in over-invalidation if two vcpus use the same VMID
to tag private S2 PTs, but this is still correct from an architecture
perspective.

Co-developed-by: Jintack Lim <jintack.lim at linaro.org>
Co-developed-by: Christoffer Dall <christoffer.dall at arm.com>
Signed-off-by: Jintack Lim <jintack.lim at linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall at arm.com>
Signed-off-by: Marc Zyngier <maz at kernel.org>
---
 arch/arm64/kvm/sys_regs.c | 51 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 4a0317883cd0..4be090ceb2ba 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -2728,6 +2728,22 @@ static const struct sys_reg_desc sys_reg_descs[] = {
 	EL2_REG(SP_EL2, NULL, reset_unknown, 0),
 };
 
+static bool kvm_supported_tlbi_s12_op(struct kvm_vcpu *vpcu, u32 instr)
+{
+	struct kvm *kvm = vpcu->kvm;
+	u8 CRm = sys_reg_CRm(instr);
+
+	if (sys_reg_CRn(instr) == TLBI_CRn_nXS &&
+	    !kvm_has_feat(kvm, ID_AA64ISAR1_EL1, XS, IMP))
+		return false;
+
+	if (CRm == TLBI_CRm_nROS &&
+	    !kvm_has_feat(kvm, ID_AA64ISAR0_EL1, TLB, OS))
+		return false;
+
+	return true;
+}
+
 /* Only defined here as this is an internal "abstraction" */
 union tlbi_info {
 	struct {
@@ -2745,6 +2761,38 @@ union tlbi_info {
 	} va;
 };
 
+static void s2_mmu_unmap_stage2_range(struct kvm_s2_mmu *mmu,
+				      const union tlbi_info *info)
+{
+	kvm_unmap_stage2_range(mmu, info->range.start, info->range.size);
+}
+
+static bool handle_vmalls12e1is(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
+				const struct sys_reg_desc *r)
+{
+	u32 sys_encoding = sys_insn(p->Op0, p->Op1, p->CRn, p->CRm, p->Op2);
+	u64 limit, vttbr;
+
+	if (!kvm_supported_tlbi_s12_op(vcpu, sys_encoding)) {
+		kvm_inject_undefined(vcpu);
+		return false;
+	}
+
+	vttbr = vcpu_read_sys_reg(vcpu, VTTBR_EL2);
+	limit = BIT_ULL(kvm_get_pa_bits(vcpu->kvm));
+
+	kvm_s2_mmu_iterate_by_vmid(vcpu->kvm, get_vmid(vttbr),
+				   &(union tlbi_info) {
+					   .range = {
+						   .start = 0,
+						   .size = limit,
+					   },
+				   },
+				   s2_mmu_unmap_stage2_range);
+
+	return true;
+}
+
 static void s2_mmu_tlbi_s1e1(struct kvm_s2_mmu *mmu,
 			     const union tlbi_info *info)
 {
@@ -2818,6 +2866,9 @@ static struct sys_reg_desc sys_insn_descs[] = {
 	SYS_INSN(TLBI_VAAE1, handle_tlbi_el1),
 	SYS_INSN(TLBI_VALE1, handle_tlbi_el1),
 	SYS_INSN(TLBI_VAALE1, handle_tlbi_el1),
+
+	SYS_INSN(TLBI_VMALLS12E1IS, handle_vmalls12e1is),
+	SYS_INSN(TLBI_VMALLS12E1, handle_vmalls12e1is),
 };
 
 static const struct sys_reg_desc *first_idreg;
-- 
2.39.2