[RFC PATCH v2 25/31] KVM: arm64: Emulate TLBI VAE2* instrutions

From: Jintack Lim
Date: Mon Oct 02 2017 - 23:15:24 EST


Emulate TLBI VAE2* instruction executed in the virtual EL2. Based on the
same principle as TLBI ALLE2 instruction, we can simply emulate those
instructions by executing corresponding VAE1* instructions with the
virtual EL2's VMID assigned by the host hypervisor.

Signed-off-by: Jintack Lim <jintack.lim@xxxxxxxxxx>
---
arch/arm64/include/asm/kvm_asm.h | 1 +
arch/arm64/kvm/hyp/tlb.c | 28 ++++++++++++++++++++++++++++
arch/arm64/kvm/sys_regs.c | 25 +++++++++++++++++++++----
3 files changed, 50 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index 4bded9d..cd7fb85 100644
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -55,6 +55,7 @@
extern void __kvm_tlb_flush_vmid_ipa(u64 vttbr, phys_addr_t ipa);
extern void __kvm_tlb_flush_vmid(u64 vttbr);
extern void __kvm_tlb_flush_local_vmid(u64 vttbr);
+extern void __kvm_tlb_vae2(u64 vttbr, u64 va, u64 sys_encoding);

extern void __kvm_at_insn(struct kvm_vcpu *vcpu, unsigned long vaddr,
bool el2_regime, int sys_encoding);
diff --git a/arch/arm64/kvm/hyp/tlb.c b/arch/arm64/kvm/hyp/tlb.c
index 680b960..bd8b92c 100644
--- a/arch/arm64/kvm/hyp/tlb.c
+++ b/arch/arm64/kvm/hyp/tlb.c
@@ -151,3 +151,31 @@ void __hyp_text __kvm_flush_vm_context(void)
asm volatile("ic ialluis" : : );
dsb(ish);
}
+
+void __hyp_text __kvm_tlb_vae2(u64 vttbr, u64 va, u64 sys_encoding)
+{
+ /* Switch to requested VMID */
+ __tlb_switch_to_guest()(vttbr);
+
+ /* Execute the EL1 version of TLBI VAE2* instruction */
+ switch (sys_encoding) {
+ case TLBI_VAE2IS:
+ __tlbi(vae1is, va);
+ break;
+ case TLBI_VALE2IS:
+ __tlbi(vale1is, va);
+ break;
+ case TLBI_VAE2:
+ __tlbi(vae1, va);
+ break;
+ case TLBI_VALE2:
+ __tlbi(vale1, va);
+ break;
+ default:
+ break;
+ }
+ dsb(nsh);
+ isb();
+
+ __tlb_switch_to_host()();
+}
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 90329b7..a1ae8fb 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1778,6 +1778,23 @@ static bool handle_alle2is(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
return true;
}

+static bool handle_vae2(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->el2_vmid, mmu);
+ int sys_encoding = sys_insn(p->Op0, p->Op1, p->CRn, p->CRm, p->Op2);
+
+ /*
+ * Based on the same principle as TLBI ALLE2 instruction emulation, we
+ * emulate TLBI VAE2* instructions by executing corresponding TLBI VAE1*
+ * instructions with the virtual EL2's VMID assigned by the host
+ * hypervisor.
+ */
+ kvm_call_hyp(__kvm_tlb_vae2, vttbr, p->regval, sys_encoding);
+ return true;
+}
+
/*
* AT instruction emulation
*
@@ -1862,16 +1879,16 @@ static bool handle_alle2is(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
SYS_INSN_TO_DESC(TLBI_IPAS2E1IS, NULL, NULL),
SYS_INSN_TO_DESC(TLBI_IPAS2LE1IS, NULL, NULL),
SYS_INSN_TO_DESC(TLBI_ALLE2IS, handle_alle2is, NULL),
- SYS_INSN_TO_DESC(TLBI_VAE2IS, NULL, NULL),
+ SYS_INSN_TO_DESC(TLBI_VAE2IS, handle_vae2, NULL),
SYS_INSN_TO_DESC(TLBI_ALLE1IS, NULL, NULL),
- SYS_INSN_TO_DESC(TLBI_VALE2IS, NULL, 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, NULL, NULL),
+ SYS_INSN_TO_DESC(TLBI_VAE2, handle_vae2, NULL),
SYS_INSN_TO_DESC(TLBI_ALLE1, NULL, NULL),
- SYS_INSN_TO_DESC(TLBI_VALE2, NULL, NULL),
+ SYS_INSN_TO_DESC(TLBI_VALE2, handle_vae2, NULL),
SYS_INSN_TO_DESC(TLBI_VMALLS12E1, NULL, NULL),
};

--
1.9.1