From: Christoffer Dall <christoffer.dall@xxxxxxx>
When running a nested hypervisor we commonly have to figure out if
the VCPU mode is running in the context of a guest hypervisor or guest
guest, or just a normal guest.
Add convenient primitives for this.
Reviewed-by: Russell King (Oracle) <rmk+kernel@xxxxxxxxxxxxxxx>
Signed-off-by: Christoffer Dall <christoffer.dall@xxxxxxx>
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
---
arch/arm64/include/asm/kvm_emulate.h | 56 ++++++++++++++++++++++++++++
1 file changed, 56 insertions(+)
diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
index b1134af843bd..c12287345ede 100644
--- a/arch/arm64/include/asm/kvm_emulate.h
+++ b/arch/arm64/include/asm/kvm_emulate.h
@@ -179,6 +179,62 @@ static __always_inline void vcpu_set_reg(struct kvm_vcpu *vcpu, u8 reg_num,
vcpu_gp_regs(vcpu)->regs[reg_num] = val;
}
+static inline bool vcpu_is_el2_ctxt(const struct kvm_cpu_context *ctxt)
+{
+ switch (ctxt->regs.pstate & (PSR_MODE32_BIT | PSR_MODE_MASK)) {
+ case PSR_MODE_EL2h:
+ case PSR_MODE_EL2t:
+ return true;
+ default:
+ return false;
+ }
+}
+
+static inline bool vcpu_is_el2(const struct kvm_vcpu *vcpu)
+{
+ return vcpu_is_el2_ctxt(&vcpu->arch.ctxt);
+}
+
+static inline bool __vcpu_el2_e2h_is_set(const struct kvm_cpu_context *ctxt)
+{
+ return ctxt_sys_reg(ctxt, HCR_EL2) & HCR_E2H;
+}
+
+static inline bool vcpu_el2_e2h_is_set(const struct kvm_vcpu *vcpu)
+{
+ return __vcpu_el2_e2h_is_set(&vcpu->arch.ctxt);
+}
+
+static inline bool __vcpu_el2_tge_is_set(const struct kvm_cpu_context *ctxt)
+{
+ return ctxt_sys_reg(ctxt, HCR_EL2) & HCR_TGE;
+}
+
+static inline bool vcpu_el2_tge_is_set(const struct kvm_vcpu *vcpu)
+{
+ return __vcpu_el2_tge_is_set(&vcpu->arch.ctxt);
+}
+
+static inline bool __is_hyp_ctxt(const struct kvm_cpu_context *ctxt)
+{
+ /*
+ * We are in a hypervisor context if the vcpu mode is EL2 or
+ * E2H and TGE bits are set. The latter means we are in the user space
+ * of the VHE kernel. ARMv8.1 ARM describes this as 'InHost'
+ *
+ * Note that the HCR_EL2.{E2H,TGE}={0,1} isn't really handled in the
+ * rest of the KVM code, and will result in a misbehaving guest.
+ */
+ return vcpu_is_el2_ctxt(ctxt) ||
+ (__vcpu_el2_e2h_is_set(ctxt) && __vcpu_el2_tge_is_set(ctxt)) ||
+ __vcpu_el2_tge_is_set(ctxt);
+}
+
+static inline bool is_hyp_ctxt(const struct kvm_vcpu *vcpu)
+{
+ return __is_hyp_ctxt(&vcpu->arch.ctxt);
+}
+
/*
* The layout of SPSR for an AArch32 state is different when observed from an
* AArch64 SPSR_ELx or an AArch32 SPSR_*. This function generates the AArch32
--
2.34.1
