[PATCH 09/59] KVM: arm64: nv: Add nested virt VCPU primitives for vEL2 VCPU state

Marc Zyngier
2019-06-21T09:39:32Z

From: Christoffer Dall <christoffer.dall@arm.com>

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.

Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
arch/arm64/include/asm/kvm_emulate.h | 55 ++++++++++++++++++++++++++++
1 file changed, 55 insertions(+)

diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
index 39ffe41855bc..8f201ea56f6e 100644
--- a/arch/arm64/include/asm/kvm_emulate.h
+++ b/arch/arm64/include/asm/kvm_emulate.h
@@ -191,6 +191,61 @@ static inline void vcpu_set_reg(struct kvm_vcpu *vcpu, u8 reg_num,
vcpu_gp_regs(vcpu)->regs.regs[reg_num] = val;
}

+static inline bool vcpu_mode_el2_ctxt(const struct kvm_cpu_context *ctxt)
+{
+ unsigned long cpsr = ctxt->gp_regs.regs.pstate;
+ u32 mode;
+
+ if (cpsr & PSR_MODE32_BIT)
+ return false;
+
+ mode = cpsr & PSR_MODE_MASK;
+
+ return mode == PSR_MODE_EL2h || mode == PSR_MODE_EL2t;
+}
+
+static inline bool vcpu_mode_el2(const struct kvm_vcpu *vcpu)
+{
+ return vcpu_mode_el2_ctxt(&vcpu->arch.ctxt);
+}
+
+static inline bool __vcpu_el2_e2h_is_set(const struct kvm_cpu_context *ctxt)
+{
+ return ctxt->sys_regs[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_regs[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'
+ */
+ return vcpu_mode_el2_ctxt(ctxt) ||
+ (__vcpu_el2_e2h_is_set(ctxt) && __vcpu_el2_tge_is_set(ctxt)) ||
+ WARN_ON(__vcpu_el2_tge_is_set(ctxt));
+}
+
+static inline bool is_hyp_ctxt(const struct kvm_vcpu *vcpu)
+{
+ return __is_hyp_ctxt(&vcpu->arch.ctxt);
+}
+
static inline unsigned long vcpu_read_spsr(const struct kvm_vcpu *vcpu)
{
if (vcpu_mode_is_32bit(vcpu))
--
2.20.1