Forward ELR_EL1, SPSR_EL1 and VBAR_EL1 traps to the guest hypervisor if it has set the NV1 bit to the virtual HCR_EL2. The guest hypervisor would set this NV1 bit to run a hypervisor in its VM (i.e. another level of nested hypervisor).
Signed-off-by: Jintack Lim <[email protected]> --- arch/arm64/include/asm/kvm_arm.h | 1 + arch/arm64/kvm/sys_regs.c | 17 +++++++++++++++++ 2 files changed, 18 insertions(+) diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h index 2a2752b..feded61 100644 --- a/arch/arm64/include/asm/kvm_arm.h +++ b/arch/arm64/include/asm/kvm_arm.h @@ -23,6 +23,7 @@ #include <asm/types.h> /* Hyp Configuration Register (HCR) bits */ +#define HCR_NV1 (UL(1) << 43) #define HCR_E2H (UL(1) << 34) #define HCR_ID (UL(1) << 33) #define HCR_CD (UL(1) << 32) diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 19d6a6e..59f9cc6 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -906,10 +906,21 @@ static inline void access_rw(struct sys_reg_params *p, u64 *sysreg) *sysreg = p->regval; } +static bool forward_nv1_traps(struct kvm_vcpu *vcpu, struct sys_reg_params *p) +{ + if (!vcpu_mode_el2(vcpu) && (vcpu_el2_reg(vcpu, HCR_EL2) & HCR_NV1)) + return true; + + return false; +} + static bool access_elr(struct kvm_vcpu *vcpu, struct sys_reg_params *p, const struct sys_reg_desc *r) { + if (forward_nv1_traps(vcpu, p)) + return kvm_inject_nested_sync(vcpu, kvm_vcpu_get_hsr(vcpu)); + access_rw(p, &vcpu->arch.ctxt.gp_regs.elr_el1); return true; } @@ -918,6 +929,9 @@ static bool access_spsr(struct kvm_vcpu *vcpu, struct sys_reg_params *p, const struct sys_reg_desc *r) { + if (forward_nv1_traps(vcpu, p)) + return kvm_inject_nested_sync(vcpu, kvm_vcpu_get_hsr(vcpu)); + access_rw(p, &vcpu->arch.ctxt.gp_regs.spsr[KVM_SPSR_EL1]); return true; } @@ -926,6 +940,9 @@ static bool access_vbar(struct kvm_vcpu *vcpu, struct sys_reg_params *p, const struct sys_reg_desc *r) { + if (forward_nv1_traps(vcpu, p)) + return kvm_inject_nested_sync(vcpu, kvm_vcpu_get_hsr(vcpu)); + access_rw(p, &vcpu_sys_reg(vcpu, r->reg)); return true; } -- 1.9.1
