From: Jintack Lim <[email protected]> Forward the EL1 virtual memory register traps to the virtual EL2 if they are not coming from the virtual EL2 and the virtual HCR_EL2.TVM or TRVM bit is set.
This is for recursive nested virtualization. Signed-off-by: Jintack Lim <[email protected]> Signed-off-by: Marc Zyngier <[email protected]> --- arch/arm64/kvm/sys_regs.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 582d62aa48b7..0f74b9277a86 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -436,6 +436,27 @@ static bool access_dcsw(struct kvm_vcpu *vcpu, return true; } +/* This function is to support the recursive nested virtualization */ +static bool forward_vm_traps(struct kvm_vcpu *vcpu, struct sys_reg_params *p) +{ + u64 hcr_el2 = __vcpu_sys_reg(vcpu, HCR_EL2); + + /* If a trap comes from the virtual EL2, the host hypervisor handles. */ + if (vcpu_mode_el2(vcpu)) + return false; + + /* + * If the virtual HCR_EL2.TVM or TRVM bit is set, we need to foward + * this trap to the virtual EL2. + */ + if ((hcr_el2 & HCR_TVM) && p->is_write) + return true; + else if ((hcr_el2 & HCR_TRVM) && !p->is_write) + return true; + + return false; +} + /* * Generic accessor for VM registers. Only called as long as HCR_TVM * is set. If the guest enables the MMU, we stop trapping the VM @@ -452,6 +473,9 @@ static bool access_vm_reg(struct kvm_vcpu *vcpu, if (el12_reg(p) && forward_nv_traps(vcpu)) return false; + if (!el12_reg(p) && forward_vm_traps(vcpu, p)) + return kvm_inject_nested_sync(vcpu, kvm_vcpu_get_hsr(vcpu)); + BUG_ON(!vcpu_mode_el2(vcpu) && !p->is_write); if (!p->is_write) { -- 2.20.1 _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
