Re: [PATCH v16 21/45] KVM: arm64: CCA: Handle realm enter/exit
From: Steven Price <steven.price@arm.com>
Date: 2026-08-13 15:29:08
Also in:
kvm, kvmarm, linux-arm-kernel, lkml
On 04/08/2026 09:57, Aneesh Kumar K.V wrote:
Steven Price [off-list ref] writes:quoted
+ switch (rec->run->exit.exit_reason) { + case RMI_EXIT_SYNC: + /* + * HPFAR_EL2_NS is hijacked to indicate a valid HPFAR value, + * see __get_fault_info() + */ + vcpu->arch.fault.hpfar_el2 = rec->run->exit.hpfar | HPFAR_EL2_NS; + rec_exit_sync(vcpu); + return ARM_EXCEPTION_TRAP; + case RMI_EXIT_IRQ: + case RMI_EXIT_FIQ: + return ARM_EXCEPTION_IRQ; + case RMI_EXIT_SERROR: + return ARM_EXCEPTION_EL1_SERROR; + case RMI_EXIT_PSCI: + rec_exit_hvc(vcpu); + kvm_make_request(KVM_REQ_RMI, vcpu); + return ARM_EXCEPTION_TRAP; + case RMI_EXIT_RIPAS_CHANGE: + rec_exit_hvc(vcpu); + return ARM_EXCEPTION_TRAP; + }Should we handle RMI_EXIT_RIPAS_CHANGE differently? Currently, the call path is: kvm_rec_exit() -> RMI_EXIT_RIPAS_CHANGE -> handle_hvc() -> kvm_rec_handle_hvc() -> kvm_prepare_memory_fault_exit() Could we instead treat RMI_EXIT_RIPAS_CHANGE as a special case and avoid redirecting it through handle_hvc()? The completion part of the RIPAS change could still be handled by kvm_rec_handle_request().
Yes that seems like it's slightly neater. Thanks, Steve
quoted hunk ↗ jump to hunk
-bool kvm_rec_handle_hvc(struct kvm_vcpu *vcpu, int *ret) +static int rec_exit_ripas_change(struct kvm_vcpu *vcpu) { - struct realm_rec *rec; + struct realm_rec *rec = &vcpu->arch.rec; struct realm *realm; unsigned long base; unsigned long ripas; unsigned long top; - if (!vcpu_is_rec(vcpu)) - return false; - - rec = &vcpu->arch.rec; - if (rec->run->exit.exit_reason != RMI_EXIT_RIPAS_CHANGE) - return false; - realm = &vcpu->kvm->arch.realm; base = rec->run->exit.ripas_base; top = rec->run->exit.ripas_top;@@ -89,8 +83,7 @@ bool kvm_rec_handle_hvc(struct kvm_vcpu *vcpu, int *ret) base, top, ripas); /* Set RMI_REJECT bit */ rec->run->enter.flags = REC_ENTER_FLAG_RIPAS_RESPONSE; - *ret = -EINVAL; - return true; + return -EINVAL; } /* Exit to VMM, the actual RIPAS change is done on next entry */@@ -102,8 +95,7 @@ bool kvm_rec_handle_hvc(struct kvm_vcpu *vcpu, int *ret) * KVM_EXIT_MEMORY_FAULT requires a return code of -EFAULT, see the * API documentation */ - *ret = -EFAULT; - return true; + return -EFAULT; } int kvm_rec_exit(struct kvm_vcpu *vcpu, int rec_run_ret)@@ -169,8 +161,7 @@ int kvm_rec_exit(struct kvm_vcpu *vcpu, int rec_run_ret) kvm_make_request(KVM_REQ_RMI, vcpu); return ARM_EXCEPTION_TRAP; case RMI_EXIT_RIPAS_CHANGE: - rec_exit_hvc(vcpu); - return ARM_EXCEPTION_TRAP; + return rec_exit_ripas_change(vcpu); } return rec_exit_fatal(vcpu, "Unsupported Realm exit reason", -aneesh