[PATCH v4 27/43] arm64: rme: allow userspace to inject aborts
From: Steven Price <steven.price@arm.com>
Date: 2024-08-21 15:40:45
Also in:
kvm, kvmarm, linux-arm-kernel, lkml
Subsystem:
arm64 port (aarch64 architecture), documentation, kernel virtual machine (kvm), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Jonathan Corbet, Paolo Bonzini, Marc Zyngier, Oliver Upton, Linus Torvalds
From: Joey Gouly <joey.gouly@arm.com> Extend KVM_SET_VCPU_EVENTS to support realms, where KVM cannot set the system registers, and the RMM must perform it on next REC entry. Signed-off-by: Joey Gouly <joey.gouly@arm.com> Signed-off-by: Steven Price <steven.price@arm.com> --- Documentation/virt/kvm/api.rst | 2 ++ arch/arm64/kvm/guest.c | 24 ++++++++++++++++++++++++ 2 files changed, 26 insertions(+)
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index 849ddd2735ca..08652004aa07 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst@@ -1278,6 +1278,8 @@ User space may need to inject several types of events to the guest. Set the pending SError exception state for this VCPU. It is not possible to 'cancel' an Serror that has been made pending. +User space cannot inject SErrors into Realms. + If the guest performed an access to I/O memory which could not be handled by userspace, for example because of missing instruction syndrome decode information or because there is no device mapped at the accessed IPA, then
diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index 8066d3f05403..88c07c880e88 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c@@ -866,6 +866,30 @@ int __kvm_arm_vcpu_set_events(struct kvm_vcpu *vcpu, bool has_esr = events->exception.serror_has_esr; bool ext_dabt_pending = events->exception.ext_dabt_pending; + if (vcpu_is_rec(vcpu)) { + /* Cannot inject SError into a Realm. */ + if (serror_pending) + return -EINVAL; + + /* + * If a data abort is pending, set the flag and let the RMM + * inject an SEA when the REC is scheduled to be run. + */ + if (ext_dabt_pending) { + /* + * Can only inject SEA into a Realm if the previous exit + * was due to a data abort of an Unprotected IPA. + */ + if (!(vcpu->arch.rec.run->enter.flags & RMI_EMULATED_MMIO)) + return -EINVAL; + + vcpu->arch.rec.run->enter.flags &= ~RMI_EMULATED_MMIO; + vcpu->arch.rec.run->enter.flags |= RMI_INJECT_SEA; + } + + return 0; + } + if (serror_pending && has_esr) { if (!cpus_have_final_cap(ARM64_HAS_RAS_EXTN)) return -EINVAL;
--
2.34.1