linux-kernel - [PATCH v4 27/43] arm64: rme: allow userspace to inject aborts

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20240821153844.60084-28-steven.price@arm.com>
Date: Wed, 21 Aug 2024 16:38:28 +0100
From: Steven Price <steven.price@....com>
To: kvm@...r.kernel.org,
	kvmarm@...ts.linux.dev
Cc: Joey Gouly <joey.gouly@....com>,
	Catalin Marinas <catalin.marinas@....com>,
	Marc Zyngier <maz@...nel.org>,
	Will Deacon <will@...nel.org>,
	James Morse <james.morse@....com>,
	Oliver Upton <oliver.upton@...ux.dev>,
	Suzuki K Poulose <suzuki.poulose@....com>,
	Zenghui Yu <yuzenghui@...wei.com>,
	linux-arm-kernel@...ts.infradead.org,
	linux-kernel@...r.kernel.org,
	Alexandru Elisei <alexandru.elisei@....com>,
	Christoffer Dall <christoffer.dall@....com>,
	Fuad Tabba <tabba@...gle.com>,
	linux-coco@...ts.linux.dev,
	Ganapatrao Kulkarni <gankulkarni@...amperecomputing.com>,
	Gavin Shan <gshan@...hat.com>,
	Shanker Donthineni <sdonthineni@...dia.com>,
	Alper Gun <alpergun@...gle.com>,
	Steven Price <steven.price@....com>
Subject: [PATCH v4 27/43] arm64: rme: allow userspace to inject aborts

From: Joey Gouly <joey.gouly@....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@....com>
Signed-off-by: Steven Price <steven.price@....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