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From: Steven Price <steven.price@arm.com>
To: kvm@vger.kernel.org,
	kvmarm@lists.linux.dev
Cc: Steven Price <steven.price@arm.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Marc Zyngier <maz@kernel.org>,
	Will Deacon <will@kernel.org>,
	James Morse <james.morse@arm.com>,
	Oliver Upton <oliver.upton@linux.dev>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Zenghui Yu <yuzenghui@huawei.com>,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org,
	Joey Gouly <joey.gouly@arm.com>,
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	Christoffer Dall <christoffer.dall@arm.com>,
	Fuad Tabba <tabba@google.com>,
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	Ganapatrao Kulkarni <gankulkarni@os.amperecomputing.com>
Subject: [PATCH v2 31/43] arm64: rme: Prevent Device mappings for Realms
Date: Fri, 12 Apr 2024 09:42:57 +0100
Message-Id: <20240412084309.1733783-32-steven.price@arm.com>
In-Reply-To: <20240412084309.1733783-1-steven.price@arm.com>
References: <20240412084056.1733704-1-steven.price@arm.com>
 <20240412084309.1733783-1-steven.price@arm.com>
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Physical device assignment is not yet supported by the RMM, so it
doesn't make much sense to allow device mappings within the realm.
Prevent them when the guest is a realm.

Signed-off-by: Steven Price <steven.price@arm.com>
---
 arch/arm64/kvm/mmu.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index d891fc3c1a10..48c957e21c83 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1101,6 +1101,10 @@ int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa,
 	if (is_protected_kvm_enabled())
 		return -EPERM;
 
+	/* We don't support mapping special pages into a Realm */
+	if (kvm_is_realm(kvm))
+		return -EINVAL;
+
 	size += offset_in_page(guest_ipa);
 	guest_ipa &= PAGE_MASK;
 
-- 
2.34.1