From: Vincent Donnefort <vdonnefort@google.com>
To: maz@kernel.org, oupton@kernel.org, kvmarm@lists.linux.dev,
linux-arm-kernel@lists.infradead.org
Cc: joey.gouly@arm.com, seiden@linux.ibm.com, suzuki.poulose@arm.com,
yuzenghui@huawei.com, catalin.marinas@arm.com, will@kernel.org,
kernel-team@android.com, tabba@google.com, qperret@google.com,
Vincent Donnefort <vdonnefort@google.com>
Subject: [PATCH v3 16/17] KVM: arm64: Reject hyp trace descriptors with fewer than 3 pages
Date: Mon, 20 Jul 2026 18:15:12 +0100 [thread overview]
Message-ID: <20260720171513.1415357-17-vdonnefort@google.com> (raw)
In-Reply-To: <20260720171513.1415357-1-vdonnefort@google.com>
A trace descriptor with 0 nr_page_va allocates a 0-size bpages
backing region, which makes the ring buffer appear unloaded. Reject
descriptors with nr_page_va < 3 in hyp_trace_desc_is_valid() as this is
in any case the lower-limit for simple_ring_buffer.
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
diff --git a/arch/arm64/kvm/hyp/nvhe/trace.c b/arch/arm64/kvm/hyp/nvhe/trace.c
index 6e716295247a..96afa3d6de2f 100644
--- a/arch/arm64/kvm/hyp/nvhe/trace.c
+++ b/arch/arm64/kvm/hyp/nvhe/trace.c
@@ -189,6 +189,10 @@ static bool hyp_trace_desc_is_valid(struct hyp_trace_desc *desc, size_t desc_siz
if ((void *)rb_desc + struct_size(rb_desc, page_va, 0) > desc_end)
return false;
+ /* simple_ring_buffer_init_mm() expects at least 3 pages */
+ if (rb_desc->nr_page_va < 3)
+ return false;
+
/* Overflow desc? */
if ((void *)rb_desc + struct_size(rb_desc, page_va, rb_desc->nr_page_va) > desc_end)
return false;
--
2.55.0.229.g6434b31f56-goog
next prev parent reply other threads:[~2026-07-20 17:16 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-20 17:14 [PATCH v3 00/17] KVM: arm64: Introduce pKVM hypervisor heap allocator Vincent Donnefort
2026-07-20 17:14 ` [PATCH v3 01/17] KVM: arm64: Add pkvm_private_va_range_pa Vincent Donnefort
2026-07-20 17:14 ` [PATCH v3 02/17] KVM: arm64: Add pkvm_remove_mappings Vincent Donnefort
2026-07-20 17:14 ` [PATCH v3 03/17] KVM: arm64: Add pkvm_map_private_va_range Vincent Donnefort
2026-07-20 17:15 ` [PATCH v3 04/17] KVM: arm64: Add a heap allocator for the pKVM hyp Vincent Donnefort
2026-07-20 17:15 ` [PATCH v3 05/17] KVM: arm64: Allow kvm_hyp_memcache usage outside of stage-2 Vincent Donnefort
2026-07-20 17:15 ` [PATCH v3 06/17] KVM: arm64: Add pkvm_hyp_req infrastructure Vincent Donnefort
2026-07-20 17:15 ` [PATCH v3 07/17] KVM: arm64: Add PKVM_HYP_REQ_HYP_ALLOC request Vincent Donnefort
2026-07-20 17:15 ` [PATCH v3 08/17] KVM: arm64: Add reclaim interface for the pKVM heap alloc Vincent Donnefort
2026-07-20 17:15 ` [PATCH v3 09/17] KVM: arm64: Add selftests for the pKVM heap allocator Vincent Donnefort
2026-07-20 17:15 ` [PATCH v3 10/17] KVM: arm64: Add a shrinker for pKVM Vincent Donnefort
2026-07-20 17:15 ` [PATCH v3 11/17] KVM: arm64: Filter out non-kernel addresses in kern_hyp_va Vincent Donnefort
2026-07-20 17:15 ` [PATCH v3 12/17] KVM: arm64: Move hyp_vm refcount into the structure Vincent Donnefort
2026-07-20 17:15 ` [PATCH v3 13/17] KVM: arm64: Alloc pkvm_hyp_vm using pKVM heap allocator Vincent Donnefort
2026-07-20 17:15 ` [PATCH v3 14/17] KVM: arm64: Alloc pkvm_hyp_vcpu " Vincent Donnefort
2026-07-20 17:15 ` [PATCH v3 15/17] KVM: arm64: Reject hyp trace descriptors with fewer CPUs than hyp_nr_cpus Vincent Donnefort
2026-07-20 17:15 ` Vincent Donnefort [this message]
2026-07-20 17:15 ` [PATCH v3 17/17] KVM: arm64: Alloc simple_buffer_page using pKVM hyp allocator Vincent Donnefort
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