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X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org While a trace descriptor with fewer CPUs than hyp_nr_cpus currently causes no functional issue, such a configuration is invalid and would cause the hypervisor to skip ring buffer initialization when allocating backing pages in EL2. Enforce nr_cpus == hyp_nr_cpus during trace descriptor validation to guarantee that every possible CPU has a valid ring buffer descriptor. Reviewed-by: Fuad Tabba Tested-by: Fuad Tabba Signed-off-by: Vincent Donnefort diff --git a/arch/arm64/kvm/hyp/nvhe/trace.c b/arch/arm64/kvm/hyp/nvhe/trace.c index e7e150ab265f..6e716295247a 100644 --- a/arch/arm64/kvm/hyp/nvhe/trace.c +++ b/arch/arm64/kvm/hyp/nvhe/trace.c @@ -181,6 +181,9 @@ static bool hyp_trace_desc_is_valid(struct hyp_trace_desc *desc, size_t desc_siz desc_end = (void *)desc + desc_size; nr_bpages = desc->bpages_backing_size / sizeof(struct simple_buffer_page); + if (desc->trace_buffer_desc.nr_cpus != hyp_nr_cpus) + return false; + for_each_ring_buffer_desc(rb_desc, cpu, &desc->trace_buffer_desc) { /* Can we read nr_page_va? */ if ((void *)rb_desc + struct_size(rb_desc, page_va, 0) > desc_end) -- 2.55.0.508.g3f0d502094-goog