From: Peter Maydell <peter.maydell@linaro.org>
To: QEMU Developers <qemu-devel@nongnu.org>
Subject: Re: [PULL 04/11] target/arm/cpu64: max cpu: Introduce sve<N> properties
Date: Tue, 12 Nov 2019 10:23:38 +0000 [thread overview]
Message-ID: <CAFEAcA-xYWLzsfDAWWmEk4DhXcO5zqKVZMrRp9=4t9MBAasaMA@mail.gmail.com> (raw)
In-Reply-To: <20191101085140.5205-5-peter.maydell@linaro.org>
On Fri, 1 Nov 2019 at 08:51, Peter Maydell <peter.maydell@linaro.org> wrote:
>
> From: Andrew Jones <drjones@redhat.com>
>
> Introduce cpu properties to give fine control over SVE vector lengths.
> We introduce a property for each valid length up to the current
> maximum supported, which is 2048-bits. The properties are named, e.g.
> sve128, sve256, sve384, sve512, ..., where the number is the number of
> bits. See the updates to docs/arm-cpu-features.rst for a description
> of the semantics and for example uses.
>
Hi; Coverity complains (CID 1407217) about an "overflowed return value":
> +static uint32_t sve_zcr_get_valid_len(ARMCPU *cpu, uint32_t start_len)
> +{
> + uint32_t start_vq = (start_len & 0xf) + 1;
> +
> + return arm_cpu_vq_map_next_smaller(cpu, start_vq + 1) - 1;
"Subtract operation overflows on operands
arm_cpu_vq_map_next_smaller(cpu, start_vq + 1U) and 1U"
Certainly it looks as if arm_cpu_vq_map_next_smaller() can
return 0, and claiming the valid length to be UINT_MAX
seems a bit odd in that case.
thanks
-- PMM
next prev parent reply other threads:[~2019-11-12 10:24 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-01 8:51 [PULL 00/11] target-arm queue Peter Maydell
2019-11-01 8:51 ` [PULL 01/11] target/arm/monitor: Introduce qmp_query_cpu_model_expansion Peter Maydell
2019-11-01 8:51 ` [PULL 02/11] tests: arm: Introduce cpu feature tests Peter Maydell
2019-11-01 8:51 ` [PULL 03/11] target/arm: Allow SVE to be disabled via a CPU property Peter Maydell
2019-11-01 8:51 ` [PULL 04/11] target/arm/cpu64: max cpu: Introduce sve<N> properties Peter Maydell
2019-11-12 10:23 ` Peter Maydell [this message]
2019-11-13 20:17 ` Richard Henderson
2019-11-13 21:30 ` Peter Maydell
2019-11-15 8:29 ` Richard Henderson
2019-11-01 8:51 ` [PULL 05/11] target/arm/kvm64: Add kvm_arch_get/put_sve Peter Maydell
2019-11-01 8:51 ` [PULL 06/11] target/arm/kvm64: max cpu: Enable SVE when available Peter Maydell
2019-11-01 8:51 ` [PULL 07/11] target/arm/kvm: scratch vcpu: Preserve input kvm_vcpu_init features Peter Maydell
2019-11-01 8:51 ` [PULL 08/11] target/arm/cpu64: max cpu: Support sve properties with KVM Peter Maydell
2019-11-01 8:51 ` [PULL 09/11] target/arm/kvm: host cpu: Add support for sve<N> properties Peter Maydell
2022-02-03 16:46 ` Peter Maydell
2022-02-03 17:36 ` Andrew Jones
2022-02-03 17:40 ` Peter Maydell
2022-02-04 11:26 ` Andrew Jones
2019-11-01 8:51 ` [PULL 10/11] hw/arm/boot: Rebuild hflags when modifying CPUState at boot Peter Maydell
2019-11-01 8:51 ` [PULL 11/11] target/arm: Allow reading flags from FPSCR for M-profile Peter Maydell
2019-11-01 9:30 ` [PULL 00/11] target-arm queue Peter Maydell
2019-11-01 9:54 ` Andrew Jones
2019-11-01 10:34 ` Peter Maydell
2019-11-01 12:53 ` Peter Maydell
2019-11-01 14:25 ` Andrew Jones
2019-11-02 17:57 ` Peter Maydell
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