Hi all,
On Mon, 17 Mar 2025 17:17:01 +1100 Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> wrote:
>
> Today's linux-next merge of the kvm-arm tree got a conflict in:
>
> arch/arm64/kernel/proton-pack.c
>
> between commits:
>
> e403e8538359 ("arm64: errata: Assume that unknown CPUs _are_ vulnerable to Spectre BHB")
> a5951389e58d ("arm64: errata: Add newer ARM cores to the spectre_bhb_loop_affected() lists")
>
> from the arm64 tree and commit:
>
> e3121298c7fc ("arm64: Modify _midr_range() functions to read MIDR/REVIDR internally")
>
> from the kvm-arm tree.
>
> I fixed it up (see below) and can carry the fix as necessary. This
> is now fixed as far as linux-next is concerned, but any non trivial
> conflicts should be mentioned to your upstream maintainer when your tree
> is submitted for merging. You may also want to consider cooperating
> with the maintainer of the conflicting tree to minimise any particularly
> complex conflicts.
>
>
> diff --cc arch/arm64/kernel/proton-pack.c
> index 0f51fd10b4b0,a573fa40d4b6..000000000000
> --- a/arch/arm64/kernel/proton-pack.c
> +++ b/arch/arm64/kernel/proton-pack.c
> @@@ -845,86 -845,52 +845,86 @@@ static unsigned long system_bhb_mitigat
> * This must be called with SCOPE_LOCAL_CPU for each type of CPU, before any
> * SCOPE_SYSTEM call will give the right answer.
> */
> -u8 spectre_bhb_loop_affected(int scope)
> +static bool is_spectre_bhb_safe(int scope)
> +{
> + static const struct midr_range spectre_bhb_safe_list[] = {
> + MIDR_ALL_VERSIONS(MIDR_CORTEX_A35),
> + MIDR_ALL_VERSIONS(MIDR_CORTEX_A53),
> + MIDR_ALL_VERSIONS(MIDR_CORTEX_A55),
> + MIDR_ALL_VERSIONS(MIDR_CORTEX_A510),
> + MIDR_ALL_VERSIONS(MIDR_CORTEX_A520),
> + MIDR_ALL_VERSIONS(MIDR_BRAHMA_B53),
> + MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_2XX_SILVER),
> + MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_3XX_SILVER),
> + MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_4XX_SILVER),
> + {},
> + };
> + static bool all_safe = true;
> +
> + if (scope != SCOPE_LOCAL_CPU)
> + return all_safe;
> +
> - if (is_midr_in_range_list(read_cpuid_id(), spectre_bhb_safe_list))
> ++ if (is_midr_in_range_list(spectre_bhb_safe_list))
> + return true;
> +
> + all_safe = false;
> +
> + return false;
> +}
> +
> +static u8 spectre_bhb_loop_affected(void)
> {
> u8 k = 0;
> - static u8 max_bhb_k;
>
> - if (scope == SCOPE_LOCAL_CPU) {
> - static const struct midr_range spectre_bhb_k32_list[] = {
> - MIDR_ALL_VERSIONS(MIDR_CORTEX_A78),
> - MIDR_ALL_VERSIONS(MIDR_CORTEX_A78AE),
> - MIDR_ALL_VERSIONS(MIDR_CORTEX_A78C),
> - MIDR_ALL_VERSIONS(MIDR_CORTEX_X1),
> - MIDR_ALL_VERSIONS(MIDR_CORTEX_A710),
> - MIDR_ALL_VERSIONS(MIDR_CORTEX_X2),
> - MIDR_ALL_VERSIONS(MIDR_NEOVERSE_N2),
> - MIDR_ALL_VERSIONS(MIDR_NEOVERSE_V1),
> - {},
> - };
> - static const struct midr_range spectre_bhb_k24_list[] = {
> - MIDR_ALL_VERSIONS(MIDR_CORTEX_A76),
> - MIDR_ALL_VERSIONS(MIDR_CORTEX_A77),
> - MIDR_ALL_VERSIONS(MIDR_NEOVERSE_N1),
> - {},
> - };
> - static const struct midr_range spectre_bhb_k11_list[] = {
> - MIDR_ALL_VERSIONS(MIDR_AMPERE1),
> - {},
> - };
> - static const struct midr_range spectre_bhb_k8_list[] = {
> - MIDR_ALL_VERSIONS(MIDR_CORTEX_A72),
> - MIDR_ALL_VERSIONS(MIDR_CORTEX_A57),
> - {},
> - };
> + static const struct midr_range spectre_bhb_k132_list[] = {
> + MIDR_ALL_VERSIONS(MIDR_CORTEX_X3),
> + MIDR_ALL_VERSIONS(MIDR_NEOVERSE_V2),
> + };
> + static const struct midr_range spectre_bhb_k38_list[] = {
> + MIDR_ALL_VERSIONS(MIDR_CORTEX_A715),
> + MIDR_ALL_VERSIONS(MIDR_CORTEX_A720),
> + };
> + static const struct midr_range spectre_bhb_k32_list[] = {
> + MIDR_ALL_VERSIONS(MIDR_CORTEX_A78),
> + MIDR_ALL_VERSIONS(MIDR_CORTEX_A78AE),
> + MIDR_ALL_VERSIONS(MIDR_CORTEX_A78C),
> + MIDR_ALL_VERSIONS(MIDR_CORTEX_X1),
> + MIDR_ALL_VERSIONS(MIDR_CORTEX_A710),
> + MIDR_ALL_VERSIONS(MIDR_CORTEX_X2),
> + MIDR_ALL_VERSIONS(MIDR_NEOVERSE_N2),
> + MIDR_ALL_VERSIONS(MIDR_NEOVERSE_V1),
> + {},
> + };
> + static const struct midr_range spectre_bhb_k24_list[] = {
> + MIDR_ALL_VERSIONS(MIDR_CORTEX_A76),
> + MIDR_ALL_VERSIONS(MIDR_CORTEX_A76AE),
> + MIDR_ALL_VERSIONS(MIDR_CORTEX_A77),
> + MIDR_ALL_VERSIONS(MIDR_NEOVERSE_N1),
> + MIDR_ALL_VERSIONS(MIDR_QCOM_KRYO_4XX_GOLD),
> + {},
> + };
> + static const struct midr_range spectre_bhb_k11_list[] = {
> + MIDR_ALL_VERSIONS(MIDR_AMPERE1),
> + {},
> + };
> + static const struct midr_range spectre_bhb_k8_list[] = {
> + MIDR_ALL_VERSIONS(MIDR_CORTEX_A72),
> + MIDR_ALL_VERSIONS(MIDR_CORTEX_A57),
> + {},
> + };
>
> - if (is_midr_in_range_list(read_cpuid_id(), spectre_bhb_k132_list))
> - if (is_midr_in_range_list(spectre_bhb_k32_list))
> - k = 32;
> - else if (is_midr_in_range_list(spectre_bhb_k24_list))
> - k = 24;
> - else if (is_midr_in_range_list(spectre_bhb_k11_list))
> - k = 11;
> - else if (is_midr_in_range_list(spectre_bhb_k8_list))
> - k = 8;
> -
> - max_bhb_k = max(max_bhb_k, k);
> - } else {
> - k = max_bhb_k;
> - }
> ++ if (is_midr_in_range_list(spectre_bhb_k132_list))
> + k = 132;
> - else if (is_midr_in_range_list(read_cpuid_id(), spectre_bhb_k38_list))
> ++ else if (is_midr_in_range_list(spectre_bhb_k38_list))
> + k = 38;
> - else if (is_midr_in_range_list(read_cpuid_id(), spectre_bhb_k32_list))
> ++ else if (is_midr_in_range_list(spectre_bhb_k32_list))
> + k = 32;
> - else if (is_midr_in_range_list(read_cpuid_id(), spectre_bhb_k24_list))
> ++ else if (is_midr_in_range_list(spectre_bhb_k24_list))
> + k = 24;
> - else if (is_midr_in_range_list(read_cpuid_id(), spectre_bhb_k11_list))
> ++ else if (is_midr_in_range_list(spectre_bhb_k11_list))
> + k = 11;
> - else if (is_midr_in_range_list(read_cpuid_id(), spectre_bhb_k8_list))
> ++ else if (is_midr_in_range_list(spectre_bhb_k8_list))
> + k = 8;
>
> return k;
> }
This is now a conflict between the kvm tree and the arm64 tree.
--
Cheers,
Stephen Rothwell
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