KVM/arm64 fixes for 6.15, round #2

 - Single fix for broken usage of 'multi-MIDR' infrastructure in PI
   code, adding an open-coded erratum check for everyone's favorite pile
   of sand: Cavium ThunderX
This commit is contained in:
Paolo Bonzini
2025-04-24 13:28:53 -04:00
4 changed files with 25 additions and 17 deletions

View File

@@ -94,17 +94,6 @@ static inline bool kaslr_requires_kpti(void)
return false;
}
/*
* Systems affected by Cavium erratum 24756 are incompatible
* with KPTI.
*/
if (IS_ENABLED(CONFIG_CAVIUM_ERRATUM_27456)) {
extern const struct midr_range cavium_erratum_27456_cpus[];
if (is_midr_in_range_list(cavium_erratum_27456_cpus))
return false;
}
return true;
}

View File

@@ -335,7 +335,7 @@ static const struct midr_range cavium_erratum_23154_cpus[] = {
#endif
#ifdef CONFIG_CAVIUM_ERRATUM_27456
const struct midr_range cavium_erratum_27456_cpus[] = {
static const struct midr_range cavium_erratum_27456_cpus[] = {
/* Cavium ThunderX, T88 pass 1.x - 2.1 */
MIDR_RANGE(MIDR_THUNDERX, 0, 0, 1, 1),
/* Cavium ThunderX, T81 pass 1.0 */

View File

@@ -47,10 +47,6 @@ PROVIDE(__pi_id_aa64smfr0_override = id_aa64smfr0_override);
PROVIDE(__pi_id_aa64zfr0_override = id_aa64zfr0_override);
PROVIDE(__pi_arm64_sw_feature_override = arm64_sw_feature_override);
PROVIDE(__pi_arm64_use_ng_mappings = arm64_use_ng_mappings);
#ifdef CONFIG_CAVIUM_ERRATUM_27456
PROVIDE(__pi_cavium_erratum_27456_cpus = cavium_erratum_27456_cpus);
PROVIDE(__pi_is_midr_in_range_list = is_midr_in_range_list);
#endif
PROVIDE(__pi__ctype = _ctype);
PROVIDE(__pi_memstart_offset_seed = memstart_offset_seed);

View File

@@ -207,6 +207,29 @@ static void __init map_fdt(u64 fdt)
dsb(ishst);
}
/*
* PI version of the Cavium Eratum 27456 detection, which makes it
* impossible to use non-global mappings.
*/
static bool __init ng_mappings_allowed(void)
{
static const struct midr_range cavium_erratum_27456_cpus[] __initconst = {
/* Cavium ThunderX, T88 pass 1.x - 2.1 */
MIDR_RANGE(MIDR_THUNDERX, 0, 0, 1, 1),
/* Cavium ThunderX, T81 pass 1.0 */
MIDR_REV(MIDR_THUNDERX_81XX, 0, 0),
{},
};
for (const struct midr_range *r = cavium_erratum_27456_cpus; r->model; r++) {
if (midr_is_cpu_model_range(read_cpuid_id(), r->model,
r->rv_min, r->rv_max))
return false;
}
return true;
}
asmlinkage void __init early_map_kernel(u64 boot_status, void *fdt)
{
static char const chosen_str[] __initconst = "/chosen";
@@ -246,7 +269,7 @@ asmlinkage void __init early_map_kernel(u64 boot_status, void *fdt)
u64 kaslr_seed = kaslr_early_init(fdt, chosen);
if (kaslr_seed && kaslr_requires_kpti())
arm64_use_ng_mappings = true;
arm64_use_ng_mappings = ng_mappings_allowed();
kaslr_offset |= kaslr_seed & ~(MIN_KIMG_ALIGN - 1);
}