[PATCH v3 3/3] arm64: paravirt: Enable errata based on implementation CPUs
Shameer Kolothum
shameerali.kolothum.thodi at huawei.com
Mon Dec 9 03:53:11 PST 2024
Retrieve any migration target implementation CPUs using the hypercall
and enable associated errata.
Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi at huawei.com>
---
Note:
One thing I am not sure here is how to handle the hypercall error.
Do we need to fail the Guest boot or just carry on without any
target implementation CPU support? At the moment it just carries on.
Thanks,
Shameer
---
arch/arm64/include/asm/cputype.h | 25 +++++++++++++++++++++++--
arch/arm64/include/asm/paravirt.h | 3 +++
arch/arm64/kernel/cpu_errata.c | 20 +++++++++++++++++---
arch/arm64/kernel/cpufeature.c | 2 ++
arch/arm64/kernel/image-vars.h | 2 ++
arch/arm64/kernel/paravirt.c | 31 +++++++++++++++++++++++++++++++
6 files changed, 78 insertions(+), 5 deletions(-)
diff --git a/arch/arm64/include/asm/cputype.h b/arch/arm64/include/asm/cputype.h
index dcf0e1ce892d..9e466f3ae9c6 100644
--- a/arch/arm64/include/asm/cputype.h
+++ b/arch/arm64/include/asm/cputype.h
@@ -265,6 +265,16 @@ struct midr_range {
#define MIDR_REV(m, v, r) MIDR_RANGE(m, v, r, v, r)
#define MIDR_ALL_VERSIONS(m) MIDR_RANGE(m, 0, 0, 0xf, 0xf)
+#define MAX_TARGET_IMPL_CPUS 64
+
+struct target_impl_cpu {
+ u32 midr;
+ u32 revidr;
+};
+
+extern u32 target_impl_cpu_num;
+extern struct target_impl_cpu target_impl_cpus[];
+
static inline bool midr_is_cpu_model_range(u32 midr, u32 model, u32 rv_min,
u32 rv_max)
{
@@ -276,8 +286,19 @@ static inline bool midr_is_cpu_model_range(u32 midr, u32 model, u32 rv_min,
static inline bool is_midr_in_range(struct midr_range const *range)
{
- return midr_is_cpu_model_range(read_cpuid_id(), range->model,
- range->rv_min, range->rv_max);
+ int i;
+
+ if (!target_impl_cpu_num)
+ return midr_is_cpu_model_range(read_cpuid_id(), range->model,
+ range->rv_min, range->rv_max);
+
+ for (i = 0; i < target_impl_cpu_num; i++) {
+ if (midr_is_cpu_model_range(target_impl_cpus[i].midr,
+ range->model,
+ range->rv_min, range->rv_max))
+ return true;
+ }
+ return false;
}
static inline bool
diff --git a/arch/arm64/include/asm/paravirt.h b/arch/arm64/include/asm/paravirt.h
index 9aa193e0e8f2..95f1c15bbb7d 100644
--- a/arch/arm64/include/asm/paravirt.h
+++ b/arch/arm64/include/asm/paravirt.h
@@ -19,11 +19,14 @@ static inline u64 paravirt_steal_clock(int cpu)
}
int __init pv_time_init(void);
+void __init pv_target_impl_cpu_init(void);
#else
#define pv_time_init() do {} while (0)
+#define pv_target_impl_cpu_init() do {} while (0)
+
#endif // CONFIG_PARAVIRT
#endif
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index 929685c00263..4055082ce69b 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -14,6 +14,9 @@
#include <asm/kvm_asm.h>
#include <asm/smp_plat.h>
+u32 target_impl_cpu_num;
+struct target_impl_cpu target_impl_cpus[MAX_TARGET_IMPL_CPUS];
+
static bool __maybe_unused
__is_affected_midr_range(const struct arm64_cpu_capabilities *entry,
u32 midr, u32 revidr)
@@ -32,9 +35,20 @@ __is_affected_midr_range(const struct arm64_cpu_capabilities *entry,
static bool __maybe_unused
is_affected_midr_range(const struct arm64_cpu_capabilities *entry, int scope)
{
- WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible());
- return __is_affected_midr_range(entry, read_cpuid_id(),
- read_cpuid(REVIDR_EL1));
+ int i;
+
+ if (!target_impl_cpu_num) {
+ WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible());
+ return __is_affected_midr_range(entry, read_cpuid_id(),
+ read_cpuid(REVIDR_EL1));
+ }
+
+ for (i = 0; i < target_impl_cpu_num; i++) {
+ if (__is_affected_midr_range(entry, target_impl_cpus[i].midr,
+ target_impl_cpus[i].midr))
+ return true;
+ }
+ return false;
}
static bool __maybe_unused
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 4cc4ae16b28d..d32c767bf189 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -85,6 +85,7 @@
#include <asm/kvm_host.h>
#include <asm/mmu_context.h>
#include <asm/mte.h>
+#include <asm/paravirt.h>
#include <asm/processor.h>
#include <asm/smp.h>
#include <asm/sysreg.h>
@@ -3642,6 +3643,7 @@ unsigned long cpu_get_elf_hwcap3(void)
static void __init setup_boot_cpu_capabilities(void)
{
+ pv_target_impl_cpu_init();
/*
* The boot CPU's feature register values have been recorded. Detect
* boot cpucaps and local cpucaps for the boot CPU, then enable and
diff --git a/arch/arm64/kernel/image-vars.h b/arch/arm64/kernel/image-vars.h
index 8f5422ed1b75..694e19709c46 100644
--- a/arch/arm64/kernel/image-vars.h
+++ b/arch/arm64/kernel/image-vars.h
@@ -49,6 +49,8 @@ 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_target_impl_cpu_num = target_impl_cpu_num);
+PROVIDE(__pi_target_impl_cpus = target_impl_cpus);
#endif
PROVIDE(__pi__ctype = _ctype);
PROVIDE(__pi_memstart_offset_seed = memstart_offset_seed);
diff --git a/arch/arm64/kernel/paravirt.c b/arch/arm64/kernel/paravirt.c
index aa718d6a9274..95fc3aae4a27 100644
--- a/arch/arm64/kernel/paravirt.c
+++ b/arch/arm64/kernel/paravirt.c
@@ -153,6 +153,37 @@ static bool __init has_pv_steal_clock(void)
return (res.a0 == SMCCC_RET_SUCCESS);
}
+void __init pv_target_impl_cpu_init(void)
+{
+ struct arm_smccc_res res;
+ int index = 0, max_idx = -1;
+
+ /* Check we have already set targets */
+ if (target_impl_cpu_num)
+ return;
+
+ do {
+ arm_smccc_1_1_invoke(ARM_SMCCC_VENDOR_HYP_KVM_DISCOVER_IMPL_CPUS_FUNC_ID,
+ index, &res);
+ if (res.a0 == SMCCC_RET_NOT_SUPPORTED)
+ return;
+
+ if (max_idx < 0) {
+ /* res.a0 should have a valid maximum CPU implementation index */
+ if (res.a0 >= MAX_TARGET_IMPL_CPUS)
+ return;
+ max_idx = res.a0;
+ }
+
+ target_impl_cpus[index].midr = res.a1;
+ target_impl_cpus[index].revidr = res.a2;
+ index++;
+ } while (index <= max_idx);
+
+ target_impl_cpu_num = index;
+ pr_info("Number of target implementation CPUs is %d\n", target_impl_cpu_num);
+}
+
int __init pv_time_init(void)
{
int ret;
--
2.47.0
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