Hi Thomas,
Am 30.05.2024 um 18:24 schrieb Thomas Gleixner:
The proper fix is obviously to unlock CPUID on Intel _before_ anything which depends on cpuid_level is evaluated.
Thanks,
tglx
--- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -969,7 +969,7 @@ static void init_speculation_control(str } }
-void get_cpu_cap(struct cpuinfo_x86 *c) +static void get_cpu_cap(struct cpuinfo_x86 *c) { u32 eax, ebx, ecx, edx;
@@ -1585,6 +1585,7 @@ static void __init early_identify_cpu(st if (have_cpuid_p()) { cpu_detect(c); get_cpu_vendor(c);
intel_unlock_cpuid_leafs(c);@@ -1744,7 +1745,7 @@ static void generic_identify(struct cpui cpu_detect(c);
get_cpu_vendor(c);
intel_unlock_cpuid_leafs(c); get_cpu_cap(c);
get_cpu_address_sizes(c);
--- a/arch/x86/kernel/cpu/cpu.h +++ b/arch/x86/kernel/cpu/cpu.h @@ -61,14 +61,15 @@ extern __ro_after_init enum tsx_ctrl_sta
extern void __init tsx_init(void); void tsx_ap_init(void); +void intel_unlock_cpuid_leafs(struct cpuinfo_x86 *c); #else static inline void tsx_init(void) { } static inline void tsx_ap_init(void) { } +static inline void intel_unlock_cpuid_leafs(struct cpuinfo_x86 *c) { } #endif /* CONFIG_CPU_SUP_INTEL */
extern void init_spectral_chicken(struct cpuinfo_x86 *c);
-extern void get_cpu_cap(struct cpuinfo_x86 *c); extern void get_cpu_address_sizes(struct cpuinfo_x86 *c); extern void cpu_detect_cache_sizes(struct cpuinfo_x86 *c); extern void init_scattered_cpuid_features(struct cpuinfo_x86 *c); --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -269,19 +269,26 @@ static void detect_tme_early(struct cpui c->x86_phys_bits -= keyid_bits; }
+void intel_unlock_cpuid_leafs(struct cpuinfo_x86 *c) +{
- if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
return;- if (c->x86 < 6 || (c->x86 == 6 && c->x86_model < 0xd))
return;- /*
* The BIOS can have limited CPUID to leaf 2, which breaks feature* enumeration. Unlock it and update the maximum leaf info.*/- if (msr_clear_bit(MSR_IA32_MISC_ENABLE, MSR_IA32_MISC_ENABLE_LIMIT_CPUID_BIT) > 0)
c->cpuid_level = cpuid_eax(0);+}
- static void early_init_intel(struct cpuinfo_x86 *c) { u64 misc_enable;
- /* Unmask CPUID levels if masked: */
- if (c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xd)) {
if (msr_clear_bit(MSR_IA32_MISC_ENABLE,MSR_IA32_MISC_ENABLE_LIMIT_CPUID_BIT) > 0) {c->cpuid_level = cpuid_eax(0);get_cpu_cap(c);}- }
- if ((c->x86 == 0xf && c->x86_model >= 0x03) || (c->x86 == 0x6 && c->x86_model >= 0x0e)) set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
With that patch applied, I now get a build error:
CC [M] drivers/gpu/drm/amd/amdgpu/../display/modules/hdcp/hdcp.o CC [M] drivers/gpu/drm/amd/amdgpu/../display/modules/hdcp/hdcp1_execution.o CC [M] drivers/gpu/drm/amd/amdgpu/../display/modules/hdcp/hdcp1_transition.o CC [M] drivers/gpu/drm/amd/amdgpu/../display/modules/hdcp/hdcp2_execution.o CC [M] drivers/gpu/drm/amd/amdgpu/../display/modules/hdcp/hdcp2_transition.o LD [M] drivers/gpu/drm/amd/amdgpu/amdgpu.o AR drivers/gpu/built-in.a AR drivers/built-in.a make[1]: *** [/usr/src/linux/Makefile:1919: .] Fehler 2 make: *** [Makefile:240: __sub-make] Fehler 2 root@linus:/usr/src/linux# make CALL scripts/checksyscalls.sh DESCEND objtool INSTALL libsubcmd_headers DESCEND bpf/resolve_btfids INSTALL libsubcmd_headers CC arch/x86/xen/enlighten_pv.o arch/x86/xen/enlighten_pv.c: In Funktion »xen_start_kernel«: arch/x86/xen/enlighten_pv.c:1388:9: Fehler: Implizite Deklaration der Funktion »get_cpu_cap«; meinten Sie »set_cpu_cap«? [-Werror=implicit-function-declaration] 1388 | get_cpu_cap(&boot_cpu_data); | ^~~~~~~~~~~ | set_cpu_cap cc1: Einige Warnungen werden als Fehler behandelt make[4]: *** [scripts/Makefile.build:244: arch/x86/xen/enlighten_pv.o] Fehler 1 make[3]: *** [scripts/Makefile.build:485: arch/x86/xen] Fehler 2 make[2]: *** [scripts/Makefile.build:485: arch/x86] Fehler 2 make[1]: *** [/usr/src/linux/Makefile:1919: .] Fehler 2 make: *** [Makefile:240: __sub-make] Fehler 2 root@linus:/usr/src/linux#
I used the kernel config of my Proxmox VE kernel, like so:
root@linus:/usr/src/linux# cp /boot/config-6.5.13-5-pve .config
and then ran "make olddefconfig", and then "make -j 48". That's how I tested all these patches, including Martin's previously mentionened SCSI patch, and this used to work. I have attached the .config file.
I am not a C programmer, let alone a kernel dev, so please bear with me if this is nonsense, but: could the reason be that with your change, you have removed the declaration of get_cpu_cap from the cpu.h header file, while it is still being referenced in arch/x86/xen/enlighten_pv.c like so:
#include "../kernel/cpu/cpu.h" /* get_cpu_cap() */
Should I try to just add it back in, and see if that works? Or would you prefer to look more deeply at this first, and then send me a reworked patch?
Beste Grüße, Peter Schneider