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linux/arch/x86/include/asm/microcode.h
Borislav Petkov f9e14dbbd4 x86/cpu: Load microcode during restore_processor_state()
When resuming from system sleep state, restore_processor_state()
restores the boot CPU MSRs. These MSRs could be emulated by microcode.
If microcode is not loaded yet, writing to emulated MSRs leads to
unchecked MSR access error:

  ...
  PM: Calling lapic_suspend+0x0/0x210
  unchecked MSR access error: WRMSR to 0x10f (tried to write 0x0...0) at rIP: ... (native_write_msr)
  Call Trace:
    <TASK>
    ? restore_processor_state
    x86_acpi_suspend_lowlevel
    acpi_suspend_enter
    suspend_devices_and_enter
    pm_suspend.cold
    state_store
    kobj_attr_store
    sysfs_kf_write
    kernfs_fop_write_iter
    new_sync_write
    vfs_write
    ksys_write
    __x64_sys_write
    do_syscall_64
    entry_SYSCALL_64_after_hwframe
   RIP: 0033:0x7fda13c260a7

To ensure microcode emulated MSRs are available for restoration, load
the microcode on the boot CPU before restoring these MSRs.

  [ Pawan: write commit message and productize it. ]

Fixes: e2a1256b17 ("x86/speculation: Restore speculation related MSRs during S3 resume")
Reported-by: Kyle D. Pelton <kyle.d.pelton@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Tested-by: Kyle D. Pelton <kyle.d.pelton@intel.com>
Cc: stable@vger.kernel.org
Link: https://bugzilla.kernel.org/show_bug.cgi?id=215841
Link: https://lore.kernel.org/r/4350dfbf785cd482d3fafa72b2b49c83102df3ce.1650386317.git.pawan.kumar.gupta@linux.intel.com
2022-04-19 19:37:05 +02:00

142 lines
3.5 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_MICROCODE_H
#define _ASM_X86_MICROCODE_H
#include <asm/cpu.h>
#include <linux/earlycpio.h>
#include <linux/initrd.h>
struct ucode_patch {
struct list_head plist;
void *data; /* Intel uses only this one */
u32 patch_id;
u16 equiv_cpu;
};
extern struct list_head microcode_cache;
struct cpu_signature {
unsigned int sig;
unsigned int pf;
unsigned int rev;
};
struct device;
enum ucode_state {
UCODE_OK = 0,
UCODE_NEW,
UCODE_UPDATED,
UCODE_NFOUND,
UCODE_ERROR,
};
struct microcode_ops {
enum ucode_state (*request_microcode_user) (int cpu,
const void __user *buf, size_t size);
enum ucode_state (*request_microcode_fw) (int cpu, struct device *,
bool refresh_fw);
void (*microcode_fini_cpu) (int cpu);
/*
* The generic 'microcode_core' part guarantees that
* the callbacks below run on a target cpu when they
* are being called.
* See also the "Synchronization" section in microcode_core.c.
*/
enum ucode_state (*apply_microcode) (int cpu);
int (*collect_cpu_info) (int cpu, struct cpu_signature *csig);
};
struct ucode_cpu_info {
struct cpu_signature cpu_sig;
int valid;
void *mc;
};
extern struct ucode_cpu_info ucode_cpu_info[];
struct cpio_data find_microcode_in_initrd(const char *path, bool use_pa);
#ifdef CONFIG_MICROCODE_INTEL
extern struct microcode_ops * __init init_intel_microcode(void);
#else
static inline struct microcode_ops * __init init_intel_microcode(void)
{
return NULL;
}
#endif /* CONFIG_MICROCODE_INTEL */
#ifdef CONFIG_MICROCODE_AMD
extern struct microcode_ops * __init init_amd_microcode(void);
extern void __exit exit_amd_microcode(void);
#else
static inline struct microcode_ops * __init init_amd_microcode(void)
{
return NULL;
}
static inline void __exit exit_amd_microcode(void) {}
#endif
#define MAX_UCODE_COUNT 128
#define QCHAR(a, b, c, d) ((a) + ((b) << 8) + ((c) << 16) + ((d) << 24))
#define CPUID_INTEL1 QCHAR('G', 'e', 'n', 'u')
#define CPUID_INTEL2 QCHAR('i', 'n', 'e', 'I')
#define CPUID_INTEL3 QCHAR('n', 't', 'e', 'l')
#define CPUID_AMD1 QCHAR('A', 'u', 't', 'h')
#define CPUID_AMD2 QCHAR('e', 'n', 't', 'i')
#define CPUID_AMD3 QCHAR('c', 'A', 'M', 'D')
#define CPUID_IS(a, b, c, ebx, ecx, edx) \
(!((ebx ^ (a))|(edx ^ (b))|(ecx ^ (c))))
/*
* In early loading microcode phase on BSP, boot_cpu_data is not set up yet.
* x86_cpuid_vendor() gets vendor id for BSP.
*
* In 32 bit AP case, accessing boot_cpu_data needs linear address. To simplify
* coding, we still use x86_cpuid_vendor() to get vendor id for AP.
*
* x86_cpuid_vendor() gets vendor information directly from CPUID.
*/
static inline int x86_cpuid_vendor(void)
{
u32 eax = 0x00000000;
u32 ebx, ecx = 0, edx;
native_cpuid(&eax, &ebx, &ecx, &edx);
if (CPUID_IS(CPUID_INTEL1, CPUID_INTEL2, CPUID_INTEL3, ebx, ecx, edx))
return X86_VENDOR_INTEL;
if (CPUID_IS(CPUID_AMD1, CPUID_AMD2, CPUID_AMD3, ebx, ecx, edx))
return X86_VENDOR_AMD;
return X86_VENDOR_UNKNOWN;
}
static inline unsigned int x86_cpuid_family(void)
{
u32 eax = 0x00000001;
u32 ebx, ecx = 0, edx;
native_cpuid(&eax, &ebx, &ecx, &edx);
return x86_family(eax);
}
#ifdef CONFIG_MICROCODE
extern void __init load_ucode_bsp(void);
extern void load_ucode_ap(void);
void reload_early_microcode(void);
extern bool initrd_gone;
void microcode_bsp_resume(void);
#else
static inline void __init load_ucode_bsp(void) { }
static inline void load_ucode_ap(void) { }
static inline void reload_early_microcode(void) { }
static inline void microcode_bsp_resume(void) { }
#endif
#endif /* _ASM_X86_MICROCODE_H */