diff options
| -rw-r--r-- | arch/x86/include/asm/tlbflush.h | 29 |
1 files changed, 18 insertions, 11 deletions
diff --git a/arch/x86/include/asm/tlbflush.h b/arch/x86/include/asm/tlbflush.h index f88ccd3ae466..8b27daff7a7f 100644 --- a/arch/x86/include/asm/tlbflush.h +++ b/arch/x86/include/asm/tlbflush.h @@ -85,20 +85,26 @@ static inline u64 inc_mm_tlb_gen(struct mm_struct *mm) */ #define MAX_ASID_AVAILABLE ((1 << CR3_AVAIL_ASID_BITS) - 2) -/* - * If PCID is on, ASID-aware code paths put the ASID+1 into the PCID bits. - * This serves two purposes. It prevents a nasty situation in which - * PCID-unaware code saves CR3, loads some other value (with PCID == 0), - * and then restores CR3, thus corrupting the TLB for ASID 0 if the saved - * ASID was nonzero. It also means that any bugs involving loading a - * PCID-enabled CR3 with CR4.PCIDE off will trigger deterministically. - */ +static inline u16 kern_pcid(u16 asid) +{ + VM_WARN_ON_ONCE(asid > MAX_ASID_AVAILABLE); + /* + * If PCID is on, ASID-aware code paths put the ASID+1 into the + * PCID bits. This serves two purposes. It prevents a nasty + * situation in which PCID-unaware code saves CR3, loads some other + * value (with PCID == 0), and then restores CR3, thus corrupting + * the TLB for ASID 0 if the saved ASID was nonzero. It also means + * that any bugs involving loading a PCID-enabled CR3 with + * CR4.PCIDE off will trigger deterministically. + */ + return asid + 1; +} + struct pgd_t; static inline unsigned long build_cr3(pgd_t *pgd, u16 asid) { if (static_cpu_has(X86_FEATURE_PCID)) { - VM_WARN_ON_ONCE(asid > MAX_ASID_AVAILABLE); - return __sme_pa(pgd) | (asid + 1); + return __sme_pa(pgd) | kern_pcid(asid); } else { VM_WARN_ON_ONCE(asid != 0); return __sme_pa(pgd); @@ -108,7 +114,8 @@ static inline unsigned long build_cr3(pgd_t *pgd, u16 asid) static inline unsigned long build_cr3_noflush(pgd_t *pgd, u16 asid) { VM_WARN_ON_ONCE(asid > MAX_ASID_AVAILABLE); - return __sme_pa(pgd) | (asid + 1) | CR3_NOFLUSH; + VM_WARN_ON_ONCE(!this_cpu_has(X86_FEATURE_PCID)); + return __sme_pa(pgd) | kern_pcid(asid) | CR3_NOFLUSH; } #ifdef CONFIG_PARAVIRT |