diff --git a/arch/x86/include/asm/tdx.h b/arch/x86/include/asm/tdx.h index a149740b24e8..bf83a974a0d5 100644 --- a/arch/x86/include/asm/tdx.h +++ b/arch/x86/include/asm/tdx.h @@ -226,11 +226,5 @@ static inline const char *tdx_dump_mce_info(struct mce *m) { return NULL; } static inline const struct tdx_sys_info *tdx_get_sysinfo(void) { return NULL; } #endif /* CONFIG_INTEL_TDX_HOST */ -#ifdef CONFIG_KEXEC_CORE -void tdx_cpu_flush_cache_for_kexec(void); -#else -static inline void tdx_cpu_flush_cache_for_kexec(void) { } -#endif - #endif /* !__ASSEMBLER__ */ #endif /* _ASM_X86_TDX_H */ diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c index 04ce321ebdf3..ed12805bbb44 100644 --- a/arch/x86/kvm/vmx/tdx.c +++ b/arch/x86/kvm/vmx/tdx.c @@ -440,16 +440,6 @@ void tdx_disable_virtualization_cpu(void) tdx_flush_vp(&arg); } local_irq_restore(flags); - - /* - * Flush cache now if kexec is possible: this is necessary to avoid - * having dirty private memory cachelines when the new kernel boots, - * but WBINVD is a relatively expensive operation and doing it during - * kexec can exacerbate races in native_stop_other_cpus(). Do it - * now, since this is a safe moment and there is going to be no more - * TDX activity on this CPU from this point on. - */ - tdx_cpu_flush_cache_for_kexec(); } #define TDX_SEAMCALL_RETRIES 10000 diff --git a/arch/x86/virt/vmx/tdx/tdx.c b/arch/x86/virt/vmx/tdx/tdx.c index cb9b3210ab71..1b2d854ba664 100644 --- a/arch/x86/virt/vmx/tdx/tdx.c +++ b/arch/x86/virt/vmx/tdx/tdx.c @@ -184,6 +184,17 @@ static int tdx_online_cpu(unsigned int cpu) return ret; } +static void tdx_cpu_flush_cache(void) +{ + lockdep_assert_preemption_disabled(); + + if (!this_cpu_read(cache_state_incoherent)) + return; + + wbinvd(); + this_cpu_write(cache_state_incoherent, false); +} + static int tdx_offline_cpu(unsigned int cpu) { int i; @@ -220,12 +231,28 @@ static int tdx_offline_cpu(unsigned int cpu) return -EBUSY; done: + /* + * Flush cache on the CPU going offline to ensure no dirty + * cachelines of TDX private memory remain. This may be + * redundant with WBINVD done elsewhere during CPU offline + * (e.g. hlt_play_dead()), but do it explicitly for safety. + */ + tdx_cpu_flush_cache(); x86_virt_put_ref(X86_FEATURE_VMX); return 0; } static void tdx_shutdown_cpu(void *ign) { + /* + * Flush cache in preparation for kexec - this is necessary to avoid + * having dirty private memory cachelines when the new kernel boots, + * but WBINVD is a relatively expensive operation and doing it during + * kexec can exacerbate races in native_stop_other_cpus(). Do it + * now, since this is a safe moment and there is going to be no more + * TDX activity on this CPU from this point on. + */ + tdx_cpu_flush_cache(); x86_virt_put_ref(X86_FEATURE_VMX); } @@ -1920,22 +1947,3 @@ u64 tdh_phymem_page_wbinvd_hkid(u64 hkid, struct page *page) return seamcall(TDH_PHYMEM_PAGE_WBINVD, &args); } EXPORT_SYMBOL_FOR_KVM(tdh_phymem_page_wbinvd_hkid); - -#ifdef CONFIG_KEXEC_CORE -void tdx_cpu_flush_cache_for_kexec(void) -{ - lockdep_assert_preemption_disabled(); - - if (!this_cpu_read(cache_state_incoherent)) - return; - - /* - * Private memory cachelines need to be clean at the time of - * kexec. Write them back now, as the caller promises that - * there should be no more SEAMCALLs on this CPU. - */ - wbinvd(); - this_cpu_write(cache_state_incoherent, false); -} -EXPORT_SYMBOL_FOR_KVM(tdx_cpu_flush_cache_for_kexec); -#endif