diff options
| -rw-r--r-- | Documentation/admin-guide/hw-vuln/processor_mmio_stale_data.rst | 4 | ||||
| -rw-r--r-- | Documentation/arch/x86/mds.rst | 8 | ||||
| -rw-r--r-- | arch/x86/entry/entry.S | 8 | ||||
| -rw-r--r-- | arch/x86/include/asm/irqflags.h | 4 | ||||
| -rw-r--r-- | arch/x86/include/asm/mwait.h | 5 | ||||
| -rw-r--r-- | arch/x86/include/asm/nospec-branch.h | 29 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/bugs.c | 12 | ||||
| -rw-r--r-- | arch/x86/kvm/vmx/vmx.c | 2 |
8 files changed, 36 insertions, 36 deletions
diff --git a/Documentation/admin-guide/hw-vuln/processor_mmio_stale_data.rst b/Documentation/admin-guide/hw-vuln/processor_mmio_stale_data.rst index 1302fd1b55e8..6dba18dbb9ab 100644 --- a/Documentation/admin-guide/hw-vuln/processor_mmio_stale_data.rst +++ b/Documentation/admin-guide/hw-vuln/processor_mmio_stale_data.rst @@ -157,9 +157,7 @@ This is achieved by using the otherwise unused and obsolete VERW instruction in combination with a microcode update. The microcode clears the affected CPU buffers when the VERW instruction is executed. -Kernel reuses the MDS function to invoke the buffer clearing: - - mds_clear_cpu_buffers() +Kernel does the buffer clearing with x86_clear_cpu_buffers(). On MDS affected CPUs, the kernel already invokes CPU buffer clear on kernel/userspace, hypervisor/guest and C-state (idle) transitions. No diff --git a/Documentation/arch/x86/mds.rst b/Documentation/arch/x86/mds.rst index 5a2e6c0ef04a..3518671e1a85 100644 --- a/Documentation/arch/x86/mds.rst +++ b/Documentation/arch/x86/mds.rst @@ -93,7 +93,7 @@ enters a C-state. The kernel provides a function to invoke the buffer clearing: - mds_clear_cpu_buffers() + x86_clear_cpu_buffers() Also macro CLEAR_CPU_BUFFERS can be used in ASM late in exit-to-user path. Other than CFLAGS.ZF, this macro doesn't clobber any registers. @@ -185,9 +185,9 @@ Mitigation points idle clearing would be a window dressing exercise and is therefore not activated. - The invocation is controlled by the static key mds_idle_clear which is - switched depending on the chosen mitigation mode and the SMT state of - the system. + The invocation is controlled by the static key cpu_buf_idle_clear which is + switched depending on the chosen mitigation mode and the SMT state of the + system. The buffer clear is only invoked before entering the C-State to prevent that stale data from the idling CPU from spilling to the Hyper-Thread diff --git a/arch/x86/entry/entry.S b/arch/x86/entry/entry.S index 5b96249734ad..b0d5ab951231 100644 --- a/arch/x86/entry/entry.S +++ b/arch/x86/entry/entry.S @@ -33,20 +33,20 @@ EXPORT_SYMBOL_GPL(entry_ibpb); /* * Define the VERW operand that is disguised as entry code so that - * it can be referenced with KPTI enabled. This ensure VERW can be + * it can be referenced with KPTI enabled. This ensures VERW can be * used late in exit-to-user path after page tables are switched. */ .pushsection .entry.text, "ax" .align L1_CACHE_BYTES, 0xcc -SYM_CODE_START_NOALIGN(mds_verw_sel) +SYM_CODE_START_NOALIGN(x86_verw_sel) UNWIND_HINT_UNDEFINED ANNOTATE_NOENDBR .word __KERNEL_DS .align L1_CACHE_BYTES, 0xcc -SYM_CODE_END(mds_verw_sel); +SYM_CODE_END(x86_verw_sel); /* For KVM */ -EXPORT_SYMBOL_GPL(mds_verw_sel); +EXPORT_SYMBOL_GPL(x86_verw_sel); .popsection diff --git a/arch/x86/include/asm/irqflags.h b/arch/x86/include/asm/irqflags.h index 1c2db11a2c3c..2b75fe80fcb2 100644 --- a/arch/x86/include/asm/irqflags.h +++ b/arch/x86/include/asm/irqflags.h @@ -44,13 +44,13 @@ static __always_inline void native_irq_enable(void) static __always_inline void native_safe_halt(void) { - mds_idle_clear_cpu_buffers(); + x86_idle_clear_cpu_buffers(); asm volatile("sti; hlt": : :"memory"); } static __always_inline void native_halt(void) { - mds_idle_clear_cpu_buffers(); + x86_idle_clear_cpu_buffers(); asm volatile("hlt": : :"memory"); } diff --git a/arch/x86/include/asm/mwait.h b/arch/x86/include/asm/mwait.h index 3e4e85f71a6a..26755a3bbd55 100644 --- a/arch/x86/include/asm/mwait.h +++ b/arch/x86/include/asm/mwait.h @@ -44,7 +44,7 @@ static __always_inline void __monitorx(const void *eax, unsigned long ecx, static __always_inline void __mwait(unsigned long eax, unsigned long ecx) { - mds_idle_clear_cpu_buffers(); + x86_idle_clear_cpu_buffers(); /* "mwait %eax, %ecx;" */ asm volatile(".byte 0x0f, 0x01, 0xc9;" @@ -98,7 +98,8 @@ static __always_inline void __mwaitx(unsigned long eax, unsigned long ebx, */ static __always_inline void __sti_mwait(unsigned long eax, unsigned long ecx) { - mds_idle_clear_cpu_buffers(); + x86_idle_clear_cpu_buffers(); + /* "mwait %eax, %ecx;" */ asm volatile("sti; .byte 0x0f, 0x01, 0xc9;" :: "a" (eax), "c" (ecx)); diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h index f7bb0016d7d9..c953844dd9bd 100644 --- a/arch/x86/include/asm/nospec-branch.h +++ b/arch/x86/include/asm/nospec-branch.h @@ -315,22 +315,22 @@ .endm /* - * Macro to execute VERW instruction that mitigate transient data sampling - * attacks such as MDS. On affected systems a microcode update overloaded VERW - * instruction to also clear the CPU buffers. VERW clobbers CFLAGS.ZF. - * + * Macro to execute VERW insns that mitigate transient data sampling + * attacks such as MDS or TSA. On affected systems a microcode update + * overloaded VERW insns to also clear the CPU buffers. VERW clobbers + * CFLAGS.ZF. * Note: Only the memory operand variant of VERW clears the CPU buffers. */ .macro CLEAR_CPU_BUFFERS #ifdef CONFIG_X86_64 - ALTERNATIVE "", "verw mds_verw_sel(%rip)", X86_FEATURE_CLEAR_CPU_BUF + ALTERNATIVE "", "verw x86_verw_sel(%rip)", X86_FEATURE_CLEAR_CPU_BUF #else /* * In 32bit mode, the memory operand must be a %cs reference. The data * segments may not be usable (vm86 mode), and the stack segment may not * be flat (ESPFIX32). */ - ALTERNATIVE "", "verw %cs:mds_verw_sel", X86_FEATURE_CLEAR_CPU_BUF + ALTERNATIVE "", "verw %cs:x86_verw_sel", X86_FEATURE_CLEAR_CPU_BUF #endif .endm @@ -582,24 +582,24 @@ DECLARE_STATIC_KEY_FALSE(switch_to_cond_stibp); DECLARE_STATIC_KEY_FALSE(switch_mm_cond_ibpb); DECLARE_STATIC_KEY_FALSE(switch_mm_always_ibpb); -DECLARE_STATIC_KEY_FALSE(mds_idle_clear); +DECLARE_STATIC_KEY_FALSE(cpu_buf_idle_clear); DECLARE_STATIC_KEY_FALSE(switch_mm_cond_l1d_flush); DECLARE_STATIC_KEY_FALSE(mmio_stale_data_clear); -extern u16 mds_verw_sel; +extern u16 x86_verw_sel; #include <asm/segment.h> /** - * mds_clear_cpu_buffers - Mitigation for MDS and TAA vulnerability + * x86_clear_cpu_buffers - Buffer clearing support for different x86 CPU vulns * * This uses the otherwise unused and obsolete VERW instruction in * combination with microcode which triggers a CPU buffer flush when the * instruction is executed. */ -static __always_inline void mds_clear_cpu_buffers(void) +static __always_inline void x86_clear_cpu_buffers(void) { static const u16 ds = __KERNEL_DS; @@ -616,14 +616,15 @@ static __always_inline void mds_clear_cpu_buffers(void) } /** - * mds_idle_clear_cpu_buffers - Mitigation for MDS vulnerability + * x86_idle_clear_cpu_buffers - Buffer clearing support in idle for the MDS + * vulnerability * * Clear CPU buffers if the corresponding static key is enabled */ -static __always_inline void mds_idle_clear_cpu_buffers(void) +static __always_inline void x86_idle_clear_cpu_buffers(void) { - if (static_branch_likely(&mds_idle_clear)) - mds_clear_cpu_buffers(); + if (static_branch_likely(&cpu_buf_idle_clear)) + x86_clear_cpu_buffers(); } #endif /* __ASSEMBLY__ */ diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index 0e9ab0b9a494..e021dd4ad3fe 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -122,9 +122,9 @@ DEFINE_STATIC_KEY_FALSE(switch_mm_cond_ibpb); /* Control unconditional IBPB in switch_mm() */ DEFINE_STATIC_KEY_FALSE(switch_mm_always_ibpb); -/* Control MDS CPU buffer clear before idling (halt, mwait) */ -DEFINE_STATIC_KEY_FALSE(mds_idle_clear); -EXPORT_SYMBOL_GPL(mds_idle_clear); +/* Control CPU buffer clear before idling (halt, mwait) */ +DEFINE_STATIC_KEY_FALSE(cpu_buf_idle_clear); +EXPORT_SYMBOL_GPL(cpu_buf_idle_clear); /* * Controls whether l1d flush based mitigations are enabled, @@ -448,7 +448,7 @@ static void __init mmio_select_mitigation(void) * is required irrespective of SMT state. */ if (!(x86_arch_cap_msr & ARCH_CAP_FBSDP_NO)) - static_branch_enable(&mds_idle_clear); + static_branch_enable(&cpu_buf_idle_clear); /* * Check if the system has the right microcode. @@ -2092,10 +2092,10 @@ static void update_mds_branch_idle(void) return; if (sched_smt_active()) { - static_branch_enable(&mds_idle_clear); + static_branch_enable(&cpu_buf_idle_clear); } else if (mmio_mitigation == MMIO_MITIGATION_OFF || (x86_arch_cap_msr & ARCH_CAP_FBSDP_NO)) { - static_branch_disable(&mds_idle_clear); + static_branch_disable(&cpu_buf_idle_clear); } } diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index bcbedddacc48..029fbf3791f1 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -7313,7 +7313,7 @@ static noinstr void vmx_vcpu_enter_exit(struct kvm_vcpu *vcpu, vmx_l1d_flush(vcpu); else if (static_branch_unlikely(&mmio_stale_data_clear) && kvm_arch_has_assigned_device(vcpu->kvm)) - mds_clear_cpu_buffers(); + x86_clear_cpu_buffers(); vmx_disable_fb_clear(vmx); |