On 25/03/21 11:29, Borislav Petkov wrote:
diff --git a/arch/x86/include/asm/tlbflush.h b/arch/x86/include/asm/tlbflush.h
index f5ca15622dc9..2bfa4deb8cae 100644
--- a/arch/x86/include/asm/tlbflush.h
+++ b/arch/x86/include/asm/tlbflush.h
@@ -245,12 +245,15 @@ static inline void __native_flush_tlb_single(unsigned long addr)
* ASID. But, userspace flushes are probably much more
* important performance-wise.
*
- * Make sure to do only a single invpcid when KAISER is
- * disabled and we have only a single ASID.
+ * In the KAISER disabled case, do an INVLPG to make sure
+ * the mapping is flushed in case it is a global one.
*/
- if (kaiser_enabled)
+ if (kaiser_enabled) {
invpcid_flush_one(X86_CR3_PCID_ASID_USER, addr);
- invpcid_flush_one(X86_CR3_PCID_ASID_KERN, addr);
+ invpcid_flush_one(X86_CR3_PCID_ASID_KERN, addr);
+ } else {
+ asm volatile("invlpg (%0)" ::"r" (addr) : "memory");
+ }
}
static inline void __flush_tlb_all(void)
Reviewed-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>