@@ -11582,24 +11582,7 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu)
"mov %%r13, %c[r13](%0) \n\t"
"mov %%r14, %c[r14](%0) \n\t"
"mov %%r15, %c[r15](%0) \n\t"
- /*
- * Clear host registers marked as clobbered to prevent
- * speculative use.
- */
- "xor %%r8d, %%r8d \n\t"
- "xor %%r9d, %%r9d \n\t"
- "xor %%r10d, %%r10d \n\t"
- "xor %%r11d, %%r11d \n\t"
- "xor %%r12d, %%r12d \n\t"
- "xor %%r13d, %%r13d \n\t"
- "xor %%r14d, %%r14d \n\t"
- "xor %%r15d, %%r15d \n\t"
#endif
-
- "xor %%eax, %%eax \n\t"
- "xor %%ebx, %%ebx \n\t"
- "xor %%esi, %%esi \n\t"
- "xor %%edi, %%edi \n\t"
"pop %%" _ASM_BP "; pop %%" _ASM_DX " \n\t"
".pushsection .rodata \n\t"
".global vmx_return \n\t"
@@ -11636,6 +11619,35 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu)
#endif
);
+ /*
+ * Explicitly clear (in addition to marking them as clobbered) all GPRs
+ * that have not been loaded with host state to prevent speculatively
+ * using the guest's values.
+ */
+ asm volatile (
+ "xor %%eax, %%eax \n\t"
+ "xor %%ebx, %%ebx \n\t"
+ "xor %%esi, %%esi \n\t"
+ "xor %%edi, %%edi \n\t"
+#ifdef CONFIG_X86_64
+ "xor %%r8d, %%r8d \n\t"
+ "xor %%r9d, %%r9d \n\t"
+ "xor %%r10d, %%r10d \n\t"
+ "xor %%r11d, %%r11d \n\t"
+ "xor %%r12d, %%r12d \n\t"
+ "xor %%r13d, %%r13d \n\t"
+ "xor %%r14d, %%r14d \n\t"
+ "xor %%r15d, %%r15d \n\t"
+#endif
+ ::: "cc"
+#ifdef CONFIG_X86_64
+ , "rax", "rbx", "rsi", "rdi"
+ , "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15"
+#else
+ , "eax", "ebx", "esi", "edi"
+#endif
+ );
+
/*
* We do not use IBRS in the kernel. If this vCPU has used the
* SPEC_CTRL MSR it may have left it on; save the value and