x86/speculation: Add virtualized speculative store bypass disable support

[mirror_ubuntu-artful-kernel.git] / arch / x86 / kernel / process.c

diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 90cfce52e1e063e342202cdab1fcf5925ddc1ff6..4d8fbdf8935fec02434e0eab145631c72c64e9e3 100644 (file)
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -388,6 +388,15 @@ static __always_inline void amd_set_core_ssb_state(unsigned long tifn)
 }
 #endif
 
+static __always_inline void amd_set_ssb_virt_state(unsigned long tifn)
+{
+       /*
+        * SSBD has the same definition in SPEC_CTRL and VIRT_SPEC_CTRL,
+        * so ssbd_tif_to_spec_ctrl() just works.
+        */
+       wrmsrl(MSR_AMD64_VIRT_SPEC_CTRL, ssbd_tif_to_spec_ctrl(tifn));
+}
+
 static __always_inline void intel_set_ssb_state(unsigned long tifn)
 {
        u64 msr = x86_spec_ctrl_base | ssbd_tif_to_spec_ctrl(tifn);
@@ -397,7 +406,9 @@ static __always_inline void intel_set_ssb_state(unsigned long tifn)
 
 static __always_inline void __speculative_store_bypass_update(unsigned long tifn)
 {
-       if (static_cpu_has(X86_FEATURE_LS_CFG_SSBD))
+       if (static_cpu_has(X86_FEATURE_VIRT_SSBD))
+               amd_set_ssb_virt_state(tifn);
+       else if (static_cpu_has(X86_FEATURE_LS_CFG_SSBD))
                amd_set_core_ssb_state(tifn);
        else
                intel_set_ssb_state(tifn);