Revert "x86/kvm: Pad RSB on VM transition"

CVE-2017-5753 (revert embargoed)
CVE-2017-5715 (revert embargoed)

This reverts commit 5369368d3520addb2ffb2413cfa7e8f3efe2e31d.

Signed-off-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 8603a8145867503fb0a71f55fc0daf31f4fa828b..78ec3cda94291ab17902e6b219bf08ff7f0685c5 100644 (file)
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -125,109 +125,6 @@ static inline gfn_t gfn_to_index(gfn_t gfn, gfn_t base_gfn, int level)
 
 #define ASYNC_PF_PER_VCPU 64
 
-static inline void stuff_RSB(void)
-{
-        __asm__ __volatile__("  \n\
-       call .label1    \n\
-       pause     \n\
-.label1:        \n\
-       call .label2    \n\
-       pause     \n\
-.label2:        \n\
-       call .label3    \n\
-       pause     \n\
-.label3:        \n\
-       call .label4    \n\
-       pause     \n\
-.label4:        \n\
-       call .label5    \n\
-       pause     \n\
-.label5:        \n\
-       call .label6    \n\
-       pause     \n\
-.label6:        \n\
-       call .label7    \n\
-       pause     \n\
-.label7:        \n\
-       call .label8    \n\
-       pause     \n\
-.label8:        \n\
-       call .label9    \n\
-       pause     \n\
-.label9:        \n\
-       call .label10   \n\
-       pause     \n\
-.label10:       \n\
-       call .label11   \n\
-       pause     \n\
-.label11:       \n\
-       call .label12   \n\
-       pause     \n\
-.label12:       \n\
-       call .label13   \n\
-       pause     \n\
-.label13:       \n\
-       call .label14   \n\
-       pause     \n\
-.label14:       \n\
-       call .label15   \n\
-       pause     \n\
-.label15:       \n\
-       call .label16   \n\
-       pause     \n\
-.label16:      \n\
-       call .label17   \n\
-       pause   \n\
-.label17:      \n\
-       call .label18   \n\
-       pause   \n\
-.label18:      \n\
-       call .label19   \n\
-       pause   \n\
-.label19:      \n\
-       call .label20   \n\
-       pause   \n\
-.label20:      \n\
-       call .label21   \n\
-       pause   \n\
-.label21:      \n\
-       call .label22   \n\
-       pause   \n\
-.label22:      \n\
-       call .label23   \n\
-       pause   \n\
-.label23:      \n\
-       call .label24   \n\
-       pause   \n\
-.label24:      \n\
-       call .label25   \n\
-       pause   \n\
-.label25:      \n\
-       call .label26   \n\
-       pause   \n\
-.label26:      \n\
-       call .label27   \n\
-       pause   \n\
-.label27:      \n\
-       call .label28   \n\
-       pause   \n\
-.label28:      \n\
-       call .label29   \n\
-       pause   \n\
-.label29:      \n\
-       call .label30   \n\
-       pause   \n\
-.label30:      \n\
-       call .label31   \n\
-       pause   \n\
-.label31:      \n\
-       call .label32   \n\
-       pause   \n\
-.label32: \n\
-       add $(32*8), %%rsp      \n\
-": : :"memory");
-}
-
 enum kvm_reg {
        VCPU_REGS_RAX = 0,
        VCPU_REGS_RCX = 1,

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 0315e04da49b751ea0e0681970a1a09a02e3b52d..ec4c9009ed9097993c3f1aa28e0a66af410a4dd5 100644 (file)
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -9154,8 +9154,6 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu)
 #endif
              );
 
-       stuff_RSB();
-
        /* MSR_IA32_DEBUGCTLMSR is zeroed on vmexit. Restore it if needed */
        if (debugctlmsr)
                update_debugctlmsr(debugctlmsr);