KVM: VMX: Fix host userspace gsbase corruption

[firefly-linux-kernel-4.4.55.git] / arch / x86 / kvm / vmx.c

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index d00c64344ee60f07e23639b6ca71e9ea84c1f399..d9c4fb6f0ff37545f95c29c520c3c9dde17c06c5 100644 (file)
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -654,10 +654,7 @@ static void vmx_save_host_state(struct kvm_vcpu *vcpu)
 #endif
 
 #ifdef CONFIG_X86_64
-       if (is_long_mode(&vmx->vcpu))
-               save_msrs(vmx->host_msrs +
-                         vmx->msr_offset_kernel_gs_base, 1);
-
+       save_msrs(vmx->host_msrs + vmx->msr_offset_kernel_gs_base, 1);
 #endif
        load_msrs(vmx->guest_msrs, vmx->save_nmsrs);
        load_transition_efer(vmx);
@@ -672,17 +669,26 @@ static void __vmx_load_host_state(struct vcpu_vmx *vmx)
        vmx->host_state.loaded = 0;
        if (vmx->host_state.fs_reload_needed)
                loadsegment(fs, vmx->host_state.fs_sel);
+#ifdef CONFIG_X86_64
+       if (is_long_mode(&vmx->vcpu))
+               save_msrs(vmx->guest_msrs + vmx->msr_offset_kernel_gs_base, 1);
+#endif
        if (vmx->host_state.gs_ldt_reload_needed) {
                kvm_load_ldt(vmx->host_state.ldt_sel);
 #ifdef CONFIG_X86_64
                load_gs_index(vmx->host_state.gs_sel);
-               wrmsrl(MSR_KERNEL_GS_BASE, current->thread.gs);
 #else
                loadsegment(gs, vmx->host_state.gs_sel);
 #endif
        }
        reload_tss();
+#ifdef CONFIG_X86_64
+       save_msrs(vmx->guest_msrs, vmx->msr_offset_kernel_gs_base);
+       save_msrs(vmx->guest_msrs + vmx->msr_offset_kernel_gs_base + 1,
+                 vmx->save_nmsrs - vmx->msr_offset_kernel_gs_base - 1);
+#else
        save_msrs(vmx->guest_msrs, vmx->save_nmsrs);
+#endif
        load_msrs(vmx->host_msrs, vmx->save_nmsrs);
        reload_host_efer(vmx);
        load_gdt(&__get_cpu_var(host_gdt));