Adding upstream version 6.1.82.upstream/6.1.82

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 12 insertions, 8 deletions

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 98d732b94..5c1590855 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -407,7 +407,8 @@ static __always_inline void vmx_enable_fb_clear(struct vcpu_vmx *vmx)
 
 static void vmx_update_fb_clear_dis(struct kvm_vcpu *vcpu, struct vcpu_vmx *vmx)
 {
-	vmx->disable_fb_clear = vmx_fb_clear_ctrl_available;
+	vmx->disable_fb_clear = !cpu_feature_enabled(X86_FEATURE_CLEAR_CPU_BUF) &&
+		vmx_fb_clear_ctrl_available;
 
 	/*
 	 * If guest will not execute VERW, there is no need to set FB_CLEAR_DIS
@@ -2469,10 +2470,10 @@ static int kvm_cpu_vmxon(u64 vmxon_pointer)
 
 	cr4_set_bits(X86_CR4_VMXE);
 
-	asm_volatile_goto("1: vmxon %[vmxon_pointer]\n\t"
-			  _ASM_EXTABLE(1b, %l[fault])
-			  : : [vmxon_pointer] "m"(vmxon_pointer)
-			  : : fault);
+	asm goto("1: vmxon %[vmxon_pointer]\n\t"
+		  _ASM_EXTABLE(1b, %l[fault])
+		  : : [vmxon_pointer] "m"(vmxon_pointer)
+		  : : fault);
 	return 0;
 
 fault:
@@ -7120,11 +7121,14 @@ static noinstr void vmx_vcpu_enter_exit(struct kvm_vcpu *vcpu,
 {
 	guest_state_enter_irqoff();
 
-	/* L1D Flush includes CPU buffer clear to mitigate MDS */
+	/*
+	 * L1D Flush includes CPU buffer clear to mitigate MDS, but VERW
+	 * mitigation for MDS is done late in VMentry and is still
+	 * executed in spite of L1D Flush. This is because an extra VERW
+	 * should not matter much after the big hammer L1D Flush.
+	 */
 	if (static_branch_unlikely(&vmx_l1d_should_flush))
 		vmx_l1d_flush(vcpu);
-	else if (static_branch_unlikely(&mds_user_clear))
-		mds_clear_cpu_buffers();
 	else if (static_branch_unlikely(&mmio_stale_data_clear) &&
 		 kvm_arch_has_assigned_device(vcpu->kvm))
 		mds_clear_cpu_buffers();