kvm: nVMX: Update MSR load counts on a VMCS switch

Commit 83bafef1a131d1b8743d63658a180948bc880a74 upstream

When L0 establishes (or removes) an MSR entry in the VM-entry or VM-exit
MSR load lists, the change should affect the dormant VMCS as well as the
current VMCS. Moreover, the vmcs02 MSR-load addresses should be
initialized.

[ dwmw2: Pulled in to 4.9 backports for L1TF ]

Signed-off-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 1918a12..1b24d15 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -10221,6 +10221,15 @@
 	vmx_set_constant_host_state(vmx);
 
 	/*
+	 * Set the MSR load/store lists to match L0's settings.
+	 */
+	vmcs_write32(VM_EXIT_MSR_STORE_COUNT, 0);
+	vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, vmx->msr_autoload.nr);
+	vmcs_write64(VM_EXIT_MSR_LOAD_ADDR, __pa(vmx->msr_autoload.host));
+	vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, vmx->msr_autoload.nr);
+	vmcs_write64(VM_ENTRY_MSR_LOAD_ADDR, __pa(vmx->msr_autoload.guest));
+
+	/*
 	 * HOST_RSP is normally set correctly in vmx_vcpu_run() just before
 	 * entry, but only if the current (host) sp changed from the value
 	 * we wrote last (vmx->host_rsp). This cache is no longer relevant
@@ -11067,6 +11076,8 @@
 	load_vmcs12_host_state(vcpu, vmcs12);
 
 	/* Update any VMCS fields that might have changed while L2 ran */
+	vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, vmx->msr_autoload.nr);
+	vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, vmx->msr_autoload.nr);
 	vmcs_write64(TSC_OFFSET, vcpu->arch.tsc_offset);
 	if (vmx->hv_deadline_tsc == -1)
 		vmcs_clear_bits(PIN_BASED_VM_EXEC_CONTROL,