KVM: x86: Add X86EMUL_F_INVLPG and pass it in em_invlpg()

Add an emulation flag X86EMUL_F_INVLPG, which is used to identify an
instruction that does TLB invalidation without true memory access.

Only invlpg & invlpga implemented in emulator belong to this kind.
invlpga doesn't need additional information for emulation. Just pass
the flag to em_invlpg().

Linear Address Masking (LAM) and Linear Address Space Separation (LASS)
don't apply to addresses that are inputs to TLB invalidation. The flag
will be consumed to support LAM/LASS virtualization.

Signed-off-by: Binbin Wu <binbin.wu@linux.intel.com>
Tested-by: Xuelian Guo <xuelian.guo@intel.com>
Link: https://lore.kernel.org/r/20230913124227.12574-5-binbin.wu@linux.intel.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

Author: Binbin Wu

arch/x86/kvm/emulate.c

@@ -3440,8 +3440,10 @@ static int em_invlpg(struct x86_emulate_ctxt *ctxt)
 {
 	int rc;
 	ulong linear;
+	unsigned int max_size;
 
-	rc = linearize(ctxt, ctxt->src.addr.mem, 1, false, &linear);
+	rc = __linearize(ctxt, ctxt->src.addr.mem, &max_size, 1, ctxt->mode,
+			 &linear, X86EMUL_F_INVLPG);
 	if (rc == X86EMUL_CONTINUE)
 		ctxt->ops->invlpg(ctxt, linear);
 	/* Disable writeback. */

arch/x86/kvm/kvm_emulate.h

@@ -92,6 +92,7 @@ struct x86_instruction_info {
 #define X86EMUL_F_WRITE			BIT(0)
 #define X86EMUL_F_FETCH			BIT(1)
 #define X86EMUL_F_IMPLICIT		BIT(2)
+#define X86EMUL_F_INVLPG		BIT(3)
 
 struct x86_emulate_ops {
 	void (*vm_bugged)(struct x86_emulate_ctxt *ctxt);