KVM: x86: Enable Intel MPX for guest

From 44c2abca2c2eadc6f2f752b66de4acc8131880c4 Mon Sep 17 00:00:00 2001
From: Liu Jinsong <jinsong.liu@intel.com>
Date: Mon, 24 Feb 2014 18:12:31 +0800
Subject: [PATCH v5 3/3] KVM: x86: Enable Intel MPX for guest

This patch enable Intel MPX feature to guest.
Signed-off-by: Xudong Hao <xudong.hao@intel.com>
Signed-off-by: Liu Jinsong <jinsong.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/cpuid.c

@@ -256,6 +256,8 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
 #endif
 	unsigned f_rdtscp = kvm_x86_ops->rdtscp_supported() ? F(RDTSCP) : 0;
 	unsigned f_invpcid = kvm_x86_ops->invpcid_supported() ? F(INVPCID) : 0;
+	unsigned f_mpx = kvm_x86_ops->mpx_supported ?
+			 (kvm_x86_ops->mpx_supported() ? F(MPX) : 0) : 0;
 
 	/* cpuid 1.edx */
 	const u32 kvm_supported_word0_x86_features =
@@ -303,7 +305,7 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
 	/* cpuid 7.0.ebx */
 	const u32 kvm_supported_word9_x86_features =
 		F(FSGSBASE) | F(BMI1) | F(HLE) | F(AVX2) | F(SMEP) |
-		F(BMI2) | F(ERMS) | f_invpcid | F(RTM) | F(RDSEED) |
+		F(BMI2) | F(ERMS) | f_invpcid | F(RTM) | f_mpx | F(RDSEED) |
 		F(ADX);
 
 	/* all calls to cpuid_count() should be made on the same cpu */

arch/x86/kvm/x86.c

@@ -616,6 +616,9 @@ int __kvm_set_xcr(struct kvm_vcpu *vcpu, u32 index, u64 xcr)
 	if (xcr0 & ~valid_bits)
 		return 1;
 
+	if ((!(xcr0 & XSTATE_BNDREGS)) != (!(xcr0 & XSTATE_BNDCSR)))
+		return 1;
+
 	kvm_put_guest_xcr0(vcpu);
 	vcpu->arch.xcr0 = xcr0;
 

arch/x86/kvm/x86.h

@@ -122,7 +122,8 @@ int kvm_write_guest_virt_system(struct x86_emulate_ctxt *ctxt,
 	gva_t addr, void *val, unsigned int bytes,
 	struct x86_exception *exception);
 
-#define KVM_SUPPORTED_XCR0	(XSTATE_FP | XSTATE_SSE | XSTATE_YMM)
+#define KVM_SUPPORTED_XCR0     (XSTATE_FP | XSTATE_SSE | XSTATE_YMM \
+				| XSTATE_BNDREGS | XSTATE_BNDCSR)
 extern u64 host_xcr0;
 
 extern unsigned int min_timer_period_us;