[Qemu-devel] [PATCH v5 3/3] KVM: x86: Enable Intel MPX for guest

[Liu, Jinsong]

>From 44c2abca2c2eadc6f2f752b66de4acc8131880c4 Mon Sep 17 00:00:00 2001
From: Liu Jinsong <jinsong....@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....@intel.com>
Signed-off-by: Liu Jinsong <jinsong....@intel.com>
---
 arch/x86/kvm/cpuid.c |    4 +++-
 arch/x86/kvm/x86.c   |    6 ++++++
 arch/x86/kvm/x86.h   |    3 ++-
 3 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index b241325..ddc8a7e 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/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 */
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 89e4e27..3570e71 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -599,6 +599,9 @@ int __kvm_set_xcr(struct kvm_vcpu *vcpu, u32 index, u64 xcr)
        u64 old_xcr0 = vcpu->arch.xcr0;
        u64 valid_bits;
 
+       if (!kvm_x86_ops->mpx_supported || !kvm_x86_ops->mpx_supported())
+               xcr0 &= ~(XSTATE_BNDREGS | XSTATE_BNDCSR);
+
        /* Only support XCR_XFEATURE_ENABLED_MASK(xcr0) now  */
        if (index != XCR_XFEATURE_ENABLED_MASK)
                return 1;
@@ -616,6 +619,9 @@ 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;
 
diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index 8da5823..392ecbf 100644
--- a/arch/x86/kvm/x86.h
+++ b/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;
-- 
1.7.1