[PATCH V3 3/6] x86/xsaves: enable xsaves/xrstors for hvm guest

[Shuai Ruan <shuai.ruan@linux.intel.com>]

This patch enables xsaves for hvm guest, includes:
1.handle xsaves vmcs init and vmexit.
2.add logic to write/read the XSS msr.

Signed-off-by: Shuai Ruan <shuai.ruan@linux.intel.com>
---
 xen/arch/x86/hvm/hvm.c             | 44 ++++++++++++++++++++++++++++++++++++++
 xen/arch/x86/hvm/vmx/vmcs.c        |  7 +++++-
 xen/arch/x86/hvm/vmx/vmx.c         | 18 ++++++++++++++++
 xen/arch/x86/xstate.c              |  4 ++--
 xen/include/asm-x86/hvm/vmx/vmcs.h |  5 +++++
 xen/include/asm-x86/hvm/vmx/vmx.h  |  2 ++
 xen/include/asm-x86/xstate.h       |  2 +-
 7 files changed, 78 insertions(+), 4 deletions(-)

diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index c07e3ef..e5cf761 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -4370,6 +4370,10 @@ void hvm_hypervisor_cpuid_leaf(uint32_t sub_idx,
     }
 }
 
+#define XSAVEOPT	(1 << 0)
+#define XSAVEC		(1 << 1)
+#define XGETBV1	(1 << 2)
+#define XSAVES		(1 << 3)
 void hvm_cpuid(unsigned int input, unsigned int *eax, unsigned int *ebx,
                                    unsigned int *ecx, unsigned int *edx)
 {
@@ -4456,6 +4460,34 @@ void hvm_cpuid(unsigned int input, unsigned int *eax, unsigned int *ebx,
                     *ebx = _eax + _ebx;
             }
         }
+        if ( count == 1 )
+        {
+            if ( cpu_has_xsaves )
+            {
+                *ebx = XSTATE_AREA_MIN_SIZE;
+                if ( v->arch.xcr0 | v->arch.msr_ia32_xss )
+                    for ( sub_leaf = 2; sub_leaf < 63; sub_leaf++ )
+                    {
+                        if ( !((v->arch.xcr0 | v->arch.msr_ia32_xss)
+			   & (1ULL << sub_leaf)) )
+                            continue;
+                        domain_cpuid(d, input, sub_leaf, &_eax, &_ebx, &_ecx,
+                                     &_edx);
+                        *ebx =  *ebx + _eax;
+                    }
+            }
+            else
+            {
+                *eax &= ~XSAVES;
+                *ebx = *ecx = *edx = 0;
+            }
+            if ( !cpu_has_xgetbv1 )
+                *eax &= ~XGETBV1;
+            if ( !cpu_has_xsavec )
+                *eax &= ~XSAVEC;
+            if ( !cpu_has_xsaveopt )
+                *eax &= ~XSAVEOPT;
+        }
         break;
 
     case 0x80000001:
@@ -4555,6 +4587,12 @@ int hvm_msr_read_intercept(unsigned int msr, uint64_t *msr_content)
         *msr_content = v->arch.hvm_vcpu.guest_efer;
         break;
 
+    case MSR_IA32_XSS:
+        if ( !cpu_has_vmx_xsaves )
+            goto gp_fault;
+        *msr_content = v->arch.msr_ia32_xss;
+        break;
+
     case MSR_IA32_TSC:
         *msr_content = _hvm_rdtsc_intercept();
         break;
@@ -4687,6 +4725,12 @@ int hvm_msr_write_intercept(unsigned int msr, uint64_t msr_content,
            return X86EMUL_EXCEPTION;
         break;
 
+    case MSR_IA32_XSS:
+        if ( !cpu_has_vmx_xsaves )
+            goto gp_fault;
+        v->arch.msr_ia32_xss = msr_content;
+        break;
+
     case MSR_IA32_TSC:
         hvm_set_guest_tsc(v, msr_content);
         break;
diff --git a/xen/arch/x86/hvm/vmx/vmcs.c b/xen/arch/x86/hvm/vmx/vmcs.c
index 4c5ceb5..8e61e3f 100644
--- a/xen/arch/x86/hvm/vmx/vmcs.c
+++ b/xen/arch/x86/hvm/vmx/vmcs.c
@@ -230,7 +230,8 @@ static int vmx_init_vmcs_config(void)
                SECONDARY_EXEC_ENABLE_EPT |
                SECONDARY_EXEC_ENABLE_RDTSCP |
                SECONDARY_EXEC_PAUSE_LOOP_EXITING |
-               SECONDARY_EXEC_ENABLE_INVPCID);
+               SECONDARY_EXEC_ENABLE_INVPCID |
+               SECONDARY_EXEC_XSAVES);
         rdmsrl(MSR_IA32_VMX_MISC, _vmx_misc_cap);
         if ( _vmx_misc_cap & VMX_MISC_VMWRITE_ALL )
             opt |= SECONDARY_EXEC_ENABLE_VMCS_SHADOWING;
@@ -921,6 +922,7 @@ void virtual_vmcs_vmwrite(void *vvmcs, u32 vmcs_encoding, u64 val)
     virtual_vmcs_exit(vvmcs);
 }
 
+#define VMX_XSS_EXIT_BITMAP 0
 static int construct_vmcs(struct vcpu *v)
 {
     struct domain *d = v->domain;
@@ -1204,6 +1206,9 @@ static int construct_vmcs(struct vcpu *v)
         __vmwrite(GUEST_PAT, guest_pat);
     }
 
+    if ( cpu_has_vmx_xsaves )
+        __vmwrite(XSS_EXIT_BITMAP, VMX_XSS_EXIT_BITMAP);
+
     vmx_vmcs_exit(v);
 
     /* PVH: paging mode is updated by arch_set_info_guest(). */
diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c
index d3183a8..64ff63b 100644
--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -2708,6 +2708,16 @@ static int vmx_handle_apic_write(void)
     return vlapic_apicv_write(current, exit_qualification & 0xfff);
 }
 
+static void vmx_handle_xsaves(void)
+{
+    WARN();
+}
+
+static void vmx_handle_xrstors(void)
+{
+    WARN();
+}
+
 void vmx_vmexit_handler(struct cpu_user_regs *regs)
 {
     unsigned long exit_qualification, exit_reason, idtv_info, intr_info = 0;
@@ -3226,6 +3236,14 @@ void vmx_vmexit_handler(struct cpu_user_regs *regs)
         vmx_vcpu_flush_pml_buffer(v);
         break;
 
+    case EXIT_REASON_XSAVES:
+        vmx_handle_xsaves();
+        break;
+
+    case EXIT_REASON_XRSTORS:
+        vmx_handle_xrstors();
+        break;
+
     case EXIT_REASON_ACCESS_GDTR_OR_IDTR:
     case EXIT_REASON_ACCESS_LDTR_OR_TR:
     case EXIT_REASON_VMX_PREEMPTION_TIMER_EXPIRED:
diff --git a/xen/arch/x86/xstate.c b/xen/arch/x86/xstate.c
index 571ce13..699058d 100644
--- a/xen/arch/x86/xstate.c
+++ b/xen/arch/x86/xstate.c
@@ -14,8 +14,8 @@
 #include <asm/xstate.h>
 #include <asm/asm_defns.h>
 
-static bool_t __read_mostly cpu_has_xsaveopt;
-static bool_t __read_mostly cpu_has_xsavec;
+bool_t __read_mostly cpu_has_xsaveopt;
+bool_t __read_mostly cpu_has_xsavec;
 bool_t __read_mostly cpu_has_xgetbv1;
 bool_t __read_mostly cpu_has_xsaves;
 
diff --git a/xen/include/asm-x86/hvm/vmx/vmcs.h b/xen/include/asm-x86/hvm/vmx/vmcs.h
index 3132644..d969a6d 100644
--- a/xen/include/asm-x86/hvm/vmx/vmcs.h
+++ b/xen/include/asm-x86/hvm/vmx/vmcs.h
@@ -225,6 +225,7 @@ extern u32 vmx_vmentry_control;
 #define SECONDARY_EXEC_ENABLE_VMFUNC            0x00002000
 #define SECONDARY_EXEC_ENABLE_VMCS_SHADOWING    0x00004000
 #define SECONDARY_EXEC_ENABLE_PML               0x00020000
+#define SECONDARY_EXEC_XSAVES                   0x00100000
 extern u32 vmx_secondary_exec_control;
 
 #define VMX_EPT_EXEC_ONLY_SUPPORTED             0x00000001
@@ -287,6 +288,8 @@ extern u32 vmx_secondary_exec_control;
     (vmx_secondary_exec_control & SECONDARY_EXEC_ENABLE_VMCS_SHADOWING)
 #define cpu_has_vmx_pml \
     (vmx_secondary_exec_control & SECONDARY_EXEC_ENABLE_PML)
+#define cpu_has_vmx_xsaves \
+    (vmx_secondary_exec_control & SECONDARY_EXEC_XSAVES)
 
 #define VMCS_RID_TYPE_MASK              0x80000000
 
@@ -356,6 +359,8 @@ enum vmcs_field {
 #define EOI_EXIT_BITMAP(n) (EOI_EXIT_BITMAP0 + (n) * 2) /* n = 0...3 */
     VMREAD_BITMAP                   = 0x00002026,
     VMWRITE_BITMAP                  = 0x00002028,
+    XSS_EXIT_BITMAP                 = 0x0000202c,
+    XSS_EXIT_BITMAP_HIGH            = 0x0000202d,
     GUEST_PHYSICAL_ADDRESS          = 0x00002400,
     VMCS_LINK_POINTER               = 0x00002800,
     GUEST_IA32_DEBUGCTL             = 0x00002802,
diff --git a/xen/include/asm-x86/hvm/vmx/vmx.h b/xen/include/asm-x86/hvm/vmx/vmx.h
index c5f3d24..07036f6 100644
--- a/xen/include/asm-x86/hvm/vmx/vmx.h
+++ b/xen/include/asm-x86/hvm/vmx/vmx.h
@@ -188,6 +188,8 @@ static inline unsigned long pi_get_pir(struct pi_desc *pi_desc, int group)
 #define EXIT_REASON_APIC_WRITE          56
 #define EXIT_REASON_INVPCID             58
 #define EXIT_REASON_PML_FULL            62
+#define EXIT_REASON_XSAVES              63
+#define EXIT_REASON_XRSTORS             64
 
 /*
  * Interruption-information format
diff --git a/xen/include/asm-x86/xstate.h b/xen/include/asm-x86/xstate.h
index 47c2f59..75fa6eb 100644
--- a/xen/include/asm-x86/xstate.h
+++ b/xen/include/asm-x86/xstate.h
@@ -44,7 +44,7 @@
 #define XSTATE_COMPACTION_ENABLED  (1ULL << 63)
 
 extern u64 xfeature_mask;
-extern bool_t cpu_has_xsaves, cpu_has_xgetbv1;
+extern bool_t cpu_has_xsaves, cpu_has_xgetbv1 ,cpu_has_xsavec, cpu_has_xsaveopt;
 
 /* extended state save area */
 struct __packed __attribute__((aligned (64))) xsave_struct
-- 
1.9.1