VMX: VMFUNC and #VE definitions and detection

Currently, neither is enabled globally but may be enabled on a per-VCPU
basis by the altp2m code.

Remove the check for EPTE bit 63 == zero in ept_split_super_page(), as
that bit is now hardware-defined.

Signed-off-by: Ed White <edmund.h.white@intel.com>

Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: George Dunlap <george.dunlap@eu.citrix.com>
Acked-by: Jun Nakajima <jun.nakajima@intel.com>
Release-acked-by: Wei Liu <wei.liu2@citrix.com>

xen/arch/x86/hvm/vmx/vmcs.c

@@ -101,6 +101,8 @@ u32 vmx_secondary_exec_control __read_mostly;
 u32 vmx_vmexit_control __read_mostly;
 u32 vmx_vmentry_control __read_mostly;
 u64 vmx_ept_vpid_cap __read_mostly;
+u64 vmx_vmfunc __read_mostly;
+bool_t vmx_virt_exception __read_mostly;
 
 const u32 vmx_introspection_force_enabled_msrs[] = {
     MSR_IA32_SYSENTER_EIP,
@@ -140,6 +142,8 @@ static void __init vmx_display_features(void)
     P(cpu_has_vmx_virtual_intr_delivery, "Virtual Interrupt Delivery");
     P(cpu_has_vmx_posted_intr_processing, "Posted Interrupt Processing");
     P(cpu_has_vmx_vmcs_shadowing, "VMCS shadowing");
+    P(cpu_has_vmx_vmfunc, "VM Functions");
+    P(cpu_has_vmx_virt_exceptions, "Virtualisation Exceptions");
     P(cpu_has_vmx_pml, "Page Modification Logging");
 #undef P
 
@@ -185,6 +189,7 @@ static int vmx_init_vmcs_config(void)
     u64 _vmx_misc_cap = 0;
     u32 _vmx_vmexit_control;
     u32 _vmx_vmentry_control;
+    u64 _vmx_vmfunc = 0;
     bool_t mismatch = 0;
 
     rdmsr(MSR_IA32_VMX_BASIC, vmx_basic_msr_low, vmx_basic_msr_high);
@@ -230,7 +235,9 @@ 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_ENABLE_VM_FUNCTIONS |
+               SECONDARY_EXEC_ENABLE_VIRT_EXCEPTIONS);
         rdmsrl(MSR_IA32_VMX_MISC, _vmx_misc_cap);
         if ( _vmx_misc_cap & VMX_MISC_VMWRITE_ALL )
             opt |= SECONDARY_EXEC_ENABLE_VMCS_SHADOWING;
@@ -341,6 +348,24 @@ static int vmx_init_vmcs_config(void)
           || !(_vmx_vmexit_control & VM_EXIT_ACK_INTR_ON_EXIT) )
         _vmx_pin_based_exec_control  &= ~ PIN_BASED_POSTED_INTERRUPT;
 
+    /* The IA32_VMX_VMFUNC MSR exists only when VMFUNC is available */
+    if ( _vmx_secondary_exec_control & SECONDARY_EXEC_ENABLE_VM_FUNCTIONS )
+    {
+        rdmsrl(MSR_IA32_VMX_VMFUNC, _vmx_vmfunc);
+
+        /*
+         * VMFUNC leaf 0 (EPTP switching) must be supported.
+         *
+         * Or we just don't use VMFUNC.
+         */
+        if ( !(_vmx_vmfunc & VMX_VMFUNC_EPTP_SWITCHING) )
+            _vmx_secondary_exec_control &= ~SECONDARY_EXEC_ENABLE_VM_FUNCTIONS;
+    }
+
+    /* Virtualization exceptions are only enabled if VMFUNC is enabled */
+    if ( !(_vmx_secondary_exec_control & SECONDARY_EXEC_ENABLE_VM_FUNCTIONS) )
+        _vmx_secondary_exec_control &= ~SECONDARY_EXEC_ENABLE_VIRT_EXCEPTIONS;
+
     min = 0;
     opt = VM_ENTRY_LOAD_GUEST_PAT | VM_ENTRY_LOAD_BNDCFGS;
     _vmx_vmentry_control = adjust_vmx_controls(
@@ -361,6 +386,9 @@ static int vmx_init_vmcs_config(void)
         vmx_vmentry_control        = _vmx_vmentry_control;
         vmx_basic_msr              = ((u64)vmx_basic_msr_high << 32) |
                                      vmx_basic_msr_low;
+        vmx_vmfunc                 = _vmx_vmfunc;
+        vmx_virt_exception         = !!(_vmx_secondary_exec_control &
+                                       SECONDARY_EXEC_ENABLE_VIRT_EXCEPTIONS);
         vmx_display_features();
 
         /* IA-32 SDM Vol 3B: VMCS size is never greater than 4kB. */
@@ -397,6 +425,9 @@ static int vmx_init_vmcs_config(void)
         mismatch |= cap_check(
             "EPT and VPID Capability",
             vmx_ept_vpid_cap, _vmx_ept_vpid_cap);
+        mismatch |= cap_check(
+            "VMFUNC Capability",
+            vmx_vmfunc, _vmx_vmfunc);
         if ( cpu_has_vmx_ins_outs_instr_info !=
              !!(vmx_basic_msr_high & (VMX_BASIC_INS_OUT_INFO >> 32)) )
         {
@@ -967,6 +998,11 @@ static int construct_vmcs(struct vcpu *v)
     /* Do not enable Monitor Trap Flag unless start single step debug */
     v->arch.hvm_vmx.exec_control &= ~CPU_BASED_MONITOR_TRAP_FLAG;
 
+    /* Disable VMFUNC and #VE for now: they may be enabled later by altp2m. */
+    v->arch.hvm_vmx.secondary_exec_control &=
+        ~(SECONDARY_EXEC_ENABLE_VM_FUNCTIONS |
+          SECONDARY_EXEC_ENABLE_VIRT_EXCEPTIONS);
+
     if ( is_pvh_domain(d) )
     {
         /* Disable virtual apics, TPR */
@@ -1790,9 +1826,9 @@ void vmcs_dump_vcpu(struct vcpu *v)
         printk("PLE Gap=%08x Window=%08x\n",
                vmr32(PLE_GAP), vmr32(PLE_WINDOW));
     if ( v->arch.hvm_vmx.secondary_exec_control &
-         (SECONDARY_EXEC_ENABLE_VPID | SECONDARY_EXEC_ENABLE_VMFUNC) )
+         (SECONDARY_EXEC_ENABLE_VPID | SECONDARY_EXEC_ENABLE_VM_FUNCTIONS) )
         printk("Virtual processor ID = 0x%04x VMfunc controls = %016lx\n",
-               vmr16(VIRTUAL_PROCESSOR_ID), vmr(VMFUNC_CONTROL));
+               vmr16(VIRTUAL_PROCESSOR_ID), vmr(VM_FUNCTION_CONTROL));
 
     vmx_vmcs_exit(v);
 }

xen/arch/x86/mm/p2m-ept.c

@@ -282,7 +282,6 @@ static int ept_split_super_page(struct p2m_domain *p2m, ept_entry_t *ept_entry,
         epte->sp = (level > 1);
         epte->mfn += i * trunk;
         epte->snp = (iommu_enabled && iommu_snoop);
-        ASSERT(!epte->avail3);
 
         ept_p2m_type_to_flags(p2m, epte, epte->sa_p2mt, epte->access);
 

xen/include/asm-x86/hvm/vmx/vmcs.h

@@ -222,9 +222,10 @@ extern u32 vmx_vmentry_control;
 #define SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY    0x00000200
 #define SECONDARY_EXEC_PAUSE_LOOP_EXITING       0x00000400
 #define SECONDARY_EXEC_ENABLE_INVPCID           0x00001000
-#define SECONDARY_EXEC_ENABLE_VMFUNC            0x00002000
+#define SECONDARY_EXEC_ENABLE_VM_FUNCTIONS      0x00002000
 #define SECONDARY_EXEC_ENABLE_VMCS_SHADOWING    0x00004000
 #define SECONDARY_EXEC_ENABLE_PML               0x00020000
+#define SECONDARY_EXEC_ENABLE_VIRT_EXCEPTIONS   0x00040000
 extern u32 vmx_secondary_exec_control;
 
 #define VMX_EPT_EXEC_ONLY_SUPPORTED             0x00000001
@@ -285,6 +286,10 @@ extern u32 vmx_secondary_exec_control;
     (vmx_pin_based_exec_control & PIN_BASED_POSTED_INTERRUPT)
 #define cpu_has_vmx_vmcs_shadowing \
     (vmx_secondary_exec_control & SECONDARY_EXEC_ENABLE_VMCS_SHADOWING)
+#define cpu_has_vmx_vmfunc \
+    (vmx_secondary_exec_control & SECONDARY_EXEC_ENABLE_VM_FUNCTIONS)
+#define cpu_has_vmx_virt_exceptions \
+    (vmx_secondary_exec_control & SECONDARY_EXEC_ENABLE_VIRT_EXCEPTIONS)
 #define cpu_has_vmx_pml \
     (vmx_secondary_exec_control & SECONDARY_EXEC_ENABLE_PML)
 
@@ -316,6 +321,9 @@ extern u64 vmx_basic_msr;
 #define VMX_GUEST_INTR_STATUS_SUBFIELD_BITMASK  0x0FF
 #define VMX_GUEST_INTR_STATUS_SVI_OFFSET        8
 
+/* VMFUNC leaf definitions */
+#define VMX_VMFUNC_EPTP_SWITCHING   (1ULL << 0)
+
 /* VMCS field encodings. */
 #define VMCS_HIGH(x) ((x) | 1)
 enum vmcs_field {
@@ -350,12 +358,14 @@ enum vmcs_field {
     VIRTUAL_APIC_PAGE_ADDR          = 0x00002012,
     APIC_ACCESS_ADDR                = 0x00002014,
     PI_DESC_ADDR                    = 0x00002016,
-    VMFUNC_CONTROL                  = 0x00002018,
+    VM_FUNCTION_CONTROL             = 0x00002018,
     EPT_POINTER                     = 0x0000201a,
     EOI_EXIT_BITMAP0                = 0x0000201c,
 #define EOI_EXIT_BITMAP(n) (EOI_EXIT_BITMAP0 + (n) * 2) /* n = 0...3 */
+    EPTP_LIST_ADDR                  = 0x00002024,
     VMREAD_BITMAP                   = 0x00002026,
     VMWRITE_BITMAP                  = 0x00002028,
+    VIRT_EXCEPTION_INFO             = 0x0000202a,
     GUEST_PHYSICAL_ADDRESS          = 0x00002400,
     VMCS_LINK_POINTER               = 0x00002800,
     GUEST_IA32_DEBUGCTL             = 0x00002802,

xen/include/asm-x86/hvm/vmx/vmx.h

@@ -47,7 +47,7 @@ typedef union {
         access      :   4,  /* bits 61:58 - p2m_access_t */
         tm          :   1,  /* bit 62 - VT-d transient-mapping hint in
                                shared EPT/VT-d usage */
-        avail3      :   1;  /* bit 63 - Software available 3 */
+        suppress_ve :   1;  /* bit 63 - suppress #VE */
     };
     u64 epte;
 } ept_entry_t;
@@ -187,6 +187,7 @@ static inline unsigned long pi_get_pir(struct pi_desc *pi_desc, int group)
 #define EXIT_REASON_XSETBV              55
 #define EXIT_REASON_APIC_WRITE          56
 #define EXIT_REASON_INVPCID             58
+#define EXIT_REASON_VMFUNC              59
 #define EXIT_REASON_PML_FULL            62
 
 /*
@@ -555,4 +556,14 @@ void p2m_init_hap_data(struct p2m_domain *p2m);
 #define EPT_L4_PAGETABLE_SHIFT      39
 #define EPT_PAGETABLE_ENTRIES       512
 
+/* #VE information page */
+typedef struct {
+    u32 exit_reason;
+    u32 semaphore;
+    u64 exit_qualification;
+    u64 gla;
+    u64 gpa;
+    u16 eptp_index;
+} ve_info_t;
+
 #endif /* __ASM_X86_HVM_VMX_VMX_H__ */

xen/include/asm-x86/msr-index.h

@@ -130,6 +130,7 @@
 #define MSR_IA32_VMX_TRUE_PROCBASED_CTLS        0x48e
 #define MSR_IA32_VMX_TRUE_EXIT_CTLS             0x48f
 #define MSR_IA32_VMX_TRUE_ENTRY_CTLS            0x490
+#define MSR_IA32_VMX_VMFUNC                     0x491
 #define IA32_FEATURE_CONTROL_MSR                0x3a
 #define IA32_FEATURE_CONTROL_MSR_LOCK                     0x0001
 #define IA32_FEATURE_CONTROL_MSR_ENABLE_VMXON_INSIDE_SMX  0x0002