[XEN PATCH v2 12/15] x86/vmx: guard access to cpu_has_vmx_* in common code

[Sergiy Kibrik <Sergiy_Kibrik@xxxxxxxx>]

There're several places in common code, outside of arch/x86/hvm/vmx,
where cpu_has_vmx_* get accessed without checking if VMX present first.
We may want to guard these macros, as they read global variables defined
inside vmx-specific files -- so VMX can be made optional later on.

Signed-off-by: Sergiy Kibrik <Sergiy_Kibrik@xxxxxxxx>
CC: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CC: Jan Beulich <jbeulich@xxxxxxxx>
---
Here I've tried a different approach from prev.patches [1,2] -- instead of
modifying whole set of cpu_has_{svm/vmx}_* macros, we can:
 1) do not touch SVM part at all, because just as Andrew pointed out they're
used inside arch/x86/hvm/svm only.
 2) track several places in common code where cpu_has_vmx_* features are
checked out and guard them using cpu_has_vmx condition
 3) two of cpu_has_vmx_* macros being used in common code are checked in a bit
more tricky way, so instead of making complex conditionals even more 
complicated,
we can instead integrate cpu_has_vmx condition inside these two macros.

This patch aims to replace [1,2] from v1 series by doing steps above.

 1. 
https://lore.kernel.org/xen-devel/20240416064402.3469959-1-Sergiy_Kibrik@xxxxxxxx/
 2. 
https://lore.kernel.org/xen-devel/20240416064606.3470052-1-Sergiy_Kibrik@xxxxxxxx/
---
changes in v2:
 - do not touch SVM code and macros
 - drop vmx_ctrl_has_feature()
 - guard cpu_has_vmx_* macros in common code instead
changes in v1:
 - introduced helper routine vmx_ctrl_has_feature() and used it for all
   cpu_has_vmx_* macros
---
 xen/arch/x86/hvm/hvm.c                  | 2 +-
 xen/arch/x86/hvm/viridian/viridian.c    | 4 ++--
 xen/arch/x86/include/asm/hvm/vmx/vmcs.h | 4 ++--
 xen/arch/x86/traps.c                    | 5 +++--
 4 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 9594e0a5c5..ab75de9779 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -5180,7 +5180,7 @@ int hvm_debug_op(struct vcpu *v, int32_t op)
     {
         case XEN_DOMCTL_DEBUG_OP_SINGLE_STEP_ON:
         case XEN_DOMCTL_DEBUG_OP_SINGLE_STEP_OFF:
-            if ( !cpu_has_monitor_trap_flag )
+            if ( !cpu_has_vmx || !cpu_has_monitor_trap_flag )
                 return -EOPNOTSUPP;
             break;
         default:
diff --git a/xen/arch/x86/hvm/viridian/viridian.c 
b/xen/arch/x86/hvm/viridian/viridian.c
index 0496c52ed5..657c6a3ea7 100644
--- a/xen/arch/x86/hvm/viridian/viridian.c
+++ b/xen/arch/x86/hvm/viridian/viridian.c
@@ -196,7 +196,7 @@ void cpuid_viridian_leaves(const struct vcpu *v, uint32_t 
leaf,
         res->a = CPUID4A_RELAX_TIMER_INT;
         if ( viridian_feature_mask(d) & HVMPV_hcall_remote_tlb_flush )
             res->a |= CPUID4A_HCALL_REMOTE_TLB_FLUSH;
-        if ( !cpu_has_vmx_apic_reg_virt )
+        if ( !cpu_has_vmx || !cpu_has_vmx_apic_reg_virt )
             res->a |= CPUID4A_MSR_BASED_APIC;
         if ( viridian_feature_mask(d) & HVMPV_hcall_ipi )
             res->a |= CPUID4A_SYNTHETIC_CLUSTER_IPI;
@@ -236,7 +236,7 @@ void cpuid_viridian_leaves(const struct vcpu *v, uint32_t 
leaf,
 
     case 6:
         /* Detected and in use hardware features. */
-        if ( cpu_has_vmx_virtualize_apic_accesses )
+        if ( cpu_has_vmx && cpu_has_vmx_virtualize_apic_accesses )
             res->a |= CPUID6A_APIC_OVERLAY;
         if ( cpu_has_vmx_msr_bitmap || (read_efer() & EFER_SVME) )
             res->a |= CPUID6A_MSR_BITMAPS;
diff --git a/xen/arch/x86/include/asm/hvm/vmx/vmcs.h 
b/xen/arch/x86/include/asm/hvm/vmx/vmcs.h
index 58140af691..aa05f9cf6e 100644
--- a/xen/arch/x86/include/asm/hvm/vmx/vmcs.h
+++ b/xen/arch/x86/include/asm/hvm/vmx/vmcs.h
@@ -306,7 +306,7 @@ extern u64 vmx_ept_vpid_cap;
 #define cpu_has_vmx_vnmi \
     (vmx_pin_based_exec_control & PIN_BASED_VIRTUAL_NMIS)
 #define cpu_has_vmx_msr_bitmap \
-    (vmx_cpu_based_exec_control & CPU_BASED_ACTIVATE_MSR_BITMAP)
+    (cpu_has_vmx && vmx_cpu_based_exec_control & CPU_BASED_ACTIVATE_MSR_BITMAP)
 #define cpu_has_vmx_secondary_exec_control \
     (vmx_cpu_based_exec_control & CPU_BASED_ACTIVATE_SECONDARY_CONTROLS)
 #define cpu_has_vmx_tertiary_exec_control \
@@ -347,7 +347,7 @@ extern u64 vmx_ept_vpid_cap;
 #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)
+    (cpu_has_vmx && vmx_secondary_exec_control & 
SECONDARY_EXEC_ENABLE_VIRT_EXCEPTIONS)
 #define cpu_has_vmx_pml \
     (vmx_secondary_exec_control & SECONDARY_EXEC_ENABLE_PML)
 #define cpu_has_vmx_mpx \
diff --git a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c
index 7b8ee45edf..3595bb379a 100644
--- a/xen/arch/x86/traps.c
+++ b/xen/arch/x86/traps.c
@@ -1130,7 +1130,7 @@ void cpuid_hypervisor_leaves(const struct vcpu *v, 
uint32_t leaf,
         if ( !is_hvm_domain(d) || subleaf != 0 )
             break;
 
-        if ( cpu_has_vmx_apic_reg_virt )
+        if ( cpu_has_vmx && cpu_has_vmx_apic_reg_virt )
             res->a |= XEN_HVM_CPUID_APIC_ACCESS_VIRT;
 
         /*
@@ -1139,7 +1139,8 @@ void cpuid_hypervisor_leaves(const struct vcpu *v, 
uint32_t leaf,
          * and wrmsr in the guest will run without VMEXITs (see
          * vmx_vlapic_msr_changed()).
          */
-        if ( cpu_has_vmx_virtualize_x2apic_mode &&
+        if ( cpu_has_vmx &&
+             cpu_has_vmx_virtualize_x2apic_mode &&
              cpu_has_vmx_apic_reg_virt &&
              cpu_has_vmx_virtual_intr_delivery )
             res->a |= XEN_HVM_CPUID_X2APIC_VIRT;
-- 
2.25.1