VMX: Eliminate cr3 store/load vmexit when UG enabled

With the feature of unrestricted guest, Xen should not cause
vmexits for cr3 accesses in non-paging mode.

Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com>
Acked-by: Jun Nakajima <jun.nakajima@intel.com>

diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c
index 9ca863248c53b7b0c87d4928dbfdff3e0f1a4d40..502caa3984cb5caa9cc5d111136be4f58eefb345 100644 (file)
--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -1086,7 +1086,7 @@ static void vmx_update_guest_cr(struct vcpu *v, unsigned int cr)
             uint32_t cr3_ctls = (CPU_BASED_CR3_LOAD_EXITING |
                                  CPU_BASED_CR3_STORE_EXITING);
             v->arch.hvm_vmx.exec_control &= ~cr3_ctls;
-            if ( !hvm_paging_enabled(v) )
+            if ( !hvm_paging_enabled(v) && !vmx_unrestricted_guest(v) )
                 v->arch.hvm_vmx.exec_control |= cr3_ctls;
 
             /* Trap CR3 updates if CR3 memory events are enabled. */
@@ -1156,7 +1156,7 @@ static void vmx_update_guest_cr(struct vcpu *v, unsigned int cr)
     case 3:
         if ( paging_mode_hap(v->domain) )
         {
-            if ( !hvm_paging_enabled(v) )
+            if ( !hvm_paging_enabled(v) && !vmx_unrestricted_guest(v) )
                 v->arch.hvm_vcpu.hw_cr[3] =
                     v->domain->arch.hvm_domain.params[HVM_PARAM_IDENT_PT];
             vmx_load_pdptrs(v);
@@ -2408,7 +2408,7 @@ void vmx_vmexit_handler(struct cpu_user_regs *regs)
 
     hvm_invalidate_regs_fields(regs);
 
-    if ( paging_mode_hap(v->domain) && hvm_paging_enabled(v) )
+    if ( paging_mode_hap(v->domain) )
     {
         __vmread(GUEST_CR3, &v->arch.hvm_vcpu.hw_cr[3]);
         v->arch.hvm_vcpu.guest_cr[3] = v->arch.hvm_vcpu.hw_cr[3];