[Xen-devel] [PATCH v5 12/14] x86/HVM: use x86emul_write_xcr()

["Jan Beulich" <JBeulich@xxxxxxxx>]

...  instead of directly calling handle_xsetbv(), to make use of the
additional checking there.

Also don't call hvm_monitor_crX(XCR0, ...) for indexes other than zero
anymore.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
---
v5: New.

--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -1961,10 +1961,11 @@ int hvm_handle_xsetbv(u32 index, u64 new
 {
     int rc;
 
-    hvm_monitor_crX(XCR0, new_bv, current->arch.xcr0);
+    if ( index == 0 )
+        hvm_monitor_crX(XCR0, new_bv, current->arch.xcr0);
 
-    rc = handle_xsetbv(index, new_bv);
-    if ( rc )
+    rc = x86emul_write_xcr(index, new_bv, NULL);
+    if ( rc != X86EMUL_OKAY )
         hvm_inject_hw_exception(TRAP_gp_fault, 0);
 
     return rc;
--- a/xen/arch/x86/hvm/svm/svm.c
+++ b/xen/arch/x86/hvm/svm/svm.c
@@ -2902,7 +2902,7 @@ void svm_vmexit_handler(struct cpu_user_
         if ( vmcb_get_cpl(vmcb) )
             hvm_inject_hw_exception(TRAP_gp_fault, 0);
         else if ( (inst_len = __get_instruction_length(v, INSTR_XSETBV)) &&
-                  hvm_handle_xsetbv(regs->ecx, msr_fold(regs)) == 0 )
+                  hvm_handle_xsetbv(regs->ecx, msr_fold(regs)) == X86EMUL_OKAY 
)
             __update_guest_eip(regs, inst_len);
         break;
 
--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -4084,7 +4084,7 @@ void vmx_vmexit_handler(struct cpu_user_
         break;
 
     case EXIT_REASON_XSETBV:
-        if ( hvm_handle_xsetbv(regs->ecx, msr_fold(regs)) == 0 )
+        if ( hvm_handle_xsetbv(regs->ecx, msr_fold(regs)) == X86EMUL_OKAY )
             update_guest_eip(); /* Safe: XSETBV */
         break;
 
--- a/xen/arch/x86/x86_emulate.c
+++ b/xen/arch/x86/x86_emulate.c
@@ -66,6 +66,7 @@ int x86emul_read_xcr(unsigned int reg, u
     return X86EMUL_OKAY;
 }
 
+/* Note: May be called with ctxt=NULL. */
 int x86emul_write_xcr(unsigned int reg, uint64_t val,
                       struct x86_emulate_ctxt *ctxt)
 {
@@ -80,7 +81,8 @@ int x86emul_write_xcr(unsigned int reg,
         /* fall through */
     default:
     gp_fault:
-        x86_emul_hw_exception(TRAP_gp_fault, 0, ctxt);
+        if ( ctxt )
+            x86_emul_hw_exception(TRAP_gp_fault, 0, ctxt);
         return X86EMUL_EXCEPTION;
     }
 




_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel