x86: clear guest's EFLAGS.RF after emulating instructions

Signed-off-by: Jan Beulich <jbeulich@novell.com>

diff --git a/xen/arch/x86/hvm/io.c b/xen/arch/x86/hvm/io.c
index 0a99dd27d621e321f7fe75ac7007dbacfe66b067..97e1215a58bdb02f3028a819dfd6561bfb42478d 100644 (file)
--- a/xen/arch/x86/hvm/io.c
+++ b/xen/arch/x86/hvm/io.c
@@ -858,6 +858,7 @@ void hvm_io_assist(void)
     }
 
     /* Copy register changes back into current guest state. */
+    regs->eflags &= ~X86_EFLAGS_RF;
     hvm_load_cpu_guest_regs(v, regs);
     memcpy(guest_cpu_user_regs(), regs, HVM_CONTEXT_STACK_BYTES);
 

diff --git a/xen/arch/x86/hvm/platform.c b/xen/arch/x86/hvm/platform.c
index 2b173c18de3c1a888047f767d8d882439811acd1..5de07703229cd2603a86dcc665ff610a9defdfac 100644 (file)
--- a/xen/arch/x86/hvm/platform.c
+++ b/xen/arch/x86/hvm/platform.c
@@ -1065,6 +1065,7 @@ void handle_mmio(unsigned long gpa)
     }
 
     regs->eip += inst_len; /* advance %eip */
+    regs->eflags &= ~X86_EFLAGS_RF;
 
     switch ( mmio_op->instr ) {
     case INSTR_MOV:
@@ -1122,6 +1123,7 @@ void handle_mmio(unsigned long gpa)
             /* IO read --> memory write */
             if ( dir == IOREQ_READ ) errcode |= PFEC_write_access;
             regs->eip -= inst_len; /* do not advance %eip */
+            regs->eflags |= X86_EFLAGS_RF; /* RF was set by original #PF */
             hvm_inject_exception(TRAP_page_fault, errcode, addr);
             return;
         }
@@ -1150,6 +1152,7 @@ void handle_mmio(unsigned long gpa)
                         /* Failed on the page-spanning copy.  Inject PF into
                          * the guest for the address where we failed */
                         regs->eip -= inst_len; /* do not advance %eip */
+                        regs->eflags |= X86_EFLAGS_RF; /* RF was set by #PF */
                         /* Must set CR2 at the failing address */ 
                         addr += size - rv;
                         gdprintk(XENLOG_DEBUG, "Pagefault on non-io side of a "

diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c
index f36b58f26169dc0ec8513fee2a91aee6e85c0db3..bb5a48aa87eb647b3a9c3a6f336c6fa652400b01 100644 (file)
--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -1315,16 +1315,20 @@ static int __get_instruction_length(void)
 
 static void inline __update_guest_eip(unsigned long inst_len)
 {
-    unsigned long current_eip, intr_shadow;
+    unsigned long x;
 
-    current_eip = __vmread(GUEST_RIP);
-    __vmwrite(GUEST_RIP, current_eip + inst_len);
+    x = __vmread(GUEST_RIP);
+    __vmwrite(GUEST_RIP, x + inst_len);
 
-    intr_shadow = __vmread(GUEST_INTERRUPTIBILITY_INFO);
-    if ( intr_shadow & (VMX_INTR_SHADOW_STI | VMX_INTR_SHADOW_MOV_SS) )
+    x = __vmread(GUEST_RFLAGS);
+    if ( x & X86_EFLAGS_RF )
+        __vmwrite(GUEST_RFLAGS, x & ~X86_EFLAGS_RF);
+
+    x = __vmread(GUEST_INTERRUPTIBILITY_INFO);
+    if ( x & (VMX_INTR_SHADOW_STI | VMX_INTR_SHADOW_MOV_SS) )
     {
-        intr_shadow &= ~(VMX_INTR_SHADOW_STI | VMX_INTR_SHADOW_MOV_SS);
-        __vmwrite(GUEST_INTERRUPTIBILITY_INFO, intr_shadow);
+        x &= ~(VMX_INTR_SHADOW_STI | VMX_INTR_SHADOW_MOV_SS);
+        __vmwrite(GUEST_INTERRUPTIBILITY_INFO, x);
     }
 }
 
@@ -1896,7 +1900,7 @@ static void vmx_world_save(struct vcpu *v, struct vmx_assist_context *c)
     c->eip += __get_instruction_length(); /* Safe: MOV Cn, LMSW, CLTS */
 
     c->esp = __vmread(GUEST_RSP);
-    c->eflags = __vmread(GUEST_RFLAGS);
+    c->eflags = __vmread(GUEST_RFLAGS) & ~X86_EFLAGS_RF;
 
     c->cr0 = v->arch.hvm_vmx.cpu_shadow_cr0;
     c->cr3 = v->arch.hvm_vmx.cpu_cr3;
@@ -2272,7 +2276,6 @@ static int vmx_set_cr0(unsigned long value)
                     "Enabling CR0.PE at %%eip 0x%lx", eip);
         if ( vmx_assist(v, VMX_ASSIST_RESTORE) )
         {
-            eip = __vmread(GUEST_RIP);
             HVM_DBG_LOG(DBG_LEVEL_1,
                         "Restoring to %%eip 0x%lx", eip);
             return 0; /* do not update eip! */

diff --git a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c
index c14847a6688b80a7d6f15f60e95383ed40832d7a..c26fde22f97550c2d422e04e5cacb5914db694f7 100644 (file)
--- a/xen/arch/x86/traps.c
+++ b/xen/arch/x86/traps.c
@@ -631,6 +631,7 @@ static int emulate_forced_invalid_op(struct cpu_user_regs *regs)
     regs->ecx = c;
     regs->edx = d;
     regs->eip = eip;
+    regs->eflags &= ~X86_EFLAGS_RF;
 
     return EXCRET_fault_fixed;
 }
@@ -1787,6 +1788,7 @@ static int emulate_privileged_op(struct cpu_user_regs *regs)
 
  done:
     regs->eip = eip;
+    regs->eflags &= ~X86_EFLAGS_RF;
     return EXCRET_fault_fixed;
 
  fail:

diff --git a/xen/arch/x86/x86_emulate.c b/xen/arch/x86/x86_emulate.c
index 70262d6131d1edf9f29b7f8a75c2485154335b2a..213da19f5d06a3fb843297d462c3a6e895634aaf 100644 (file)
--- a/xen/arch/x86/x86_emulate.c
+++ b/xen/arch/x86/x86_emulate.c
@@ -1630,6 +1630,7 @@ x86_emulate(
     }
 
     /* Commit shadow register state. */
+    _regs.eflags &= ~EF_RF;
     *ctxt->regs = _regs;
 
  done:

diff --git a/xen/include/asm-x86/hvm/svm/emulate.h b/xen/include/asm-x86/hvm/svm/emulate.h
index 8a4e139d22dad866e8d51e5304e71b33544d7d5d..8c183b89de2fb7c9ffddd22cbb08ce687e85be55 100644 (file)
--- a/xen/include/asm-x86/hvm/svm/emulate.h
+++ b/xen/include/asm-x86/hvm/svm/emulate.h
@@ -138,6 +138,7 @@ static void inline __update_guest_eip(
 {
     ASSERT(inst_len > 0);
     vmcb->rip += inst_len;
+    vmcb->rflags &= ~X86_EFLAGS_RF;
 }
 
 #endif /* __ASM_X86_HVM_SVM_EMULATE_H__ */