[Xen-changelog] [xen-unstable] x86: clear guest's EFLAGS.RF after emulating instructions

[Xen patchbot-unstable <patchbot-unstable@xxxxxxxxxxxxxxxxxxx>]

# HG changeset patch
# User kfraser@xxxxxxxxxxxxxxxxxxxxx
# Date 1182431037 -3600
# Node ID 899a44cb6ef605d0920acf68cfd55c72b112c033
# Parent  acb7aa72fac70e60c4b1aa9679834976e3788530
x86: clear guest's EFLAGS.RF after emulating instructions
Signed-off-by: Jan Beulich <jbeulich@xxxxxxxxxx>
---
 xen/arch/x86/hvm/io.c                 |    1 +
 xen/arch/x86/hvm/platform.c           |    3 +++
 xen/arch/x86/hvm/vmx/vmx.c            |   27 +++++++++++++++------------
 xen/arch/x86/traps.c                  |    2 ++
 xen/arch/x86/x86_emulate.c            |    1 +
 xen/include/asm-x86/hvm/svm/emulate.h |    1 +
 6 files changed, 23 insertions(+), 12 deletions(-)

diff -r acb7aa72fac7 -r 899a44cb6ef6 xen/arch/x86/hvm/io.c
--- a/xen/arch/x86/hvm/io.c     Thu Jun 21 12:13:06 2007 +0100
+++ b/xen/arch/x86/hvm/io.c     Thu Jun 21 14:03:57 2007 +0100
@@ -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 -r acb7aa72fac7 -r 899a44cb6ef6 xen/arch/x86/hvm/platform.c
--- a/xen/arch/x86/hvm/platform.c       Thu Jun 21 12:13:06 2007 +0100
+++ b/xen/arch/x86/hvm/platform.c       Thu Jun 21 14:03:57 2007 +0100
@@ -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 -r acb7aa72fac7 -r 899a44cb6ef6 xen/arch/x86/hvm/vmx/vmx.c
--- a/xen/arch/x86/hvm/vmx/vmx.c        Thu Jun 21 12:13:06 2007 +0100
+++ b/xen/arch/x86/hvm/vmx/vmx.c        Thu Jun 21 14:03:57 2007 +0100
@@ -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;
-
-    current_eip = __vmread(GUEST_RIP);
-    __vmwrite(GUEST_RIP, current_eip + inst_len);
-
-    intr_shadow = __vmread(GUEST_INTERRUPTIBILITY_INFO);
-    if ( intr_shadow & (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);
+    unsigned long x;
+
+    x = __vmread(GUEST_RIP);
+    __vmwrite(GUEST_RIP, x + inst_len);
+
+    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) )
+    {
+        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 *
     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 val
                     "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 -r acb7aa72fac7 -r 899a44cb6ef6 xen/arch/x86/traps.c
--- a/xen/arch/x86/traps.c      Thu Jun 21 12:13:06 2007 +0100
+++ b/xen/arch/x86/traps.c      Thu Jun 21 14:03:57 2007 +0100
@@ -631,6 +631,7 @@ static int emulate_forced_invalid_op(str
     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 
 
  done:
     regs->eip = eip;
+    regs->eflags &= ~X86_EFLAGS_RF;
     return EXCRET_fault_fixed;
 
  fail:
diff -r acb7aa72fac7 -r 899a44cb6ef6 xen/arch/x86/x86_emulate.c
--- a/xen/arch/x86/x86_emulate.c        Thu Jun 21 12:13:06 2007 +0100
+++ b/xen/arch/x86/x86_emulate.c        Thu Jun 21 14:03:57 2007 +0100
@@ -1630,6 +1630,7 @@ x86_emulate(
     }
 
     /* Commit shadow register state. */
+    _regs.eflags &= ~EF_RF;
     *ctxt->regs = _regs;
 
  done:
diff -r acb7aa72fac7 -r 899a44cb6ef6 xen/include/asm-x86/hvm/svm/emulate.h
--- a/xen/include/asm-x86/hvm/svm/emulate.h     Thu Jun 21 12:13:06 2007 +0100
+++ b/xen/include/asm-x86/hvm/svm/emulate.h     Thu Jun 21 14:03:57 2007 +0100
@@ -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__ */

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