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KVM: x86: Clear rflags.rf on emulated instructions

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When an instruction is emulated RFLAGS.RF should be cleared. KVM previously did
not do so. This patch clears RFLAGS.RF after interception is done.  If a fault
occurs during the instruction, RFLAGS.RF will be set by a previous patch.  This
patch does not handle the case of traps/interrupts during rep-strings. Traps
are only expected to occur on debug watchpoints, and those are anyhow not
handled by the emulator.

Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Nadav Amit 2014-07-21 14:37:29 +03:00 committed by Paolo Bonzini
parent 163b135e7b
commit 4467c3f1ad
1 changed files with 3 additions and 0 deletions
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3
arch/x86/kvm/emulate.c
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@ -4640,6 +4640,7 @@ int x86_emulate_insn(struct x86_emulate_ctxt *ctxt)
/* All REP prefixes have the same first termination condition */
if (address_mask(ctxt, reg_read(ctxt, VCPU_REGS_RCX)) == 0) {
ctxt->eip = ctxt->_eip;
ctxt->eflags &= ~EFLG_RF;
goto done;
}
}
@ -4682,6 +4683,8 @@ special_insn:
goto done;
}
ctxt->eflags &= ~EFLG_RF;
if (ctxt->execute) {
if (ctxt->d & Fastop) {
void (*fop)(struct fastop *) = (void *)ctxt->execute;