Messages in this thread Patch in this message | | | From | Nadav Amit <> | Subject | [PATCH 1/2] KVM: x86: Setting rflags.rf during rep-string emulation | Date | Thu, 24 Jul 2014 14:51:23 +0300 |
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This patch updates RF for rep-string emulation. The flag is set upon the first iteration, and cleared after the last (if emulated). It is intended to make sure that if a trap (in future data/io #DB emulation) or interrupt is delivered to the guest during the rep-string instruction, RF will be set correctly. RF affects whether instruction breakpoint in the guest is masked.
Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> --- arch/x86/kvm/emulate.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 8d41556..57743ed 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -4683,7 +4683,10 @@ special_insn: goto done; } - ctxt->eflags &= ~EFLG_RF; + if (ctxt->rep_prefix && (ctxt->d & String)) + ctxt->eflags |= EFLG_RF; + else + ctxt->eflags &= ~EFLG_RF; if (ctxt->execute) { if (ctxt->d & Fastop) { @@ -4824,6 +4827,7 @@ writeback: } goto done; /* skip rip writeback */ } + ctxt->eflags &= ~EFLG_RF; } ctxt->eip = ctxt->_eip; -- 1.9.1
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