KVM: x86 emulator: advance RIP outside x86 emulator code

Return new RIP as part of instruction emulation result instead of
updating KVM's RIP from x86 emulator code.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index d7a18a0..437f31b 100644 (file)
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -2496,8 +2496,9 @@ int emulator_task_switch(struct x86_emulate_ctxt *ctxt,
 
        if (rc == X86EMUL_CONTINUE) {
                memcpy(ctxt->vcpu->arch.regs, c->regs, sizeof c->regs);
-               kvm_rip_write(ctxt->vcpu, c->eip);
                rc = writeback(ctxt, ops);
+               if (rc == X86EMUL_CONTINUE)
+                       ctxt->eip = c->eip;
        }
 
        return (rc == X86EMUL_UNHANDLEABLE) ? -1 : 0;
@@ -2554,7 +2555,7 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
                if (address_mask(c, c->regs[VCPU_REGS_RCX]) == 0) {
                string_done:
                        ctxt->restart = false;
-                       kvm_rip_write(ctxt->vcpu, c->eip);
+                       ctxt->eip = c->eip;
                        goto done;
                }
                /* The second termination condition only applies for REPE
@@ -3032,7 +3033,7 @@ writeback:
        ctxt->decode.mem_read.end = 0;
        /* Commit shadow register state. */
        memcpy(ctxt->vcpu->arch.regs, c->regs, sizeof c->regs);
-       kvm_rip_write(ctxt->vcpu, c->eip);
+       ctxt->eip = c->eip;
        ops->set_rflags(ctxt->vcpu, ctxt->eflags);
 
 done:

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 9e5a833..8f45cc7 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3941,6 +3941,7 @@ restart:
 
        shadow_mask = vcpu->arch.emulate_ctxt.interruptibility;
        kvm_x86_ops->set_interrupt_shadow(vcpu, shadow_mask);
+       kvm_rip_write(vcpu, vcpu->arch.emulate_ctxt.eip);
 
        if (vcpu->arch.pio.count) {
                if (!vcpu->arch.pio.in)
@@ -4945,6 +4946,7 @@ int kvm_task_switch(struct kvm_vcpu *vcpu, u16 tss_selector, int reason,
        if (ret)
                return EMULATE_FAIL;
 
+       kvm_rip_write(vcpu, vcpu->arch.emulate_ctxt.eip);
        kvm_x86_ops->set_rflags(vcpu, vcpu->arch.emulate_ctxt.eflags);
        return EMULATE_DONE;
 }