Commit 95cb2295 authored by Gleb Natapov's avatar Gleb Natapov Committed by Avi Kivity
Browse files

KVM: x86 emulator: move interruptibility state tracking out of emulator 



Emulator shouldn't access vcpu directly.

Signed-off-by: default avatarGleb Natapov <gleb@redhat.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent 4d2179e1

arch/x86/kvm/emulate.c

+2 −17
Original line number Diff line number Diff line
@@ -1843,20 +1843,6 @@ static inline int writeback(struct x86_emulate_ctxt *ctxt, 
	return X86EMUL_CONTINUE;

}



static void toggle_interruptibility(struct x86_emulate_ctxt *ctxt, u32 mask)

{

	u32 int_shadow = kvm_x86_ops->get_interrupt_shadow(ctxt->vcpu, mask);

	/*

	 * an sti; sti; sequence only disable interrupts for the first

	 * instruction. So, if the last instruction, be it emulated or

	 * not, left the system with the INT_STI flag enabled, it

	 * means that the last instruction is an sti. We should not

	 * leave the flag on in this case. The same goes for mov ss

	 */

	if (!(int_shadow & mask))

		ctxt->interruptibility = mask;

}



static inline void

setup_syscalls_segments(struct x86_emulate_ctxt *ctxt,

			struct x86_emulate_ops *ops, struct desc_struct *cs,
@@ -2516,7 +2502,6 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) 
	int rc = X86EMUL_CONTINUE;

	int saved_dst_type = c->dst.type;



	ctxt->interruptibility = 0;

	ctxt->decode.mem_read.pos = 0;



	if (ctxt->mode == X86EMUL_MODE_PROT64 && (c->d & No64)) {
@@ -2789,7 +2774,7 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) 
		}



		if (c->modrm_reg == VCPU_SREG_SS)

			toggle_interruptibility(ctxt, KVM_X86_SHADOW_INT_MOV_SS);

			ctxt->interruptibility = KVM_X86_SHADOW_INT_MOV_SS;



		rc = load_segment_descriptor(ctxt, ops, sel, c->modrm_reg);
@@ -2958,7 +2943,7 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) 
		if (emulator_bad_iopl(ctxt, ops))

			kvm_inject_gp(ctxt->vcpu, 0);

		else {

			toggle_interruptibility(ctxt, KVM_X86_SHADOW_INT_STI);

			ctxt->interruptibility = KVM_X86_SHADOW_INT_STI;

			ctxt->eflags |= X86_EFLAGS_IF;

			c->dst.type = OP_NONE;	/* Disable writeback. */

		}

arch/x86/kvm/x86.c

+17 −3
Original line number Diff line number Diff line
@@ -3838,12 +3838,26 @@ static void cache_all_regs(struct kvm_vcpu *vcpu) 
	vcpu->arch.regs_dirty = ~0;

}



static void toggle_interruptibility(struct kvm_vcpu *vcpu, u32 mask)

{

	u32 int_shadow = kvm_x86_ops->get_interrupt_shadow(vcpu, mask);

	/*

	 * an sti; sti; sequence only disable interrupts for the first

	 * instruction. So, if the last instruction, be it emulated or

	 * not, left the system with the INT_STI flag enabled, it

	 * means that the last instruction is an sti. We should not

	 * leave the flag on in this case. The same goes for mov ss

	 */

	if (!(int_shadow & mask))

		kvm_x86_ops->set_interrupt_shadow(vcpu, mask);

}



int emulate_instruction(struct kvm_vcpu *vcpu,

			unsigned long cr2,

			u16 error_code,

			int emulation_type)

{

	int r, shadow_mask;

	int r;

	struct decode_cache *c = &vcpu->arch.emulate_ctxt.decode;



	kvm_clear_exception_queue(vcpu);
@@ -3871,6 +3885,7 @@ int emulate_instruction(struct kvm_vcpu *vcpu, 
			? X86EMUL_MODE_PROT32 : X86EMUL_MODE_PROT16;

		memset(c, 0, sizeof(struct decode_cache));

		memcpy(c->regs, vcpu->arch.regs, sizeof c->regs);

		vcpu->arch.emulate_ctxt.interruptibility = 0;



		r = x86_decode_insn(&vcpu->arch.emulate_ctxt, &emulate_ops);

		trace_kvm_emulate_insn_start(vcpu);
@@ -3938,8 +3953,7 @@ int emulate_instruction(struct kvm_vcpu *vcpu, 
		return EMULATE_FAIL;

	}



	shadow_mask = vcpu->arch.emulate_ctxt.interruptibility;

	kvm_x86_ops->set_interrupt_shadow(vcpu, shadow_mask);

	toggle_interruptibility(vcpu, vcpu->arch.emulate_ctxt.interruptibility);

	kvm_x86_ops->set_rflags(vcpu, vcpu->arch.emulate_ctxt.eflags);

	memcpy(vcpu->arch.regs, c->regs, sizeof c->regs);

	kvm_rip_write(vcpu, vcpu->arch.emulate_ctxt.eip);