Commit 0967b7bf authored by Avi Kivity's avatar Avi Kivity
Browse files

KVM: Skip pio instruction when it is emulated, not executed 



If we defer updating rip until pio instructions are executed, we have a
problem with reset:  a pio reset updates rip, and when the instruction
completes we skip the emulated instruction, pointing rip somewhere completely
unrelated.

Fix by updating rip when we see decode the instruction, not after emulation.

Signed-off-by: default avatarAvi Kivity <avi@qumranet.com>
parent 535eabcf

drivers/kvm/kvm_main.c

+5 −2
Original line number Diff line number Diff line
@@ -1815,8 +1815,6 @@ static int complete_pio(struct kvm_vcpu *vcpu) 
	io->count -= io->cur_count;

	io->cur_count = 0;



	if (!io->count)

		kvm_x86_ops->skip_emulated_instruction(vcpu);

	return 0;

}
@@ -1876,6 +1874,8 @@ int kvm_emulate_pio (struct kvm_vcpu *vcpu, struct kvm_run *run, int in, 
	memcpy(vcpu->pio_data, &vcpu->regs[VCPU_REGS_RAX], 4);

	kvm_x86_ops->decache_regs(vcpu);



	kvm_x86_ops->skip_emulated_instruction(vcpu);



	pio_dev = vcpu_find_pio_dev(vcpu, port);

	if (pio_dev) {

		kernel_pio(pio_dev, vcpu, vcpu->pio_data);
@@ -1938,6 +1938,9 @@ int kvm_emulate_pio_string(struct kvm_vcpu *vcpu, struct kvm_run *run, int in, 
	vcpu->run->io.count = now;

	vcpu->pio.cur_count = now;



	if (vcpu->pio.cur_count == vcpu->pio.count)

		kvm_x86_ops->skip_emulated_instruction(vcpu);



	for (i = 0; i < nr_pages; ++i) {

		mutex_lock(&vcpu->kvm->lock);

		page = gva_to_page(vcpu, address + i * PAGE_SIZE);

CRA Git | Maintained and supported by SUSTech CRA and CCSE