KVM: X86: Don't report L2 emulation failures to user-space

This patch prevents that emulation failures which result
from emulating an instruction for an L2-Guest results in
being reported to userspace.
Without this patch a malicious L2-Guest would be able to
kill the L1 by triggering a race-condition between an vmexit
and the instruction emulator.
With this patch the L2 will most likely only kill itself in
this situation.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
				  struct kvm_sregs *sregs)
{
	struct desc_ptr dt;

	kvm_get_segment(vcpu, &sregs->cs, VCPU_SREG_CS);
	kvm_get_segment(vcpu, &sregs->ds, VCPU_SREG_DS);
	kvm_get_segment(vcpu, &sregs->es, VCPU_SREG_ES);
	kvm_get_segment(vcpu, &sregs->fs, VCPU_SREG_FS);
	kvm_get_segment(vcpu, &sregs->gs, VCPU_SREG_GS);
	kvm_get_segment(vcpu, &sregs->ss, VCPU_SREG_SS);

	kvm_get_segment(vcpu, &sregs->tr, VCPU_SREG_TR);
	kvm_get_segment(vcpu, &sregs->ldt, VCPU_SREG_LDTR);

	kvm_x86_ops->get_idt(vcpu, &dt);
	sregs->idt.limit = dt.size;
	sregs->idt.base = dt.address;
	kvm_x86_ops->get_gdt(vcpu, &dt);
	sregs->gdt.limit = dt.size;
	sregs->gdt.base = dt.address;

	sregs->cr0 = kvm_read_cr0(vcpu);
	sregs->cr2 = vcpu->arch.cr2;
	sregs->cr3 = vcpu->arch.cr3;
	sregs->cr4 = kvm_read_cr4(vcpu);
	sregs->cr8 = kvm_get_cr8(vcpu);
	sregs->efer = vcpu->arch.efer;
	sregs->apic_base = kvm_get_apic_base(vcpu);

	memset(sregs->interrupt_bitmap, 0, sizeof sregs->interrupt_bitmap);

	if (vcpu->arch.interrupt.pending && !vcpu->arch.interrupt.soft)
		set_bit(vcpu->arch.interrupt.nr,
			(unsigned long *)sregs->interrupt_bitmap);

	return 0;
}

int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
				  struct kvm_sregs *sregs)
{
	struct desc_ptr dt;

	kvm_get_segment(vcpu, &sregs->cs, VCPU_SREG_CS);
	kvm_get_segment(vcpu, &sregs->ds, VCPU_SREG_DS);
	kvm_get_segment(vcpu, &sregs->es, VCPU_SREG_ES);
	kvm_get_segment(vcpu, &sregs->fs, VCPU_SREG_FS);
	kvm_get_segment(vcpu, &sregs->gs, VCPU_SREG_GS);
	kvm_get_segment(vcpu, &sregs->ss, VCPU_SREG_SS);

	kvm_get_segment(vcpu, &sregs->tr, VCPU_SREG_TR);
	kvm_get_segment(vcpu, &sregs->ldt, VCPU_SREG_LDTR);

	kvm_x86_ops->get_idt(vcpu, &dt);
	sregs->idt.limit = dt.size;
	sregs->idt.base = dt.address;
	kvm_x86_ops->get_gdt(vcpu, &dt);
	sregs->gdt.limit = dt.size;
	sregs->gdt.base = dt.address;

	sregs->cr0 = kvm_read_cr0(vcpu);
	sregs->cr2 = vcpu->arch.cr2;
	sregs->cr3 = vcpu->arch.cr3;
	sregs->cr4 = kvm_read_cr4(vcpu);
	sregs->cr8 = kvm_get_cr8(vcpu);
	sregs->efer = vcpu->arch.efer;
	sregs->apic_base = kvm_get_apic_base(vcpu);

	memset(sregs->interrupt_bitmap, 0, sizeof sregs->interrupt_bitmap);

	if (vcpu->arch.interrupt.pending && !vcpu->arch.interrupt.soft)
		set_bit(vcpu->arch.interrupt.nr,
			(unsigned long *)sregs->interrupt_bitmap);

	return 0;
}
