Commit a89a8fb9 authored by Mohammed Gamal's avatar Mohammed Gamal Committed by Avi Kivity
Browse files

KVM: VMX: Modify mode switching and vmentry functions 



This patch modifies mode switching and vmentry function in order to
drive invalid guest state emulation.

Signed-off-by: default avatarMohammed Gamal <m.gamal005@gmail.com>
Signed-off-by: default avatarAvi Kivity <avi@qumranet.com>
parent ea953ef0

arch/x86/kvm/vmx.c

+20 −0
Original line number Diff line number Diff line
@@ -1298,7 +1298,9 @@ static void fix_pmode_dataseg(int seg, struct kvm_save_segment *save) 
static void enter_pmode(struct kvm_vcpu *vcpu)

{

	unsigned long flags;

	struct vcpu_vmx *vmx = to_vmx(vcpu);



	vmx->emulation_required = 1;

	vcpu->arch.rmode.active = 0;



	vmcs_writel(GUEST_TR_BASE, vcpu->arch.rmode.tr.base);
@@ -1315,6 +1317,9 @@ static void enter_pmode(struct kvm_vcpu *vcpu) 


	update_exception_bitmap(vcpu);



	if (emulate_invalid_guest_state)

		return;



	fix_pmode_dataseg(VCPU_SREG_ES, &vcpu->arch.rmode.es);

	fix_pmode_dataseg(VCPU_SREG_DS, &vcpu->arch.rmode.ds);

	fix_pmode_dataseg(VCPU_SREG_GS, &vcpu->arch.rmode.gs);
@@ -1355,7 +1360,9 @@ static void fix_rmode_seg(int seg, struct kvm_save_segment *save) 
static void enter_rmode(struct kvm_vcpu *vcpu)

{

	unsigned long flags;

	struct vcpu_vmx *vmx = to_vmx(vcpu);



	vmx->emulation_required = 1;

	vcpu->arch.rmode.active = 1;



	vcpu->arch.rmode.tr.base = vmcs_readl(GUEST_TR_BASE);
@@ -1377,6 +1384,9 @@ static void enter_rmode(struct kvm_vcpu *vcpu) 
	vmcs_writel(GUEST_CR4, vmcs_readl(GUEST_CR4) | X86_CR4_VME);

	update_exception_bitmap(vcpu);



	if (emulate_invalid_guest_state)

		goto continue_rmode;



	vmcs_write16(GUEST_SS_SELECTOR, vmcs_readl(GUEST_SS_BASE) >> 4);

	vmcs_write32(GUEST_SS_LIMIT, 0xffff);

	vmcs_write32(GUEST_SS_AR_BYTES, 0xf3);
@@ -1392,6 +1402,7 @@ static void enter_rmode(struct kvm_vcpu *vcpu) 
	fix_rmode_seg(VCPU_SREG_GS, &vcpu->arch.rmode.gs);

	fix_rmode_seg(VCPU_SREG_FS, &vcpu->arch.rmode.fs);



continue_rmode:

	kvm_mmu_reset_context(vcpu);

	init_rmode(vcpu->kvm);

}
@@ -2317,6 +2328,9 @@ static int vmx_vcpu_reset(struct kvm_vcpu *vcpu) 


	ret = 0;



	/* HACK: Don't enable emulation on guest boot/reset */

	vmx->emulation_required = 0;



out:

	up_read(&vcpu->kvm->slots_lock);

	return ret;
@@ -3190,6 +3204,12 @@ static void vmx_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) 
	struct vcpu_vmx *vmx = to_vmx(vcpu);

	u32 intr_info;



	/* Handle invalid guest state instead of entering VMX */

	if (vmx->emulation_required && emulate_invalid_guest_state) {

		handle_invalid_guest_state(vcpu, kvm_run);

		return;

	}



	if (test_bit(VCPU_REGS_RSP, (unsigned long *)&vcpu->arch.regs_dirty))

		vmcs_writel(GUEST_RSP, vcpu->arch.regs[VCPU_REGS_RSP]);

	if (test_bit(VCPU_REGS_RIP, (unsigned long *)&vcpu->arch.regs_dirty))