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: Mohammed Gamal <m.gamal005@gmail.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index eae1f2c..9840f37 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -1298,7 +1298,9 @@
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 @@
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 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 @@
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 @@
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 @@
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 @@
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))
