[PATCH 4/8] KVM: Add a helper for checking if the guest is in protected mode

Avi Kivity
2010-01-21T13:31:54Z

Signed-off-by: Avi Kivity <avi@redhat.com>
---
arch/x86/kvm/emulate.c | 9 ++++-----
arch/x86/kvm/vmx.c | 4 ++--
arch/x86/kvm/x86.c | 7 +++----
arch/x86/kvm/x86.h | 6 ++++++
4 files changed, 15 insertions(+), 11 deletions(-)

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 0f89e32..e46f276 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -32,6 +32,7 @@
#include <linux/module.h>
#include <asm/kvm_emulate.h>

+#include "x86.h"
#include "mmu.h" /* for is_long_mode() */

/*
@@ -1515,7 +1516,7 @@ emulate_syscall(struct x86_emulate_ctxt *ctxt)

/* syscall is not available in real mode */
if (c->lock_prefix || ctxt->mode == X86EMUL_MODE_REAL
- || !kvm_read_cr0_bits(ctxt->vcpu, X86_CR0_PE))
+ || !is_protmode(ctxt->vcpu))
return -1;

setup_syscalls_segments(ctxt, &cs, &ss);
@@ -1568,8 +1569,7 @@ emulate_sysenter(struct x86_emulate_ctxt *ctxt)
return -1;

/* inject #GP if in real mode or paging is disabled */
- if (ctxt->mode == X86EMUL_MODE_REAL ||
- !kvm_read_cr0_bits(ctxt->vcpu, X86_CR0_PE)) {
+ if (ctxt->mode == X86EMUL_MODE_REAL || !is_protmode(ctxt->vcpu)) {
kvm_inject_gp(ctxt->vcpu, 0);
return -1;
}
@@ -1634,8 +1634,7 @@ emulate_sysexit(struct x86_emulate_ctxt *ctxt)
return -1;

/* inject #GP if in real mode or paging is disabled */
- if (ctxt->mode == X86EMUL_MODE_REAL
- || !kvm_read_cr0_bits(ctxt->vcpu, X86_CR0_PE)) {
+ if (ctxt->mode == X86EMUL_MODE_REAL || !is_protmode(ctxt->vcpu)) {
kvm_inject_gp(ctxt->vcpu, 0);
return -1;
}
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 372bc38..cd78049 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -1853,7 +1853,7 @@ static void vmx_get_segment(struct kvm_vcpu *vcpu,

static int vmx_get_cpl(struct kvm_vcpu *vcpu)
{
- if (!kvm_read_cr0_bits(vcpu, X86_CR0_PE)) /* if real mode */
+ if (!is_protmode(vcpu))
return 0;

if (vmx_get_rflags(vcpu) & X86_EFLAGS_VM) /* if virtual 8086 */
@@ -2108,7 +2108,7 @@ static bool cs_ss_rpl_check(struct kvm_vcpu *vcpu)
static bool guest_state_valid(struct kvm_vcpu *vcpu)
{
/* real mode guest state checks */
- if (!kvm_read_cr0_bits(vcpu, X86_CR0_PE)) {
+ if (!is_protmode(vcpu)) {
if (!rmode_segment_valid(vcpu, VCPU_SREG_CS))
return false;
if (!rmode_segment_valid(vcpu, VCPU_SREG_SS))
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 09207ba..6cdead0 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3798,8 +3798,7 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
* hypercall generates UD from non zero cpl and real mode
* per HYPER-V spec
*/
- if (kvm_x86_ops->get_cpl(vcpu) != 0 ||
- !kvm_read_cr0_bits(vcpu, X86_CR0_PE)) {
+ if (kvm_x86_ops->get_cpl(vcpu) != 0 || !is_protmode(vcpu)) {
kvm_queue_exception(vcpu, UD_VECTOR);
return 0;
}
@@ -4763,7 +4762,7 @@ int kvm_load_segment_descriptor(struct kvm_vcpu *vcpu, u16 selector,
{
struct kvm_segment kvm_seg;

- if (is_vm86_segment(vcpu, seg) || !(kvm_read_cr0_bits(vcpu, X86_CR0_PE)))
+ if (is_vm86_segment(vcpu, seg) || !is_protmode(vcpu))
return kvm_load_realmode_segment(vcpu, selector, seg);
if (load_segment_descriptor_to_kvm_desct(vcpu, selector, &kvm_seg))
return 1;
@@ -5115,7 +5114,7 @@ int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
/* Older userspace won't unhalt the vcpu on reset. */
if (kvm_vcpu_is_bsp(vcpu) && kvm_rip_read(vcpu) == 0xfff0 &&
sregs->cs.selector == 0xf000 && sregs->cs.base == 0xffff0000 &&
- !(kvm_read_cr0_bits(vcpu, X86_CR0_PE)))
+ !is_protmode(vcpu))
vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;

vcpu_put(vcpu);
diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index 5eadea5..f783d8f 100644
--- a/arch/x86/kvm/x86.h
+++ b/arch/x86/kvm/x86.h
@@ -2,6 +2,7 @@
#define ARCH_X86_KVM_X86_H

#include <linux/kvm_host.h>
+#include "kvm_cache_regs.h"

static inline void kvm_clear_exception_queue(struct kvm_vcpu *vcpu)
{
@@ -35,4 +36,9 @@ static inline bool kvm_exception_is_soft(unsigned int nr)
struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu,
u32 function, u32 index);

+static inline bool is_protmode(struct kvm_vcpu *vcpu)
+{
+ return kvm_read_cr0_bits(vcpu, X86_CR0_PE);
+}
+
#endif
--
1.6.5.3