KVM: Remove set_cr0_no_modeswitch() arch op

set_cr0_no_modeswitch() was a hack to avoid corrupting segment registers.
As we now cache the protected mode values on entry to real mode, this
isn't an issue anymore, and it interferes with reboot (which usually _is_
a modeswitch).

Signed-off-by: Avi Kivity <avi@qumranet.com>

4 files changed, 1 insertions, 21 deletions

diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index a4331da816d..7361c45d70c 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -383,8 +383,6 @@ struct kvm_arch_ops {
         void (*get_cs_db_l_bits)(struct kvm_vcpu *vcpu, int *db, int *l);
         void (*decache_cr0_cr4_guest_bits)(struct kvm_vcpu *vcpu);
         void (*set_cr0)(struct kvm_vcpu *vcpu, unsigned long cr0);
-        void (*set_cr0_no_modeswitch)(struct kvm_vcpu *vcpu,
-                                      unsigned long cr0);
         void (*set_cr3)(struct kvm_vcpu *vcpu, unsigned long cr3);
         void (*set_cr4)(struct kvm_vcpu *vcpu, unsigned long cr4);
         void (*set_efer)(struct kvm_vcpu *vcpu, u64 efer);
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index 205998c141f..b998bc68e9f 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -1936,7 +1936,7 @@ static int kvm_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
         kvm_arch_ops->decache_cr0_cr4_guest_bits(vcpu);
 
         mmu_reset_needed |= vcpu->cr0 != sregs->cr0;
-        kvm_arch_ops->set_cr0_no_modeswitch(vcpu, sregs->cr0);
+        kvm_arch_ops->set_cr0(vcpu, sregs->cr0);
 
         mmu_reset_needed |= vcpu->cr4 != sregs->cr4;
         kvm_arch_ops->set_cr4(vcpu, sregs->cr4);
diff --git a/drivers/kvm/svm.c b/drivers/kvm/svm.c
index 64afc5cf890..d3cc1157d23 100644
--- a/drivers/kvm/svm.c
+++ b/drivers/kvm/svm.c
@@ -1716,7 +1716,6 @@ static struct kvm_arch_ops svm_arch_ops = {
         .get_cs_db_l_bits = svm_get_cs_db_l_bits,
         .decache_cr0_cr4_guest_bits = svm_decache_cr0_cr4_guest_bits,
         .set_cr0 = svm_set_cr0,
-        .set_cr0_no_modeswitch = svm_set_cr0,
         .set_cr3 = svm_set_cr3,
         .set_cr4 = svm_set_cr4,
         .set_efer = svm_set_efer,
diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c
index aa7e2ba6fb5..027a9625ef9 100644
--- a/drivers/kvm/vmx.c
+++ b/drivers/kvm/vmx.c
@@ -788,22 +788,6 @@ static void vmx_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
         vcpu->cr0 = cr0;
 }
 
-/*
- * Used when restoring the VM to avoid corrupting segment registers
- */
-static void vmx_set_cr0_no_modeswitch(struct kvm_vcpu *vcpu, unsigned long cr0)
-{
-        if (!vcpu->rmode.active && !(cr0 & CR0_PE_MASK))
-                enter_rmode(vcpu);
-
-        vcpu->rmode.active = ((cr0 & CR0_PE_MASK) == 0);
-        update_exception_bitmap(vcpu);
-        vmcs_writel(CR0_READ_SHADOW, cr0);
-        vmcs_writel(GUEST_CR0,
-                    (cr0 & ~KVM_GUEST_CR0_MASK) | KVM_VM_CR0_ALWAYS_ON);
-        vcpu->cr0 = cr0;
-}
-
 static void vmx_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
 {
         vmcs_writel(GUEST_CR3, cr3);
@@ -2069,7 +2053,6 @@ static struct kvm_arch_ops vmx_arch_ops = {
         .get_cs_db_l_bits = vmx_get_cs_db_l_bits,
         .decache_cr0_cr4_guest_bits = vmx_decache_cr0_cr4_guest_bits,
         .set_cr0 = vmx_set_cr0,
-        .set_cr0_no_modeswitch = vmx_set_cr0_no_modeswitch,
         .set_cr3 = vmx_set_cr3,
         .set_cr4 = vmx_set_cr4,
 #ifdef CONFIG_X86_64