1 files changed, 43 insertions, 66 deletions

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 9f1cdb011cff..5916191420c7 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3184,6 +3184,10 @@ static void seg_desct_to_kvm_desct(struct desc_struct *seg_desc, u16 selector,
         kvm_desct->base |= seg_desc->base2 << 24;
         kvm_desct->limit = seg_desc->limit0;
         kvm_desct->limit |= seg_desc->limit << 16;
+        if (seg_desc->g) {
+                kvm_desct->limit <<= 12;
+                kvm_desct->limit |= 0xfff;
+        }
         kvm_desct->selector = selector;
         kvm_desct->type = seg_desc->type;
         kvm_desct->present = seg_desc->p;
@@ -3223,6 +3227,7 @@ static void get_segment_descritptor_dtable(struct kvm_vcpu *vcpu,
 static int load_guest_segment_descriptor(struct kvm_vcpu *vcpu, u16 selector,
                                          struct desc_struct *seg_desc)
 {
+        gpa_t gpa;
         struct descriptor_table dtable;
         u16 index = selector >> 3;
 
@@ -3232,13 +3237,16 @@ static int load_guest_segment_descriptor(struct kvm_vcpu *vcpu, u16 selector,
                 kvm_queue_exception_e(vcpu, GP_VECTOR, selector & 0xfffc);
                 return 1;
         }
-        return kvm_read_guest(vcpu->kvm, dtable.base + index * 8, seg_desc, 8);
+        gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, dtable.base);
+        gpa += index * 8;
+        return kvm_read_guest(vcpu->kvm, gpa, seg_desc, 8);
 }
 
 /* allowed just for 8 bytes segments */
 static int save_guest_segment_descriptor(struct kvm_vcpu *vcpu, u16 selector,
                                          struct desc_struct *seg_desc)
 {
+        gpa_t gpa;
         struct descriptor_table dtable;
         u16 index = selector >> 3;
 
@@ -3246,7 +3254,9 @@ static int save_guest_segment_descriptor(struct kvm_vcpu *vcpu, u16 selector,
 
         if (dtable.limit < index * 8 + 7)
                 return 1;
-        return kvm_write_guest(vcpu->kvm, dtable.base + index * 8, seg_desc, 8);
+        gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, dtable.base);
+        gpa += index * 8;
+        return kvm_write_guest(vcpu->kvm, gpa, seg_desc, 8);
 }
 
 static u32 get_tss_base_addr(struct kvm_vcpu *vcpu,
@@ -3258,55 +3268,7 @@ static u32 get_tss_base_addr(struct kvm_vcpu *vcpu,
         base_addr |= (seg_desc->base1 << 16);
         base_addr |= (seg_desc->base2 << 24);
 
-        return base_addr;
-}
-
-static int load_tss_segment32(struct kvm_vcpu *vcpu,
-                              struct desc_struct *seg_desc,
-                              struct tss_segment_32 *tss)
-{
-        u32 base_addr;
-
-        base_addr = get_tss_base_addr(vcpu, seg_desc);
-
-        return kvm_read_guest(vcpu->kvm, base_addr, tss,
-                              sizeof(struct tss_segment_32));
-}
-
-static int save_tss_segment32(struct kvm_vcpu *vcpu,
-                              struct desc_struct *seg_desc,
-                              struct tss_segment_32 *tss)
-{
-        u32 base_addr;
-
-        base_addr = get_tss_base_addr(vcpu, seg_desc);
-
-        return kvm_write_guest(vcpu->kvm, base_addr, tss,
-                               sizeof(struct tss_segment_32));
-}
-
-static int load_tss_segment16(struct kvm_vcpu *vcpu,
-                              struct desc_struct *seg_desc,
-                              struct tss_segment_16 *tss)
-{
-        u32 base_addr;
-
-        base_addr = get_tss_base_addr(vcpu, seg_desc);
-
-        return kvm_read_guest(vcpu->kvm, base_addr, tss,
-                              sizeof(struct tss_segment_16));
-}
-
-static int save_tss_segment16(struct kvm_vcpu *vcpu,
-                              struct desc_struct *seg_desc,
-                              struct tss_segment_16 *tss)
-{
-        u32 base_addr;
-
-        base_addr = get_tss_base_addr(vcpu, seg_desc);
-
-        return kvm_write_guest(vcpu->kvm, base_addr, tss,
-                               sizeof(struct tss_segment_16));
+        return vcpu->arch.mmu.gva_to_gpa(vcpu, base_addr);
 }
 
 static u16 get_segment_selector(struct kvm_vcpu *vcpu, int seg)
@@ -3466,20 +3428,26 @@ static int load_state_from_tss16(struct kvm_vcpu *vcpu,
 }
 
 static int kvm_task_switch_16(struct kvm_vcpu *vcpu, u16 tss_selector,
-                       struct desc_struct *cseg_desc,
+                       u32 old_tss_base,
                        struct desc_struct *nseg_desc)
 {
         struct tss_segment_16 tss_segment_16;
         int ret = 0;
 
-        if (load_tss_segment16(vcpu, cseg_desc, &tss_segment_16))
+        if (kvm_read_guest(vcpu->kvm, old_tss_base, &tss_segment_16,
+                           sizeof tss_segment_16))
                 goto out;
 
         save_state_to_tss16(vcpu, &tss_segment_16);
-        save_tss_segment16(vcpu, cseg_desc, &tss_segment_16);
 
-        if (load_tss_segment16(vcpu, nseg_desc, &tss_segment_16))
+        if (kvm_write_guest(vcpu->kvm, old_tss_base, &tss_segment_16,
+                            sizeof tss_segment_16))
                 goto out;
+
+        if (kvm_read_guest(vcpu->kvm, get_tss_base_addr(vcpu, nseg_desc),
+                           &tss_segment_16, sizeof tss_segment_16))
+                goto out;
+
         if (load_state_from_tss16(vcpu, &tss_segment_16))
                 goto out;
 
@@ -3489,20 +3457,26 @@ out:
 }
 
 static int kvm_task_switch_32(struct kvm_vcpu *vcpu, u16 tss_selector,
-                       struct desc_struct *cseg_desc,
+                       u32 old_tss_base,
                        struct desc_struct *nseg_desc)
 {
         struct tss_segment_32 tss_segment_32;
         int ret = 0;
 
-        if (load_tss_segment32(vcpu, cseg_desc, &tss_segment_32))
+        if (kvm_read_guest(vcpu->kvm, old_tss_base, &tss_segment_32,
+                           sizeof tss_segment_32))
                 goto out;
 
         save_state_to_tss32(vcpu, &tss_segment_32);
-        save_tss_segment32(vcpu, cseg_desc, &tss_segment_32);
 
-        if (load_tss_segment32(vcpu, nseg_desc, &tss_segment_32))
+        if (kvm_write_guest(vcpu->kvm, old_tss_base, &tss_segment_32,
+                            sizeof tss_segment_32))
+                goto out;
+
+        if (kvm_read_guest(vcpu->kvm, get_tss_base_addr(vcpu, nseg_desc),
+                           &tss_segment_32, sizeof tss_segment_32))
                 goto out;
+
         if (load_state_from_tss32(vcpu, &tss_segment_32))
                 goto out;
 
@@ -3517,16 +3491,20 @@ int kvm_task_switch(struct kvm_vcpu *vcpu, u16 tss_selector, int reason)
         struct desc_struct cseg_desc;
         struct desc_struct nseg_desc;
         int ret = 0;
+        u32 old_tss_base = get_segment_base(vcpu, VCPU_SREG_TR);
+        u16 old_tss_sel = get_segment_selector(vcpu, VCPU_SREG_TR);
 
-        kvm_get_segment(vcpu, &tr_seg, VCPU_SREG_TR);
+        old_tss_base = vcpu->arch.mmu.gva_to_gpa(vcpu, old_tss_base);
 
+        /* FIXME: Handle errors. Failure to read either TSS or their
+         * descriptors should generate a pagefault.
+         */
         if (load_guest_segment_descriptor(vcpu, tss_selector, &nseg_desc))
                 goto out;
 
-        if (load_guest_segment_descriptor(vcpu, tr_seg.selector, &cseg_desc))
+        if (load_guest_segment_descriptor(vcpu, old_tss_sel, &cseg_desc))
                 goto out;
 
-
         if (reason != TASK_SWITCH_IRET) {
                 int cpl;
 
@@ -3544,8 +3522,7 @@ int kvm_task_switch(struct kvm_vcpu *vcpu, u16 tss_selector, int reason)
 
         if (reason == TASK_SWITCH_IRET || reason == TASK_SWITCH_JMP) {
                 cseg_desc.type &= ~(1 << 1); //clear the B flag
-                save_guest_segment_descriptor(vcpu, tr_seg.selector,
-                                              &cseg_desc);
+                save_guest_segment_descriptor(vcpu, old_tss_sel, &cseg_desc);
         }
 
         if (reason == TASK_SWITCH_IRET) {
@@ -3557,10 +3534,10 @@ int kvm_task_switch(struct kvm_vcpu *vcpu, u16 tss_selector, int reason)
         kvm_x86_ops->cache_regs(vcpu);
 
         if (nseg_desc.type & 8)
-                ret = kvm_task_switch_32(vcpu, tss_selector, &cseg_desc,
+                ret = kvm_task_switch_32(vcpu, tss_selector, old_tss_base,
                                          &nseg_desc);
         else
-                ret = kvm_task_switch_16(vcpu, tss_selector, &cseg_desc,
+                ret = kvm_task_switch_16(vcpu, tss_selector, old_tss_base,
                                          &nseg_desc);
 
         if (reason == TASK_SWITCH_CALL || reason == TASK_SWITCH_GATE) {