KVM: Use kvm_{read,write}_guest_virt() to read and write segment descriptors

Segment descriptors tables can be placed on two non-contiguous pages.
This patch makes reading segment descriptors by linear address.

Signed-off-by: Mikhail Ershov <Mike.Ershov@gmail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index c0e9427..59a8ba4 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4021,7 +4021,6 @@ static void get_segment_descriptor_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;
 
@@ -4031,16 +4030,13 @@ static int load_guest_segment_descriptor(struct kvm_vcpu *vcpu, u16 selector,
                kvm_queue_exception_e(vcpu, GP_VECTOR, selector & 0xfffc);
                return 1;
        }
-       gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, dtable.base);
-       gpa += index * 8;
-       return kvm_read_guest(vcpu->kvm, gpa, seg_desc, 8);
+       return kvm_read_guest_virt(dtable.base + index*8, seg_desc, sizeof(*seg_desc), vcpu);
 }
 
 /* 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;
 
@@ -4048,9 +4044,7 @@ static int save_guest_segment_descriptor(struct kvm_vcpu *vcpu, u16 selector,
 
        if (dtable.limit < index * 8 + 7)
                return 1;
-       gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, dtable.base);
-       gpa += index * 8;
-       return kvm_write_guest(vcpu->kvm, gpa, seg_desc, 8);
+       return kvm_write_guest_virt(dtable.base + index*8, seg_desc, sizeof(*seg_desc), vcpu);
 }
 
 static u32 get_tss_base_addr(struct kvm_vcpu *vcpu,