selftests: kvm: Fix the segment descriptor layout to match the actual layout

Fix the layout of 'struct desc64' to match the layout described in the
SDM Vol 3, Chapter 3 "Protected-Mode Memory Management", section 3.4.5
"Segment Descriptors", Figure 3-8 "Segment Descriptor".  The test added
later in this series relies on this and crashes if this layout is not
correct.

Signed-off-by: Aaron Lewis <aaronlewis@google.com>
Reviewed-by: Alexander Graf <graf@amazon.com>
Message-Id: <20201012194716.3950330-2-aaronlewis@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h
index 82b7fe1..0a65e7b 100644 (file)
--- a/tools/testing/selftests/kvm/include/x86_64/processor.h
+++ b/tools/testing/selftests/kvm/include/x86_64/processor.h
@@ -59,7 +59,7 @@ struct gpr64_regs {
 struct desc64 {
        uint16_t limit0;
        uint16_t base0;
-       unsigned base1:8, s:1, type:4, dpl:2, p:1;
+       unsigned base1:8, type:4, s:1, dpl:2, p:1;
        unsigned limit1:4, avl:1, l:1, db:1, g:1, base2:8;
        uint32_t base3;
        uint32_t zero1;

diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c
index f6eb34e..1ccf6c9 100644 (file)
--- a/tools/testing/selftests/kvm/lib/x86_64/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c
@@ -392,11 +392,12 @@ static void kvm_seg_fill_gdt_64bit(struct kvm_vm *vm, struct kvm_segment *segp)
        desc->limit0 = segp->limit & 0xFFFF;
        desc->base0 = segp->base & 0xFFFF;
        desc->base1 = segp->base >> 16;
-       desc->s = segp->s;
        desc->type = segp->type;
+       desc->s = segp->s;
        desc->dpl = segp->dpl;
        desc->p = segp->present;
        desc->limit1 = segp->limit >> 16;
+       desc->avl = segp->avl;
        desc->l = segp->l;
        desc->db = segp->db;
        desc->g = segp->g;