x86/hyperv: Fix 'struct hv_enlightened_vmcs' definition
authorVitaly Kuznetsov <vkuznets@redhat.com>
Tue, 30 Aug 2022 13:37:05 +0000 (15:37 +0200)
committerPaolo Bonzini <pbonzini@redhat.com>
Mon, 26 Sep 2022 16:02:36 +0000 (12:02 -0400)
Section 1.9 of TLFS v6.0b says:

"All structures are padded in such a way that fields are aligned
naturally (that is, an 8-byte field is aligned to an offset of 8 bytes
and so on)".

'struct enlightened_vmcs' has a glitch:

...
        struct {
                u32                nested_flush_hypercall:1; /*   836: 0  4 */
                u32                msr_bitmap:1;         /*   836: 1  4 */
                u32                reserved:30;          /*   836: 2  4 */
        } hv_enlightenments_control;                     /*   836     4 */
        u32                        hv_vp_id;             /*   840     4 */
        u64                        hv_vm_id;             /*   844     8 */
        u64                        partition_assist_page; /*   852     8 */
...

And the observed values in 'partition_assist_page' make no sense at
all. Fix the layout by padding the structure properly.

Fixes: 68d1eb72ee99 ("x86/hyper-v: define struct hv_enlightened_vmcs and clean field bits")
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20220830133737.1539624-2-vkuznets@redhat.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
arch/x86/include/asm/hyperv-tlfs.h

index 0a9407d..6f0acc4 100644 (file)
@@ -546,7 +546,7 @@ struct hv_enlightened_vmcs {
        u64 guest_rip;
 
        u32 hv_clean_fields;
-       u32 hv_padding_32;
+       u32 padding32_1;
        u32 hv_synthetic_controls;
        struct {
                u32 nested_flush_hypercall:1;
@@ -554,7 +554,7 @@ struct hv_enlightened_vmcs {
                u32 reserved:30;
        }  __packed hv_enlightenments_control;
        u32 hv_vp_id;
-
+       u32 padding32_2;
        u64 hv_vm_id;
        u64 partition_assist_page;
        u64 padding64_4[4];