[PATCH v4 02/25] x86/hyperv: Fix 'struct hv_enlightened_vmcs' definition

Vitaly Kuznetsov
2022-07-14T09:13:52Z

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>
---
arch/x86/include/asm/hyperv-tlfs.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h
index 0a9407dc0859..6f0acc45e67a 100644
--- a/arch/x86/include/asm/hyperv-tlfs.h
+++ b/arch/x86/include/asm/hyperv-tlfs.h
@@ -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];
--
2.35.3