KVM: x86: hyperv: Remove duplicate definitions of Reference TSC Page

The Hyper-V Reference TSC Page structure is defined twice. struct
ms_hyperv_tsc_page has padding out to a full 4 Kbyte page size. But
the padding is not needed because the declaration includes a union
with HV_HYP_PAGE_SIZE.  KVM uses the second definition, which is
struct _HV_REFERENCE_TSC_PAGE, because it does not have the padding.

Fix the duplication by removing the padding from ms_hyperv_tsc_page.
Fix up the KVM code to use it. Remove the no longer used struct
_HV_REFERENCE_TSC_PAGE.

There is no functional change.
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Link: https://lore.kernel.org/r/20200422195737.10223-2-mikelley@microsoft.comSigned-off-by: Wei Liu <wei.liu@kernel.org>

arch/x86/include/asm/hyperv-tlfs.h

@@ -303,7 +303,6 @@ struct ms_hyperv_tsc_page {
 	u32 reserved1;
 	volatile u64 tsc_scale;
 	volatile s64 tsc_offset;
-	u64 reserved2[509];
 }  __packed;
 
 /*
@@ -433,13 +432,6 @@ enum HV_GENERIC_SET_FORMAT {
  */
 #define HV_CLOCK_HZ (NSEC_PER_SEC/100)
 
-typedef struct _HV_REFERENCE_TSC_PAGE {
-	__u32 tsc_sequence;
-	__u32 res1;
-	__u64 tsc_scale;
-	__s64 tsc_offset;
-}  __packed HV_REFERENCE_TSC_PAGE, *PHV_REFERENCE_TSC_PAGE;
-
 /* Define the number of synthetic interrupt sources. */
 #define HV_SYNIC_SINT_COUNT		(16)
 /* Define the expected SynIC version. */

arch/x86/include/asm/kvm_host.h

@@ -865,7 +865,7 @@ struct kvm_hv {
 	u64 hv_crash_param[HV_X64_MSR_CRASH_PARAMS];
 	u64 hv_crash_ctl;
 
-	HV_REFERENCE_TSC_PAGE tsc_ref;
+	struct ms_hyperv_tsc_page tsc_ref;
 
 	struct idr conn_to_evt;
 

arch/x86/kvm/hyperv.c

@@ -900,7 +900,7 @@ static int kvm_hv_msr_set_crash_data(struct kvm_vcpu *vcpu,
  * These two equivalencies are implemented in this function.
  */
 static bool compute_tsc_page_parameters(struct pvclock_vcpu_time_info *hv_clock,
-					HV_REFERENCE_TSC_PAGE *tsc_ref)
+					struct ms_hyperv_tsc_page *tsc_ref)
 {
 	u64 max_mul;
 
@@ -941,7 +941,7 @@ void kvm_hv_setup_tsc_page(struct kvm *kvm,
 	u64 gfn;
 
 	BUILD_BUG_ON(sizeof(tsc_seq) != sizeof(hv->tsc_ref.tsc_sequence));
-	BUILD_BUG_ON(offsetof(HV_REFERENCE_TSC_PAGE, tsc_sequence) != 0);
+	BUILD_BUG_ON(offsetof(struct ms_hyperv_tsc_page, tsc_sequence) != 0);
 
 	if (!(hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE))
 		return;