Michael Kelley <mikelley@xxxxxxxxxxxxx> writes:
> 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@xxxxxxxxxxxxx>
> ---
> arch/x86/include/asm/hyperv-tlfs.h | 8 --------
> arch/x86/include/asm/kvm_host.h | 2 +-
> arch/x86/kvm/hyperv.c | 4 ++--
> 3 files changed, 3 insertions(+), 11 deletions(-)
>
> diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h
> index 29336574d0bc..0e4d76920957 100644
> --- a/arch/x86/include/asm/hyperv-tlfs.h
> +++ b/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. */
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index 42a2d0d3984a..4698343b9a05 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/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;
>
> diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
> index bcefa9d4e57e..1f3c6fd3cdaa 100644
> --- a/arch/x86/kvm/hyperv.c
> +++ b/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;
Reviewed-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
--
Vitaly
