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[1/4] KVM: x86: hyperv: Remove duplicate definitions of Reference TSC Page

Message ID 20200420173838.24672-2-mikelley@microsoft.com (mailing list archive)
State New, archived
Headers show
Series Split hyperv-tlfs.h into generic and arch specific files | expand

Commit Message

Michael Kelley (LINUX) April 20, 2020, 5:38 p.m. UTC
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>
---
 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(-)

Comments

Wei Liu April 21, 2020, 9:29 a.m. UTC | #1
On Mon, Apr 20, 2020 at 10:38:35AM -0700, Michael Kelley wrote:
> 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>
> ---
>  arch/x86/include/asm/hyperv-tlfs.h | 8 --------
>  arch/x86/include/asm/kvm_host.h    | 2 +-
>  arch/x86/kvm/hyperv.c              | 4 ++--

Paolo, this patch touches KVM code. Let me know how you would like to
handle this.

Wei.
Paolo Bonzini April 21, 2020, 11:16 a.m. UTC | #2
On 21/04/20 11:29, Wei Liu wrote:
> On Mon, Apr 20, 2020 at 10:38:35AM -0700, Michael Kelley wrote:
>> 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>
>> ---
>>  arch/x86/include/asm/hyperv-tlfs.h | 8 --------
>>  arch/x86/include/asm/kvm_host.h    | 2 +-
>>  arch/x86/kvm/hyperv.c              | 4 ++--
> 
> Paolo, this patch touches KVM code. Let me know how you would like to
> handle this.

Just include it, I don't expect conflicts.

Acked-by: Paolo Bonzini <pbonzini@redhat.com>

Paolo
Wei Liu April 21, 2020, 11:18 a.m. UTC | #3
On Tue, Apr 21, 2020 at 01:16:42PM +0200, Paolo Bonzini wrote:
> On 21/04/20 11:29, Wei Liu wrote:
> > On Mon, Apr 20, 2020 at 10:38:35AM -0700, Michael Kelley wrote:
> >> 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>
> >> ---
> >>  arch/x86/include/asm/hyperv-tlfs.h | 8 --------
> >>  arch/x86/include/asm/kvm_host.h    | 2 +-
> >>  arch/x86/kvm/hyperv.c              | 4 ++--
> > 
> > Paolo, this patch touches KVM code. Let me know how you would like to
> > handle this.
> 
> Just include it, I don't expect conflicts.
> 
> Acked-by: Paolo Bonzini <pbonzini@redhat.com>

Ack.
Vitaly Kuznetsov April 21, 2020, 12:37 p.m. UTC | #4
Michael Kelley <mikelley@microsoft.com> 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@microsoft.com>
> ---
>  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@redhat.com>
diff mbox series

Patch

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;