All of lore.kernel.org
 help / color / mirror / Atom feed
* [PATCH v2 0/3] x86/perfc: assorted adjustments
@ 2022-01-05 13:56 Jan Beulich
  2022-01-05 13:57 ` [PATCH v2 1/3] VMX: sync VM-exit perf counters with known VM-exit reasons Jan Beulich
                   ` (3 more replies)
  0 siblings, 4 replies; 9+ messages in thread
From: Jan Beulich @ 2022-01-05 13:56 UTC (permalink / raw)
  To: xen-devel; +Cc: Andrew Cooper, Wei Liu, Roger Pau Monné

Addressing some observations made while reviewing other patches.

1: VMX: sync VM-exit perf counters with known VM-exit reasons
2: SVM: sync VM-exit perf counters with known VM-exit reasons
3: x86/perfc: fold HVM's VM-exit counter arrays

Jan



^ permalink raw reply	[flat|nested] 9+ messages in thread
* [PATCH v2 1/3] VMX: sync VM-exit perf counters with known VM-exit reasons
  2022-01-05 13:56 [PATCH v2 0/3] x86/perfc: assorted adjustments Jan Beulich
@ 2022-01-05 13:57 ` Jan Beulich
  2022-01-30  3:08   ` Tian, Kevin
  2022-01-05 13:58 ` [PATCH v2 2/3] SVM: " Jan Beulich
                   ` (2 subsequent siblings)
  3 siblings, 1 reply; 9+ messages in thread
From: Jan Beulich @ 2022-01-05 13:57 UTC (permalink / raw)
  To: xen-devel
  Cc: Andrew Cooper, Wei Liu, Roger Pau Monné, Kevin Tian, Jun Nakajima

This has gone out of sync over time. Introduce a simplistic mechanism to
hopefully keep things in sync going forward.

Also limit the array index to just the "basic exit reason" part, which is
what the pseudo-enumeration covers.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
---
v2: Use sentinel comment only.

--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -3869,7 +3869,7 @@ void vmx_vmexit_handler(struct cpu_user_
     else
         HVMTRACE_ND(VMEXIT, 0, 1/*cycles*/, exit_reason, regs->eip);
 
-    perfc_incra(vmexits, exit_reason);
+    perfc_incra(vmexits, (uint16_t)exit_reason);
 
     /* Handle the interrupt we missed before allowing any more in. */
     switch ( (uint16_t)exit_reason )
--- a/xen/arch/x86/include/asm/hvm/vmx/vmx.h
+++ b/xen/arch/x86/include/asm/hvm/vmx/vmx.h
@@ -219,6 +219,7 @@ static inline void pi_clear_sn(struct pi
 #define EXIT_REASON_PML_FULL            62
 #define EXIT_REASON_XSAVES              63
 #define EXIT_REASON_XRSTORS             64
+/* Remember to also update VMX_PERF_EXIT_REASON_SIZE! */
 
 /*
  * Interruption-information format
--- a/xen/arch/x86/include/asm/perfc_defn.h
+++ b/xen/arch/x86/include/asm/perfc_defn.h
@@ -6,7 +6,7 @@ PERFCOUNTER_ARRAY(exceptions,
 
 #ifdef CONFIG_HVM
 
-#define VMX_PERF_EXIT_REASON_SIZE 56
+#define VMX_PERF_EXIT_REASON_SIZE 65
 #define VMX_PERF_VECTOR_SIZE 0x20
 PERFCOUNTER_ARRAY(vmexits,              "vmexits", VMX_PERF_EXIT_REASON_SIZE)
 PERFCOUNTER_ARRAY(cause_vector,         "cause vector", VMX_PERF_VECTOR_SIZE)



^ permalink raw reply	[flat|nested] 9+ messages in thread
* [PATCH v2 2/3] SVM: sync VM-exit perf counters with known VM-exit reasons
  2022-01-05 13:56 [PATCH v2 0/3] x86/perfc: assorted adjustments Jan Beulich
  2022-01-05 13:57 ` [PATCH v2 1/3] VMX: sync VM-exit perf counters with known VM-exit reasons Jan Beulich
@ 2022-01-05 13:58 ` Jan Beulich
  2022-02-22  9:21   ` Roger Pau Monné
  2022-01-05 13:59 ` [PATCH v2 3/3] x86/perfc: fold HVM's VM-exit counter arrays Jan Beulich
  2022-02-18  8:41 ` Ping: [PATCH v2 0/3] x86/perfc: assorted adjustments Jan Beulich
  3 siblings, 1 reply; 9+ messages in thread
From: Jan Beulich @ 2022-01-05 13:58 UTC (permalink / raw)
  To: xen-devel; +Cc: Andrew Cooper, Wei Liu, Roger Pau Monné

This has gone out of sync over time, resulting in NPF and XSETBV exits
incrementing the same counter. Introduce a simplistic mechanism to
hopefully keep things in better sync going forward.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
---
v2: Use sentinel comments only.

--- a/xen/arch/x86/include/asm/hvm/svm/vmcb.h
+++ b/xen/arch/x86/include/asm/hvm/svm/vmcb.h
@@ -302,7 +302,9 @@ enum VMEXIT_EXITCODE
     VMEXIT_MWAIT_CONDITIONAL= 140, /* 0x8c */
     VMEXIT_XSETBV           = 141, /* 0x8d */
     VMEXIT_RDPRU            = 142, /* 0x8e */
+    /* Remember to also update VMEXIT_NPF_PERFC! */
     VMEXIT_NPF              = 1024, /* 0x400, nested paging fault */
+    /* Remember to also update SVM_PERF_EXIT_REASON_SIZE! */
     VMEXIT_INVALID          =  -1
 };
 
--- a/xen/arch/x86/include/asm/perfc_defn.h
+++ b/xen/arch/x86/include/asm/perfc_defn.h
@@ -11,8 +11,8 @@ PERFCOUNTER_ARRAY(exceptions,
 PERFCOUNTER_ARRAY(vmexits,              "vmexits", VMX_PERF_EXIT_REASON_SIZE)
 PERFCOUNTER_ARRAY(cause_vector,         "cause vector", VMX_PERF_VECTOR_SIZE)
 
-#define VMEXIT_NPF_PERFC 141
-#define SVM_PERF_EXIT_REASON_SIZE (1+141)
+#define VMEXIT_NPF_PERFC 143
+#define SVM_PERF_EXIT_REASON_SIZE (VMEXIT_NPF_PERFC + 1)
 PERFCOUNTER_ARRAY(svmexits,             "SVMexits", SVM_PERF_EXIT_REASON_SIZE)
 
 #endif /* CONFIG_HVM */



^ permalink raw reply	[flat|nested] 9+ messages in thread
* [PATCH v2 3/3] x86/perfc: fold HVM's VM-exit counter arrays
  2022-01-05 13:56 [PATCH v2 0/3] x86/perfc: assorted adjustments Jan Beulich
  2022-01-05 13:57 ` [PATCH v2 1/3] VMX: sync VM-exit perf counters with known VM-exit reasons Jan Beulich
  2022-01-05 13:58 ` [PATCH v2 2/3] SVM: " Jan Beulich
@ 2022-01-05 13:59 ` Jan Beulich
  2022-02-22  9:40   ` Roger Pau Monné
  2022-02-18  8:41 ` Ping: [PATCH v2 0/3] x86/perfc: assorted adjustments Jan Beulich
  3 siblings, 1 reply; 9+ messages in thread
From: Jan Beulich @ 2022-01-05 13:59 UTC (permalink / raw)
  To: xen-devel; +Cc: Andrew Cooper, Wei Liu, Roger Pau Monné

Only one of them can be in use at a time, so make the whole set union-
like. While doing the rename in SVM code, combine the two perf_incra(),
generalizing the range upwards of VMEXIT_NPF.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
---
v2: New.

--- a/xen/arch/x86/hvm/svm/svm.c
+++ b/xen/arch/x86/hvm/svm/svm.c
@@ -2644,7 +2644,10 @@ void svm_vmexit_handler(struct cpu_user_
         goto out;
     }
 
-    perfc_incra(svmexits, exit_reason);
+    perfc_incra(vmexits,
+                exit_reason < VMEXIT_NPF
+                ? exit_reason
+                : exit_reason - VMEXIT_NPF + VMEXIT_NPF_PERFC);
 
     hvm_maybe_deassert_evtchn_irq();
 
@@ -2973,7 +2976,6 @@ void svm_vmexit_handler(struct cpu_user_
         break;
 
     case VMEXIT_NPF:
-        perfc_incra(svmexits, VMEXIT_NPF_PERFC);
         if ( cpu_has_svm_decode )
             v->arch.hvm.svm.cached_insn_len = vmcb->guest_ins_len & 0xf;
         rc = vmcb->exitinfo1 & PFEC_page_present
--- a/xen/arch/x86/include/asm/perfc_defn.h
+++ b/xen/arch/x86/include/asm/perfc_defn.h
@@ -7,13 +7,13 @@ PERFCOUNTER_ARRAY(exceptions,
 #ifdef CONFIG_HVM
 
 #define VMX_PERF_EXIT_REASON_SIZE 65
-#define VMX_PERF_VECTOR_SIZE 0x20
-PERFCOUNTER_ARRAY(vmexits,              "vmexits", VMX_PERF_EXIT_REASON_SIZE)
-PERFCOUNTER_ARRAY(cause_vector,         "cause vector", VMX_PERF_VECTOR_SIZE)
-
 #define VMEXIT_NPF_PERFC 143
 #define SVM_PERF_EXIT_REASON_SIZE (VMEXIT_NPF_PERFC + 1)
-PERFCOUNTER_ARRAY(svmexits,             "SVMexits", SVM_PERF_EXIT_REASON_SIZE)
+PERFCOUNTER_ARRAY(vmexits,              "vmexits",
+                  MAX(VMX_PERF_EXIT_REASON_SIZE, SVM_PERF_EXIT_REASON_SIZE))
+
+#define VMX_PERF_VECTOR_SIZE 0x20
+PERFCOUNTER_ARRAY(cause_vector,         "cause vector", VMX_PERF_VECTOR_SIZE)
 
 #endif /* CONFIG_HVM */
 



^ permalink raw reply	[flat|nested] 9+ messages in thread
* RE: [PATCH v2 1/3] VMX: sync VM-exit perf counters with known VM-exit reasons
  2022-01-05 13:57 ` [PATCH v2 1/3] VMX: sync VM-exit perf counters with known VM-exit reasons Jan Beulich
@ 2022-01-30  3:08   ` Tian, Kevin
  0 siblings, 0 replies; 9+ messages in thread
From: Tian, Kevin @ 2022-01-30  3:08 UTC (permalink / raw)
  To: Beulich, Jan, xen-devel
  Cc: Cooper, Andrew, Wei Liu, Pau Monné, Roger, Nakajima, Jun

> From: Beulich
> Sent: Wednesday, January 5, 2022 9:58 PM
> 
> This has gone out of sync over time. Introduce a simplistic mechanism to
> hopefully keep things in sync going forward.
> 
> Also limit the array index to just the "basic exit reason" part, which is
> what the pseudo-enumeration covers.
> 
> Signed-off-by: Jan Beulich <jbeulich@suse.com>

Reviewed-by: Kevin Tian <kevin.tian@intel.com>

> ---
> v2: Use sentinel comment only.
> 
> --- a/xen/arch/x86/hvm/vmx/vmx.c
> +++ b/xen/arch/x86/hvm/vmx/vmx.c
> @@ -3869,7 +3869,7 @@ void vmx_vmexit_handler(struct cpu_user_
>      else
>          HVMTRACE_ND(VMEXIT, 0, 1/*cycles*/, exit_reason, regs->eip);
> 
> -    perfc_incra(vmexits, exit_reason);
> +    perfc_incra(vmexits, (uint16_t)exit_reason);
> 
>      /* Handle the interrupt we missed before allowing any more in. */
>      switch ( (uint16_t)exit_reason )
> --- a/xen/arch/x86/include/asm/hvm/vmx/vmx.h
> +++ b/xen/arch/x86/include/asm/hvm/vmx/vmx.h
> @@ -219,6 +219,7 @@ static inline void pi_clear_sn(struct pi
>  #define EXIT_REASON_PML_FULL            62
>  #define EXIT_REASON_XSAVES              63
>  #define EXIT_REASON_XRSTORS             64
> +/* Remember to also update VMX_PERF_EXIT_REASON_SIZE! */
> 
>  /*
>   * Interruption-information format
> --- a/xen/arch/x86/include/asm/perfc_defn.h
> +++ b/xen/arch/x86/include/asm/perfc_defn.h
> @@ -6,7 +6,7 @@ PERFCOUNTER_ARRAY(exceptions,
> 
>  #ifdef CONFIG_HVM
> 
> -#define VMX_PERF_EXIT_REASON_SIZE 56
> +#define VMX_PERF_EXIT_REASON_SIZE 65
>  #define VMX_PERF_VECTOR_SIZE 0x20
>  PERFCOUNTER_ARRAY(vmexits,              "vmexits",
> VMX_PERF_EXIT_REASON_SIZE)
>  PERFCOUNTER_ARRAY(cause_vector,         "cause vector",
> VMX_PERF_VECTOR_SIZE)
> 


^ permalink raw reply	[flat|nested] 9+ messages in thread
* Ping: [PATCH v2 0/3] x86/perfc: assorted adjustments
  2022-01-05 13:56 [PATCH v2 0/3] x86/perfc: assorted adjustments Jan Beulich
                   ` (2 preceding siblings ...)
  2022-01-05 13:59 ` [PATCH v2 3/3] x86/perfc: fold HVM's VM-exit counter arrays Jan Beulich
@ 2022-02-18  8:41 ` Jan Beulich
  3 siblings, 0 replies; 9+ messages in thread
From: Jan Beulich @ 2022-02-18  8:41 UTC (permalink / raw)
  To: Andrew Cooper, Roger Pau Monné; +Cc: Wei Liu, xen-devel

On 05.01.2022 14:56, Jan Beulich wrote:
> Addressing some observations made while reviewing other patches.
> 
> 1: VMX: sync VM-exit perf counters with known VM-exit reasons
> 2: SVM: sync VM-exit perf counters with known VM-exit reasons
> 3: x86/perfc: fold HVM's VM-exit counter arrays

Patch 1 has gone in a little while ago. Would be nice for the other
two to also be acked, or for adjustment requests to be voiced.

Thanks, Jan



^ permalink raw reply	[flat|nested] 9+ messages in thread
* Re: [PATCH v2 2/3] SVM: sync VM-exit perf counters with known VM-exit reasons
  2022-01-05 13:58 ` [PATCH v2 2/3] SVM: " Jan Beulich
@ 2022-02-22  9:21   ` Roger Pau Monné
  0 siblings, 0 replies; 9+ messages in thread
From: Roger Pau Monné @ 2022-02-22  9:21 UTC (permalink / raw)
  To: Jan Beulich; +Cc: xen-devel, Andrew Cooper, Wei Liu

On Wed, Jan 05, 2022 at 02:58:11PM +0100, Jan Beulich wrote:
> This has gone out of sync over time, resulting in NPF and XSETBV exits
> incrementing the same counter. Introduce a simplistic mechanism to
> hopefully keep things in better sync going forward.
> 
> Signed-off-by: Jan Beulich <jbeulich@suse.com>

Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>

Thanks, Roger.


^ permalink raw reply	[flat|nested] 9+ messages in thread
* Re: [PATCH v2 3/3] x86/perfc: fold HVM's VM-exit counter arrays
  2022-01-05 13:59 ` [PATCH v2 3/3] x86/perfc: fold HVM's VM-exit counter arrays Jan Beulich
@ 2022-02-22  9:40   ` Roger Pau Monné
  2022-02-22  9:59     ` Jan Beulich
  0 siblings, 1 reply; 9+ messages in thread
From: Roger Pau Monné @ 2022-02-22  9:40 UTC (permalink / raw)
  To: Jan Beulich; +Cc: xen-devel, Andrew Cooper, Wei Liu

On Wed, Jan 05, 2022 at 02:59:03PM +0100, Jan Beulich wrote:
> Only one of them can be in use at a time, so make the whole set union-
> like. While doing the rename in SVM code, combine the two perf_incra(),
> generalizing the range upwards of VMEXIT_NPF.
> 
> Signed-off-by: Jan Beulich <jbeulich@suse.com>

Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>

> ---
> v2: New.
> 
> --- a/xen/arch/x86/hvm/svm/svm.c
> +++ b/xen/arch/x86/hvm/svm/svm.c
> @@ -2644,7 +2644,10 @@ void svm_vmexit_handler(struct cpu_user_
>          goto out;
>      }
>  
> -    perfc_incra(svmexits, exit_reason);
> +    perfc_incra(vmexits,
> +                exit_reason < VMEXIT_NPF
> +                ? exit_reason
> +                : exit_reason - VMEXIT_NPF + VMEXIT_NPF_PERFC);

Should we assert that the index used here < SVM_PERF_EXIT_REASON_SIZE?

Just so that adding new exit reasons without increasing
SVM_PERF_EXIT_REASON_SIZE is not likely to go unnoticed?

Thanks, Roger.


^ permalink raw reply	[flat|nested] 9+ messages in thread
* Re: [PATCH v2 3/3] x86/perfc: fold HVM's VM-exit counter arrays
  2022-02-22  9:40   ` Roger Pau Monné
@ 2022-02-22  9:59     ` Jan Beulich
  0 siblings, 0 replies; 9+ messages in thread
From: Jan Beulich @ 2022-02-22  9:59 UTC (permalink / raw)
  To: Roger Pau Monné; +Cc: xen-devel, Andrew Cooper, Wei Liu

On 22.02.2022 10:40, Roger Pau Monné wrote:
> On Wed, Jan 05, 2022 at 02:59:03PM +0100, Jan Beulich wrote:
>> Only one of them can be in use at a time, so make the whole set union-
>> like. While doing the rename in SVM code, combine the two perf_incra(),
>> generalizing the range upwards of VMEXIT_NPF.
>>
>> Signed-off-by: Jan Beulich <jbeulich@suse.com>
> 
> Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>

Thanks.

>> --- a/xen/arch/x86/hvm/svm/svm.c
>> +++ b/xen/arch/x86/hvm/svm/svm.c
>> @@ -2644,7 +2644,10 @@ void svm_vmexit_handler(struct cpu_user_
>>          goto out;
>>      }
>>  
>> -    perfc_incra(svmexits, exit_reason);
>> +    perfc_incra(vmexits,
>> +                exit_reason < VMEXIT_NPF
>> +                ? exit_reason
>> +                : exit_reason - VMEXIT_NPF + VMEXIT_NPF_PERFC);
> 
> Should we assert that the index used here < SVM_PERF_EXIT_REASON_SIZE?
> 
> Just so that adding new exit reasons without increasing
> SVM_PERF_EXIT_REASON_SIZE is not likely to go unnoticed?

But that's what the comments are for that the previous patch adds.

Jan



^ permalink raw reply	[flat|nested] 9+ messages in thread
end of thread, other threads:[~2022-02-22  9:59 UTC | newest]

Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-01-05 13:56 [PATCH v2 0/3] x86/perfc: assorted adjustments Jan Beulich
2022-01-05 13:57 ` [PATCH v2 1/3] VMX: sync VM-exit perf counters with known VM-exit reasons Jan Beulich
2022-01-30  3:08   ` Tian, Kevin
2022-01-05 13:58 ` [PATCH v2 2/3] SVM: " Jan Beulich
2022-02-22  9:21   ` Roger Pau Monné
2022-01-05 13:59 ` [PATCH v2 3/3] x86/perfc: fold HVM's VM-exit counter arrays Jan Beulich
2022-02-22  9:40   ` Roger Pau Monné
2022-02-22  9:59     ` Jan Beulich
2022-02-18  8:41 ` Ping: [PATCH v2 0/3] x86/perfc: assorted adjustments Jan Beulich

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.