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* [PATCH] i386/cpu: Adjust cpuid addresable id count to match the spec
@ 2022-10-10  2:49 Ilya Oleinik
  2022-10-28  0:53 ` Wang, Lei
  0 siblings, 1 reply; 3+ messages in thread
From: Ilya Oleinik @ 2022-10-10  2:49 UTC (permalink / raw)
  To: qemu-devel; +Cc: pbonzini, yang.zhong, f4bug, richard.henderson

For EBX bits 23 - 16 in CPUID[01] Intel's manual states:
"
*   The nearest power-of-2 integer that is not smaller than EBX[23:16]
    is the number of unique initial APICIDs reserved for addressing
    different logical processors in a physical package. This field is
    only valid if CPUID.1.EDX.HTT[bit 28]= 1.
"
Ensure this condition is met.

Additionally, apply efb3934adf9ee7794db7e0ade9f576c634592891 to
non passthrough cache mode.

Signed-off-by: Ilya Oleinik <ilyaoleinik1@gmail.com>
---
 target/i386/cpu.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index ad623d91e4..e793bcc03f 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -245,8 +245,8 @@ static void encode_cache_cpuid4(CPUCacheInfo *cache,
     *eax = CACHE_TYPE(cache->type) |
            CACHE_LEVEL(cache->level) |
            (cache->self_init ? CACHE_SELF_INIT_LEVEL : 0) |
-           ((num_cores - 1) << 26) |
-           ((num_apic_ids - 1) << 14);
+           ((pow2ceil(num_cores) - 1) << 26) |
+           ((pow2ceil(num_apic_ids) - 1) << 14);
 
     assert(cache->line_size > 0);
     assert(cache->partitions > 0);
@@ -5258,7 +5258,7 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count,
         }
         *edx = env->features[FEAT_1_EDX];
         if (cs->nr_cores * cs->nr_threads > 1) {
-            *ebx |= (cs->nr_cores * cs->nr_threads) << 16;
+            *ebx |= (pow2ceil(cs->nr_cores * cs->nr_threads)) << 16;
             *edx |= CPUID_HT;
         }
         if (!cpu->enable_pmu) {
@@ -5313,12 +5313,12 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count,
             switch (count) {
             case 0: /* L1 dcache info */
                 encode_cache_cpuid4(env->cache_info_cpuid4.l1d_cache,
-                                    1, cs->nr_cores,
+                                    cs->nr_threads, cs->nr_cores,
                                     eax, ebx, ecx, edx);
                 break;
             case 1: /* L1 icache info */
                 encode_cache_cpuid4(env->cache_info_cpuid4.l1i_cache,
-                                    1, cs->nr_cores,
+                                    cs->nr_threads, cs->nr_cores,
                                     eax, ebx, ecx, edx);
                 break;
             case 2: /* L2 cache info */
-- 
2.37.2.windows.2



^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH] i386/cpu: Adjust cpuid addresable id count to match the spec
  2022-10-10  2:49 [PATCH] i386/cpu: Adjust cpuid addresable id count to match the spec Ilya Oleinik
@ 2022-10-28  0:53 ` Wang, Lei
  2022-11-03  8:11   ` Ilya Oleinik
  0 siblings, 1 reply; 3+ messages in thread
From: Wang, Lei @ 2022-10-28  0:53 UTC (permalink / raw)
  To: Ilya Oleinik, qemu-devel; +Cc: pbonzini, yang.zhong, f4bug, richard.henderson


On 10/10/2022 10:49 AM, Ilya Oleinik wrote:
> For EBX bits 23 - 16 in CPUID[01] Intel's manual states:
> "
> *   The nearest power-of-2 integer that is not smaller than EBX[23:16]
>     is the number of unique initial APICIDs reserved for addressing
>     different logical processors in a physical package. This field is
>     only valid if CPUID.1.EDX.HTT[bit 28]= 1.
> "
> Ensure this condition is met.
> 
> Additionally, apply efb3934adf9ee7794db7e0ade9f576c634592891 to
> non passthrough cache mode.
> 
> Signed-off-by: Ilya Oleinik <ilyaoleinik1@gmail.com>
> ---
>  target/i386/cpu.c | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> index ad623d91e4..e793bcc03f 100644
> --- a/target/i386/cpu.c
> +++ b/target/i386/cpu.c
> @@ -245,8 +245,8 @@ static void encode_cache_cpuid4(CPUCacheInfo *cache,
>      *eax = CACHE_TYPE(cache->type) |
>             CACHE_LEVEL(cache->level) |
>             (cache->self_init ? CACHE_SELF_INIT_LEVEL : 0) |
> -           ((num_cores - 1) << 26) |
> -           ((num_apic_ids - 1) << 14);
> +           ((pow2ceil(num_cores) - 1) << 26) |
> +           ((pow2ceil(num_apic_ids) - 1) << 14);
>  
>      assert(cache->line_size > 0);
>      assert(cache->partitions > 0);
> @@ -5258,7 +5258,7 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count,
>          }
>          *edx = env->features[FEAT_1_EDX];
>          if (cs->nr_cores * cs->nr_threads > 1) {
> -            *ebx |= (cs->nr_cores * cs->nr_threads) << 16;
> +            *ebx |= (pow2ceil(cs->nr_cores * cs->nr_threads)) << 16;
>              *edx |= CPUID_HT;
>          }
>          if (!cpu->enable_pmu) {
> @@ -5313,12 +5313,12 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count,
>              switch (count) {
>              case 0: /* L1 dcache info */
>                  encode_cache_cpuid4(env->cache_info_cpuid4.l1d_cache,
> -                                    1, cs->nr_cores,

Hi Ilya,

Just curious why the origin implementation is hard-coded to 1 and is there any
bug reported related to this?

> +                                    cs->nr_threads, cs->nr_cores,
>                                      eax, ebx, ecx, edx);
>                  break;
>              case 1: /* L1 icache info */
>                  encode_cache_cpuid4(env->cache_info_cpuid4.l1i_cache,
> -                                    1, cs->nr_cores,
> +                                    cs->nr_threads, cs->nr_cores,
>                                      eax, ebx, ecx, edx);
>                  break;
>              case 2: /* L2 cache info */


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] i386/cpu: Adjust cpuid addresable id count to match the spec
  2022-10-28  0:53 ` Wang, Lei
@ 2022-11-03  8:11   ` Ilya Oleinik
  0 siblings, 0 replies; 3+ messages in thread
From: Ilya Oleinik @ 2022-11-03  8:11 UTC (permalink / raw)
  To: Wang, Lei; +Cc: qemu-devel, pbonzini, yang.zhong, f4bug, richard.henderson

[-- Attachment #1: Type: text/plain, Size: 2981 bytes --]

I'm not aware of any bug reports. L1 cache is typically shared between
logical threads, so it seemed reasonable to correct this.

On Fri, Oct 28, 2022 at 9:54 AM Wang, Lei <lei4.wang@intel.com> wrote:

>
> On 10/10/2022 10:49 AM, Ilya Oleinik wrote:
> > For EBX bits 23 - 16 in CPUID[01] Intel's manual states:
> > "
> > *   The nearest power-of-2 integer that is not smaller than EBX[23:16]
> >     is the number of unique initial APICIDs reserved for addressing
> >     different logical processors in a physical package. This field is
> >     only valid if CPUID.1.EDX.HTT[bit 28]= 1.
> > "
> > Ensure this condition is met.
> >
> > Additionally, apply efb3934adf9ee7794db7e0ade9f576c634592891 to
> > non passthrough cache mode.
> >
> > Signed-off-by: Ilya Oleinik <ilyaoleinik1@gmail.com>
> > ---
> >  target/i386/cpu.c | 10 +++++-----
> >  1 file changed, 5 insertions(+), 5 deletions(-)
> >
> > diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> > index ad623d91e4..e793bcc03f 100644
> > --- a/target/i386/cpu.c
> > +++ b/target/i386/cpu.c
> > @@ -245,8 +245,8 @@ static void encode_cache_cpuid4(CPUCacheInfo *cache,
> >      *eax = CACHE_TYPE(cache->type) |
> >             CACHE_LEVEL(cache->level) |
> >             (cache->self_init ? CACHE_SELF_INIT_LEVEL : 0) |
> > -           ((num_cores - 1) << 26) |
> > -           ((num_apic_ids - 1) << 14);
> > +           ((pow2ceil(num_cores) - 1) << 26) |
> > +           ((pow2ceil(num_apic_ids) - 1) << 14);
> >
> >      assert(cache->line_size > 0);
> >      assert(cache->partitions > 0);
> > @@ -5258,7 +5258,7 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t
> index, uint32_t count,
> >          }
> >          *edx = env->features[FEAT_1_EDX];
> >          if (cs->nr_cores * cs->nr_threads > 1) {
> > -            *ebx |= (cs->nr_cores * cs->nr_threads) << 16;
> > +            *ebx |= (pow2ceil(cs->nr_cores * cs->nr_threads)) << 16;
> >              *edx |= CPUID_HT;
> >          }
> >          if (!cpu->enable_pmu) {
> > @@ -5313,12 +5313,12 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t
> index, uint32_t count,
> >              switch (count) {
> >              case 0: /* L1 dcache info */
> >                  encode_cache_cpuid4(env->cache_info_cpuid4.l1d_cache,
> > -                                    1, cs->nr_cores,
>
> Hi Ilya,
>
> Just curious why the origin implementation is hard-coded to 1 and is there
> any
> bug reported related to this?
>
> > +                                    cs->nr_threads, cs->nr_cores,
> >                                      eax, ebx, ecx, edx);
> >                  break;
> >              case 1: /* L1 icache info */
> >                  encode_cache_cpuid4(env->cache_info_cpuid4.l1i_cache,
> > -                                    1, cs->nr_cores,
> > +                                    cs->nr_threads, cs->nr_cores,
> >                                      eax, ebx, ecx, edx);
> >                  break;
> >              case 2: /* L2 cache info */
>

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^ permalink raw reply	[flat|nested] 3+ messages in thread

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2022-10-10  2:49 [PATCH] i386/cpu: Adjust cpuid addresable id count to match the spec Ilya Oleinik
2022-10-28  0:53 ` Wang, Lei
2022-11-03  8:11   ` Ilya Oleinik

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