diff mbox

[v7,7/9] i386: Add support for CPUID_8000_001E for AMD

Message ID 1524760009-24710-8-git-send-email-babu.moger@amd.com (mailing list archive)
State New, archived
Headers show

Commit Message

Babu Moger April 26, 2018, 4:26 p.m. UTC
Populate threads/core_id/apic_ids/socket_id when CPUID_EXT3_TOPOEXT
feature is supported. This is required to support hyperthreading feature
on AMD CPUs. This is supported via CPUID_8000_001E extended functions.

Signed-off-by: Babu Moger <babu.moger@amd.com>
Tested-by: Geoffrey McRae <geoff@hostfission.com>
---
 target/i386/cpu.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

Comments

Eduardo Habkost May 7, 2018, 7:39 p.m. UTC | #1
On Thu, Apr 26, 2018 at 11:26:47AM -0500, Babu Moger wrote:
> Populate threads/core_id/apic_ids/socket_id when CPUID_EXT3_TOPOEXT
> feature is supported. This is required to support hyperthreading feature
> on AMD CPUs. This is supported via CPUID_8000_001E extended functions.
> 
> Signed-off-by: Babu Moger <babu.moger@amd.com>
> Tested-by: Geoffrey McRae <geoff@hostfission.com>
> ---
>  target/i386/cpu.c | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
> 
> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> index 1024b09..1b15023 100644
> --- a/target/i386/cpu.c
> +++ b/target/i386/cpu.c
> @@ -315,6 +315,12 @@ static uint32_t encode_cache_cpuid80000005(CPUCacheInfo *cache)
>                           (((CORES_IN_CMPLX - 1) * 2) + 1)  : \
>                           (CORES_IN_CMPLX - 1))
>  
> +/* Definitions used on CPUID Leaf 0x8000001E */
> +#define EXTENDED_APIC_ID(threads, socket_id, core_id, thread_id) \
> +                        ((threads) ? \
> +                         ((socket_id << 6) | (core_id << 1) | thread_id) : \
> +                         ((socket_id << 6) | core_id))

I suggest moving this to i386/topology.h.


> +
>  /*
>   * Encode cache info for CPUID[0x80000006].ECX and CPUID[0x80000006].EDX
>   * @l3 can be NULL.
> @@ -4105,6 +4111,14 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count,
>              break;
>          }
>          break;
> +    case 0x8000001E:
> +        assert(cpu->core_id <= 255);

Where's the code that ensures this assert() line can't be
triggered by any command-line configuration?

> +        *eax = EXTENDED_APIC_ID((cs->nr_threads - 1),
> +               cpu->socket_id, cpu->core_id, cpu->thread_id);
> +        *ebx = (cs->nr_threads - 1) << 8 | cpu->core_id;
> +        *ecx = cpu->socket_id;
> +        *edx = 0;
> +        break;
>      case 0xC0000000:
>          *eax = env->cpuid_xlevel2;
>          *ebx = 0;
> -- 
> 2.7.4
> 
>
Babu Moger May 7, 2018, 11:44 p.m. UTC | #2
> -----Original Message-----
> From: Eduardo Habkost [mailto:ehabkost@redhat.com]
> Sent: Monday, May 7, 2018 2:40 PM
> To: Moger, Babu <Babu.Moger@amd.com>
> Cc: mst@redhat.com; marcel@redhat.com; pbonzini@redhat.com;
> rth@twiddle.net; mtosatti@redhat.com; geoff@hostfission.com;
> kash@tripleback.net; qemu-devel@nongnu.org; kvm@vger.kernel.org
> Subject: Re: [Qemu-devel] [PATCH v7 7/9] i386: Add support for
> CPUID_8000_001E for AMD
> 
> On Thu, Apr 26, 2018 at 11:26:47AM -0500, Babu Moger wrote:
> > Populate threads/core_id/apic_ids/socket_id when CPUID_EXT3_TOPOEXT
> > feature is supported. This is required to support hyperthreading feature
> > on AMD CPUs. This is supported via CPUID_8000_001E extended functions.
> >
> > Signed-off-by: Babu Moger <babu.moger@amd.com>
> > Tested-by: Geoffrey McRae <geoff@hostfission.com>
> > ---
> >  target/i386/cpu.c | 14 ++++++++++++++
> >  1 file changed, 14 insertions(+)
> >
> > diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> > index 1024b09..1b15023 100644
> > --- a/target/i386/cpu.c
> > +++ b/target/i386/cpu.c
> > @@ -315,6 +315,12 @@ static uint32_t
> encode_cache_cpuid80000005(CPUCacheInfo *cache)
> >                           (((CORES_IN_CMPLX - 1) * 2) + 1)  : \
> >                           (CORES_IN_CMPLX - 1))
> >
> > +/* Definitions used on CPUID Leaf 0x8000001E */
> > +#define EXTENDED_APIC_ID(threads, socket_id, core_id, thread_id) \
> > +                        ((threads) ? \
> > +                         ((socket_id << 6) | (core_id << 1) | thread_id) : \
> > +                         ((socket_id << 6) | core_id))
> 
> I suggest moving this to i386/topology.h.


Ok. Will do that.

> 
> 
> > +
> >  /*
> >   * Encode cache info for CPUID[0x80000006].ECX and
> CPUID[0x80000006].EDX
> >   * @l3 can be NULL.
> > @@ -4105,6 +4111,14 @@ void cpu_x86_cpuid(CPUX86State *env,
> uint32_t index, uint32_t count,
> >              break;
> >          }
> >          break;
> > +    case 0x8000001E:
> > +        assert(cpu->core_id <= 255);
> 
> Where's the code that ensures this assert() line can't be
> triggered by any command-line configuration?

I did not understand this. Can you please elaborate. Thanks 

> 
> > +        *eax = EXTENDED_APIC_ID((cs->nr_threads - 1),
> > +               cpu->socket_id, cpu->core_id, cpu->thread_id);
> > +        *ebx = (cs->nr_threads - 1) << 8 | cpu->core_id;
> > +        *ecx = cpu->socket_id;
> > +        *edx = 0;
> > +        break;
> >      case 0xC0000000:
> >          *eax = env->cpuid_xlevel2;
> >          *ebx = 0;
> > --
> > 2.7.4
> >
> >
> 
> --
> Eduardo
Eduardo Habkost May 8, 2018, 2:16 p.m. UTC | #3
On Mon, May 07, 2018 at 11:44:31PM +0000, Moger, Babu wrote:
[...]
> > > +
> > >  /*
> > >   * Encode cache info for CPUID[0x80000006].ECX and
> > CPUID[0x80000006].EDX
> > >   * @l3 can be NULL.
> > > @@ -4105,6 +4111,14 @@ void cpu_x86_cpuid(CPUX86State *env,
> > uint32_t index, uint32_t count,
> > >              break;
> > >          }
> > >          break;
> > > +    case 0x8000001E:
> > > +        assert(cpu->core_id <= 255);
> > 
> > Where's the code that ensures this assert() line can't be
> > triggered by any command-line configuration?
> 
> I did not understand this. Can you please elaborate. Thanks 

The user must not be able to trigger an assert(), so we need to
ensure that core_id will never be larger than 255.  Is there
existing code that ensures that?

> 
> > 
> > > +        *eax = EXTENDED_APIC_ID((cs->nr_threads - 1),
> > > +               cpu->socket_id, cpu->core_id, cpu->thread_id);
> > > +        *ebx = (cs->nr_threads - 1) << 8 | cpu->core_id;
> > > +        *ecx = cpu->socket_id;
> > > +        *edx = 0;
> > > +        break;
> > >      case 0xC0000000:
> > >          *eax = env->cpuid_xlevel2;
> > >          *ebx = 0;
> > > --
> > > 2.7.4
> > >
> > >
> > 
> > --
> > Eduardo
Babu Moger May 8, 2018, 3:02 p.m. UTC | #4
> -----Original Message-----
> From: Eduardo Habkost [mailto:ehabkost@redhat.com]
> Sent: Tuesday, May 8, 2018 9:17 AM
> To: Moger, Babu <Babu.Moger@amd.com>
> Cc: mst@redhat.com; marcel@redhat.com; pbonzini@redhat.com;
> rth@twiddle.net; mtosatti@redhat.com; geoff@hostfission.com;
> kash@tripleback.net; qemu-devel@nongnu.org; kvm@vger.kernel.org
> Subject: Re: [Qemu-devel] [PATCH v7 7/9] i386: Add support for
> CPUID_8000_001E for AMD
> 
> On Mon, May 07, 2018 at 11:44:31PM +0000, Moger, Babu wrote:
> [...]
> > > > +
> > > >  /*
> > > >   * Encode cache info for CPUID[0x80000006].ECX and
> > > CPUID[0x80000006].EDX
> > > >   * @l3 can be NULL.
> > > > @@ -4105,6 +4111,14 @@ void cpu_x86_cpuid(CPUX86State *env,
> > > uint32_t index, uint32_t count,
> > > >              break;
> > > >          }
> > > >          break;
> > > > +    case 0x8000001E:
> > > > +        assert(cpu->core_id <= 255);
> > >
> > > Where's the code that ensures this assert() line can't be
> > > triggered by any command-line configuration?
> >
> > I did not understand this. Can you please elaborate. Thanks
> 
> The user must not be able to trigger an assert(), so we need to
> ensure that core_id will never be larger than 255.  Is there
> existing code that ensures that?

I see that max_cpus is set to 255 and also there are checks to make sure core_id does not go above 255.
I verified it while testing.  So, probably we don't need assert here.  Radim asked me to add this assert.
I can remove it if no abjections. 
 
> 
> >
> > >
> > > > +        *eax = EXTENDED_APIC_ID((cs->nr_threads - 1),
> > > > +               cpu->socket_id, cpu->core_id, cpu->thread_id);
> > > > +        *ebx = (cs->nr_threads - 1) << 8 | cpu->core_id;
> > > > +        *ecx = cpu->socket_id;
> > > > +        *edx = 0;
> > > > +        break;
> > > >      case 0xC0000000:
> > > >          *eax = env->cpuid_xlevel2;
> > > >          *ebx = 0;
> > > > --
> > > > 2.7.4
> > > >
> > > >
> > >
> > > --
> > > Eduardo
> 
> --
> Eduardo
Eduardo Habkost May 11, 2018, 2:12 p.m. UTC | #5
On Tue, May 08, 2018 at 03:02:07PM +0000, Moger, Babu wrote:
> 
> > -----Original Message-----
> > From: Eduardo Habkost [mailto:ehabkost@redhat.com]
> > Sent: Tuesday, May 8, 2018 9:17 AM
> > To: Moger, Babu <Babu.Moger@amd.com>
> > Cc: mst@redhat.com; marcel@redhat.com; pbonzini@redhat.com;
> > rth@twiddle.net; mtosatti@redhat.com; geoff@hostfission.com;
> > kash@tripleback.net; qemu-devel@nongnu.org; kvm@vger.kernel.org
> > Subject: Re: [Qemu-devel] [PATCH v7 7/9] i386: Add support for
> > CPUID_8000_001E for AMD
> > 
> > On Mon, May 07, 2018 at 11:44:31PM +0000, Moger, Babu wrote:
> > [...]
> > > > > +
> > > > >  /*
> > > > >   * Encode cache info for CPUID[0x80000006].ECX and
> > > > CPUID[0x80000006].EDX
> > > > >   * @l3 can be NULL.
> > > > > @@ -4105,6 +4111,14 @@ void cpu_x86_cpuid(CPUX86State *env,
> > > > uint32_t index, uint32_t count,
> > > > >              break;
> > > > >          }
> > > > >          break;
> > > > > +    case 0x8000001E:
> > > > > +        assert(cpu->core_id <= 255);
> > > >
> > > > Where's the code that ensures this assert() line can't be
> > > > triggered by any command-line configuration?
> > >
> > > I did not understand this. Can you please elaborate. Thanks
> > 
> > The user must not be able to trigger an assert(), so we need to
> > ensure that core_id will never be larger than 255.  Is there
> > existing code that ensures that?
> 
> I see that max_cpus is set to 255 and also there are checks to make sure core_id does not go above 255.
> I verified it while testing.  So, probably we don't need assert here.  Radim asked me to add this assert.
> I can remove it if no abjections. 

Sorry for not replying to this before: no objection to the
assert(), especially considering it will trigger very early on
initialization if we break it one day.
Babu Moger May 11, 2018, 2:44 p.m. UTC | #6
> -----Original Message-----
> From: Eduardo Habkost [mailto:ehabkost@redhat.com]
> Sent: Friday, May 11, 2018 9:12 AM
> To: Moger, Babu <Babu.Moger@amd.com>
> Cc: mst@redhat.com; marcel@redhat.com; pbonzini@redhat.com;
> rth@twiddle.net; mtosatti@redhat.com; geoff@hostfission.com;
> kash@tripleback.net; qemu-devel@nongnu.org; kvm@vger.kernel.org
> Subject: Re: [Qemu-devel] [PATCH v7 7/9] i386: Add support for
> CPUID_8000_001E for AMD
> 
> On Tue, May 08, 2018 at 03:02:07PM +0000, Moger, Babu wrote:
> >
> > > -----Original Message-----
> > > From: Eduardo Habkost [mailto:ehabkost@redhat.com]
> > > Sent: Tuesday, May 8, 2018 9:17 AM
> > > To: Moger, Babu <Babu.Moger@amd.com>
> > > Cc: mst@redhat.com; marcel@redhat.com; pbonzini@redhat.com;
> > > rth@twiddle.net; mtosatti@redhat.com; geoff@hostfission.com;
> > > kash@tripleback.net; qemu-devel@nongnu.org; kvm@vger.kernel.org
> > > Subject: Re: [Qemu-devel] [PATCH v7 7/9] i386: Add support for
> > > CPUID_8000_001E for AMD
> > >
> > > On Mon, May 07, 2018 at 11:44:31PM +0000, Moger, Babu wrote:
> > > [...]
> > > > > > +
> > > > > >  /*
> > > > > >   * Encode cache info for CPUID[0x80000006].ECX and
> > > > > CPUID[0x80000006].EDX
> > > > > >   * @l3 can be NULL.
> > > > > > @@ -4105,6 +4111,14 @@ void cpu_x86_cpuid(CPUX86State *env,
> > > > > uint32_t index, uint32_t count,
> > > > > >              break;
> > > > > >          }
> > > > > >          break;
> > > > > > +    case 0x8000001E:
> > > > > > +        assert(cpu->core_id <= 255);
> > > > >
> > > > > Where's the code that ensures this assert() line can't be
> > > > > triggered by any command-line configuration?
> > > >
> > > > I did not understand this. Can you please elaborate. Thanks
> > >
> > > The user must not be able to trigger an assert(), so we need to
> > > ensure that core_id will never be larger than 255.  Is there
> > > existing code that ensures that?
> >
> > I see that max_cpus is set to 255 and also there are checks to make sure
> core_id does not go above 255.
> > I verified it while testing.  So, probably we don't need assert here.  Radim
> asked me to add this assert.
> > I can remove it if no abjections.
> 
> Sorry for not replying to this before: no objection to the
> assert(), especially considering it will trigger very early on
> initialization if we break it one day.

Ok. No problem.  I will add it back and send a v9 version. 
Please let me know if you have any other feedback for v8 version(sent yesterday).
 
> 
> --
> Eduardo
Eduardo Habkost May 11, 2018, 2:59 p.m. UTC | #7
On Fri, May 11, 2018 at 02:44:11PM +0000, Moger, Babu wrote:
> 
> 
> > -----Original Message-----
> > From: Eduardo Habkost [mailto:ehabkost@redhat.com]
> > Sent: Friday, May 11, 2018 9:12 AM
> > To: Moger, Babu <Babu.Moger@amd.com>
> > Cc: mst@redhat.com; marcel@redhat.com; pbonzini@redhat.com;
> > rth@twiddle.net; mtosatti@redhat.com; geoff@hostfission.com;
> > kash@tripleback.net; qemu-devel@nongnu.org; kvm@vger.kernel.org
> > Subject: Re: [Qemu-devel] [PATCH v7 7/9] i386: Add support for
> > CPUID_8000_001E for AMD
> > 
> > On Tue, May 08, 2018 at 03:02:07PM +0000, Moger, Babu wrote:
> > >
> > > > -----Original Message-----
> > > > From: Eduardo Habkost [mailto:ehabkost@redhat.com]
> > > > Sent: Tuesday, May 8, 2018 9:17 AM
> > > > To: Moger, Babu <Babu.Moger@amd.com>
> > > > Cc: mst@redhat.com; marcel@redhat.com; pbonzini@redhat.com;
> > > > rth@twiddle.net; mtosatti@redhat.com; geoff@hostfission.com;
> > > > kash@tripleback.net; qemu-devel@nongnu.org; kvm@vger.kernel.org
> > > > Subject: Re: [Qemu-devel] [PATCH v7 7/9] i386: Add support for
> > > > CPUID_8000_001E for AMD
> > > >
> > > > On Mon, May 07, 2018 at 11:44:31PM +0000, Moger, Babu wrote:
> > > > [...]
> > > > > > > +
> > > > > > >  /*
> > > > > > >   * Encode cache info for CPUID[0x80000006].ECX and
> > > > > > CPUID[0x80000006].EDX
> > > > > > >   * @l3 can be NULL.
> > > > > > > @@ -4105,6 +4111,14 @@ void cpu_x86_cpuid(CPUX86State *env,
> > > > > > uint32_t index, uint32_t count,
> > > > > > >              break;
> > > > > > >          }
> > > > > > >          break;
> > > > > > > +    case 0x8000001E:
> > > > > > > +        assert(cpu->core_id <= 255);
> > > > > >
> > > > > > Where's the code that ensures this assert() line can't be
> > > > > > triggered by any command-line configuration?
> > > > >
> > > > > I did not understand this. Can you please elaborate. Thanks
> > > >
> > > > The user must not be able to trigger an assert(), so we need to
> > > > ensure that core_id will never be larger than 255.  Is there
> > > > existing code that ensures that?
> > >
> > > I see that max_cpus is set to 255 and also there are checks to make sure
> > core_id does not go above 255.
> > > I verified it while testing.  So, probably we don't need assert here.  Radim
> > asked me to add this assert.
> > > I can remove it if no abjections.
> > 
> > Sorry for not replying to this before: no objection to the
> > assert(), especially considering it will trigger very early on
> > initialization if we break it one day.
> 
> Ok. No problem.  I will add it back and send a v9 version. 
> Please let me know if you have any other feedback for v8 version(sent yesterday).

Thanks, I just saw v8 on my mailbox.  No need to send v9 just
because of the assert(), I can re-add it while committing if
necessary.
diff mbox

Patch

diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 1024b09..1b15023 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -315,6 +315,12 @@  static uint32_t encode_cache_cpuid80000005(CPUCacheInfo *cache)
                          (((CORES_IN_CMPLX - 1) * 2) + 1)  : \
                          (CORES_IN_CMPLX - 1))
 
+/* Definitions used on CPUID Leaf 0x8000001E */
+#define EXTENDED_APIC_ID(threads, socket_id, core_id, thread_id) \
+                        ((threads) ? \
+                         ((socket_id << 6) | (core_id << 1) | thread_id) : \
+                         ((socket_id << 6) | core_id))
+
 /*
  * Encode cache info for CPUID[0x80000006].ECX and CPUID[0x80000006].EDX
  * @l3 can be NULL.
@@ -4105,6 +4111,14 @@  void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count,
             break;
         }
         break;
+    case 0x8000001E:
+        assert(cpu->core_id <= 255);
+        *eax = EXTENDED_APIC_ID((cs->nr_threads - 1),
+               cpu->socket_id, cpu->core_id, cpu->thread_id);
+        *ebx = (cs->nr_threads - 1) << 8 | cpu->core_id;
+        *ecx = cpu->socket_id;
+        *edx = 0;
+        break;
     case 0xC0000000:
         *eax = env->cpuid_xlevel2;
         *ebx = 0;