[Qemu-devel] [patch] kvm: also fill 0x40000000 (vmm) cpuid leafes.

[Qemu-devel] [patch] kvm: also fill 0x40000000 (vmm) cpuid leafes.

[Gerd Hoffmann]

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  Hi,

$subject says all, patch attached.

please apply,
  Gerd

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>From e95b11a187d6ca344b544a8aef7910c8cbacf297 Mon Sep 17 00:00:00 2001
From: Gerd Hoffmann <kraxel@redhat.com>
Date: Fri, 7 Nov 2008 09:35:58 +0100
Subject: [PATCH] kvm: handle cpuid 0x40000000


Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 target-i386/kvm.c |   14 ++++++++++++++
 1 files changed, 14 insertions(+), 0 deletions(-)

diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index f22f30a..1f37a52 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -58,6 +58,20 @@ int kvm_arch_init_vcpu(CPUState *env)
         c->edx = edx;
     }
 
+    cpu_x86_cpuid(env, 0x40000000, &eax, &ebx, &ecx, &edx);
+    limit = eax;
+
+    for (i = 0x40000000; i <= limit; i++) {
+        struct kvm_cpuid_entry *c = &cpuid_data.entries[cpuid_i++];
+
+        cpu_x86_cpuid(env, i, &eax, &ebx, &ecx, &edx);
+        c->function = i;
+        c->eax = eax;
+        c->ebx = ebx;
+        c->ecx = ecx;
+        c->edx = edx;
+    }
+
     cpu_x86_cpuid(env, 0x80000000, &eax, &ebx, &ecx, &edx);
     limit = eax;
 
-- 
1.5.6.5

Re: [Qemu-devel] [patch] kvm: also fill 0x40000000 (vmm) cpuid leafes.

[Anthony Liguori]

Gerd Hoffmann wrote:
>   Hi,
>
> $subject says all, patch attached.
>   

It really doesn't :-)

0x4000xxxx are the virtualization leaves, that we don't set so there is 
no functional change from this patch.  The KVM PV ABI doesn't use eax as 
the max CPUID leaf of 0x40000000 so that's at least one example of them 
not behaving like this.

So can you be a lot more specific about how you intend on using these 
leaves?

Regards,

Anthony Liguori

> please apply,
>   Gerd
>   

Re: [Qemu-devel] [patch] kvm: also fill 0x40000000 (vmm) cpuid leafes.

[Gerd Hoffmann]

Anthony Liguori wrote:
> Gerd Hoffmann wrote:
>>   Hi,
>>
>> $subject says all, patch attached.
>>   
> 
> It really doesn't :-)
> 
> 0x4000xxxx are the virtualization leaves, that we don't set so there is
> no functional change from this patch.

Not yet.  For now it hasn't any effect.  I can keep it in my patch queue
until I submit the patches depending on that one.  But I expect more
users that xenner, so I thought it might be useful for others too and
submitted it right away ...

> The KVM PV ABI doesn't use eax as
> the max CPUID leaf of 0x40000000 so that's at least one example of them
> not behaving like this.

Oops.  I think we should fix it then to follow the usual eax convention.
 Xenner (standalone version, not qemu-integrated) actually does that and
sets eax to KVM_CPUID_FEATURES.

> So can you be a lot more specific about how you intend on using these
> leaves?

qemu-integrated xenner can handle full virtualized guests with xen pv
drivers installed.  Must provide xen virt cpuid leaves then.

cheers,
  Gerd