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[PATCH v3] target/i386: Set maximum APIC ID to KVM prior to vCPU creation

Zeng Guang posted 1 patch 1 year, 8 months ago
Failed in applying to current master (apply log)
Maintainers: Paolo Bonzini <pbonzini@redhat.com>, Richard Henderson <richard.henderson@linaro.org>, Eduardo Habkost <eduardo@habkost.net>, "Michael S. Tsirkin" <mst@redhat.com>, Marcel Apfelbaum <marcel.apfelbaum@gmail.com>, Marcelo Tosatti <mtosatti@redhat.com>
hw/i386/x86.c              | 4 ++++
target/i386/kvm/kvm-stub.c | 5 +++++
target/i386/kvm/kvm.c      | 5 +++++
target/i386/kvm/kvm_i386.h | 1 +
4 files changed, 15 insertions(+)
[PATCH v3] target/i386: Set maximum APIC ID to KVM prior to vCPU creation
Posted by Zeng Guang 1 year, 8 months ago 
Specify maximum possible APIC ID assigned for current VM session to KVM
prior to the creation of vCPUs. By this setting, KVM can set up VM-scoped
data structure indexed by the APIC ID, e.g. Posted-Interrupt Descriptor
pointer table to support Intel IPI virtualization, with the most optimal
memory footprint.

It can be achieved by calling KVM_ENABLE_CAP for KVM_CAP_MAX_VCPU_ID
capability once KVM has enabled it. Ignoring the return error if KVM
doesn't support this capability yet.

Signed-off-by: Zeng Guang <guang.zeng@intel.com>
---
 hw/i386/x86.c              | 4 ++++
 target/i386/kvm/kvm-stub.c | 5 +++++
 target/i386/kvm/kvm.c      | 5 +++++
 target/i386/kvm/kvm_i386.h | 1 +
 4 files changed, 15 insertions(+)

diff --git a/hw/i386/x86.c b/hw/i386/x86.c
index 050eedc0c8..4831193c86 100644
--- a/hw/i386/x86.c
+++ b/hw/i386/x86.c
@@ -139,6 +139,10 @@ void x86_cpus_init(X86MachineState *x86ms, int default_cpu_version)
         exit(EXIT_FAILURE);
     }
 
+    if (kvm_enabled()) {
+        kvm_set_max_apic_id(x86ms->apic_id_limit);
+    }
+
     possible_cpus = mc->possible_cpu_arch_ids(ms);
     for (i = 0; i < ms->smp.cpus; i++) {
         x86_cpu_new(x86ms, possible_cpus->cpus[i].arch_id, &error_fatal);
diff --git a/target/i386/kvm/kvm-stub.c b/target/i386/kvm/kvm-stub.c
index f6e7e4466e..e052f1c7b0 100644
--- a/target/i386/kvm/kvm-stub.c
+++ b/target/i386/kvm/kvm-stub.c
@@ -44,3 +44,8 @@ bool kvm_hyperv_expand_features(X86CPU *cpu, Error **errp)
 {
     abort();
 }
+
+void kvm_set_max_apic_id(uint32_t max_apic_id)
+{
+    return;
+}
diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index f148a6d52f..af4ef1e8f0 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -5428,3 +5428,8 @@ void kvm_request_xsave_components(X86CPU *cpu, uint64_t mask)
         mask &= ~BIT_ULL(bit);
     }
 }
+
+void kvm_set_max_apic_id(uint32_t max_apic_id)
+{
+    kvm_vm_enable_cap(kvm_state, KVM_CAP_MAX_VCPU_ID, 0, max_apic_id);
+}
diff --git a/target/i386/kvm/kvm_i386.h b/target/i386/kvm/kvm_i386.h
index 4124912c20..c133b32a58 100644
--- a/target/i386/kvm/kvm_i386.h
+++ b/target/i386/kvm/kvm_i386.h
@@ -54,4 +54,5 @@ uint64_t kvm_swizzle_msi_ext_dest_id(uint64_t address);
 bool kvm_enable_sgx_provisioning(KVMState *s);
 void kvm_request_xsave_components(X86CPU *cpu, uint64_t mask);
 
+void kvm_set_max_apic_id(uint32_t max_apic_id);
 #endif
-- 
2.27.0
Re: [PATCH v3] target/i386: Set maximum APIC ID to KVM prior to vCPU creation
Posted by Paolo Bonzini 1 year, 6 months ago 
Queued, thanks.

Paolo
Re: [PATCH v3] target/i386: Set maximum APIC ID to KVM prior to vCPU creation
Posted by Peter Xu 1 year, 7 months ago 
On Thu, Aug 25, 2022 at 10:52:46AM +0800, Zeng Guang wrote:
> Specify maximum possible APIC ID assigned for current VM session to KVM
> prior to the creation of vCPUs. By this setting, KVM can set up VM-scoped
> data structure indexed by the APIC ID, e.g. Posted-Interrupt Descriptor
> pointer table to support Intel IPI virtualization, with the most optimal
> memory footprint.
> 
> It can be achieved by calling KVM_ENABLE_CAP for KVM_CAP_MAX_VCPU_ID
> capability once KVM has enabled it. Ignoring the return error if KVM
> doesn't support this capability yet.
> 
> Signed-off-by: Zeng Guang <guang.zeng@intel.com>

Acked-by: Peter Xu <peterx@redhat.com>

-- 
Peter Xu
Re: [PATCH v3] target/i386: Set maximum APIC ID to KVM prior to vCPU creation
Posted by Zeng Guang 1 year, 8 months ago 
Kindly PING!

On 8/25/2022 10:52 AM, Zeng Guang wrote:
> Specify maximum possible APIC ID assigned for current VM session to KVM
> prior to the creation of vCPUs. By this setting, KVM can set up VM-scoped
> data structure indexed by the APIC ID, e.g. Posted-Interrupt Descriptor
> pointer table to support Intel IPI virtualization, with the most optimal
> memory footprint.
>
> It can be achieved by calling KVM_ENABLE_CAP for KVM_CAP_MAX_VCPU_ID
> capability once KVM has enabled it. Ignoring the return error if KVM
> doesn't support this capability yet.
>
> Signed-off-by: Zeng Guang <guang.zeng@intel.com>
> ---
>   hw/i386/x86.c              | 4 ++++
>   target/i386/kvm/kvm-stub.c | 5 +++++
>   target/i386/kvm/kvm.c      | 5 +++++
>   target/i386/kvm/kvm_i386.h | 1 +
>   4 files changed, 15 insertions(+)
>
> diff --git a/hw/i386/x86.c b/hw/i386/x86.c
> index 050eedc0c8..4831193c86 100644
> --- a/hw/i386/x86.c
> +++ b/hw/i386/x86.c
> @@ -139,6 +139,10 @@ void x86_cpus_init(X86MachineState *x86ms, int default_cpu_version)
>           exit(EXIT_FAILURE);
>       }
>   
> +    if (kvm_enabled()) {
> +        kvm_set_max_apic_id(x86ms->apic_id_limit);
> +    }
> +
>       possible_cpus = mc->possible_cpu_arch_ids(ms);
>       for (i = 0; i < ms->smp.cpus; i++) {
>           x86_cpu_new(x86ms, possible_cpus->cpus[i].arch_id, &error_fatal);
> diff --git a/target/i386/kvm/kvm-stub.c b/target/i386/kvm/kvm-stub.c
> index f6e7e4466e..e052f1c7b0 100644
> --- a/target/i386/kvm/kvm-stub.c
> +++ b/target/i386/kvm/kvm-stub.c
> @@ -44,3 +44,8 @@ bool kvm_hyperv_expand_features(X86CPU *cpu, Error **errp)
>   {
>       abort();
>   }
> +
> +void kvm_set_max_apic_id(uint32_t max_apic_id)
> +{
> +    return;
> +}
> diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
> index f148a6d52f..af4ef1e8f0 100644
> --- a/target/i386/kvm/kvm.c
> +++ b/target/i386/kvm/kvm.c
> @@ -5428,3 +5428,8 @@ void kvm_request_xsave_components(X86CPU *cpu, uint64_t mask)
>           mask &= ~BIT_ULL(bit);
>       }
>   }
> +
> +void kvm_set_max_apic_id(uint32_t max_apic_id)
> +{
> +    kvm_vm_enable_cap(kvm_state, KVM_CAP_MAX_VCPU_ID, 0, max_apic_id);
> +}
> diff --git a/target/i386/kvm/kvm_i386.h b/target/i386/kvm/kvm_i386.h
> index 4124912c20..c133b32a58 100644
> --- a/target/i386/kvm/kvm_i386.h
> +++ b/target/i386/kvm/kvm_i386.h
> @@ -54,4 +54,5 @@ uint64_t kvm_swizzle_msi_ext_dest_id(uint64_t address);
>   bool kvm_enable_sgx_provisioning(KVMState *s);
>   void kvm_request_xsave_components(X86CPU *cpu, uint64_t mask);
>   
> +void kvm_set_max_apic_id(uint32_t max_apic_id);
>   #endif
Re: [PATCH v3] target/i386: Set maximum APIC ID to KVM prior to vCPU creation
Posted by Zeng Guang 1 year, 6 months ago 
PING again !
This QEMU patch is to optimize max APIC ID set for current VM session 
introduced since linux v6.0. It's also compatible with previous linux 
version.

Thanks.

On 9/5/2022 9:27 AM, Zeng Guang wrote:
> Kindly PING!
>
> On 8/25/2022 10:52 AM, Zeng Guang wrote:
>> Specify maximum possible APIC ID assigned for current VM session to KVM
>> prior to the creation of vCPUs. By this setting, KVM can set up VM-scoped
>> data structure indexed by the APIC ID, e.g. Posted-Interrupt Descriptor
>> pointer table to support Intel IPI virtualization, with the most optimal
>> memory footprint.
>>
>> It can be achieved by calling KVM_ENABLE_CAP for KVM_CAP_MAX_VCPU_ID
>> capability once KVM has enabled it. Ignoring the return error if KVM
>> doesn't support this capability yet.
>>
>> Signed-off-by: Zeng Guang <guang.zeng@intel.com>
>> ---
>>    hw/i386/x86.c              | 4 ++++
>>    target/i386/kvm/kvm-stub.c | 5 +++++
>>    target/i386/kvm/kvm.c      | 5 +++++
>>    target/i386/kvm/kvm_i386.h | 1 +
>>    4 files changed, 15 insertions(+)
>>
>> diff --git a/hw/i386/x86.c b/hw/i386/x86.c
>> index 050eedc0c8..4831193c86 100644
>> --- a/hw/i386/x86.c
>> +++ b/hw/i386/x86.c
>> @@ -139,6 +139,10 @@ void x86_cpus_init(X86MachineState *x86ms, int default_cpu_version)
>>            exit(EXIT_FAILURE);
>>        }
>>    
>> +    if (kvm_enabled()) {
>> +        kvm_set_max_apic_id(x86ms->apic_id_limit);
>> +    }
>> +
>>        possible_cpus = mc->possible_cpu_arch_ids(ms);
>>        for (i = 0; i < ms->smp.cpus; i++) {
>>            x86_cpu_new(x86ms, possible_cpus->cpus[i].arch_id, &error_fatal);
>> diff --git a/target/i386/kvm/kvm-stub.c b/target/i386/kvm/kvm-stub.c
>> index f6e7e4466e..e052f1c7b0 100644
>> --- a/target/i386/kvm/kvm-stub.c
>> +++ b/target/i386/kvm/kvm-stub.c
>> @@ -44,3 +44,8 @@ bool kvm_hyperv_expand_features(X86CPU *cpu, Error **errp)
>>    {
>>        abort();
>>    }
>> +
>> +void kvm_set_max_apic_id(uint32_t max_apic_id)
>> +{
>> +    return;
>> +}
>> diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
>> index f148a6d52f..af4ef1e8f0 100644
>> --- a/target/i386/kvm/kvm.c
>> +++ b/target/i386/kvm/kvm.c
>> @@ -5428,3 +5428,8 @@ void kvm_request_xsave_components(X86CPU *cpu, uint64_t mask)
>>            mask &= ~BIT_ULL(bit);
>>        }
>>    }
>> +
>> +void kvm_set_max_apic_id(uint32_t max_apic_id)
>> +{
>> +    kvm_vm_enable_cap(kvm_state, KVM_CAP_MAX_VCPU_ID, 0, max_apic_id);
>> +}
>> diff --git a/target/i386/kvm/kvm_i386.h b/target/i386/kvm/kvm_i386.h
>> index 4124912c20..c133b32a58 100644
>> --- a/target/i386/kvm/kvm_i386.h
>> +++ b/target/i386/kvm/kvm_i386.h
>> @@ -54,4 +54,5 @@ uint64_t kvm_swizzle_msi_ext_dest_id(uint64_t address);
>>    bool kvm_enable_sgx_provisioning(KVMState *s);
>>    void kvm_request_xsave_components(X86CPU *cpu, uint64_t mask);
>>    
>> +void kvm_set_max_apic_id(uint32_t max_apic_id);
>>    #endif
Re: [PATCH v3] target/i386: Set maximum APIC ID to KVM prior to vCPU creation
Posted by Michael S. Tsirkin 1 year, 6 months ago 
On Fri, Oct 14, 2022 at 09:01:02AM +0800, Zeng Guang wrote:
> PING again !
> This QEMU patch is to optimize max APIC ID set for current VM session
> introduced since linux v6.0. It's also compatible with previous linux
> version.
> 
> Thanks.
> 
> On 9/5/2022 9:27 AM, Zeng Guang wrote:
> > Kindly PING!
> > 
> > On 8/25/2022 10:52 AM, Zeng Guang wrote:
> > > Specify maximum possible APIC ID assigned for current VM session to KVM
> > > prior to the creation of vCPUs. By this setting, KVM can set up VM-scoped
> > > data structure indexed by the APIC ID, e.g. Posted-Interrupt Descriptor
> > > pointer table to support Intel IPI virtualization, with the most optimal
> > > memory footprint.
> > > 
> > > It can be achieved by calling KVM_ENABLE_CAP for KVM_CAP_MAX_VCPU_ID
> > > capability once KVM has enabled it. Ignoring the return error if KVM
> > > doesn't support this capability yet.
> > > 
> > > Signed-off-by: Zeng Guang <guang.zeng@intel.com>
> > > ---
> > >    hw/i386/x86.c              | 4 ++++
> > >    target/i386/kvm/kvm-stub.c | 5 +++++
> > >    target/i386/kvm/kvm.c      | 5 +++++
> > >    target/i386/kvm/kvm_i386.h | 1 +
> > >    4 files changed, 15 insertions(+)
> > > 
> > > diff --git a/hw/i386/x86.c b/hw/i386/x86.c
> > > index 050eedc0c8..4831193c86 100644
> > > --- a/hw/i386/x86.c
> > > +++ b/hw/i386/x86.c
> > > @@ -139,6 +139,10 @@ void x86_cpus_init(X86MachineState *x86ms, int default_cpu_version)
> > >            exit(EXIT_FAILURE);
> > >        }
> > > +    if (kvm_enabled()) {
> > > +        kvm_set_max_apic_id(x86ms->apic_id_limit);
> > > +    }
> > > +
> > >        possible_cpus = mc->possible_cpu_arch_ids(ms);
> > >        for (i = 0; i < ms->smp.cpus; i++) {
> > >            x86_cpu_new(x86ms, possible_cpus->cpus[i].arch_id, &error_fatal);
> > > diff --git a/target/i386/kvm/kvm-stub.c b/target/i386/kvm/kvm-stub.c
> > > index f6e7e4466e..e052f1c7b0 100644
> > > --- a/target/i386/kvm/kvm-stub.c
> > > +++ b/target/i386/kvm/kvm-stub.c
> > > @@ -44,3 +44,8 @@ bool kvm_hyperv_expand_features(X86CPU *cpu, Error **errp)
> > >    {
> > >        abort();
> > >    }
> > > +
> > > +void kvm_set_max_apic_id(uint32_t max_apic_id)
> > > +{
> > > +    return;
> > > +}
> > > diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
> > > index f148a6d52f..af4ef1e8f0 100644
> > > --- a/target/i386/kvm/kvm.c
> > > +++ b/target/i386/kvm/kvm.c
> > > @@ -5428,3 +5428,8 @@ void kvm_request_xsave_components(X86CPU *cpu, uint64_t mask)
> > >            mask &= ~BIT_ULL(bit);
> > >        }
> > >    }
> > > +
> > > +void kvm_set_max_apic_id(uint32_t max_apic_id)
> > > +{
> > > +    kvm_vm_enable_cap(kvm_state, KVM_CAP_MAX_VCPU_ID, 0, max_apic_id);
> > > +}
> > > diff --git a/target/i386/kvm/kvm_i386.h b/target/i386/kvm/kvm_i386.h
> > > index 4124912c20..c133b32a58 100644
> > > --- a/target/i386/kvm/kvm_i386.h
> > > +++ b/target/i386/kvm/kvm_i386.h
> > > @@ -54,4 +54,5 @@ uint64_t kvm_swizzle_msi_ext_dest_id(uint64_t address);
> > >    bool kvm_enable_sgx_provisioning(KVMState *s);
> > >    void kvm_request_xsave_components(X86CPU *cpu, uint64_t mask);
> > > +void kvm_set_max_apic_id(uint32_t max_apic_id);
> > >    #endif


Looks ok on the surface, but this is Paolo's area.

Acked-by: Michael S. Tsirkin <mst@redhat.com>

-- 
MST

Patchew 2.1-devel-0870f84

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