* [Qemu-devel] [PATCH] target-i386: adds PV_DEDICATED hint CPUID feature bit
@ 2018-02-08 9:44 Wanpeng Li
2018-02-08 18:12 ` Eduardo Habkost
2018-02-09 8:41 ` Paolo Bonzini
0 siblings, 2 replies; 11+ messages in thread
From: Wanpeng Li @ 2018-02-08 9:44 UTC (permalink / raw)
To: qemu-devel, kvm
Cc: Paolo Bonzini, Radim Krčmář, Eduardo Habkost
From: Wanpeng Li <wanpengli@tencent.com>
Add PV_DEDICATED hint cpuid feature bit.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
---
target/i386/cpu.c | 4 ++++
target/i386/cpu.h | 3 +++
2 files changed, 7 insertions(+)
diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index d70954b..cf48931 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -4076,6 +4076,9 @@ static int x86_cpu_filter_features(X86CPU *cpu)
x86_cpu_get_supported_feature_word(w, false);
uint32_t requested_features = env->features[w];
env->features[w] &= host_feat;
+ if (cpu->pv_dedicated && (w == FEAT_KVM)) {
+ env->features[w] |= CPUID_PV_DEDICATED;
+ }
cpu->filtered_features[w] = requested_features & ~env->features[w];
if (cpu->filtered_features[w]) {
rv = 1;
@@ -4682,6 +4685,7 @@ static Property x86_cpu_properties[] = {
false),
DEFINE_PROP_BOOL("vmware-cpuid-freq", X86CPU, vmware_cpuid_freq, true),
DEFINE_PROP_BOOL("tcg-cpuid", X86CPU, expose_tcg, true),
+ DEFINE_PROP_BOOL("pv-dedicated", X86CPU, pv_dedicated, false),
/*
* From "Requirements for Implementing the Microsoft
diff --git a/target/i386/cpu.h b/target/i386/cpu.h
index f91e37d..8000da5 100644
--- a/target/i386/cpu.h
+++ b/target/i386/cpu.h
@@ -672,6 +672,8 @@ typedef uint32_t FeatureWordArray[FEATURE_WORDS];
#define CPUID_8000_0008_EBX_IBPB (1U << 12) /* Indirect Branch Prediction Barrier */
+#define CPUID_PV_DEDICATED (1U << 8)
+
#define CPUID_XSAVE_XSAVEOPT (1U << 0)
#define CPUID_XSAVE_XSAVEC (1U << 1)
#define CPUID_XSAVE_XGETBV1 (1U << 2)
@@ -1276,6 +1278,7 @@ struct X86CPU {
bool expose_kvm;
bool expose_tcg;
bool migratable;
+ bool pv_dedicated;
bool max_features; /* Enable all supported features automatically */
uint32_t apic_id;
--
2.7.4
^ permalink raw reply related [flat|nested] 11+ messages in thread
* Re: [Qemu-devel] [PATCH] target-i386: adds PV_DEDICATED hint CPUID feature bit
2018-02-08 9:44 [Qemu-devel] [PATCH] target-i386: adds PV_DEDICATED hint CPUID feature bit Wanpeng Li
@ 2018-02-08 18:12 ` Eduardo Habkost
2018-02-09 3:18 ` Wanpeng Li
2018-02-09 8:41 ` Paolo Bonzini
2018-02-09 8:41 ` Paolo Bonzini
1 sibling, 2 replies; 11+ messages in thread
From: Eduardo Habkost @ 2018-02-08 18:12 UTC (permalink / raw)
To: Wanpeng Li; +Cc: qemu-devel, kvm, Paolo Bonzini, Radim Krčmář
On Thu, Feb 08, 2018 at 05:44:20PM +0800, Wanpeng Li wrote:
> From: Wanpeng Li <wanpengli@tencent.com>
>
> Add PV_DEDICATED hint cpuid feature bit.
>
[...]
> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> index d70954b..cf48931 100644
> --- a/target/i386/cpu.c
> +++ b/target/i386/cpu.c
> @@ -4076,6 +4076,9 @@ static int x86_cpu_filter_features(X86CPU *cpu)
> x86_cpu_get_supported_feature_word(w, false);
> uint32_t requested_features = env->features[w];
> env->features[w] &= host_feat;
> + if (cpu->pv_dedicated && (w == FEAT_KVM)) {
> + env->features[w] |= CPUID_PV_DEDICATED;
> + }
Why do this trick here instead of just adding "pv-dedicated" to
feature_word_info[FEAT_KVM].feat_names?
> [...]
--
Eduardo
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [Qemu-devel] [PATCH] target-i386: adds PV_DEDICATED hint CPUID feature bit
2018-02-08 18:12 ` Eduardo Habkost
@ 2018-02-09 3:18 ` Wanpeng Li
2018-02-09 8:41 ` Paolo Bonzini
1 sibling, 0 replies; 11+ messages in thread
From: Wanpeng Li @ 2018-02-09 3:18 UTC (permalink / raw)
To: Eduardo Habkost
Cc: qemu-devel@nongnu.org Developers, kvm, Paolo Bonzini,
Radim Krčmář
2018-02-09 2:12 GMT+08:00 Eduardo Habkost <ehabkost@redhat.com>:
> On Thu, Feb 08, 2018 at 05:44:20PM +0800, Wanpeng Li wrote:
>> From: Wanpeng Li <wanpengli@tencent.com>
>>
>> Add PV_DEDICATED hint cpuid feature bit.
>>
> [...]
>> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
>> index d70954b..cf48931 100644
>> --- a/target/i386/cpu.c
>> +++ b/target/i386/cpu.c
>> @@ -4076,6 +4076,9 @@ static int x86_cpu_filter_features(X86CPU *cpu)
>> x86_cpu_get_supported_feature_word(w, false);
>> uint32_t requested_features = env->features[w];
>> env->features[w] &= host_feat;
>> + if (cpu->pv_dedicated && (w == FEAT_KVM)) {
>> + env->features[w] |= CPUID_PV_DEDICATED;
>> + }
>
> Why do this trick here instead of just adding "pv-dedicated" to
> feature_word_info[FEAT_KVM].feat_names?
Actually this hint doesn't depend on KVM, just qemu command-line gives
a hint and then guest kernel can recognize it. Is there a nicer
proposal in qemu? Paolo?
Regards,
Wanpeng Li
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [Qemu-devel] [PATCH] target-i386: adds PV_DEDICATED hint CPUID feature bit
2018-02-08 9:44 [Qemu-devel] [PATCH] target-i386: adds PV_DEDICATED hint CPUID feature bit Wanpeng Li
2018-02-08 18:12 ` Eduardo Habkost
@ 2018-02-09 8:41 ` Paolo Bonzini
2018-02-09 14:27 ` Wanpeng Li
1 sibling, 1 reply; 11+ messages in thread
From: Paolo Bonzini @ 2018-02-09 8:41 UTC (permalink / raw)
To: Wanpeng Li, qemu-devel, kvm; +Cc: Radim Krčmář, Eduardo Habkost
On 08/02/2018 10:44, Wanpeng Li wrote:
> From: Wanpeng Li <wanpengli@tencent.com>
>
> Add PV_DEDICATED hint cpuid feature bit.
Please add a new feature word, since this is not a PV feature but more
like a performance hint.
Thanks,
Paolo
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> Cc: Radim Krčmář <rkrcmar@redhat.com>
> Cc: Eduardo Habkost <ehabkost@redhat.com>
> Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
> ---
> target/i386/cpu.c | 4 ++++
> target/i386/cpu.h | 3 +++
> 2 files changed, 7 insertions(+)
>
> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> index d70954b..cf48931 100644
> --- a/target/i386/cpu.c
> +++ b/target/i386/cpu.c
> @@ -4076,6 +4076,9 @@ static int x86_cpu_filter_features(X86CPU *cpu)
> x86_cpu_get_supported_feature_word(w, false);
> uint32_t requested_features = env->features[w];
> env->features[w] &= host_feat;
> + if (cpu->pv_dedicated && (w == FEAT_KVM)) {
> + env->features[w] |= CPUID_PV_DEDICATED;
> + }
> cpu->filtered_features[w] = requested_features & ~env->features[w];
> if (cpu->filtered_features[w]) {
> rv = 1;
> @@ -4682,6 +4685,7 @@ static Property x86_cpu_properties[] = {
> false),
> DEFINE_PROP_BOOL("vmware-cpuid-freq", X86CPU, vmware_cpuid_freq, true),
> DEFINE_PROP_BOOL("tcg-cpuid", X86CPU, expose_tcg, true),
> + DEFINE_PROP_BOOL("pv-dedicated", X86CPU, pv_dedicated, false),
>
> /*
> * From "Requirements for Implementing the Microsoft
> diff --git a/target/i386/cpu.h b/target/i386/cpu.h
> index f91e37d..8000da5 100644
> --- a/target/i386/cpu.h
> +++ b/target/i386/cpu.h
> @@ -672,6 +672,8 @@ typedef uint32_t FeatureWordArray[FEATURE_WORDS];
>
> #define CPUID_8000_0008_EBX_IBPB (1U << 12) /* Indirect Branch Prediction Barrier */
>
> +#define CPUID_PV_DEDICATED (1U << 8)
> +
> #define CPUID_XSAVE_XSAVEOPT (1U << 0)
> #define CPUID_XSAVE_XSAVEC (1U << 1)
> #define CPUID_XSAVE_XGETBV1 (1U << 2)
> @@ -1276,6 +1278,7 @@ struct X86CPU {
> bool expose_kvm;
> bool expose_tcg;
> bool migratable;
> + bool pv_dedicated;
> bool max_features; /* Enable all supported features automatically */
> uint32_t apic_id;
>
>
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [Qemu-devel] [PATCH] target-i386: adds PV_DEDICATED hint CPUID feature bit
2018-02-08 18:12 ` Eduardo Habkost
2018-02-09 3:18 ` Wanpeng Li
@ 2018-02-09 8:41 ` Paolo Bonzini
2018-02-09 11:46 ` Eduardo Habkost
1 sibling, 1 reply; 11+ messages in thread
From: Paolo Bonzini @ 2018-02-09 8:41 UTC (permalink / raw)
To: Eduardo Habkost, Wanpeng Li; +Cc: qemu-devel, kvm, Radim Krčmář
On 08/02/2018 19:12, Eduardo Habkost wrote:
> On Thu, Feb 08, 2018 at 05:44:20PM +0800, Wanpeng Li wrote:
>> From: Wanpeng Li <wanpengli@tencent.com>
>>
>> Add PV_DEDICATED hint cpuid feature bit.
>>
> [...]
>> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
>> index d70954b..cf48931 100644
>> --- a/target/i386/cpu.c
>> +++ b/target/i386/cpu.c
>> @@ -4076,6 +4076,9 @@ static int x86_cpu_filter_features(X86CPU *cpu)
>> x86_cpu_get_supported_feature_word(w, false);
>> uint32_t requested_features = env->features[w];
>> env->features[w] &= host_feat;
>> + if (cpu->pv_dedicated && (w == FEAT_KVM)) {
>> + env->features[w] |= CPUID_PV_DEDICATED;
>> + }
>
> Why do this trick here instead of just adding "pv-dedicated" to
> feature_word_info[FEAT_KVM].feat_names?
I think because it can be added independent of KVM_GET_SUPPORTED_CPUID.
Paolo
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [Qemu-devel] [PATCH] target-i386: adds PV_DEDICATED hint CPUID feature bit
2018-02-09 8:41 ` Paolo Bonzini
@ 2018-02-09 11:46 ` Eduardo Habkost
2018-02-09 12:24 ` Wanpeng Li
0 siblings, 1 reply; 11+ messages in thread
From: Eduardo Habkost @ 2018-02-09 11:46 UTC (permalink / raw)
To: Paolo Bonzini; +Cc: Wanpeng Li, qemu-devel, kvm, Radim Krčmář
On Fri, Feb 09, 2018 at 09:41:41AM +0100, Paolo Bonzini wrote:
> On 08/02/2018 19:12, Eduardo Habkost wrote:
> > On Thu, Feb 08, 2018 at 05:44:20PM +0800, Wanpeng Li wrote:
> >> From: Wanpeng Li <wanpengli@tencent.com>
> >>
> >> Add PV_DEDICATED hint cpuid feature bit.
> >>
> > [...]
> >> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> >> index d70954b..cf48931 100644
> >> --- a/target/i386/cpu.c
> >> +++ b/target/i386/cpu.c
> >> @@ -4076,6 +4076,9 @@ static int x86_cpu_filter_features(X86CPU *cpu)
> >> x86_cpu_get_supported_feature_word(w, false);
> >> uint32_t requested_features = env->features[w];
> >> env->features[w] &= host_feat;
> >> + if (cpu->pv_dedicated && (w == FEAT_KVM)) {
> >> + env->features[w] |= CPUID_PV_DEDICATED;
> >> + }
> >
> > Why do this trick here instead of just adding "pv-dedicated" to
> > feature_word_info[FEAT_KVM].feat_names?
>
> I think because it can be added independent of KVM_GET_SUPPORTED_CPUID.
If QEMU knows it can be enabled if outside GET_SUPPORTED_CPUID,
kvm_arch_get_supported_cpuid() can return it as supported.
--
Eduardo
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [Qemu-devel] [PATCH] target-i386: adds PV_DEDICATED hint CPUID feature bit
2018-02-09 11:46 ` Eduardo Habkost
@ 2018-02-09 12:24 ` Wanpeng Li
2018-02-09 12:46 ` Paolo Bonzini
2018-02-09 12:46 ` Eduardo Habkost
0 siblings, 2 replies; 11+ messages in thread
From: Wanpeng Li @ 2018-02-09 12:24 UTC (permalink / raw)
To: Eduardo Habkost
Cc: Paolo Bonzini, qemu-devel@nongnu.org Developers, kvm,
Radim Krčmář
2018-02-09 19:46 GMT+08:00 Eduardo Habkost <ehabkost@redhat.com>:
> On Fri, Feb 09, 2018 at 09:41:41AM +0100, Paolo Bonzini wrote:
>> On 08/02/2018 19:12, Eduardo Habkost wrote:
>> > On Thu, Feb 08, 2018 at 05:44:20PM +0800, Wanpeng Li wrote:
>> >> From: Wanpeng Li <wanpengli@tencent.com>
>> >>
>> >> Add PV_DEDICATED hint cpuid feature bit.
>> >>
>> > [...]
>> >> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
>> >> index d70954b..cf48931 100644
>> >> --- a/target/i386/cpu.c
>> >> +++ b/target/i386/cpu.c
>> >> @@ -4076,6 +4076,9 @@ static int x86_cpu_filter_features(X86CPU *cpu)
>> >> x86_cpu_get_supported_feature_word(w, false);
>> >> uint32_t requested_features = env->features[w];
>> >> env->features[w] &= host_feat;
>> >> + if (cpu->pv_dedicated && (w == FEAT_KVM)) {
>> >> + env->features[w] |= CPUID_PV_DEDICATED;
>> >> + }
>> >
>> > Why do this trick here instead of just adding "pv-dedicated" to
>> > feature_word_info[FEAT_KVM].feat_names?
>>
>> I think because it can be added independent of KVM_GET_SUPPORTED_CPUID.
>
> If QEMU knows it can be enabled if outside GET_SUPPORTED_CPUID,
> kvm_arch_get_supported_cpuid() can return it as supported.
The guest fails to detect the new cpuid this time.
diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index d70954b..e2974ad 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -358,6 +358,20 @@ static FeatureWordInfo feature_word_info[FEATURE_WORDS] = {
.cpuid_eax = KVM_CPUID_FEATURES, .cpuid_reg = R_EAX,
.tcg_features = TCG_KVM_FEATURES,
},
+ [FEAT_KVM_HINTS] = {
+ .feat_names = {
+ "hint-dedicated", NULL, NULL, NULL,
+ NULL, NULL, NULL, NULL,
+ NULL, NULL, NULL, NULL,
+ NULL, NULL, NULL, NULL,
+ NULL, NULL, NULL, NULL,
+ NULL, NULL, NULL, NULL,
+ NULL, NULL, NULL, NULL,
+ NULL, NULL, NULL, NULL,
+ },
+ .cpuid_eax = KVM_CPUID_FEATURES, .cpuid_reg = R_EDX,
+ .tcg_features = TCG_KVM_FEATURES,
+ },
[FEAT_HYPERV_EAX] = {
.feat_names = {
NULL /* hv_msr_vp_runtime_access */, NULL /*
hv_msr_time_refcount_access */,
diff --git a/target/i386/cpu.h b/target/i386/cpu.h
index f91e37d..9f73692 100644
--- a/target/i386/cpu.h
+++ b/target/i386/cpu.h
@@ -475,6 +475,7 @@ typedef enum FeatureWord {
FEAT_8000_0008_EBX, /* CPUID[8000_0008].EBX */
FEAT_C000_0001_EDX, /* CPUID[C000_0001].EDX */
FEAT_KVM, /* CPUID[4000_0001].EAX (KVM_CPUID_FEATURES) */
+ FEAT_KVM_HINTS, /* CPUID[4000_0001].EDX */
FEAT_HYPERV_EAX, /* CPUID[4000_0003].EAX */
FEAT_HYPERV_EBX, /* CPUID[4000_0003].EBX */
FEAT_HYPERV_EDX, /* CPUID[4000_0003].EDX */
@@ -670,6 +671,8 @@ typedef uint32_t FeatureWordArray[FEATURE_WORDS];
#define CPUID_7_0_EDX_AVX512_4FMAPS (1U << 3) /* AVX512 Multiply
Accumulation Single Precision */
#define CPUID_7_0_EDX_SPEC_CTRL (1U << 26) /* Speculation Control */
+#define KVM_HINTS_DEDICATED (1U << 0)
+
#define CPUID_8000_0008_EBX_IBPB (1U << 12) /* Indirect Branch
Prediction Barrier */
#define CPUID_XSAVE_XSAVEOPT (1U << 0)
diff --git a/target/i386/kvm.c b/target/i386/kvm.c
index ad4b159..a0aad80 100644
--- a/target/i386/kvm.c
+++ b/target/i386/kvm.c
@@ -383,6 +383,9 @@ uint32_t kvm_arch_get_supported_cpuid(KVMState *s,
uint32_t function,
if (!kvm_irqchip_in_kernel()) {
ret &= ~(1U << KVM_FEATURE_PV_UNHALT);
}
+ } else if (function == KVM_CPUID_FEATURES && reg == R_EDX) {
+ ret |= KVM_HINTS_DEDICATED;
+ found = 1;
}
/* fallback for older kernels */
Regards,
Wanpeng Li
^ permalink raw reply related [flat|nested] 11+ messages in thread
* Re: [Qemu-devel] [PATCH] target-i386: adds PV_DEDICATED hint CPUID feature bit
2018-02-09 12:24 ` Wanpeng Li
@ 2018-02-09 12:46 ` Paolo Bonzini
2018-02-09 12:46 ` Eduardo Habkost
1 sibling, 0 replies; 11+ messages in thread
From: Paolo Bonzini @ 2018-02-09 12:46 UTC (permalink / raw)
To: Wanpeng Li, Eduardo Habkost
Cc: qemu-devel@nongnu.org Developers, kvm, Radim Krčmář
On 09/02/2018 13:24, Wanpeng Li wrote:
> The guest fails to detect the new cpuid this time.
You have to debug the KVM_SET_CPUID2 ioctls and see why it is not set.
Paolo
> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> index d70954b..e2974ad 100644
> --- a/target/i386/cpu.c
> +++ b/target/i386/cpu.c
> @@ -358,6 +358,20 @@ static FeatureWordInfo feature_word_info[FEATURE_WORDS] = {
> .cpuid_eax = KVM_CPUID_FEATURES, .cpuid_reg = R_EAX,
> .tcg_features = TCG_KVM_FEATURES,
> },
> + [FEAT_KVM_HINTS] = {
> + .feat_names = {
> + "hint-dedicated", NULL, NULL, NULL,
> + NULL, NULL, NULL, NULL,
> + NULL, NULL, NULL, NULL,
> + NULL, NULL, NULL, NULL,
> + NULL, NULL, NULL, NULL,
> + NULL, NULL, NULL, NULL,
> + NULL, NULL, NULL, NULL,
> + NULL, NULL, NULL, NULL,
> + },
> + .cpuid_eax = KVM_CPUID_FEATURES, .cpuid_reg = R_EDX,
> + .tcg_features = TCG_KVM_FEATURES,
> + },
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [Qemu-devel] [PATCH] target-i386: adds PV_DEDICATED hint CPUID feature bit
2018-02-09 12:24 ` Wanpeng Li
2018-02-09 12:46 ` Paolo Bonzini
@ 2018-02-09 12:46 ` Eduardo Habkost
2018-02-09 14:26 ` Wanpeng Li
1 sibling, 1 reply; 11+ messages in thread
From: Eduardo Habkost @ 2018-02-09 12:46 UTC (permalink / raw)
To: Wanpeng Li
Cc: Paolo Bonzini, qemu-devel@nongnu.org Developers, kvm,
Radim Krčmář
On Fri, Feb 09, 2018 at 08:24:26PM +0800, Wanpeng Li wrote:
> 2018-02-09 19:46 GMT+08:00 Eduardo Habkost <ehabkost@redhat.com>:
> > On Fri, Feb 09, 2018 at 09:41:41AM +0100, Paolo Bonzini wrote:
> >> On 08/02/2018 19:12, Eduardo Habkost wrote:
> >> > On Thu, Feb 08, 2018 at 05:44:20PM +0800, Wanpeng Li wrote:
> >> >> From: Wanpeng Li <wanpengli@tencent.com>
> >> >>
> >> >> Add PV_DEDICATED hint cpuid feature bit.
> >> >>
> >> > [...]
> >> >> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> >> >> index d70954b..cf48931 100644
> >> >> --- a/target/i386/cpu.c
> >> >> +++ b/target/i386/cpu.c
> >> >> @@ -4076,6 +4076,9 @@ static int x86_cpu_filter_features(X86CPU *cpu)
> >> >> x86_cpu_get_supported_feature_word(w, false);
> >> >> uint32_t requested_features = env->features[w];
> >> >> env->features[w] &= host_feat;
> >> >> + if (cpu->pv_dedicated && (w == FEAT_KVM)) {
> >> >> + env->features[w] |= CPUID_PV_DEDICATED;
> >> >> + }
> >> >
> >> > Why do this trick here instead of just adding "pv-dedicated" to
> >> > feature_word_info[FEAT_KVM].feat_names?
> >>
> >> I think because it can be added independent of KVM_GET_SUPPORTED_CPUID.
> >
> > If QEMU knows it can be enabled if outside GET_SUPPORTED_CPUID,
> > kvm_arch_get_supported_cpuid() can return it as supported.
>
> The guest fails to detect the new cpuid this time.
This should fix it:
diff --git a/target/i386/kvm.c b/target/i386/kvm.c
index a0aad808bd..44ee524188 100644
--- a/target/i386/kvm.c
+++ b/target/i386/kvm.c
@@ -804,6 +804,7 @@ int kvm_arch_init_vcpu(CPUState *cs)
c = &cpuid_data.entries[cpuid_i++];
c->function = KVM_CPUID_FEATURES | kvm_base;
c->eax = env->features[FEAT_KVM];
+ c->edx = env->features[FEAT_KVM_HINTS];
}
cpu_x86_cpuid(env, 0, 0, &limit, &unused, &unused, &unused);
>
> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> index d70954b..e2974ad 100644
> --- a/target/i386/cpu.c
> +++ b/target/i386/cpu.c
> @@ -358,6 +358,20 @@ static FeatureWordInfo feature_word_info[FEATURE_WORDS] = {
> .cpuid_eax = KVM_CPUID_FEATURES, .cpuid_reg = R_EAX,
> .tcg_features = TCG_KVM_FEATURES,
> },
> + [FEAT_KVM_HINTS] = {
> + .feat_names = {
> + "hint-dedicated", NULL, NULL, NULL,
> + NULL, NULL, NULL, NULL,
> + NULL, NULL, NULL, NULL,
> + NULL, NULL, NULL, NULL,
> + NULL, NULL, NULL, NULL,
> + NULL, NULL, NULL, NULL,
> + NULL, NULL, NULL, NULL,
> + NULL, NULL, NULL, NULL,
> + },
> + .cpuid_eax = KVM_CPUID_FEATURES, .cpuid_reg = R_EDX,
> + .tcg_features = TCG_KVM_FEATURES,
> + },
> [FEAT_HYPERV_EAX] = {
> .feat_names = {
> NULL /* hv_msr_vp_runtime_access */, NULL /*
> hv_msr_time_refcount_access */,
> diff --git a/target/i386/cpu.h b/target/i386/cpu.h
> index f91e37d..9f73692 100644
> --- a/target/i386/cpu.h
> +++ b/target/i386/cpu.h
> @@ -475,6 +475,7 @@ typedef enum FeatureWord {
> FEAT_8000_0008_EBX, /* CPUID[8000_0008].EBX */
> FEAT_C000_0001_EDX, /* CPUID[C000_0001].EDX */
> FEAT_KVM, /* CPUID[4000_0001].EAX (KVM_CPUID_FEATURES) */
> + FEAT_KVM_HINTS, /* CPUID[4000_0001].EDX */
> FEAT_HYPERV_EAX, /* CPUID[4000_0003].EAX */
> FEAT_HYPERV_EBX, /* CPUID[4000_0003].EBX */
> FEAT_HYPERV_EDX, /* CPUID[4000_0003].EDX */
> @@ -670,6 +671,8 @@ typedef uint32_t FeatureWordArray[FEATURE_WORDS];
> #define CPUID_7_0_EDX_AVX512_4FMAPS (1U << 3) /* AVX512 Multiply
> Accumulation Single Precision */
> #define CPUID_7_0_EDX_SPEC_CTRL (1U << 26) /* Speculation Control */
>
> +#define KVM_HINTS_DEDICATED (1U << 0)
> +
> #define CPUID_8000_0008_EBX_IBPB (1U << 12) /* Indirect Branch
> Prediction Barrier */
>
> #define CPUID_XSAVE_XSAVEOPT (1U << 0)
> diff --git a/target/i386/kvm.c b/target/i386/kvm.c
> index ad4b159..a0aad80 100644
> --- a/target/i386/kvm.c
> +++ b/target/i386/kvm.c
> @@ -383,6 +383,9 @@ uint32_t kvm_arch_get_supported_cpuid(KVMState *s,
> uint32_t function,
> if (!kvm_irqchip_in_kernel()) {
> ret &= ~(1U << KVM_FEATURE_PV_UNHALT);
> }
> + } else if (function == KVM_CPUID_FEATURES && reg == R_EDX) {
> + ret |= KVM_HINTS_DEDICATED;
> + found = 1;
> }
>
> /* fallback for older kernels */
>
>
> Regards,
> Wanpeng Li
--
Eduardo
^ permalink raw reply related [flat|nested] 11+ messages in thread
* Re: [Qemu-devel] [PATCH] target-i386: adds PV_DEDICATED hint CPUID feature bit
2018-02-09 12:46 ` Eduardo Habkost
@ 2018-02-09 14:26 ` Wanpeng Li
0 siblings, 0 replies; 11+ messages in thread
From: Wanpeng Li @ 2018-02-09 14:26 UTC (permalink / raw)
To: Eduardo Habkost
Cc: Paolo Bonzini, qemu-devel@nongnu.org Developers, kvm,
Radim Krčmář
2018-02-09 20:46 GMT+08:00 Eduardo Habkost <ehabkost@redhat.com>:
> On Fri, Feb 09, 2018 at 08:24:26PM +0800, Wanpeng Li wrote:
>> 2018-02-09 19:46 GMT+08:00 Eduardo Habkost <ehabkost@redhat.com>:
>> > On Fri, Feb 09, 2018 at 09:41:41AM +0100, Paolo Bonzini wrote:
>> >> On 08/02/2018 19:12, Eduardo Habkost wrote:
>> >> > On Thu, Feb 08, 2018 at 05:44:20PM +0800, Wanpeng Li wrote:
>> >> >> From: Wanpeng Li <wanpengli@tencent.com>
>> >> >>
>> >> >> Add PV_DEDICATED hint cpuid feature bit.
>> >> >>
>> >> > [...]
>> >> >> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
>> >> >> index d70954b..cf48931 100644
>> >> >> --- a/target/i386/cpu.c
>> >> >> +++ b/target/i386/cpu.c
>> >> >> @@ -4076,6 +4076,9 @@ static int x86_cpu_filter_features(X86CPU *cpu)
>> >> >> x86_cpu_get_supported_feature_word(w, false);
>> >> >> uint32_t requested_features = env->features[w];
>> >> >> env->features[w] &= host_feat;
>> >> >> + if (cpu->pv_dedicated && (w == FEAT_KVM)) {
>> >> >> + env->features[w] |= CPUID_PV_DEDICATED;
>> >> >> + }
>> >> >
>> >> > Why do this trick here instead of just adding "pv-dedicated" to
>> >> > feature_word_info[FEAT_KVM].feat_names?
>> >>
>> >> I think because it can be added independent of KVM_GET_SUPPORTED_CPUID.
>> >
>> > If QEMU knows it can be enabled if outside GET_SUPPORTED_CPUID,
>> > kvm_arch_get_supported_cpuid() can return it as supported.
>>
>> The guest fails to detect the new cpuid this time.
>
> This should fix it:
>
> diff --git a/target/i386/kvm.c b/target/i386/kvm.c
> index a0aad808bd..44ee524188 100644
> --- a/target/i386/kvm.c
> +++ b/target/i386/kvm.c
> @@ -804,6 +804,7 @@ int kvm_arch_init_vcpu(CPUState *cs)
> c = &cpuid_data.entries[cpuid_i++];
> c->function = KVM_CPUID_FEATURES | kvm_base;
> c->eax = env->features[FEAT_KVM];
> + c->edx = env->features[FEAT_KVM_HINTS];
> }
>
> cpu_x86_cpuid(env, 0, 0, &limit, &unused, &unused, &unused);
>
Yeah, thanks, fold this in v2.
Regards,
Wanpeng Li
>>
>> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
>> index d70954b..e2974ad 100644
>> --- a/target/i386/cpu.c
>> +++ b/target/i386/cpu.c
>> @@ -358,6 +358,20 @@ static FeatureWordInfo feature_word_info[FEATURE_WORDS] = {
>> .cpuid_eax = KVM_CPUID_FEATURES, .cpuid_reg = R_EAX,
>> .tcg_features = TCG_KVM_FEATURES,
>> },
>> + [FEAT_KVM_HINTS] = {
>> + .feat_names = {
>> + "hint-dedicated", NULL, NULL, NULL,
>> + NULL, NULL, NULL, NULL,
>> + NULL, NULL, NULL, NULL,
>> + NULL, NULL, NULL, NULL,
>> + NULL, NULL, NULL, NULL,
>> + NULL, NULL, NULL, NULL,
>> + NULL, NULL, NULL, NULL,
>> + NULL, NULL, NULL, NULL,
>> + },
>> + .cpuid_eax = KVM_CPUID_FEATURES, .cpuid_reg = R_EDX,
>> + .tcg_features = TCG_KVM_FEATURES,
>> + },
>> [FEAT_HYPERV_EAX] = {
>> .feat_names = {
>> NULL /* hv_msr_vp_runtime_access */, NULL /*
>> hv_msr_time_refcount_access */,
>> diff --git a/target/i386/cpu.h b/target/i386/cpu.h
>> index f91e37d..9f73692 100644
>> --- a/target/i386/cpu.h
>> +++ b/target/i386/cpu.h
>> @@ -475,6 +475,7 @@ typedef enum FeatureWord {
>> FEAT_8000_0008_EBX, /* CPUID[8000_0008].EBX */
>> FEAT_C000_0001_EDX, /* CPUID[C000_0001].EDX */
>> FEAT_KVM, /* CPUID[4000_0001].EAX (KVM_CPUID_FEATURES) */
>> + FEAT_KVM_HINTS, /* CPUID[4000_0001].EDX */
>> FEAT_HYPERV_EAX, /* CPUID[4000_0003].EAX */
>> FEAT_HYPERV_EBX, /* CPUID[4000_0003].EBX */
>> FEAT_HYPERV_EDX, /* CPUID[4000_0003].EDX */
>> @@ -670,6 +671,8 @@ typedef uint32_t FeatureWordArray[FEATURE_WORDS];
>> #define CPUID_7_0_EDX_AVX512_4FMAPS (1U << 3) /* AVX512 Multiply
>> Accumulation Single Precision */
>> #define CPUID_7_0_EDX_SPEC_CTRL (1U << 26) /* Speculation Control */
>>
>> +#define KVM_HINTS_DEDICATED (1U << 0)
>> +
>> #define CPUID_8000_0008_EBX_IBPB (1U << 12) /* Indirect Branch
>> Prediction Barrier */
>>
>> #define CPUID_XSAVE_XSAVEOPT (1U << 0)
>> diff --git a/target/i386/kvm.c b/target/i386/kvm.c
>> index ad4b159..a0aad80 100644
>> --- a/target/i386/kvm.c
>> +++ b/target/i386/kvm.c
>> @@ -383,6 +383,9 @@ uint32_t kvm_arch_get_supported_cpuid(KVMState *s,
>> uint32_t function,
>> if (!kvm_irqchip_in_kernel()) {
>> ret &= ~(1U << KVM_FEATURE_PV_UNHALT);
>> }
>> + } else if (function == KVM_CPUID_FEATURES && reg == R_EDX) {
>> + ret |= KVM_HINTS_DEDICATED;
>> + found = 1;
>> }
>>
>> /* fallback for older kernels */
>>
>>
>> Regards,
>> Wanpeng Li
>
> --
> Eduardo
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [Qemu-devel] [PATCH] target-i386: adds PV_DEDICATED hint CPUID feature bit
2018-02-09 8:41 ` Paolo Bonzini
@ 2018-02-09 14:27 ` Wanpeng Li
0 siblings, 0 replies; 11+ messages in thread
From: Wanpeng Li @ 2018-02-09 14:27 UTC (permalink / raw)
To: Paolo Bonzini
Cc: qemu-devel@nongnu.org Developers, kvm,
Radim Krčmář,
Eduardo Habkost
2018-02-09 16:41 GMT+08:00 Paolo Bonzini <bonzini@gnu.org>:
> On 08/02/2018 10:44, Wanpeng Li wrote:
>> From: Wanpeng Li <wanpengli@tencent.com>
>>
>> Add PV_DEDICATED hint cpuid feature bit.
>
> Please add a new feature word, since this is not a PV feature but more
> like a performance hint.
Do it in v2.
Regards,
Wanpeng Li
>
> Thanks,
>
> Paolo
>
>> Cc: Paolo Bonzini <pbonzini@redhat.com>
>> Cc: Radim Krčmář <rkrcmar@redhat.com>
>> Cc: Eduardo Habkost <ehabkost@redhat.com>
>> Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
>> ---
>> target/i386/cpu.c | 4 ++++
>> target/i386/cpu.h | 3 +++
>> 2 files changed, 7 insertions(+)
>>
>> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
>> index d70954b..cf48931 100644
>> --- a/target/i386/cpu.c
>> +++ b/target/i386/cpu.c
>> @@ -4076,6 +4076,9 @@ static int x86_cpu_filter_features(X86CPU *cpu)
>> x86_cpu_get_supported_feature_word(w, false);
>> uint32_t requested_features = env->features[w];
>> env->features[w] &= host_feat;
>> + if (cpu->pv_dedicated && (w == FEAT_KVM)) {
>> + env->features[w] |= CPUID_PV_DEDICATED;
>> + }
>> cpu->filtered_features[w] = requested_features & ~env->features[w];
>> if (cpu->filtered_features[w]) {
>> rv = 1;
>> @@ -4682,6 +4685,7 @@ static Property x86_cpu_properties[] = {
>> false),
>> DEFINE_PROP_BOOL("vmware-cpuid-freq", X86CPU, vmware_cpuid_freq, true),
>> DEFINE_PROP_BOOL("tcg-cpuid", X86CPU, expose_tcg, true),
>> + DEFINE_PROP_BOOL("pv-dedicated", X86CPU, pv_dedicated, false),
>>
>> /*
>> * From "Requirements for Implementing the Microsoft
>> diff --git a/target/i386/cpu.h b/target/i386/cpu.h
>> index f91e37d..8000da5 100644
>> --- a/target/i386/cpu.h
>> +++ b/target/i386/cpu.h
>> @@ -672,6 +672,8 @@ typedef uint32_t FeatureWordArray[FEATURE_WORDS];
>>
>> #define CPUID_8000_0008_EBX_IBPB (1U << 12) /* Indirect Branch Prediction Barrier */
>>
>> +#define CPUID_PV_DEDICATED (1U << 8)
>> +
>> #define CPUID_XSAVE_XSAVEOPT (1U << 0)
>> #define CPUID_XSAVE_XSAVEC (1U << 1)
>> #define CPUID_XSAVE_XGETBV1 (1U << 2)
>> @@ -1276,6 +1278,7 @@ struct X86CPU {
>> bool expose_kvm;
>> bool expose_tcg;
>> bool migratable;
>> + bool pv_dedicated;
>> bool max_features; /* Enable all supported features automatically */
>> uint32_t apic_id;
>>
>>
>
^ permalink raw reply [flat|nested] 11+ messages in thread
end of thread, other threads:[~2018-02-09 14:27 UTC | newest]
Thread overview: 11+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-02-08 9:44 [Qemu-devel] [PATCH] target-i386: adds PV_DEDICATED hint CPUID feature bit Wanpeng Li
2018-02-08 18:12 ` Eduardo Habkost
2018-02-09 3:18 ` Wanpeng Li
2018-02-09 8:41 ` Paolo Bonzini
2018-02-09 11:46 ` Eduardo Habkost
2018-02-09 12:24 ` Wanpeng Li
2018-02-09 12:46 ` Paolo Bonzini
2018-02-09 12:46 ` Eduardo Habkost
2018-02-09 14:26 ` Wanpeng Li
2018-02-09 8:41 ` Paolo Bonzini
2018-02-09 14:27 ` Wanpeng Li
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