[Qemu-devel] [PATCH v2 0/2] i386/kvm: enable Hyper-V PV IPI mechanism

[Qemu-devel] [PATCH v2 0/2] i386/kvm: enable Hyper-V PV IPI mechanism

[Vitaly Kuznetsov]

Hyper-V PV IPI enlightenment was merged to KVM (kvm/queue currently).
Support the feature enablement in Qemu.

Changes since v1 [Roman Kagan]:
- Strip kvm.h with 'make headers_install' before putting to Qemu.
- Add Reviewed-by: to PATCH2

Vitaly Kuznetsov (2):
  linux-headers: update to pre-4.20 (kvm/queue)
  i386/kvm: add support for Hyper-V IPI send

 linux-headers/linux/kvm.h  |  3 +++
 target/i386/cpu.c          |  1 +
 target/i386/cpu.h          |  1 +
 target/i386/hyperv-proto.h |  1 +
 target/i386/kvm.c          | 14 +++++++++++++-
 5 files changed, 19 insertions(+), 1 deletion(-)

-- 
2.17.1

[Qemu-devel] [PATCH v2 1/2] linux-headers: update to pre-4.20 (kvm/queue)

[Vitaly Kuznetsov]

This brings us three new defines: KVM_CAP_ARM_INJECT_SERROR_ESR,
KVM_CAP_MSR_PLATFORM_INFO and KVM_CAP_HYPERV_SEND_IPI.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
 linux-headers/linux/kvm.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/linux-headers/linux/kvm.h b/linux-headers/linux/kvm.h
index 66790724f1..711f5a2c8e 100644
--- a/linux-headers/linux/kvm.h
+++ b/linux-headers/linux/kvm.h
@@ -951,6 +951,9 @@ struct kvm_ppc_resize_hpt {
 #define KVM_CAP_HYPERV_TLBFLUSH 155
 #define KVM_CAP_S390_HPAGE_1M 156
 #define KVM_CAP_NESTED_STATE 157
+#define KVM_CAP_ARM_INJECT_SERROR_ESR 158
+#define KVM_CAP_MSR_PLATFORM_INFO 159
+#define KVM_CAP_HYPERV_SEND_IPI 160
 
 #ifdef KVM_CAP_IRQ_ROUTING
 
-- 
2.17.1

[Qemu-devel] [PATCH v2 2/2] i386/kvm: add support for Hyper-V IPI send

[Vitaly Kuznetsov]

Hyper-V PV IPI support is merged to KVM, enable the feature in Qemu. When
enabled, this allows Windows guests to send IPIs to other vCPUs with a
single hypercall even when there are >64 vCPUs in the request.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
---
 target/i386/cpu.c          |  1 +
 target/i386/cpu.h          |  1 +
 target/i386/hyperv-proto.h |  1 +
 target/i386/kvm.c          | 14 +++++++++++++-
 4 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index c88876dfe3..32ea041c06 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -5564,6 +5564,7 @@ static Property x86_cpu_properties[] = {
     DEFINE_PROP_BOOL("hv-frequencies", X86CPU, hyperv_frequencies, false),
     DEFINE_PROP_BOOL("hv-reenlightenment", X86CPU, hyperv_reenlightenment, false),
     DEFINE_PROP_BOOL("hv-tlbflush", X86CPU, hyperv_tlbflush, false),
+    DEFINE_PROP_BOOL("hv-ipi", X86CPU, hyperv_ipi, false),
     DEFINE_PROP_BOOL("check", X86CPU, check_cpuid, true),
     DEFINE_PROP_BOOL("enforce", X86CPU, enforce_cpuid, false),
     DEFINE_PROP_BOOL("kvm", X86CPU, expose_kvm, true),
diff --git a/target/i386/cpu.h b/target/i386/cpu.h
index 730c06f80a..caa1544b2e 100644
--- a/target/i386/cpu.h
+++ b/target/i386/cpu.h
@@ -1382,6 +1382,7 @@ struct X86CPU {
     bool hyperv_frequencies;
     bool hyperv_reenlightenment;
     bool hyperv_tlbflush;
+    bool hyperv_ipi;
     bool check_cpuid;
     bool enforce_cpuid;
     bool expose_kvm;
diff --git a/target/i386/hyperv-proto.h b/target/i386/hyperv-proto.h
index d6d5a79293..87f36d14e8 100644
--- a/target/i386/hyperv-proto.h
+++ b/target/i386/hyperv-proto.h
@@ -58,6 +58,7 @@
 #define HV_APIC_ACCESS_RECOMMENDED          (1u << 3)
 #define HV_SYSTEM_RESET_RECOMMENDED         (1u << 4)
 #define HV_RELAXED_TIMING_RECOMMENDED       (1u << 5)
+#define HV_CLUSTER_IPI_RECOMMENDED          (1u << 10)
 #define HV_EX_PROCESSOR_MASKS_RECOMMENDED   (1u << 11)
 
 /*
diff --git a/target/i386/kvm.c b/target/i386/kvm.c
index dc4047b02f..795aa52938 100644
--- a/target/i386/kvm.c
+++ b/target/i386/kvm.c
@@ -608,7 +608,8 @@ static bool hyperv_enabled(X86CPU *cpu)
             cpu->hyperv_synic ||
             cpu->hyperv_stimer ||
             cpu->hyperv_reenlightenment ||
-            cpu->hyperv_tlbflush);
+            cpu->hyperv_tlbflush ||
+            cpu->hyperv_ipi);
 }
 
 static int kvm_arch_set_tsc_khz(CPUState *cs)
@@ -888,6 +889,17 @@ int kvm_arch_init_vcpu(CPUState *cs)
             c->eax |= HV_REMOTE_TLB_FLUSH_RECOMMENDED;
             c->eax |= HV_EX_PROCESSOR_MASKS_RECOMMENDED;
         }
+        if (cpu->hyperv_ipi) {
+            if (kvm_check_extension(cs->kvm_state,
+                                    KVM_CAP_HYPERV_SEND_IPI) <= 0) {
+                fprintf(stderr, "Hyper-V IPI send support "
+                        "(requested by 'hv-ipi' cpu flag) "
+                        " is not supported by kernel\n");
+                return -ENOSYS;
+            }
+            c->eax |= HV_CLUSTER_IPI_RECOMMENDED;
+            c->eax |= HV_EX_PROCESSOR_MASKS_RECOMMENDED;
+        }
 
         c->ebx = cpu->hyperv_spinlock_attempts;
 
-- 
2.17.1

Re: [Qemu-devel] [PATCH v2 2/2] i386/kvm: add support for Hyper-V IPI send

[Paolo Bonzini]

On 09/10/2018 15:08, Vitaly Kuznetsov wrote:
> Hyper-V PV IPI support is merged to KVM, enable the feature in Qemu. When
> enabled, this allows Windows guests to send IPIs to other vCPUs with a
> single hypercall even when there are >64 vCPUs in the request.
> 
> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
> Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
> ---
>  target/i386/cpu.c          |  1 +
>  target/i386/cpu.h          |  1 +
>  target/i386/hyperv-proto.h |  1 +
>  target/i386/kvm.c          | 14 +++++++++++++-
>  4 files changed, 16 insertions(+), 1 deletion(-)
> 
> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> index c88876dfe3..32ea041c06 100644
> --- a/target/i386/cpu.c
> +++ b/target/i386/cpu.c
> @@ -5564,6 +5564,7 @@ static Property x86_cpu_properties[] = {
>      DEFINE_PROP_BOOL("hv-frequencies", X86CPU, hyperv_frequencies, false),
>      DEFINE_PROP_BOOL("hv-reenlightenment", X86CPU, hyperv_reenlightenment, false),
>      DEFINE_PROP_BOOL("hv-tlbflush", X86CPU, hyperv_tlbflush, false),
> +    DEFINE_PROP_BOOL("hv-ipi", X86CPU, hyperv_ipi, false),
>      DEFINE_PROP_BOOL("check", X86CPU, check_cpuid, true),
>      DEFINE_PROP_BOOL("enforce", X86CPU, enforce_cpuid, false),
>      DEFINE_PROP_BOOL("kvm", X86CPU, expose_kvm, true),
> diff --git a/target/i386/cpu.h b/target/i386/cpu.h
> index 730c06f80a..caa1544b2e 100644
> --- a/target/i386/cpu.h
> +++ b/target/i386/cpu.h
> @@ -1382,6 +1382,7 @@ struct X86CPU {
>      bool hyperv_frequencies;
>      bool hyperv_reenlightenment;
>      bool hyperv_tlbflush;
> +    bool hyperv_ipi;
>      bool check_cpuid;
>      bool enforce_cpuid;
>      bool expose_kvm;
> diff --git a/target/i386/hyperv-proto.h b/target/i386/hyperv-proto.h
> index d6d5a79293..87f36d14e8 100644
> --- a/target/i386/hyperv-proto.h
> +++ b/target/i386/hyperv-proto.h
> @@ -58,6 +58,7 @@
>  #define HV_APIC_ACCESS_RECOMMENDED          (1u << 3)
>  #define HV_SYSTEM_RESET_RECOMMENDED         (1u << 4)
>  #define HV_RELAXED_TIMING_RECOMMENDED       (1u << 5)
> +#define HV_CLUSTER_IPI_RECOMMENDED          (1u << 10)
>  #define HV_EX_PROCESSOR_MASKS_RECOMMENDED   (1u << 11)
>  
>  /*
> diff --git a/target/i386/kvm.c b/target/i386/kvm.c
> index dc4047b02f..795aa52938 100644
> --- a/target/i386/kvm.c
> +++ b/target/i386/kvm.c
> @@ -608,7 +608,8 @@ static bool hyperv_enabled(X86CPU *cpu)
>              cpu->hyperv_synic ||
>              cpu->hyperv_stimer ||
>              cpu->hyperv_reenlightenment ||
> -            cpu->hyperv_tlbflush);
> +            cpu->hyperv_tlbflush ||
> +            cpu->hyperv_ipi);
>  }
>  
>  static int kvm_arch_set_tsc_khz(CPUState *cs)
> @@ -888,6 +889,17 @@ int kvm_arch_init_vcpu(CPUState *cs)
>              c->eax |= HV_REMOTE_TLB_FLUSH_RECOMMENDED;
>              c->eax |= HV_EX_PROCESSOR_MASKS_RECOMMENDED;
>          }
> +        if (cpu->hyperv_ipi) {
> +            if (kvm_check_extension(cs->kvm_state,
> +                                    KVM_CAP_HYPERV_SEND_IPI) <= 0) {
> +                fprintf(stderr, "Hyper-V IPI send support "
> +                        "(requested by 'hv-ipi' cpu flag) "
> +                        " is not supported by kernel\n");
> +                return -ENOSYS;
> +            }
> +            c->eax |= HV_CLUSTER_IPI_RECOMMENDED;
> +            c->eax |= HV_EX_PROCESSOR_MASKS_RECOMMENDED;
> +        }
>  
>          c->ebx = cpu->hyperv_spinlock_attempts;
>  
> 

Queued patch 2, thanks.

Paolo