From: Andrew Jones <drjones@redhat.com> To: kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu Cc: maz@kernel.org, steven.price@arm.com, pbonzini@redhat.com Subject: [PATCH v2 6/6] arm64/x86: KVM: Introduce steal-time cap Date: Tue, 4 Aug 2020 19:06:04 +0200 [thread overview] Message-ID: <20200804170604.42662-7-drjones@redhat.com> (raw) In-Reply-To: <20200804170604.42662-1-drjones@redhat.com> arm64 requires a vcpu fd (KVM_HAS_DEVICE_ATTR vcpu ioctl) to probe support for steal-time. However this is unnecessary, as only a KVM fd is required, and it complicates userspace (userspace may prefer delaying vcpu creation until after feature probing). Introduce a cap that can be checked instead. While x86 can already probe steal-time support with a kvm fd (KVM_GET_SUPPORTED_CPUID), we add the cap there too for consistency. Reviewed-by: Steven Price <steven.price@arm.com> Signed-off-by: Andrew Jones <drjones@redhat.com> --- Documentation/virt/kvm/api.rst | 13 +++++++++++++ arch/arm64/include/asm/kvm_host.h | 1 + arch/arm64/kvm/arm.c | 3 +++ arch/arm64/kvm/pvtime.c | 2 +- arch/x86/kvm/x86.c | 3 +++ include/uapi/linux/kvm.h | 1 + 6 files changed, 22 insertions(+), 1 deletion(-) diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index 3bd96c1a3962..51208c5d6ac2 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -6152,3 +6152,16 @@ KVM can therefore start protected VMs. This capability governs the KVM_S390_PV_COMMAND ioctl and the KVM_MP_STATE_LOAD MP_STATE. KVM_SET_MP_STATE can fail for protected guests when the state change is invalid. + +8.24 KVM_CAP_STEAL_TIME +----------------------- + +:Architectures: arm64, x86 + +This capability indicates that KVM supports steal time accounting. +When steal time accounting is supported it may be enabled with +architecture-specific interfaces. This capability and the architecture- +specific interfaces must be consistent, i.e. if one says the feature +is supported, than the other should as well and vice versa. For arm64 +see Documentation/virt/kvm/devices/vcpu.rst "KVM_ARM_VCPU_PVTIME_CTRL". +For x86 see Documentation/virt/kvm/msr.rst "MSR_KVM_STEAL_TIME". diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 1b65dfeb6fed..57c44bc56087 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -505,6 +505,7 @@ long kvm_hypercall_pv_features(struct kvm_vcpu *vcpu); gpa_t kvm_init_stolen_time(struct kvm_vcpu *vcpu); void kvm_update_stolen_time(struct kvm_vcpu *vcpu); +bool kvm_arm_pvtime_supported(void); int kvm_arm_pvtime_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr); int kvm_arm_pvtime_get_attr(struct kvm_vcpu *vcpu, diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 90cb90561446..0f7f8cd2f341 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -222,6 +222,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) */ r = 1; break; + case KVM_CAP_STEAL_TIME: + r = kvm_arm_pvtime_supported(); + break; default: r = kvm_arch_vm_ioctl_check_extension(kvm, ext); break; diff --git a/arch/arm64/kvm/pvtime.c b/arch/arm64/kvm/pvtime.c index 75234321d896..920ac43077ad 100644 --- a/arch/arm64/kvm/pvtime.c +++ b/arch/arm64/kvm/pvtime.c @@ -71,7 +71,7 @@ gpa_t kvm_init_stolen_time(struct kvm_vcpu *vcpu) return base; } -static bool kvm_arm_pvtime_supported(void) +bool kvm_arm_pvtime_supported(void) { return !!sched_info_on(); } diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 88c593f83b28..27fc86bb28c4 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3538,6 +3538,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) case KVM_CAP_HYPERV_ENLIGHTENED_VMCS: r = kvm_x86_ops.nested_ops->enable_evmcs != NULL; break; + case KVM_CAP_STEAL_TIME: + r = sched_info_on(); + break; default: break; } diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 4fdf30316582..121fb29ac004 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1031,6 +1031,7 @@ struct kvm_ppc_resize_hpt { #define KVM_CAP_PPC_SECURE_GUEST 181 #define KVM_CAP_HALT_POLL 182 #define KVM_CAP_ASYNC_PF_INT 183 +#define KVM_CAP_STEAL_TIME 184 #ifdef KVM_CAP_IRQ_ROUTING -- 2.25.4
WARNING: multiple messages have this Message-ID (diff)
From: Andrew Jones <drjones@redhat.com> To: kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu Cc: maz@kernel.org, pbonzini@redhat.com, steven.price@arm.com Subject: [PATCH v2 6/6] arm64/x86: KVM: Introduce steal-time cap Date: Tue, 4 Aug 2020 19:06:04 +0200 [thread overview] Message-ID: <20200804170604.42662-7-drjones@redhat.com> (raw) In-Reply-To: <20200804170604.42662-1-drjones@redhat.com> arm64 requires a vcpu fd (KVM_HAS_DEVICE_ATTR vcpu ioctl) to probe support for steal-time. However this is unnecessary, as only a KVM fd is required, and it complicates userspace (userspace may prefer delaying vcpu creation until after feature probing). Introduce a cap that can be checked instead. While x86 can already probe steal-time support with a kvm fd (KVM_GET_SUPPORTED_CPUID), we add the cap there too for consistency. Reviewed-by: Steven Price <steven.price@arm.com> Signed-off-by: Andrew Jones <drjones@redhat.com> --- Documentation/virt/kvm/api.rst | 13 +++++++++++++ arch/arm64/include/asm/kvm_host.h | 1 + arch/arm64/kvm/arm.c | 3 +++ arch/arm64/kvm/pvtime.c | 2 +- arch/x86/kvm/x86.c | 3 +++ include/uapi/linux/kvm.h | 1 + 6 files changed, 22 insertions(+), 1 deletion(-) diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index 3bd96c1a3962..51208c5d6ac2 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -6152,3 +6152,16 @@ KVM can therefore start protected VMs. This capability governs the KVM_S390_PV_COMMAND ioctl and the KVM_MP_STATE_LOAD MP_STATE. KVM_SET_MP_STATE can fail for protected guests when the state change is invalid. + +8.24 KVM_CAP_STEAL_TIME +----------------------- + +:Architectures: arm64, x86 + +This capability indicates that KVM supports steal time accounting. +When steal time accounting is supported it may be enabled with +architecture-specific interfaces. This capability and the architecture- +specific interfaces must be consistent, i.e. if one says the feature +is supported, than the other should as well and vice versa. For arm64 +see Documentation/virt/kvm/devices/vcpu.rst "KVM_ARM_VCPU_PVTIME_CTRL". +For x86 see Documentation/virt/kvm/msr.rst "MSR_KVM_STEAL_TIME". diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 1b65dfeb6fed..57c44bc56087 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -505,6 +505,7 @@ long kvm_hypercall_pv_features(struct kvm_vcpu *vcpu); gpa_t kvm_init_stolen_time(struct kvm_vcpu *vcpu); void kvm_update_stolen_time(struct kvm_vcpu *vcpu); +bool kvm_arm_pvtime_supported(void); int kvm_arm_pvtime_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr); int kvm_arm_pvtime_get_attr(struct kvm_vcpu *vcpu, diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 90cb90561446..0f7f8cd2f341 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -222,6 +222,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) */ r = 1; break; + case KVM_CAP_STEAL_TIME: + r = kvm_arm_pvtime_supported(); + break; default: r = kvm_arch_vm_ioctl_check_extension(kvm, ext); break; diff --git a/arch/arm64/kvm/pvtime.c b/arch/arm64/kvm/pvtime.c index 75234321d896..920ac43077ad 100644 --- a/arch/arm64/kvm/pvtime.c +++ b/arch/arm64/kvm/pvtime.c @@ -71,7 +71,7 @@ gpa_t kvm_init_stolen_time(struct kvm_vcpu *vcpu) return base; } -static bool kvm_arm_pvtime_supported(void) +bool kvm_arm_pvtime_supported(void) { return !!sched_info_on(); } diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 88c593f83b28..27fc86bb28c4 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3538,6 +3538,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) case KVM_CAP_HYPERV_ENLIGHTENED_VMCS: r = kvm_x86_ops.nested_ops->enable_evmcs != NULL; break; + case KVM_CAP_STEAL_TIME: + r = sched_info_on(); + break; default: break; } diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 4fdf30316582..121fb29ac004 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1031,6 +1031,7 @@ struct kvm_ppc_resize_hpt { #define KVM_CAP_PPC_SECURE_GUEST 181 #define KVM_CAP_HALT_POLL 182 #define KVM_CAP_ASYNC_PF_INT 183 +#define KVM_CAP_STEAL_TIME 184 #ifdef KVM_CAP_IRQ_ROUTING -- 2.25.4 _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
next prev parent reply other threads:[~2020-08-04 17:08 UTC|newest] Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-08-04 17:05 [PATCH v2 0/6] KVM: arm64: pvtime: Fixes and a new cap Andrew Jones 2020-08-04 17:05 ` Andrew Jones 2020-08-04 17:05 ` [PATCH v2 1/6] KVM: arm64: pvtime: steal-time is only supported when configured Andrew Jones 2020-08-04 17:05 ` Andrew Jones 2020-08-04 17:06 ` [PATCH v2 2/6] KVM: arm64: pvtime: Fix potential loss of stolen time Andrew Jones 2020-08-04 17:06 ` Andrew Jones 2020-08-04 17:06 ` [PATCH v2 3/6] KVM: arm64: Drop type input from kvm_put_guest Andrew Jones 2020-08-04 17:06 ` Andrew Jones 2020-08-04 17:06 ` [PATCH v2 4/6] KVM: arm64: pvtime: Fix stolen time accounting across migration Andrew Jones 2020-08-04 17:06 ` Andrew Jones 2020-08-04 17:06 ` [PATCH v2 5/6] KVM: Documentation: Minor fixups Andrew Jones 2020-08-04 17:06 ` Andrew Jones 2020-08-04 17:06 ` Andrew Jones [this message] 2020-08-04 17:06 ` [PATCH v2 6/6] arm64/x86: KVM: Introduce steal-time cap Andrew Jones 2020-08-05 15:37 ` [PATCH v2 0/6] KVM: arm64: pvtime: Fixes and a new cap Steven Price 2020-08-05 15:37 ` Steven Price 2020-08-19 12:50 ` Andrew Jones 2020-08-19 12:50 ` Andrew Jones 2020-08-21 13:04 ` Marc Zyngier 2020-08-21 13:04 ` Marc Zyngier
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20200804170604.42662-7-drjones@redhat.com \ --to=drjones@redhat.com \ --cc=kvm@vger.kernel.org \ --cc=kvmarm@lists.cs.columbia.edu \ --cc=maz@kernel.org \ --cc=pbonzini@redhat.com \ --cc=steven.price@arm.com \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.