From 30b5c851af7991ad08abe90c1e7c31615fa98a1a Mon Sep 17 00:00:00 2001 From: David Woodhouse Date: Mon, 1 Mar 2021 12:53:09 +0000 Subject: KVM: x86/xen: Add support for vCPU runstate information This is how Xen guests do steal time accounting. The hypervisor records the amount of time spent in each of running/runnable/blocked/offline states. In the Xen accounting, a vCPU is still in state RUNSTATE_running while in Xen for a hypercall or I/O trap, etc. Only if Xen explicitly schedules does the state become RUNSTATE_blocked. In KVM this means that even when the vCPU exits the kvm_run loop, the state remains RUNSTATE_running. The VMM can explicitly set the vCPU to RUNSTATE_blocked by using the KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_CURRENT attribute, and can also use KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADJUST to retrospectively add a given amount of time to the blocked state and subtract it from the running state. The state_entry_time corresponds to get_kvmclock_ns() at the time the vCPU entered the current state, and the total times of all four states should always add up to state_entry_time. Co-developed-by: Joao Martins Signed-off-by: Joao Martins Signed-off-by: David Woodhouse Message-Id: <20210301125309.874953-2-dwmw2@infradead.org> Signed-off-by: Paolo Bonzini --- include/uapi/linux/kvm.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'include') diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 8b281f722e5b..f6afee209620 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1154,6 +1154,7 @@ struct kvm_x86_mce { #define KVM_XEN_HVM_CONFIG_HYPERCALL_MSR (1 << 0) #define KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL (1 << 1) #define KVM_XEN_HVM_CONFIG_SHARED_INFO (1 << 2) +#define KVM_XEN_HVM_CONFIG_RUNSTATE (1 << 3) struct kvm_xen_hvm_config { __u32 flags; @@ -1621,12 +1622,24 @@ struct kvm_xen_vcpu_attr { union { __u64 gpa; __u64 pad[8]; + struct { + __u64 state; + __u64 state_entry_time; + __u64 time_running; + __u64 time_runnable; + __u64 time_blocked; + __u64 time_offline; + } runstate; } u; }; /* Available with KVM_CAP_XEN_HVM / KVM_XEN_HVM_CONFIG_SHARED_INFO */ #define KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO 0x0 #define KVM_XEN_VCPU_ATTR_TYPE_VCPU_TIME_INFO 0x1 +#define KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADDR 0x2 +#define KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_CURRENT 0x3 +#define KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_DATA 0x4 +#define KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADJUST 0x5 /* Secure Encrypted Virtualization command */ enum sev_cmd_id { -- cgit v1.2.3-70-g09d2