diff options
| author | David Woodhouse <dwmw@amazon.co.uk> | 2022-03-03 16:41:23 +0100 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-04-02 11:41:16 +0200 |
| commit | 28d1629f751c4a5f9437fbaa0ee4ed81d1a8e587 (patch) | |
| tree | 7bb6ea3c92b73d698db299b5c6edff4bfc678d0b | |
| parent | KVM: x86/xen: handle PV timers oneshot mode (diff) | |
| download | linux-28d1629f751c4a5f9437fbaa0ee4ed81d1a8e587.tar.xz linux-28d1629f751c4a5f9437fbaa0ee4ed81d1a8e587.zip | |
KVM: x86/xen: Kernel acceleration for XENVER_version
Turns out this is a fast path for PV guests because they use it to
trigger the event channel upcall. So letting it bounce all the way up
to userspace is not great.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20220303154127.202856-14-dwmw2@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | arch/x86/include/asm/kvm_host.h | 1 | ||||
| -rw-r--r-- | arch/x86/kvm/xen.c | 19 | ||||
| -rw-r--r-- | include/uapi/linux/kvm.h | 3 |
3 files changed, 22 insertions, 1 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 8193d5285544..f3fba9d8ddc6 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1026,6 +1026,7 @@ struct msr_bitmap_range { /* Xen emulation context */ struct kvm_xen { + u32 xen_version; bool long_mode; u8 upcall_vector; struct gfn_to_pfn_cache shinfo_cache; diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c index 0e1595dc8c5f..98438f27f6b3 100644 --- a/arch/x86/kvm/xen.c +++ b/arch/x86/kvm/xen.c @@ -18,6 +18,7 @@ #include <trace/events/kvm.h> #include <xen/interface/xen.h> #include <xen/interface/vcpu.h> +#include <xen/interface/version.h> #include <xen/interface/event_channel.h> #include <xen/interface/sched.h> @@ -465,6 +466,13 @@ int kvm_xen_hvm_set_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data) r = kvm_xen_setattr_evtchn(kvm, data); break; + case KVM_XEN_ATTR_TYPE_XEN_VERSION: + mutex_lock(&kvm->lock); + kvm->arch.xen.xen_version = data->u.xen_version; + mutex_unlock(&kvm->lock); + r = 0; + break; + default: break; } @@ -497,6 +505,11 @@ int kvm_xen_hvm_get_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data) r = 0; break; + case KVM_XEN_ATTR_TYPE_XEN_VERSION: + data->u.xen_version = kvm->arch.xen.xen_version; + r = 0; + break; + default: break; } @@ -1059,6 +1072,12 @@ int kvm_xen_hypercall(struct kvm_vcpu *vcpu) params[3], params[4], params[5]); switch (input) { + case __HYPERVISOR_xen_version: + if (params[0] == XENVER_version && vcpu->kvm->arch.xen.xen_version) { + r = vcpu->kvm->arch.xen.xen_version; + handled = true; + } + break; case __HYPERVISOR_event_channel_op: if (params[0] == EVTCHNOP_send) handled = kvm_xen_hcall_evtchn_send(vcpu, params[1], &r); diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index cb223e425223..4dda3896ed71 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1711,7 +1711,7 @@ struct kvm_xen_hvm_attr { __u32 padding[4]; } deliver; } evtchn; - + __u32 xen_version; __u64 pad[8]; } u; }; @@ -1722,6 +1722,7 @@ struct kvm_xen_hvm_attr { #define KVM_XEN_ATTR_TYPE_UPCALL_VECTOR 0x2 /* Available with KVM_CAP_XEN_HVM / KVM_XEN_HVM_CONFIG_EVTCHN_SEND */ #define KVM_XEN_ATTR_TYPE_EVTCHN 0x3 +#define KVM_XEN_ATTR_TYPE_XEN_VERSION 0x4 /* Per-vCPU Xen attributes */ #define KVM_XEN_VCPU_GET_ATTR _IOWR(KVMIO, 0xca, struct kvm_xen_vcpu_attr) |