diff options
| author | David Woodhouse <dwmw@amazon.co.uk> | 2022-03-03 18:41:23 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-04-02 12:41:16 +0300 |
| commit | 28d1629f751c4a5f9437fbaa0ee4ed81d1a8e587 (patch) | |
| tree | 7bb6ea3c92b73d698db299b5c6edff4bfc678d0b /arch/x86/kvm/xen.c | |
| parent | 536395260582be7443b0b35b0bbb89ffe3947f62 (diff) | |
| download | linux-28d1629f751c4a5f9437fbaa0ee4ed81d1a8e587.tar.xz | |
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>
Diffstat (limited to 'arch/x86/kvm/xen.c')
| -rw-r--r-- | arch/x86/kvm/xen.c | 19 |
1 files changed, 19 insertions, 0 deletions
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); |