On 2/8/21 11:23 PM, David Woodhouse wrote:
> From: David Woodhouse <dwmw@xxxxxxxxxxxx>
>
> In order to support Xen SHUTDOWN_soft_reset (for guest kexec, etc.) the
> VMM needs to be able to tear everything down and return the Xen features
> to a clean slate.
>
> Signed-off-by: David Woodhouse <dwmw@xxxxxxxxxxxx>
Reviewed-by: Joao Martins <joao.m.martins@xxxxxxxxxx>
> ---
> arch/x86/kvm/xen.c | 38 ++++++++++++++++++++++++++++----------
> 1 file changed, 28 insertions(+), 10 deletions(-)
>
> diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c
> index 39a7ffcdcf22..06fec10ffc4f 100644
> --- a/arch/x86/kvm/xen.c
> +++ b/arch/x86/kvm/xen.c
> @@ -118,12 +118,17 @@ int kvm_xen_hvm_set_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data)
> break;
>
> case KVM_XEN_ATTR_TYPE_SHARED_INFO:
> + if (data->u.shared_info.gfn == GPA_INVALID) {
> + kvm->arch.xen.shinfo_set = false;
> + r = 0;
> + break;
> + }
> r = kvm_xen_shared_info_init(kvm, data->u.shared_info.gfn);
> break;
>
>
> case KVM_XEN_ATTR_TYPE_UPCALL_VECTOR:
> - if (data->u.vector < 0x10)
> + if (data->u.vector && data->u.vector < 0x10)
> r = -EINVAL;
> else {
> kvm->arch.xen.upcall_vector = data->u.vector;
> @@ -152,10 +157,11 @@ int kvm_xen_hvm_get_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data)
> break;
>
> case KVM_XEN_ATTR_TYPE_SHARED_INFO:
> - if (kvm->arch.xen.shinfo_set) {
> + if (kvm->arch.xen.shinfo_set)
> data->u.shared_info.gfn = gpa_to_gfn(kvm->arch.xen.shinfo_cache.gpa);
> - r = 0;
> - }
> + else
> + data->u.shared_info.gfn = GPA_INVALID;
> + r = 0;
> break;
>
> case KVM_XEN_ATTR_TYPE_UPCALL_VECTOR:
> @@ -184,6 +190,11 @@ int kvm_xen_vcpu_set_attr(struct kvm_vcpu *vcpu, struct kvm_xen_vcpu_attr *data)
> BUILD_BUG_ON(sizeof(struct vcpu_info) !=
> sizeof(struct compat_vcpu_info));
>
> + if (data->u.gpa == GPA_INVALID) {
> + vcpu->arch.xen.vcpu_info_set = false;
> + break;
> + }
> +
> r = kvm_gfn_to_hva_cache_init(vcpu->kvm,
> &vcpu->arch.xen.vcpu_info_cache,
> data->u.gpa,
> @@ -195,6 +206,11 @@ int kvm_xen_vcpu_set_attr(struct kvm_vcpu *vcpu, struct kvm_xen_vcpu_attr *data)
> break;
>
> case KVM_XEN_VCPU_ATTR_TYPE_VCPU_TIME_INFO:
> + if (data->u.gpa == GPA_INVALID) {
> + vcpu->arch.xen.vcpu_time_info_set = false;
> + break;
> + }
> +
> r = kvm_gfn_to_hva_cache_init(vcpu->kvm,
> &vcpu->arch.xen.vcpu_time_info_cache,
> data->u.gpa,
> @@ -222,17 +238,19 @@ int kvm_xen_vcpu_get_attr(struct kvm_vcpu *vcpu, struct kvm_xen_vcpu_attr *data)
>
> switch (data->type) {
> case KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO:
> - if (vcpu->arch.xen.vcpu_info_set) {
> + if (vcpu->arch.xen.vcpu_info_set)
> data->u.gpa = vcpu->arch.xen.vcpu_info_cache.gpa;
> - r = 0;
> - }
> + else
> + data->u.gpa = GPA_INVALID;
> + r = 0;
> break;
>
> case KVM_XEN_VCPU_ATTR_TYPE_VCPU_TIME_INFO:
> - if (vcpu->arch.xen.vcpu_time_info_set) {
> + if (vcpu->arch.xen.vcpu_time_info_set)
> data->u.gpa = vcpu->arch.xen.vcpu_time_info_cache.gpa;
> - r = 0;
> - }
> + else
> + data->u.gpa = GPA_INVALID;
> + r = 0;
> break;
>
> default:
>
