Currently, APF mechanism relies on the #PF abuse where the token is being passed through CR2. If we switch to using interrupts to deliver page-ready notifications we need a different way to pass the data. Extent the existing 'struct kvm_vcpu_pv_apf_data' with token information for page-ready notifications.
The newly introduced apf_put_user_ready() temporary puts both reason and token information, this will be changed to put token only when we switch to interrupt based notifications. Signed-off-by: Vitaly Kuznetsov <[email protected]> --- arch/x86/include/uapi/asm/kvm_para.h | 3 ++- arch/x86/kvm/x86.c | 17 +++++++++++++---- 2 files changed, 15 insertions(+), 5 deletions(-) diff --git a/arch/x86/include/uapi/asm/kvm_para.h b/arch/x86/include/uapi/asm/kvm_para.h index 2a8e0b6b9805..e3602a1de136 100644 --- a/arch/x86/include/uapi/asm/kvm_para.h +++ b/arch/x86/include/uapi/asm/kvm_para.h @@ -113,7 +113,8 @@ struct kvm_mmu_op_release_pt { struct kvm_vcpu_pv_apf_data { __u32 reason; - __u8 pad[60]; + __u32 pageready_token; + __u8 pad[56]; __u32 enabled; }; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index edd4a6415b92..28868cc16e4d 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2662,7 +2662,7 @@ static int kvm_pv_enable_async_pf(struct kvm_vcpu *vcpu, u64 data) } if (kvm_gfn_to_hva_cache_init(vcpu->kvm, &vcpu->arch.apf.data, gpa, - sizeof(u32))) + sizeof(u64))) return 1; vcpu->arch.apf.send_user_only = !(data & KVM_ASYNC_PF_SEND_ALWAYS); @@ -10352,8 +10352,17 @@ static void kvm_del_async_pf_gfn(struct kvm_vcpu *vcpu, gfn_t gfn) } } -static int apf_put_user(struct kvm_vcpu *vcpu, u32 val) +static inline int apf_put_user_notpresent(struct kvm_vcpu *vcpu) { + u32 reason = KVM_PV_REASON_PAGE_NOT_PRESENT; + + return kvm_write_guest_cached(vcpu->kvm, &vcpu->arch.apf.data, &reason, + sizeof(reason)); +} + +static inline int apf_put_user_ready(struct kvm_vcpu *vcpu, u32 token) +{ + u64 val = (u64)token << 32 | KVM_PV_REASON_PAGE_READY; return kvm_write_guest_cached(vcpu->kvm, &vcpu->arch.apf.data, &val, sizeof(val)); @@ -10398,7 +10407,7 @@ void kvm_arch_async_page_not_present(struct kvm_vcpu *vcpu, kvm_add_async_pf_gfn(vcpu, work->arch.gfn); if (kvm_can_deliver_async_pf(vcpu) && - !apf_put_user(vcpu, KVM_PV_REASON_PAGE_NOT_PRESENT)) { + !apf_put_user_notpresent(vcpu)) { fault.vector = PF_VECTOR; fault.error_code_valid = true; fault.error_code = 0; @@ -10431,7 +10440,7 @@ void kvm_arch_async_page_present(struct kvm_vcpu *vcpu, trace_kvm_async_pf_ready(work->arch.token, work->cr2_or_gpa); if (vcpu->arch.apf.msr_val & KVM_ASYNC_PF_ENABLED && - !apf_put_user(vcpu, KVM_PV_REASON_PAGE_READY)) { + !apf_put_user_ready(vcpu, work->arch.token)) { fault.vector = PF_VECTOR; fault.error_code_valid = true; fault.error_code = 0; -- 2.25.4
