On Mon, Feb 5, 2018 at 10:48 AM KarimAllah Ahmed <karahmed@xxxxxxxxx> wrote: > @@ -5264,9 +5264,8 @@ static void vmx_complete_nested_posted_interrupt(struct kvm_vcpu *vcpu) > max_irr = find_last_bit((unsigned long *)vmx->nested.pi_desc->pir, 256); > if (max_irr != 256) { > - vapic_page = kmap(vmx->nested.virtual_apic_page); > + vapic_page = vmx->nested.virtual_apic_mapping.kaddr; > __kvm_apic_update_irr(vmx->nested.pi_desc->pir, vapic_page); > - kunmap(vmx->nested.virtual_apic_page); Your kernel mapping now survives exits to userspace. I didn't think that was kosher, but I'd be happy to hear that I'm wrong. > @@ -7502,10 +7501,8 @@ static void free_nested(struct vcpu_vmx *vmx) > /* Unpin physical memory we referred to in the vmcs02 */ > if (vmx->nested.apic_access_mapping.pfn) kvm_release_host_mapping(&vmx->nested.apic_access_mapping, true); > - if (vmx->nested.virtual_apic_page) { > - kvm_release_page_dirty(vmx->nested.virtual_apic_page); > - vmx->nested.virtual_apic_page = NULL; > - } > + if (vmx->nested.virtual_apic_mapping.pfn) > + kvm_release_host_mapping(&vmx->nested.virtual_apic_mapping, true); Is the host PFN guaranteed to be non-zero?