Use kvm_vcpu_map() to get/pin the backing for vmcs12's APIC-access page, there's no reason it has to be restricted to 'struct page' backing. The APIC-access page actually doesn't need to be backed by anything, which is ironically why it got left behind by the series which introduced kvm_vcpu_map()[1]; the plan was to shove a dummy pfn into vmcs02[2], but that code never got merged. Switching the APIC-access page to kvm_vcpu_map() doesn't preclude using a magic pfn in the future, and will allow a future patch to drop kvm_vcpu_gpa_to_page(). [1] https://lore.kernel.org/all/1547026933-31226-1-git-send-email-karahmed@xxxxxxxxx [2] https://lore.kernel.org/lkml/1543845551-4403-1-git-send-email-karahmed@xxxxxxxxx Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx> --- arch/x86/kvm/vmx/nested.c | 39 ++++++++++++--------------------------- arch/x86/kvm/vmx/vmx.h | 2 +- 2 files changed, 13 insertions(+), 28 deletions(-) diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index a6688663da4d..cc1c7836f172 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -311,11 +311,12 @@ static void free_nested(struct kvm_vcpu *vcpu) vmx->nested.cached_vmcs12 = NULL; kfree(vmx->nested.cached_shadow_vmcs12); vmx->nested.cached_shadow_vmcs12 = NULL; - /* Unpin physical memory we referred to in the vmcs02 */ - if (vmx->nested.apic_access_page) { - kvm_release_page_clean(vmx->nested.apic_access_page); - vmx->nested.apic_access_page = NULL; - } + /* + * Unpin physical memory we referred to in the vmcs02. The APIC access + * page's backing page (yeah, confusing) shouldn't actually be accessed, + * and if it is written, the contents are irrelevant. + */ + kvm_vcpu_unmap(vcpu, &vmx->nested.apic_access_page_map, false); kvm_vcpu_unmap(vcpu, &vmx->nested.virtual_apic_map, true); kvm_vcpu_unmap(vcpu, &vmx->nested.pi_desc_map, true); vmx->nested.pi_desc = NULL; @@ -3159,8 +3160,6 @@ static bool nested_get_vmcs12_pages(struct kvm_vcpu *vcpu) struct vmcs12 *vmcs12 = get_vmcs12(vcpu); struct vcpu_vmx *vmx = to_vmx(vcpu); struct kvm_host_map *map; - struct page *page; - u64 hpa; if (!vcpu->arch.pdptrs_from_userspace && !nested_cpu_has_ept(vmcs12) && is_pae_paging(vcpu)) { @@ -3175,23 +3174,12 @@ static bool nested_get_vmcs12_pages(struct kvm_vcpu *vcpu) if (nested_cpu_has2(vmcs12, SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES)) { - /* - * Translate L1 physical address to host physical - * address for vmcs02. Keep the page pinned, so this - * physical address remains valid. We keep a reference - * to it so we can release it later. - */ - if (vmx->nested.apic_access_page) { /* shouldn't happen */ - kvm_release_page_clean(vmx->nested.apic_access_page); - vmx->nested.apic_access_page = NULL; - } - page = kvm_vcpu_gpa_to_page(vcpu, vmcs12->apic_access_addr); - if (!is_error_page(page)) { - vmx->nested.apic_access_page = page; - hpa = page_to_phys(vmx->nested.apic_access_page); - vmcs_write64(APIC_ACCESS_ADDR, hpa); + map = &vmx->nested.apic_access_page_map; + + if (!kvm_vcpu_map(vcpu, gpa_to_gfn(vmcs12->apic_access_addr), map)) { + vmcs_write64(APIC_ACCESS_ADDR, pfn_to_hpa(map->pfn)); } else { - pr_debug_ratelimited("%s: no backing 'struct page' for APIC-access address in vmcs12\n", + pr_debug_ratelimited("%s: no backing for APIC-access address in vmcs12\n", __func__); vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR; vcpu->run->internal.suberror = @@ -4627,10 +4615,7 @@ void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 vm_exit_reason, } /* Unpin physical memory we referred to in vmcs02 */ - if (vmx->nested.apic_access_page) { - kvm_release_page_clean(vmx->nested.apic_access_page); - vmx->nested.apic_access_page = NULL; - } + kvm_vcpu_unmap(vcpu, &vmx->nested.apic_access_page_map, false); kvm_vcpu_unmap(vcpu, &vmx->nested.virtual_apic_map, true); kvm_vcpu_unmap(vcpu, &vmx->nested.pi_desc_map, true); vmx->nested.pi_desc = NULL; diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h index 9c6bfcd84008..2498774f36b2 100644 --- a/arch/x86/kvm/vmx/vmx.h +++ b/arch/x86/kvm/vmx/vmx.h @@ -203,7 +203,7 @@ struct nested_vmx { * Guest pages referred to in the vmcs02 with host-physical * pointers, so we must keep them pinned while L2 runs. */ - struct page *apic_access_page; + struct kvm_host_map apic_access_page_map; struct kvm_host_map virtual_apic_map; struct kvm_host_map pi_desc_map; -- 2.36.0.464.gb9c8b46e94-goog
