From: Ackerley Tng <[email protected]> Update tdx_gmem_post_populate() to handle cases where userspace requests "no source page". To handle "no source page", populate (perform TDH.MEM.PAGE.ADD) using memory in-place at the target PFN.
Signed-off-by: Sean Christopherson <[email protected]> Tested-by: Shivank Garg <[email protected]> Signed-off-by: Ackerley Tng <[email protected]> --- Documentation/virt/kvm/x86/intel-tdx.rst | 4 ++++ arch/x86/kvm/vmx/tdx.c | 8 +++++--- 2 files changed, 9 insertions(+), 3 deletions(-) diff --git a/Documentation/virt/kvm/x86/intel-tdx.rst b/Documentation/virt/kvm/x86/intel-tdx.rst index 6a222e9d09541..d8d9409120e61 100644 --- a/Documentation/virt/kvm/x86/intel-tdx.rst +++ b/Documentation/virt/kvm/x86/intel-tdx.rst @@ -158,6 +158,10 @@ KVM_TDX_INIT_MEM_REGION Initialize @nr_pages TDX guest private memory starting from @gpa with userspace provided data from @source_addr. @source_addr must be PAGE_SIZE-aligned. +If guest_memfd in-place conversion is enabled, pass 0 for @source_addr +to represent "no source page". A source page is required if in-place +conversion is not enabled or not supported. + Note, before calling this sub command, memory attribute of the range [gpa, gpa + nr_pages] needs to be private. Userspace can use KVM_SET_MEMORY_ATTRIBUTES to set the attribute. diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c index d1af0a752e97e..e890da5f18aed 100644 --- a/arch/x86/kvm/vmx/tdx.c +++ b/arch/x86/kvm/vmx/tdx.c @@ -3192,7 +3192,7 @@ static int tdx_gmem_post_populate(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn, if (KVM_BUG_ON(kvm_tdx->page_add_src, kvm)) return -EIO; - kvm_tdx->page_add_src = src_page; + kvm_tdx->page_add_src = src_page ?: pfn_to_page(pfn); ret = kvm_tdp_mmu_map_private_pfn(arg->vcpu, gfn, pfn); kvm_tdx->page_add_src = NULL; @@ -3238,7 +3238,8 @@ static int tdx_vcpu_init_mem_region(struct kvm_vcpu *vcpu, struct kvm_tdx_cmd *c if (copy_from_user(®ion, u64_to_user_ptr(cmd->data), sizeof(region))) return -EFAULT; - if (!PAGE_ALIGNED(region.source_addr) || !region.source_addr || + if (!PAGE_ALIGNED(region.source_addr) || + (!gmem_in_place_conversion && !region.source_addr) || !PAGE_ALIGNED(region.gpa) || !region.nr_pages || region.gpa + (region.nr_pages << PAGE_SHIFT) <= region.gpa || !vt_is_tdx_private_gpa(kvm, region.gpa) || @@ -3269,7 +3270,8 @@ static int tdx_vcpu_init_mem_region(struct kvm_vcpu *vcpu, struct kvm_tdx_cmd *c break; } - region.source_addr += PAGE_SIZE; + if (region.source_addr) + region.source_addr += PAGE_SIZE; region.gpa += PAGE_SIZE; region.nr_pages--; -- 2.55.0.508.g3f0d502094-goog
