On Mon, Dec 3, 2018 at 1:31 AM KarimAllah Ahmed <[email protected]> wrote: > > Copy the VMCS12 directly from guest memory instead of the map->copy->unmap > sequence. This also avoids using kvm_vcpu_gpa_to_page() and kmap() which > assumes that there is a "struct page" for guest memory. > > Signed-off-by: KarimAllah Ahmed <[email protected]> > --- > v3 -> v4: > - Return VMXERR_VMPTRLD_INCORRECT_VMCS_REVISION_ID on failure (jmattson@) > v1 -> v2: > - Massage commit message a bit. > --- > arch/x86/kvm/vmx.c | 24 ++++++++++++------------ > 1 file changed, 12 insertions(+), 12 deletions(-) > > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index b84f230..75817cb 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -9301,20 +9301,22 @@ static int handle_vmptrld(struct kvm_vcpu *vcpu) > return 1; > > if (vmx->nested.current_vmptr != vmptr) { > - struct vmcs12 *new_vmcs12; > - struct page *page; > - page = kvm_vcpu_gpa_to_page(vcpu, vmptr); > - if (is_error_page(page)) > - return nested_vmx_failInvalid(vcpu); > + struct vmcs12 *new_vmcs12 = (struct vmcs12 > *)__get_free_page(GFP_KERNEL); > + > + if (!new_vmcs12 || > + kvm_read_guest(vcpu->kvm, vmptr, new_vmcs12, > + sizeof(*new_vmcs12))) {
Isn't this a lot slower than kmap() when there is a struct page? > + free_page((unsigned long)new_vmcs12); > + return nested_vmx_failValid(vcpu, > + > VMXERR_VMPTRLD_INCORRECT_VMCS_REVISION_ID); I agree with David that this isn't the right thing to do for -ENOMEM.
