| Message ID | 1540074145-31285-3-git-send-email-karahmed@amazon.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM/X86: Introduce a new guest mapping interface | expand |
On Sat, Oct 20, 2018 at 3:22 PM, KarimAllah Ahmed <karahmed@amazon.de> 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 <karahmed@amazon.de> > --- > v1 -> v2: > - Massage commit message a bit. > --- > arch/x86/kvm/vmx.c | 23 +++++++++-------------- > 1 file changed, 9 insertions(+), 14 deletions(-) > > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index 358759a..bc45347 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -8879,33 +8879,28 @@ static int handle_vmptrld(struct kvm_vcpu *vcpu) > } > > 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)) { > + 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))) { > + free_page((unsigned long)new_vmcs12); > nested_vmx_failInvalid(vcpu); I believe that this failure, like the one below, should be: nested_vmx_failValid(vcpu, VMXERR_VMPTRLD_INCORRECT_VMCS_REVISION_ID); First, if there is a valid current VMCS, then nested_vmx_failInvalid is incorrect. Second, if there is no backing memory, then by PCI bus error semantics, we should read all 1's, which isn't the correct VMCS revision ID. > return kvm_skip_emulated_instruction(vcpu); > } > - new_vmcs12 = kmap(page); > + > if (new_vmcs12->hdr.revision_id != VMCS12_REVISION || > (new_vmcs12->hdr.shadow_vmcs && > !nested_cpu_has_vmx_shadow_vmcs(vcpu))) { > - kunmap(page); > - kvm_release_page_clean(page); > + free_page((unsigned long)new_vmcs12); > nested_vmx_failValid(vcpu, > VMXERR_VMPTRLD_INCORRECT_VMCS_REVISION_ID); > return kvm_skip_emulated_instruction(vcpu); > } > > nested_release_vmcs12(vmx); > - /* > - * Load VMCS12 from guest memory since it is not already > - * cached. > - */ > memcpy(vmx->nested.cached_vmcs12, new_vmcs12, VMCS12_SIZE); > - kunmap(page); > - kvm_release_page_clean(page); > - > + free_page((unsigned long)new_vmcs12); > set_current_vmptr(vmx, vmptr); > } > > -- > 2.7.4 >
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 358759a..bc45347 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -8879,33 +8879,28 @@ static int handle_vmptrld(struct kvm_vcpu *vcpu) } 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)) { + 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))) { + free_page((unsigned long)new_vmcs12); nested_vmx_failInvalid(vcpu); return kvm_skip_emulated_instruction(vcpu); } - new_vmcs12 = kmap(page); + if (new_vmcs12->hdr.revision_id != VMCS12_REVISION || (new_vmcs12->hdr.shadow_vmcs && !nested_cpu_has_vmx_shadow_vmcs(vcpu))) { - kunmap(page); - kvm_release_page_clean(page); + free_page((unsigned long)new_vmcs12); nested_vmx_failValid(vcpu, VMXERR_VMPTRLD_INCORRECT_VMCS_REVISION_ID); return kvm_skip_emulated_instruction(vcpu); } nested_release_vmcs12(vmx); - /* - * Load VMCS12 from guest memory since it is not already - * cached. - */ memcpy(vmx->nested.cached_vmcs12, new_vmcs12, VMCS12_SIZE); - kunmap(page); - kvm_release_page_clean(page); - + free_page((unsigned long)new_vmcs12); set_current_vmptr(vmx, vmptr); }
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 <karahmed@amazon.de> --- v1 -> v2: - Massage commit message a bit. --- arch/x86/kvm/vmx.c | 23 +++++++++-------------- 1 file changed, 9 insertions(+), 14 deletions(-)