From mboxrd@z Thu Jan 1 00:00:00 1970 From: Konrad Rzeszutek Wilk Subject: Re: [PATCH v5 01/13] X86/nVMX: handle_vmon: Read 4 bytes from guest memory Date: Wed, 23 Jan 2019 11:59:45 -0500 Message-ID: <20190123165932.GF19289@Konrads-MacBook-Pro.local> References: <1547026933-31226-1-git-send-email-karahmed@amazon.de> <1547026933-31226-2-git-send-email-karahmed@amazon.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, pbonzini@redhat.com, rkrcmar@redhat.com To: KarimAllah Ahmed Return-path: Content-Disposition: inline In-Reply-To: <1547026933-31226-2-git-send-email-karahmed@amazon.de> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On Wed, Jan 09, 2019 at 10:42:01AM +0100, KarimAllah Ahmed wrote: > Read the data directly from guest memory instead of the map->read->unmap > sequence. This also avoids using kvm_vcpu_gpa_to_page() and kmap() which > assumes that there is a "struct page" for guest memory. > > Suggested-by: Jim Mattson > Signed-off-by: KarimAllah Ahmed > Reviewed-by: Jim Mattson > Reviewed-by: David Hildenbrand Mind if I join party? Reviewed-by: Konrad Rzeszutek Wilk > > --- > v1 -> v2: > - Massage commit message a bit. > --- > arch/x86/kvm/vmx/nested.c | 14 +++----------- > 1 file changed, 3 insertions(+), 11 deletions(-) > > diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c > index 3170e29..536468a 100644 > --- a/arch/x86/kvm/vmx/nested.c > +++ b/arch/x86/kvm/vmx/nested.c > @@ -4192,7 +4192,7 @@ static int handle_vmon(struct kvm_vcpu *vcpu) > { > int ret; > gpa_t vmptr; > - struct page *page; > + uint32_t revision; > struct vcpu_vmx *vmx = to_vmx(vcpu); > const u64 VMXON_NEEDED_FEATURES = FEATURE_CONTROL_LOCKED > | FEATURE_CONTROL_VMXON_ENABLED_OUTSIDE_SMX; > @@ -4241,18 +4241,10 @@ static int handle_vmon(struct kvm_vcpu *vcpu) > if (!PAGE_ALIGNED(vmptr) || (vmptr >> cpuid_maxphyaddr(vcpu))) > return nested_vmx_failInvalid(vcpu); > > - page = kvm_vcpu_gpa_to_page(vcpu, vmptr); > - if (is_error_page(page)) > + if (kvm_read_guest(vcpu->kvm, vmptr, &revision, sizeof(revision)) || > + revision != VMCS12_REVISION) > return nested_vmx_failInvalid(vcpu); > > - if (*(u32 *)kmap(page) != VMCS12_REVISION) { > - kunmap(page); > - kvm_release_page_clean(page); > - return nested_vmx_failInvalid(vcpu); > - } > - kunmap(page); > - kvm_release_page_clean(page); > - > vmx->nested.vmxon_ptr = vmptr; > ret = enter_vmx_operation(vcpu); > if (ret) > -- > 2.7.4 >