| Submitter | 蓝天宇 |
|---|---|
| Date | Dec. 6, 2018, 7:34 a.m. |
| Message ID | <20181206073437.1995-1-Tianyu.Lan@microsoft.com> |
| Download | mbox | patch |
| Permalink | /patch/673835/ |
| State | New |
| Headers | show |
Comments
On 06/12/18 08:34, lantianyu1986@gmail.com wrote: > From: Lan Tianyu <Tianyu.Lan@microsoft.com> > > This patch is to initialize ept_pointer to INVALID_PAGE and check it > before flushing ept tlb. If ept_pointer is invalid, bypass the flush > request. > > Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com> Can you explain better *why* this patch is needed? Also, should vmx->ept_pointer be cleared at reset time, rather than vCPU creation? Thanks, Paolo > --- > arch/x86/kvm/vmx.c | 13 +++++++++++-- > 1 file changed, 11 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index c379d0bfdcba..6577ec8cbb0f 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -1582,11 +1582,18 @@ static int vmx_hv_remote_flush_tlb(struct kvm *kvm) > /* > * FLUSH_GUEST_PHYSICAL_ADDRESS_SPACE hypercall needs the address of the > * base of EPT PML4 table, strip off EPT configuration information. > + * If ept_pointer is invalid pointer, bypass the flush request. > */ > if (to_kvm_vmx(kvm)->ept_pointers_match != EPT_POINTERS_MATCH) { > - kvm_for_each_vcpu(i, vcpu, kvm) > + kvm_for_each_vcpu(i, vcpu, kvm) { > + u64 ept_pointer = to_vmx(vcpu)->ept_pointer; > + > + if (!VALID_PAGE(ept_pointer)) > + continue; > + > ret |= hyperv_flush_guest_mapping( > - to_vmx(kvm_get_vcpu(kvm, i))->ept_pointer & PAGE_MASK); > + ept_pointer & PAGE_MASK); > + } > } else { > ret = hyperv_flush_guest_mapping( > to_vmx(kvm_get_vcpu(kvm, 0))->ept_pointer & PAGE_MASK); > @@ -11614,6 +11621,8 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id) > vmx->pi_desc.nv = POSTED_INTR_VECTOR; > vmx->pi_desc.sn = 1; > > + vmx->ept_pointer = INVALID_PAGE; > + > return &vmx->vcpu; > > free_vmcs: >
On Fri, Dec 14, 2018 at 7:00 PM Paolo Bonzini <pbonzini@redhat.com> wrote: > > On 06/12/18 08:34, lantianyu1986@gmail.com wrote: > > From: Lan Tianyu <Tianyu.Lan@microsoft.com> > > > > This patch is to initialize ept_pointer to INVALID_PAGE and check it > > before flushing ept tlb. If ept_pointer is invalid, bypass the flush > > request. > > > > Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com> > > Can you explain better *why* this patch is needed? Yes, hypercall still maybe called when ept_pointers aren't initialized. Such case happens during guest boot up when BP works at first and APs aren't activated. > Also, should vmx->ept_pointer be cleared at reset time, rather than vCPU creation? > Yes, that make sense. Thanks for suggestion. > Thanks, > > Paolo > > > --- > > arch/x86/kvm/vmx.c | 13 +++++++++++-- > > 1 file changed, 11 insertions(+), 2 deletions(-) > > > > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > > index c379d0bfdcba..6577ec8cbb0f 100644 > > --- a/arch/x86/kvm/vmx.c > > +++ b/arch/x86/kvm/vmx.c > > @@ -1582,11 +1582,18 @@ static int vmx_hv_remote_flush_tlb(struct kvm *kvm) > > /* > > * FLUSH_GUEST_PHYSICAL_ADDRESS_SPACE hypercall needs the address of the > > * base of EPT PML4 table, strip off EPT configuration information. > > + * If ept_pointer is invalid pointer, bypass the flush request. > > */ > > if (to_kvm_vmx(kvm)->ept_pointers_match != EPT_POINTERS_MATCH) { > > - kvm_for_each_vcpu(i, vcpu, kvm) > > + kvm_for_each_vcpu(i, vcpu, kvm) { > > + u64 ept_pointer = to_vmx(vcpu)->ept_pointer; > > + > > + if (!VALID_PAGE(ept_pointer)) > > + continue; > > + > > ret |= hyperv_flush_guest_mapping( > > - to_vmx(kvm_get_vcpu(kvm, i))->ept_pointer & PAGE_MASK); > > + ept_pointer & PAGE_MASK); > > + } > > } else { > > ret = hyperv_flush_guest_mapping( > > to_vmx(kvm_get_vcpu(kvm, 0))->ept_pointer & PAGE_MASK); > > @@ -11614,6 +11621,8 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id) > > vmx->pi_desc.nv = POSTED_INTR_VECTOR; > > vmx->pi_desc.sn = 1; > > > > + vmx->ept_pointer = INVALID_PAGE; > > + > > return &vmx->vcpu; > > > > free_vmcs: > > >
Patch
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index c379d0bfdcba..6577ec8cbb0f 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -1582,11 +1582,18 @@ static int vmx_hv_remote_flush_tlb(struct kvm *kvm) /* * FLUSH_GUEST_PHYSICAL_ADDRESS_SPACE hypercall needs the address of the * base of EPT PML4 table, strip off EPT configuration information. + * If ept_pointer is invalid pointer, bypass the flush request. */ if (to_kvm_vmx(kvm)->ept_pointers_match != EPT_POINTERS_MATCH) { - kvm_for_each_vcpu(i, vcpu, kvm) + kvm_for_each_vcpu(i, vcpu, kvm) { + u64 ept_pointer = to_vmx(vcpu)->ept_pointer; + + if (!VALID_PAGE(ept_pointer)) + continue; + ret |= hyperv_flush_guest_mapping( - to_vmx(kvm_get_vcpu(kvm, i))->ept_pointer & PAGE_MASK); + ept_pointer & PAGE_MASK); + } } else { ret = hyperv_flush_guest_mapping( to_vmx(kvm_get_vcpu(kvm, 0))->ept_pointer & PAGE_MASK); @@ -11614,6 +11621,8 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id) vmx->pi_desc.nv = POSTED_INTR_VECTOR; vmx->pi_desc.sn = 1; + vmx->ept_pointer = INVALID_PAGE; + return &vmx->vcpu; free_vmcs: