On Mon, Jan 25, 2016 at 11:12:36AM +1100, David Gibson wrote: > On Thu, Jan 21, 2016 at 06:39:36PM +1100, Alexey Kardashevskiy wrote: > > Upcoming multi-tce support (H_PUT_TCE_INDIRECT/H_STUFF_TCE hypercalls) > > will validate TCE (not to have unexpected bits) and IO address > > (to be within the DMA window boundaries). > > > > This introduces helpers to validate TCE and IO address. The helpers are > > exported as they compile into vmlinux (to work in realmode) and will be > > used later by KVM kernel module in virtual mode. > > > > Signed-off-by: Alexey Kardashevskiy <aik@xxxxxxxxx> > > --- > > Changes: > > v2: > > * added note to the commit log about why new helpers are exported > > * did not add a note that xxx_validate() validate TCEs for KVM (not for > > host kernel DMA) as the helper names and file location tell what are > > they for > > --- > > arch/powerpc/include/asm/kvm_ppc.h | 4 ++ > > arch/powerpc/kvm/book3s_64_vio_hv.c | 92 ++++++++++++++++++++++++++++++++----- > > 2 files changed, 84 insertions(+), 12 deletions(-) > > > > diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h > > index 2241d53..9513911 100644 > > --- a/arch/powerpc/include/asm/kvm_ppc.h > > +++ b/arch/powerpc/include/asm/kvm_ppc.h > > @@ -166,6 +166,10 @@ extern int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu); > > > > extern long kvm_vm_ioctl_create_spapr_tce(struct kvm *kvm, > > struct kvm_create_spapr_tce *args); > > +extern long kvmppc_ioba_validate(struct kvmppc_spapr_tce_table *stt, > > + unsigned long ioba, unsigned long npages); > > +extern long kvmppc_tce_validate(struct kvmppc_spapr_tce_table *tt, > > + unsigned long tce); > > extern long kvmppc_h_put_tce(struct kvm_vcpu *vcpu, unsigned long liobn, > > unsigned long ioba, unsigned long tce); > > extern long kvmppc_h_get_tce(struct kvm_vcpu *vcpu, unsigned long liobn, > > diff --git a/arch/powerpc/kvm/book3s_64_vio_hv.c b/arch/powerpc/kvm/book3s_64_vio_hv.c > > index e142171..8cd3a95 100644 > > --- a/arch/powerpc/kvm/book3s_64_vio_hv.c > > +++ b/arch/powerpc/kvm/book3s_64_vio_hv.c > > @@ -36,6 +36,7 @@ > > #include <asm/kvm_host.h> > > #include <asm/udbg.h> > > #include <asm/iommu.h> > > +#include <asm/tce.h> > > > > #define TCES_PER_PAGE (PAGE_SIZE / sizeof(u64)) > > > > @@ -64,18 +65,90 @@ static struct kvmppc_spapr_tce_table *kvmppc_find_table(struct kvm_vcpu *vcpu, > > * WARNING: This will be called in real-mode on HV KVM and virtual > > * mode on PR KVM > > */ > > -static long kvmppc_ioba_validate(struct kvmppc_spapr_tce_table *stt, > > +long kvmppc_ioba_validate(struct kvmppc_spapr_tce_table *stt, > > unsigned long ioba, unsigned long npages) > > { > > - unsigned long mask = (1ULL << IOMMU_PAGE_SHIFT_4K) - 1; > > + unsigned long mask = IOMMU_PAGE_MASK_4K; > > unsigned long idx = ioba >> IOMMU_PAGE_SHIFT_4K; > > unsigned long size = stt->window_size >> IOMMU_PAGE_SHIFT_4K; > > > > - if ((ioba & mask) || (idx + npages > size)) > > + if ((ioba & ~mask) || (idx + npages > size)) > > return H_PARAMETER; > > > > return H_SUCCESS; > > } > > +EXPORT_SYMBOL_GPL(kvmppc_ioba_validate); > > + > > +/* > > + * Validates TCE address. > > + * At the moment flags and page mask are validated. > > + * As the host kernel does not access those addresses (just puts them > > + * to the table and user space is supposed to process them), we can skip > > + * checking other things (such as TCE is a guest RAM address or the page > > + * was actually allocated). > > + * > > + * WARNING: This will be called in real-mode on HV KVM and virtual > > + * mode on PR KVM > > + */ > > +long kvmppc_tce_validate(struct kvmppc_spapr_tce_table *stt, > > unsigned long tce) > > It would be nice to write this in terms of kvmppc_ioba_validate() above. Duh, sorry. Realised shortly afterwards that's nonsense. One is looking at the IOBA, the other at the real address. -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson
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