From: David Gibson <david@gibson.dropbear.id.au>
To: Alexey Kardashevskiy <aik@ozlabs.ru>
Cc: linuxppc-dev@lists.ozlabs.org,
Alex Williamson <alex.williamson@redhat.com>,
Paul Mackerras <paulus@samba.org>,
kvm-ppc@vger.kernel.org, kvm@vger.kernel.org
Subject: Re: [PATCH kernel v6 09/10] KVM: PPC: iommu: Unify TCE checking
Date: Fri, 3 Mar 2017 16:08:56 +1100 [thread overview]
Message-ID: <20170303050856.GI667@umbus.fritz.box> (raw)
In-Reply-To: <20170302085644.41828-10-aik@ozlabs.ru>
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On Thu, Mar 02, 2017 at 07:56:43PM +1100, Alexey Kardashevskiy wrote:
> This reworks helpers for checking TCE update parameters in way they
> can be used in KVM.
>
> This should cause no behavioral change.
>
> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
> ---
> Changes:
> v6:
> * s/tce/gpa/ as TCE without permission bits is a GPA and this is what is
> passed everywhere
> ---
> arch/powerpc/include/asm/iommu.h | 20 +++++++++++++++-----
> arch/powerpc/include/asm/kvm_ppc.h | 6 ++++--
> arch/powerpc/kernel/iommu.c | 37 +++++++++++++------------------------
> arch/powerpc/kvm/book3s_64_vio_hv.c | 31 +++++++------------------------
> 4 files changed, 39 insertions(+), 55 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/iommu.h b/arch/powerpc/include/asm/iommu.h
> index 82e77ebf85f4..1e6b03339a68 100644
> --- a/arch/powerpc/include/asm/iommu.h
> +++ b/arch/powerpc/include/asm/iommu.h
> @@ -296,11 +296,21 @@ static inline void iommu_restore(void)
> #endif
>
> /* The API to support IOMMU operations for VFIO */
> -extern int iommu_tce_clear_param_check(struct iommu_table *tbl,
> - unsigned long ioba, unsigned long tce_value,
> - unsigned long npages);
> -extern int iommu_tce_put_param_check(struct iommu_table *tbl,
> - unsigned long ioba, unsigned long tce);
> +extern int iommu_tce_check_ioba(unsigned long page_shift,
> + unsigned long offset, unsigned long size,
> + unsigned long ioba, unsigned long npages);
> +extern int iommu_tce_check_gpa(unsigned long page_shift,
> + unsigned long gpa);
> +
> +#define iommu_tce_clear_param_check(tbl, ioba, tce_value, npages) \
> + (iommu_tce_check_ioba((tbl)->it_page_shift, \
> + (tbl)->it_offset, (tbl)->it_size, \
> + (ioba), (npages)) || (tce_value))
> +#define iommu_tce_put_param_check(tbl, ioba, gpa) \
> + (iommu_tce_check_ioba((tbl)->it_page_shift, \
> + (tbl)->it_offset, (tbl)->it_size, \
> + (ioba), 1) || \
> + iommu_tce_check_gpa((tbl)->it_page_shift, (gpa)))
>
> extern void iommu_flush_tce(struct iommu_table *tbl);
> extern int iommu_take_ownership(struct iommu_table *tbl);
> diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
> index eba8988d8443..72c2a155641f 100644
> --- a/arch/powerpc/include/asm/kvm_ppc.h
> +++ b/arch/powerpc/include/asm/kvm_ppc.h
> @@ -169,8 +169,10 @@ extern long kvm_vm_ioctl_create_spapr_tce(struct kvm *kvm,
> struct kvm_create_spapr_tce_64 *args);
> extern struct kvmppc_spapr_tce_table *kvmppc_find_table(
> struct kvm *kvm, unsigned long liobn);
> -extern long kvmppc_ioba_validate(struct kvmppc_spapr_tce_table *stt,
> - unsigned long ioba, unsigned long npages);
> +#define kvmppc_ioba_validate(stt, ioba, npages) \
> + (iommu_tce_check_ioba((stt)->page_shift, (stt)->offset, \
> + (stt)->size, (ioba), (npages)) ? \
> + H_PARAMETER : H_SUCCESS)
> extern long kvmppc_tce_validate(struct kvmppc_spapr_tce_table *tt,
> unsigned long tce);
> extern long kvmppc_gpa_to_ua(struct kvm *kvm, unsigned long gpa,
> diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
> index d02b8d22fb50..4269f9f1623b 100644
> --- a/arch/powerpc/kernel/iommu.c
> +++ b/arch/powerpc/kernel/iommu.c
> @@ -960,47 +960,36 @@ void iommu_flush_tce(struct iommu_table *tbl)
> }
> EXPORT_SYMBOL_GPL(iommu_flush_tce);
>
> -int iommu_tce_clear_param_check(struct iommu_table *tbl,
> - unsigned long ioba, unsigned long tce_value,
> - unsigned long npages)
> +int iommu_tce_check_ioba(unsigned long page_shift,
> + unsigned long offset, unsigned long size,
> + unsigned long ioba, unsigned long npages)
> {
> - /* tbl->it_ops->clear() does not support any value but 0 */
> - if (tce_value)
> - return -EINVAL;
> + unsigned long mask = (1UL << page_shift) - 1;
>
> - if (ioba & ~IOMMU_PAGE_MASK(tbl))
> + if (ioba & mask)
> return -EINVAL;
>
> - ioba >>= tbl->it_page_shift;
> - if (ioba < tbl->it_offset)
> + ioba >>= page_shift;
> + if (ioba < offset)
> return -EINVAL;
>
> - if ((ioba + npages) > (tbl->it_offset + tbl->it_size))
> + if ((ioba + 1) > (offset + size))
> return -EINVAL;
>
> return 0;
> }
> -EXPORT_SYMBOL_GPL(iommu_tce_clear_param_check);
> +EXPORT_SYMBOL_GPL(iommu_tce_check_ioba);
>
> -int iommu_tce_put_param_check(struct iommu_table *tbl,
> - unsigned long ioba, unsigned long tce)
> +int iommu_tce_check_gpa(unsigned long page_shift, unsigned long gpa)
> {
> - if (tce & ~IOMMU_PAGE_MASK(tbl))
> - return -EINVAL;
> -
> - if (ioba & ~IOMMU_PAGE_MASK(tbl))
> - return -EINVAL;
> -
> - ioba >>= tbl->it_page_shift;
> - if (ioba < tbl->it_offset)
> - return -EINVAL;
> + unsigned long mask = (1UL << page_shift) - 1;
>
> - if ((ioba + 1) > (tbl->it_offset + tbl->it_size))
> + if (gpa & mask)
> return -EINVAL;
>
> return 0;
> }
> -EXPORT_SYMBOL_GPL(iommu_tce_put_param_check);
> +EXPORT_SYMBOL_GPL(iommu_tce_check_gpa);
>
> long iommu_tce_xchg(struct iommu_table *tbl, unsigned long entry,
> unsigned long *hpa, enum dma_data_direction *direction)
> diff --git a/arch/powerpc/kvm/book3s_64_vio_hv.c b/arch/powerpc/kvm/book3s_64_vio_hv.c
> index 0f145fc7a3a5..440d3ab5dc32 100644
> --- a/arch/powerpc/kvm/book3s_64_vio_hv.c
> +++ b/arch/powerpc/kvm/book3s_64_vio_hv.c
> @@ -62,27 +62,6 @@ struct kvmppc_spapr_tce_table *kvmppc_find_table(struct kvm *kvm,
> EXPORT_SYMBOL_GPL(kvmppc_find_table);
>
> /*
> - * Validates IO address.
> - *
> - * WARNING: This will be called in real-mode on HV KVM and virtual
> - * mode on PR KVM
> - */
> -long kvmppc_ioba_validate(struct kvmppc_spapr_tce_table *stt,
> - unsigned long ioba, unsigned long npages)
> -{
> - unsigned long mask = (1ULL << stt->page_shift) - 1;
> - unsigned long idx = ioba >> stt->page_shift;
> -
> - if ((ioba & mask) || (idx < stt->offset) ||
> - (idx - stt->offset + npages > stt->size) ||
> - (idx + npages < idx))
> - 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
> @@ -95,10 +74,14 @@ EXPORT_SYMBOL_GPL(kvmppc_ioba_validate);
> */
> long kvmppc_tce_validate(struct kvmppc_spapr_tce_table *stt, unsigned long tce)
> {
> - unsigned long page_mask = ~((1ULL << stt->page_shift) - 1);
> - unsigned long mask = ~(page_mask | TCE_PCI_WRITE | TCE_PCI_READ);
> + unsigned long gpa = tce & ~(TCE_PCI_READ | TCE_PCI_WRITE);
> + enum dma_data_direction dir = iommu_tce_direction(tce);
>
> - if (tce & mask)
> + /* Allow userspace to poison TCE table */
> + if (dir == DMA_NONE)
> + return H_SUCCESS;
> +
> + if (iommu_tce_check_gpa(stt->page_shift, gpa))
> return H_PARAMETER;
>
> return H_SUCCESS;
--
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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next prev parent reply other threads:[~2017-03-03 5:59 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-02 8:56 [PATCH kernel v6 00/10] powerpc/kvm/vfio: Enable in-kernel acceleration Alexey Kardashevskiy
2017-03-02 8:56 ` [PATCH kernel v6 01/10] powerpc/mmu: Add real mode support for IOMMU preregistered memory Alexey Kardashevskiy
2017-03-02 8:56 ` [PATCH kernel v6 02/10] powerpc/powernv/iommu: Add real mode version of iommu_table_ops::exchange() Alexey Kardashevskiy
2017-03-02 8:56 ` [PATCH kernel v6 03/10] powerpc/iommu/vfio_spapr_tce: Cleanup iommu_table disposal Alexey Kardashevskiy
2017-03-02 8:56 ` [PATCH kernel v6 04/10] powerpc/vfio_spapr_tce: Add reference counting to iommu_table Alexey Kardashevskiy
2017-03-02 8:56 ` [PATCH kernel v6 05/10] KVM: PPC: Reserve KVM_CAP_SPAPR_TCE_VFIO capability number Alexey Kardashevskiy
2017-03-02 8:56 ` [PATCH kernel v6 06/10] KVM: PPC: Enable IOMMU_API for KVM_BOOK3S_64 permanently Alexey Kardashevskiy
2017-03-02 8:56 ` [PATCH kernel v6 07/10] KVM: PPC: Pass kvm* to kvmppc_find_table() Alexey Kardashevskiy
2017-03-02 8:56 ` [PATCH kernel v6 08/10] KVM: PPC: Use preregistered memory API to access TCE list Alexey Kardashevskiy
2017-03-02 8:56 ` [PATCH kernel v6 09/10] KVM: PPC: iommu: Unify TCE checking Alexey Kardashevskiy
2017-03-03 5:08 ` David Gibson [this message]
2017-03-02 8:56 ` [PATCH kernel v6 10/10] KVM: PPC: VFIO: Add in-kernel acceleration for VFIO Alexey Kardashevskiy
2017-03-03 5:59 ` David Gibson
2017-03-03 7:09 ` Alexey Kardashevskiy
2017-03-06 4:30 ` David Gibson
2017-03-06 5:04 ` Alexey Kardashevskiy
2017-03-07 11:07 ` Alexey Kardashevskiy
2017-03-07 12:08 ` David Gibson
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