[PATCH kernel 2/4] KVM: PPC: Add @page_shift to kvmppc_spapr_tce_table
David Gibson
david at gibson.dropbear.id.au
Mon Jan 25 16:30:49 AEDT 2016
On Thu, Jan 21, 2016 at 07:15:24PM +1100, Alexey Kardashevskiy wrote:
> At the moment the kvmppc_spapr_tce_table struct can only describe
> 4GB windows and handle fixed size (4K) pages. Dynamic DMA windows
> support more so these limits need to be extended.
>
> This replaces window_size (in bytes, 4GB max) with page_shift (32bit)
> and size (64bit, in pages).
>
> This should cause no behavioural change.
This commit message could be clearer about the fact that this is
changing the internal structures only - the user interface still only
allows one to create a 32-bit table with 4KiB pages at this stage.
> Signed-off-by: Alexey Kardashevskiy <aik at ozlabs.ru>
Apart from that,
Reviewed-by: David Gibson <david at gibson.dropbear.id.au>
> ---
> arch/powerpc/include/asm/kvm_host.h | 3 ++-
> arch/powerpc/kvm/book3s_64_vio.c | 29 +++++++++++++++--------------
> arch/powerpc/kvm/book3s_64_vio_hv.c | 20 ++++++++++----------
> 3 files changed, 27 insertions(+), 25 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
> index c7ee696..a4ed9f5 100644
> --- a/arch/powerpc/include/asm/kvm_host.h
> +++ b/arch/powerpc/include/asm/kvm_host.h
> @@ -183,8 +183,9 @@ struct kvmppc_spapr_tce_table {
> struct list_head list;
> struct kvm *kvm;
> u64 liobn;
> - u32 window_size;
> struct rcu_head rcu;
> + u32 page_shift;
> + u64 size; /* in pages */
> struct page *pages[0];
> };
>
> diff --git a/arch/powerpc/kvm/book3s_64_vio.c b/arch/powerpc/kvm/book3s_64_vio.c
> index 987f406..85ee572 100644
> --- a/arch/powerpc/kvm/book3s_64_vio.c
> +++ b/arch/powerpc/kvm/book3s_64_vio.c
> @@ -40,10 +40,9 @@
> #include <asm/iommu.h>
> #include <asm/tce.h>
>
> -static unsigned long kvmppc_stt_npages(unsigned long window_size)
> +static unsigned long kvmppc_stt_npages(unsigned long size)
> {
> - return ALIGN((window_size >> IOMMU_PAGE_SHIFT_4K)
> - * sizeof(u64), PAGE_SIZE) / PAGE_SIZE;
> + return ALIGN(size * sizeof(u64), PAGE_SIZE) / PAGE_SIZE;
> }
>
> static long kvmppc_account_memlimit(unsigned long npages, bool inc)
> @@ -92,8 +91,8 @@ static void release_spapr_tce_table(struct rcu_head *head)
> {
> struct kvmppc_spapr_tce_table *stt = container_of(head,
> struct kvmppc_spapr_tce_table, rcu);
> - int i;
> - unsigned long npages = kvmppc_stt_npages(stt->window_size);
> + unsigned long i;
> + unsigned long npages = kvmppc_stt_npages(stt->size);
>
> for (i = 0; i < npages; i++)
> __free_page(stt->pages[i]);
> @@ -106,7 +105,7 @@ static int kvm_spapr_tce_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
> struct kvmppc_spapr_tce_table *stt = vma->vm_file->private_data;
> struct page *page;
>
> - if (vmf->pgoff >= kvmppc_stt_npages(stt->window_size))
> + if (vmf->pgoff >= kvmppc_stt_npages(stt->size))
> return VM_FAULT_SIGBUS;
>
> page = stt->pages[vmf->pgoff];
> @@ -133,7 +132,7 @@ static int kvm_spapr_tce_release(struct inode *inode, struct file *filp)
>
> kvm_put_kvm(stt->kvm);
>
> - kvmppc_account_memlimit(kvmppc_stt_npages(stt->window_size), false);
> + kvmppc_account_memlimit(kvmppc_stt_npages(stt->size), false);
> call_rcu(&stt->rcu, release_spapr_tce_table);
>
> return 0;
> @@ -148,7 +147,7 @@ long kvm_vm_ioctl_create_spapr_tce(struct kvm *kvm,
> struct kvm_create_spapr_tce *args)
> {
> struct kvmppc_spapr_tce_table *stt = NULL;
> - unsigned long npages;
> + unsigned long npages, size;
> int ret = -ENOMEM;
> int i;
>
> @@ -158,7 +157,8 @@ long kvm_vm_ioctl_create_spapr_tce(struct kvm *kvm,
> return -EBUSY;
> }
>
> - npages = kvmppc_stt_npages(args->window_size);
> + size = args->window_size >> IOMMU_PAGE_SHIFT_4K;
> + npages = kvmppc_stt_npages(size);
> ret = kvmppc_account_memlimit(npages, true);
> if (ret) {
> stt = NULL;
> @@ -171,7 +171,8 @@ long kvm_vm_ioctl_create_spapr_tce(struct kvm *kvm,
> goto fail;
>
> stt->liobn = args->liobn;
> - stt->window_size = args->window_size;
> + stt->page_shift = IOMMU_PAGE_SHIFT_4K;
> + stt->size = size;
> stt->kvm = kvm;
>
> for (i = 0; i < npages; i++) {
> @@ -220,7 +221,7 @@ long kvmppc_h_put_tce(struct kvm_vcpu *vcpu,
> if (ret != H_SUCCESS)
> return ret;
>
> - kvmppc_tce_put(stt, ioba >> IOMMU_PAGE_SHIFT_4K, tce);
> + kvmppc_tce_put(stt, ioba >> stt->page_shift, tce);
>
> return H_SUCCESS;
> }
> @@ -239,7 +240,7 @@ long kvmppc_h_put_tce_indirect(struct kvm_vcpu *vcpu,
> if (!stt)
> return H_TOO_HARD;
>
> - entry = ioba >> IOMMU_PAGE_SHIFT_4K;
> + entry = ioba >> stt->page_shift;
> /*
> * SPAPR spec says that the maximum size of the list is 512 TCEs
> * so the whole table fits in 4K page
> @@ -300,8 +301,8 @@ long kvmppc_h_stuff_tce(struct kvm_vcpu *vcpu,
> if (tce_value & (TCE_PCI_WRITE | TCE_PCI_READ))
> return H_PARAMETER;
>
> - for (i = 0; i < npages; ++i, ioba += IOMMU_PAGE_SIZE_4K)
> - kvmppc_tce_put(stt, ioba >> IOMMU_PAGE_SHIFT_4K, tce_value);
> + for (i = 0; i < npages; ++i, ioba += (1ULL << stt->page_shift))
> + kvmppc_tce_put(stt, ioba >> stt->page_shift, tce_value);
>
> return H_SUCCESS;
> }
> diff --git a/arch/powerpc/kvm/book3s_64_vio_hv.c b/arch/powerpc/kvm/book3s_64_vio_hv.c
> index 58c63ed..01ef9f9 100644
> --- a/arch/powerpc/kvm/book3s_64_vio_hv.c
> +++ b/arch/powerpc/kvm/book3s_64_vio_hv.c
> @@ -72,11 +72,10 @@ EXPORT_SYMBOL_GPL(kvmppc_find_table);
> long kvmppc_ioba_validate(struct kvmppc_spapr_tce_table *stt,
> unsigned long ioba, unsigned long npages)
> {
> - 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;
> + unsigned long mask = ~((1ULL << stt->page_shift) - 1);
> + unsigned long idx = ioba >> stt->page_shift;
>
> - if ((ioba & ~mask) || (idx + npages > size))
> + if ((ioba & ~mask) || (idx + npages > stt->size))
> return H_PARAMETER;
>
> return H_SUCCESS;
> @@ -96,7 +95,8 @@ EXPORT_SYMBOL_GPL(kvmppc_ioba_validate);
> */
> long kvmppc_tce_validate(struct kvmppc_spapr_tce_table *stt, unsigned long tce)
> {
> - unsigned long mask = IOMMU_PAGE_MASK_4K | TCE_PCI_WRITE | TCE_PCI_READ;
> + unsigned long mask = ~((1ULL << stt->page_shift) - 1) |
> + TCE_PCI_WRITE | TCE_PCI_READ;
>
> if (tce & ~mask)
> return H_PARAMETER;
> @@ -197,7 +197,7 @@ long kvmppc_rm_h_put_tce(struct kvm_vcpu *vcpu, unsigned long liobn,
> if (ret != H_SUCCESS)
> return ret;
>
> - kvmppc_tce_put(stt, ioba >> IOMMU_PAGE_SHIFT_4K, tce);
> + kvmppc_tce_put(stt, ioba >> stt->page_shift, tce);
>
> return H_SUCCESS;
> }
> @@ -242,7 +242,7 @@ long kvmppc_rm_h_put_tce_indirect(struct kvm_vcpu *vcpu,
> if (!stt)
> return H_TOO_HARD;
>
> - entry = ioba >> IOMMU_PAGE_SHIFT_4K;
> + entry = ioba >> stt->page_shift;
> /*
> * The spec says that the maximum size of the list is 512 TCEs
> * so the whole table addressed resides in 4K page
> @@ -302,8 +302,8 @@ long kvmppc_rm_h_stuff_tce(struct kvm_vcpu *vcpu,
> if (tce_value & (TCE_PCI_WRITE | TCE_PCI_READ))
> return H_PARAMETER;
>
> - for (i = 0; i < npages; ++i, ioba += IOMMU_PAGE_SIZE_4K)
> - kvmppc_tce_put(stt, ioba >> IOMMU_PAGE_SHIFT_4K, tce_value);
> + for (i = 0; i < npages; ++i, ioba += (1ULL << stt->page_shift))
> + kvmppc_tce_put(stt, ioba >> stt->page_shift, tce_value);
>
> return H_SUCCESS;
> }
> @@ -324,7 +324,7 @@ long kvmppc_h_get_tce(struct kvm_vcpu *vcpu, unsigned long liobn,
> if (ret != H_SUCCESS)
> return ret;
>
> - idx = ioba >> IOMMU_PAGE_SHIFT_4K;
> + idx = ioba >> stt->page_shift;
> page = stt->pages[idx / TCES_PER_PAGE];
> tbl = (u64 *)page_address(page);
>
--
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
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 819 bytes
Desc: not available
URL: <http://lists.ozlabs.org/pipermail/linuxppc-dev/attachments/20160125/3528baf1/attachment-0001.sig>
More information about the Linuxppc-dev
mailing list