From: David Gibson <d...@au1.ibm.com> This improves I/O performance for guests using the PAPR paravirtualization interface by making the H_PUT_TCE hcall faster, by implementing it in real mode. H_PUT_TCE is used for updating virtual IOMMU tables, and is used both for virtual I/O and for real I/O in the PAPR interface.
Since this moves the IOMMU tables into the kernel, we define a new KVM_CREATE_SPAPR_TCE ioctl to allow qemu to create the tables. The ioctl returns a file descriptor which can be used to mmap the newly created table. Signed-off-by: Paul Mackerras <pau...@samba.org> --- arch/powerpc/include/asm/kvm.h | 9 +++ arch/powerpc/include/asm/kvm_book3s_64.h | 2 + arch/powerpc/include/asm/kvm_host.h | 9 +++ arch/powerpc/include/asm/kvm_ppc.h | 2 + arch/powerpc/kvm/Makefile | 3 +- arch/powerpc/kvm/book3s_64_vio_hv.c | 73 +++++++++++++++++++ arch/powerpc/kvm/book3s_hv.c | 116 +++++++++++++++++++++++++++++- arch/powerpc/kvm/book3s_hv_rmhandlers.S | 2 +- arch/powerpc/kvm/powerpc.c | 18 +++++ include/linux/kvm.h | 5 ++ 10 files changed, 236 insertions(+), 3 deletions(-) create mode 100644 arch/powerpc/kvm/book3s_64_vio_hv.c diff --git a/arch/powerpc/include/asm/kvm.h b/arch/powerpc/include/asm/kvm.h index 18ea696..a9e641b 100644 --- a/arch/powerpc/include/asm/kvm.h +++ b/arch/powerpc/include/asm/kvm.h @@ -22,6 +22,9 @@ #include <linux/types.h> +/* Select powerpc specific features in <linux/kvm.h> */ +#define __KVM_HAVE_SPAPR_TCE + struct kvm_regs { __u64 pc; __u64 cr; @@ -88,4 +91,10 @@ struct kvm_guest_debug_arch { #define KVM_INTERRUPT_UNSET -2U #define KVM_INTERRUPT_SET_LEVEL -3U +/* for KVM_CAP_SPAPR_TCE */ +struct kvm_create_spapr_tce { + __u64 liobn; + __u32 window_size; +}; + #endif /* __LINUX_KVM_POWERPC_H */ diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h index 4cadd61..e1a096b 100644 --- a/arch/powerpc/include/asm/kvm_book3s_64.h +++ b/arch/powerpc/include/asm/kvm_book3s_64.h @@ -25,4 +25,6 @@ static inline struct kvmppc_book3s_shadow_vcpu *to_svcpu(struct kvm_vcpu *vcpu) return &get_paca()->shadow_vcpu; } +#define SPAPR_TCE_SHIFT 12 + #endif /* __ASM_KVM_BOOK3S_64_H__ */ diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h index af6703e..cda183e 100644 --- a/arch/powerpc/include/asm/kvm_host.h +++ b/arch/powerpc/include/asm/kvm_host.h @@ -144,6 +144,14 @@ struct kvmppc_pginfo { atomic_t refcnt; }; +struct kvmppc_spapr_tce_table { + struct list_head list; + struct kvm *kvm; + u64 liobn; + u32 window_size; + struct page *pages[0]; +}; + struct kvm_arch { unsigned long hpt_virt; unsigned long ram_npages; @@ -157,6 +165,7 @@ struct kvm_arch { unsigned long host_sdr1; int tlbie_lock; unsigned short last_vcpu[NR_CPUS]; + struct list_head spapr_tce_tables; }; struct kvmppc_pte { diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h index b4ee11a..de683fa 100644 --- a/arch/powerpc/include/asm/kvm_ppc.h +++ b/arch/powerpc/include/asm/kvm_ppc.h @@ -117,6 +117,8 @@ extern long kvmppc_prepare_vrma(struct kvm *kvm, extern void kvmppc_map_vrma(struct kvm *kvm, struct kvm_userspace_memory_region *mem); 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 int kvmppc_core_init_vm(struct kvm *kvm); extern void kvmppc_core_destroy_vm(struct kvm *kvm); extern int kvmppc_core_prepare_memory_region(struct kvm *kvm, diff --git a/arch/powerpc/kvm/Makefile b/arch/powerpc/kvm/Makefile index 37c1a60..8ba062f 100644 --- a/arch/powerpc/kvm/Makefile +++ b/arch/powerpc/kvm/Makefile @@ -59,7 +59,8 @@ kvm-book3s_64_hv-objs := \ book3s.o \ book3s_hv.o \ book3s_hv_interrupts.o \ - book3s_64_mmu_hv.o + book3s_64_mmu_hv.o \ + book3s_64_vio_hv.o kvm-objs-$(CONFIG_KVM_BOOK3S_64_HV) := $(kvm-book3s_64_hv-objs) kvm-book3s_32-objs := \ diff --git a/arch/powerpc/kvm/book3s_64_vio_hv.c b/arch/powerpc/kvm/book3s_64_vio_hv.c new file mode 100644 index 0000000..ea0f8c5 --- /dev/null +++ b/arch/powerpc/kvm/book3s_64_vio_hv.c @@ -0,0 +1,73 @@ +/* + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License, version 2, as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + * + * Copyright 2010 Paul Mackerras, IBM Corp. <pau...@au1.ibm.com> + * Copyright 2011 David Gibson, IBM Corporation <d...@au1.ibm.com> + */ + +#include <linux/types.h> +#include <linux/string.h> +#include <linux/kvm.h> +#include <linux/kvm_host.h> +#include <linux/highmem.h> +#include <linux/gfp.h> +#include <linux/slab.h> +#include <linux/hugetlb.h> +#include <linux/list.h> + +#include <asm/tlbflush.h> +#include <asm/kvm_ppc.h> +#include <asm/kvm_book3s.h> +#include <asm/mmu-hash64.h> +#include <asm/hvcall.h> +#include <asm/synch.h> +#include <asm/ppc-opcode.h> +#include <asm/kvm_host.h> +#include <asm/udbg.h> + +#define TCES_PER_PAGE (PAGE_SIZE / sizeof(u64)) + +long kvmppc_h_put_tce(struct kvm_vcpu *vcpu, unsigned long liobn, + unsigned long ioba, unsigned long tce) +{ + struct kvm *kvm = vcpu->kvm; + struct kvmppc_spapr_tce_table *stt; + + /* udbg_printf("H_PUT_TCE(): liobn=0x%lx ioba=0x%lx, tce=0x%lx\n", */ + /* liobn, ioba, tce); */ + + list_for_each_entry(stt, &kvm->arch.spapr_tce_tables, list) { + if (stt->liobn == liobn) { + unsigned long idx = ioba >> SPAPR_TCE_SHIFT; + struct page *page; + u64 *tbl; + + /* udbg_printf("H_PUT_TCE: liobn 0x%lx => stt=%p window_size=0x%x\n", */ + /* liobn, stt, stt->window_size); */ + if (ioba >= stt->window_size) + return H_PARAMETER; + + page = stt->pages[idx / TCES_PER_PAGE]; + tbl = (u64 *)page_address(page); + + /* FIXME: Need to validate the TCE itself */ + /* udbg_printf("tce @ %p\n", &tbl[idx % TCES_PER_PAGE]); */ + tbl[idx % TCES_PER_PAGE] = tce; + return H_SUCCESS; + } + } + + /* Didn't find the liobn, punt it to userspace */ + return H_TOO_HARD; +} diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 377a35a..eed2c10 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -506,6 +506,116 @@ int kvmppc_vcpu_run(struct kvm_run *run, struct kvm_vcpu *vcpu) return r; } +static long kvmppc_stt_npages(unsigned long window_size) +{ + return ALIGN((window_size >> SPAPR_TCE_SHIFT) + * sizeof(u64), PAGE_SIZE) / PAGE_SIZE; +} + +static void release_spapr_tce_table(struct kvmppc_spapr_tce_table *stt) +{ + struct kvm *kvm = stt->kvm; + int i; + + mutex_lock(&kvm->lock); + list_del(&stt->list); + for (i = 0; i < kvmppc_stt_npages(stt->window_size); i++) + __free_page(stt->pages[i]); + kfree(stt); + mutex_unlock(&kvm->lock); + + kvm_put_kvm(kvm); +} + +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)) + return VM_FAULT_SIGBUS; + + page = stt->pages[vmf->pgoff]; + get_page(page); + vmf->page = page; + return 0; +} + +static const struct vm_operations_struct kvm_spapr_tce_vm_ops = { + .fault = kvm_spapr_tce_fault, +}; + +static int kvm_spapr_tce_mmap(struct file *file, struct vm_area_struct *vma) +{ + vma->vm_ops = &kvm_spapr_tce_vm_ops; + return 0; +} + +static int kvm_spapr_tce_release(struct inode *inode, struct file *filp) +{ + struct kvmppc_spapr_tce_table *stt = filp->private_data; + + release_spapr_tce_table(stt); + return 0; +} + +static struct file_operations kvm_spapr_tce_fops = { + .mmap = kvm_spapr_tce_mmap, + .release = kvm_spapr_tce_release, +}; + +long kvm_vm_ioctl_create_spapr_tce(struct kvm *kvm, + struct kvm_create_spapr_tce *args) +{ + struct kvmppc_spapr_tce_table *stt = NULL; + long npages; + int ret = -ENOMEM; + int i; + + /* Check this LIOBN hasn't been previously allocated */ + list_for_each_entry(stt, &kvm->arch.spapr_tce_tables, list) { + if (stt->liobn == args->liobn) + return -EBUSY; + } + + npages = kvmppc_stt_npages(args->window_size); + + stt = kzalloc(sizeof(*stt) + npages* sizeof(struct page *), + GFP_KERNEL); + if (!stt) + goto fail; + + stt->liobn = args->liobn; + stt->window_size = args->window_size; + stt->kvm = kvm; + + for (i = 0; i < npages; i++) { + stt->pages[i] = alloc_page(GFP_KERNEL | __GFP_ZERO); + if (!stt->pages[i]) + goto fail; + } + + kvm_get_kvm(kvm); + + mutex_lock(&kvm->lock); + list_add(&stt->list, &kvm->arch.spapr_tce_tables); + + mutex_unlock(&kvm->lock); + + return anon_inode_getfd("kvm-spapr-tce", &kvm_spapr_tce_fops, + stt, O_RDONLY); + +fail: + if (stt) { + for (i = 0; i < npages; i++) + if (stt->pages[i]) + __free_page(stt->pages[i]); + + kfree(stt); + } + return ret; +} + int kvmppc_core_prepare_memory_region(struct kvm *kvm, struct kvm_userspace_memory_region *mem) { @@ -527,13 +637,17 @@ int kvmppc_core_init_vm(struct kvm *kvm) /* Allocate hashed page table */ r = kvmppc_alloc_hpt(kvm); + if (r) + return r; - return r; + INIT_LIST_HEAD(&kvm->arch.spapr_tce_tables); + return 0; } void kvmppc_core_destroy_vm(struct kvm *kvm) { kvmppc_free_hpt(kvm); + WARN_ON(!list_empty(&kvm->arch.spapr_tce_tables)); } /* These are stubs for now */ diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S index e8a8f3c..95f6386 100644 --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -722,7 +722,7 @@ hcall_real_table: .long 0 /* 0x14 - H_CLEAR_REF */ .long .kvmppc_h_protect - hcall_real_table .long 0 /* 0x1c - H_GET_TCE */ - .long 0 /* 0x20 - H_SET_TCE */ + .long .kvmppc_h_put_tce - hcall_real_table .long 0 /* 0x24 - H_SET_SPRG0 */ .long .kvmppc_h_set_dabr - hcall_real_table .long 0 /* 0x2c */ diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index 7bfe413..10f777a 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -196,6 +196,11 @@ int kvm_dev_ioctl_check_extension(long ext) r = KVM_COALESCED_MMIO_PAGE_OFFSET; break; #endif +#ifdef CONFIG_KVM_BOOK3S_64_HV + case KVM_CAP_SPAPR_TCE: + r = 1; + break; +#endif default: r = 0; break; @@ -628,6 +633,19 @@ long kvm_arch_vm_ioctl(struct file *filp, break; } +#ifdef CONFIG_KVM_BOOK3S_64_HV + case KVM_CREATE_SPAPR_TCE: { + struct kvm_create_spapr_tce create_tce; + struct kvm *kvm = filp->private_data; + + r = -EFAULT; + if (copy_from_user(&create_tce, argp, sizeof(create_tce))) + goto out; + r = kvm_vm_ioctl_create_spapr_tce(kvm, &create_tce); + goto out; + } +#endif /* CONFIG_KVM_BOOK3S_64_HV */ + default: r = -ENOTTY; } diff --git a/include/linux/kvm.h b/include/linux/kvm.h index a4447ce..3d3cdf1 100644 --- a/include/linux/kvm.h +++ b/include/linux/kvm.h @@ -547,6 +547,9 @@ struct kvm_ppc_pvinfo { #define KVM_CAP_PPC_GET_PVINFO 57 #define KVM_CAP_PPC_IRQ_LEVEL 58 #define KVM_CAP_ASYNC_PF 59 +#ifdef __KVM_HAVE_SPAPR_TCE +#define KVM_CAP_SPAPR_TCE 60 +#endif #ifdef KVM_CAP_IRQ_ROUTING @@ -746,6 +749,8 @@ struct kvm_clock_data { /* Available with KVM_CAP_XCRS */ #define KVM_GET_XCRS _IOR(KVMIO, 0xa6, struct kvm_xcrs) #define KVM_SET_XCRS _IOW(KVMIO, 0xa7, struct kvm_xcrs) +/* Available with KVM_CAP_SPAPR_TCE */ +#define KVM_CREATE_SPAPR_TCE _IOW(KVMIO, 0xa8, struct kvm_create_spapr_tce) #define KVM_DEV_ASSIGN_ENABLE_IOMMU (1 << 0) -- 1.7.4.4 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html