[PATCH -V3 3/4] powerpc/kvm: Contiguous memory allocator based RMA allocation
Alexander Graf
agraf at suse.de
Wed Jul 3 01:17:11 EST 2013
On 07/02/2013 07:45 AM, Aneesh Kumar K.V wrote:
> From: "Aneesh Kumar K.V"<aneesh.kumar at linux.vnet.ibm.com>
>
> Older version of power architecture use Real Mode Offset register and Real Mode Limit
> Selector for mapping guest Real Mode Area. The guest RMA should be physically
> contigous since we use the range when address translation is not enabled.
>
> This patch switch RMA allocation code to use contigous memory allocator. The patch
> also remove the the linear allocator which not used any more
>
> Acked-by: Paul Mackerras<paulus at samba.org>
> Signed-off-by: Aneesh Kumar K.V<aneesh.kumar at linux.vnet.ibm.com>
> ---
> arch/powerpc/include/asm/kvm_book3s_64.h | 1 +
> arch/powerpc/include/asm/kvm_host.h | 12 +--
> arch/powerpc/include/asm/kvm_ppc.h | 8 +-
> arch/powerpc/kernel/setup_64.c | 2 -
> arch/powerpc/kvm/book3s_hv.c | 27 +++--
> arch/powerpc/kvm/book3s_hv_builtin.c | 167 ++++++++-----------------------
> 6 files changed, 65 insertions(+), 152 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h
> index f8355a9..76ff0b5 100644
> --- a/arch/powerpc/include/asm/kvm_book3s_64.h
> +++ b/arch/powerpc/include/asm/kvm_book3s_64.h
> @@ -37,6 +37,7 @@ static inline void svcpu_put(struct kvmppc_book3s_shadow_vcpu *svcpu)
>
> #ifdef CONFIG_KVM_BOOK3S_64_HV
> #define KVM_DEFAULT_HPT_ORDER 24 /* 16MB HPT by default */
> +extern unsigned long kvm_rma_pages;
> #endif
>
> #define VRMA_VSID 0x1ffffffUL /* 1TB VSID reserved for VRMA */
> diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
> index 0097dab..3328353 100644
> --- a/arch/powerpc/include/asm/kvm_host.h
> +++ b/arch/powerpc/include/asm/kvm_host.h
> @@ -183,13 +183,9 @@ struct kvmppc_spapr_tce_table {
> struct page *pages[0];
> };
>
> -struct kvmppc_linear_info {
> - void *base_virt;
> - unsigned long base_pfn;
> - unsigned long npages;
> - struct list_head list;
> - atomic_t use_count;
> - int type;
> +struct kvm_rma_info {
> + atomic_t use_count;
> + unsigned long base_pfn;
> };
>
> /* XICS components, defined in book3s_xics.c */
> @@ -246,7 +242,7 @@ struct kvm_arch {
> int tlbie_lock;
> unsigned long lpcr;
> unsigned long rmor;
> - struct kvmppc_linear_info *rma;
> + struct kvm_rma_info *rma;
> unsigned long vrma_slb_v;
> int rma_setup_done;
> int using_mmu_notifiers;
> diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
> index b5ef7a3..5a26bfc 100644
> --- a/arch/powerpc/include/asm/kvm_ppc.h
> +++ b/arch/powerpc/include/asm/kvm_ppc.h
> @@ -137,8 +137,8 @@ extern long kvmppc_h_put_tce(struct kvm_vcpu *vcpu, unsigned long liobn,
> unsigned long ioba, unsigned long tce);
> extern long kvm_vm_ioctl_allocate_rma(struct kvm *kvm,
> struct kvm_allocate_rma *rma);
> -extern struct kvmppc_linear_info *kvm_alloc_rma(void);
> -extern void kvm_release_rma(struct kvmppc_linear_info *ri);
> +extern struct kvm_rma_info *kvm_alloc_rma(void);
> +extern void kvm_release_rma(struct kvm_rma_info *ri);
> extern struct page *kvm_alloc_hpt(unsigned long nr_pages);
> extern void kvm_release_hpt(struct page *page, unsigned long nr_pages);
> extern int kvmppc_core_init_vm(struct kvm *kvm);
> @@ -282,7 +282,6 @@ static inline void kvmppc_set_host_ipi(int cpu, u8 host_ipi)
> }
>
> extern void kvmppc_fast_vcpu_kick(struct kvm_vcpu *vcpu);
> -extern void kvm_linear_init(void);
>
> #else
> static inline void __init kvm_cma_reserve(void)
> @@ -291,9 +290,6 @@ static inline void __init kvm_cma_reserve(void)
> static inline void kvmppc_set_xics_phys(int cpu, unsigned long addr)
> {}
>
> -static inline void kvm_linear_init(void)
> -{}
> -
> static inline u32 kvmppc_get_xics_latch(void)
> {
> return 0;
> diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
> index ee28d1f..8a022f5 100644
> --- a/arch/powerpc/kernel/setup_64.c
> +++ b/arch/powerpc/kernel/setup_64.c
> @@ -611,8 +611,6 @@ void __init setup_arch(char **cmdline_p)
> /* Initialize the MMU context management stuff */
> mmu_context_init();
>
> - kvm_linear_init();
> -
> /* Interrupt code needs to be 64K-aligned */
> if ((unsigned long)_stext& 0xffff)
> panic("Kernelbase not 64K-aligned (0x%lx)!\n",
> diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
> index 550f592..55c8519 100644
> --- a/arch/powerpc/kvm/book3s_hv.c
> +++ b/arch/powerpc/kvm/book3s_hv.c
> @@ -1511,10 +1511,10 @@ static inline int lpcr_rmls(unsigned long rma_size)
>
> static int kvm_rma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
> {
> - struct kvmppc_linear_info *ri = vma->vm_file->private_data;
> struct page *page;
> + struct kvm_rma_info *ri = vma->vm_file->private_data;
>
> - if (vmf->pgoff>= ri->npages)
> + if (vmf->pgoff>= kvm_rma_pages)
> return VM_FAULT_SIGBUS;
>
> page = pfn_to_page(ri->base_pfn + vmf->pgoff);
> @@ -1536,7 +1536,7 @@ static int kvm_rma_mmap(struct file *file, struct vm_area_struct *vma)
>
> static int kvm_rma_release(struct inode *inode, struct file *filp)
> {
> - struct kvmppc_linear_info *ri = filp->private_data;
> + struct kvm_rma_info *ri = filp->private_data;
>
> kvm_release_rma(ri);
> return 0;
> @@ -1549,8 +1549,17 @@ static const struct file_operations kvm_rma_fops = {
>
> long kvm_vm_ioctl_allocate_rma(struct kvm *kvm, struct kvm_allocate_rma *ret)
> {
> - struct kvmppc_linear_info *ri;
> long fd;
> + struct kvm_rma_info *ri;
> + /*
> + * Only do this on PPC970 in HV mode
> + */
> + if (!cpu_has_feature(CPU_FTR_HVMODE) ||
> + !cpu_has_feature(CPU_FTR_ARCH_201))
> + return -EINVAL;
Is this really what we want? User space may want to use an RMA on POWER7
systems, no?
> +
> + if (!kvm_rma_pages)
> + return -EINVAL;
>
> ri = kvm_alloc_rma();
> if (!ri)
> @@ -1560,7 +1569,7 @@ long kvm_vm_ioctl_allocate_rma(struct kvm *kvm, struct kvm_allocate_rma *ret)
> if (fd< 0)
> kvm_release_rma(ri);
>
> - ret->rma_size = ri->npages<< PAGE_SHIFT;
> + ret->rma_size = kvm_rma_pages<< PAGE_SHIFT;
> return fd;
> }
>
> @@ -1725,7 +1734,7 @@ static int kvmppc_hv_setup_htab_rma(struct kvm_vcpu *vcpu)
> {
> int err = 0;
> struct kvm *kvm = vcpu->kvm;
> - struct kvmppc_linear_info *ri = NULL;
> + struct kvm_rma_info *ri = NULL;
> unsigned long hva;
> struct kvm_memory_slot *memslot;
> struct vm_area_struct *vma;
> @@ -1803,7 +1812,7 @@ static int kvmppc_hv_setup_htab_rma(struct kvm_vcpu *vcpu)
>
> } else {
> /* Set up to use an RMO region */
> - rma_size = ri->npages;
> + rma_size = kvm_rma_pages;
> if (rma_size> memslot->npages)
> rma_size = memslot->npages;
> rma_size<<= PAGE_SHIFT;
> @@ -1831,14 +1840,14 @@ static int kvmppc_hv_setup_htab_rma(struct kvm_vcpu *vcpu)
> /* POWER7 */
> lpcr&= ~(LPCR_VPM0 | LPCR_VRMA_L);
> lpcr |= rmls<< LPCR_RMLS_SH;
> - kvm->arch.rmor = kvm->arch.rma->base_pfn<< PAGE_SHIFT;
> + kvm->arch.rmor = ri->base_pfn<< PAGE_SHIFT;
> }
> kvm->arch.lpcr = lpcr;
> pr_info("KVM: Using RMO at %lx size %lx (LPCR = %lx)\n",
> ri->base_pfn<< PAGE_SHIFT, rma_size, lpcr);
>
> /* Initialize phys addrs of pages in RMO */
> - npages = ri->npages;
> + npages = kvm_rma_pages;
> porder = __ilog2(npages);
> physp = memslot->arch.slot_phys;
> if (physp) {
> diff --git a/arch/powerpc/kvm/book3s_hv_builtin.c b/arch/powerpc/kvm/book3s_hv_builtin.c
> index 4b865c5..8cd0dae 100644
> --- a/arch/powerpc/kvm/book3s_hv_builtin.c
> +++ b/arch/powerpc/kvm/book3s_hv_builtin.c
> @@ -21,13 +21,6 @@
> #include<asm/kvm_book3s.h>
>
> #include "book3s_hv_cma.h"
> -
> -#define KVM_LINEAR_RMA 0
> -#define KVM_LINEAR_HPT 1
> -
> -static void __init kvm_linear_init_one(ulong size, int count, int type);
> -static struct kvmppc_linear_info *kvm_alloc_linear(int type);
> -static void kvm_release_linear(struct kvmppc_linear_info *ri);
> /*
> * Hash page table alignment on newer cpus(CPU_FTR_ARCH_206)
> * should be power of 2.
> @@ -37,19 +30,17 @@ static void kvm_release_linear(struct kvmppc_linear_info *ri);
> * By default we reserve 5% of memory for hash pagetable allocation.
> */
> static unsigned long kvm_cma_resv_ratio = 5;
> -
> -/*************** RMA *************/
> -
> /*
> - * This maintains a list of RMAs (real mode areas) for KVM guests to use.
> + * We allocate RMAs (real mode areas) for KVM guests from the KVM CMA area.
> * Each RMA has to be physically contiguous and of a size that the
> * hardware supports. PPC970 and POWER7 support 64MB, 128MB and 256MB,
> * and other larger sizes. Since we are unlikely to be allocate that
> * much physically contiguous memory after the system is up and running,
> - * we preallocate a set of RMAs in early boot for KVM to use.
> + * we preallocate a set of RMAs in early boot using CMA.
> + * should be power of 2.
> */
> -static unsigned long kvm_rma_size = 64<< 20; /* 64MB */
> -static unsigned long kvm_rma_count;
> +unsigned long kvm_rma_pages = (1<< 27)>> PAGE_SHIFT; /* 128MB */
> +EXPORT_SYMBOL_GPL(kvm_rma_pages);
>
> /* Work out RMLS (real mode limit selector) field value for a given RMA size.
> Assumes POWER7 or PPC970. */
> @@ -79,35 +70,50 @@ static inline int lpcr_rmls(unsigned long rma_size)
>
> static int __init early_parse_rma_size(char *p)
> {
> - if (!p)
> - return 1;
> + unsigned long kvm_rma_size;
>
> + pr_debug("%s(%s)\n", __func__, p);
> + if (!p)
> + return -EINVAL;
> kvm_rma_size = memparse(p,&p);
> -
> + /*
> + * Check that the requested size is one supported in hardware
> + */
> + if (lpcr_rmls(kvm_rma_size)< 0) {
> + pr_err("RMA size of 0x%lx not supported\n", kvm_rma_size);
> + return -EINVAL;
> + }
> + kvm_rma_pages = kvm_rma_size>> PAGE_SHIFT;
> return 0;
> }
> early_param("kvm_rma_size", early_parse_rma_size);
>
> -static int __init early_parse_rma_count(char *p)
> +struct kvm_rma_info *kvm_alloc_rma()
> {
> - if (!p)
> - return 1;
> -
> - kvm_rma_count = simple_strtoul(p, NULL, 0);
> -
> - return 0;
> -}
> -early_param("kvm_rma_count", early_parse_rma_count);
> -
> -struct kvmppc_linear_info *kvm_alloc_rma(void)
> -{
> - return kvm_alloc_linear(KVM_LINEAR_RMA);
> + struct page *page;
> + struct kvm_rma_info *ri;
> +
> + ri = kmalloc(sizeof(struct kvm_rma_info), GFP_KERNEL);
> + if (!ri)
> + return NULL;
> + page = kvm_alloc_cma(kvm_rma_pages, kvm_rma_pages);
> + if (!page)
> + goto err_out;
> + atomic_set(&ri->use_count, 1);
> + ri->base_pfn = page_to_pfn(page);
> + return ri;
> +err_out:
> + kfree(ri);
> + return NULL;
> }
> EXPORT_SYMBOL_GPL(kvm_alloc_rma);
>
> -void kvm_release_rma(struct kvmppc_linear_info *ri)
> +void kvm_release_rma(struct kvm_rma_info *ri)
> {
> - kvm_release_linear(ri);
> + if (atomic_dec_and_test(&ri->use_count)) {
> + kvm_release_cma(pfn_to_page(ri->base_pfn), kvm_rma_pages);
> + kfree(ri);
> + }
> }
> EXPORT_SYMBOL_GPL(kvm_release_rma);
>
> @@ -137,101 +143,6 @@ void kvm_release_hpt(struct page *page, unsigned long nr_pages)
> }
> EXPORT_SYMBOL_GPL(kvm_release_hpt);
>
> -/*************** generic *************/
> -
> -static LIST_HEAD(free_linears);
> -static DEFINE_SPINLOCK(linear_lock);
> -
> -static void __init kvm_linear_init_one(ulong size, int count, int type)
Please split the linar removal bits out into a separate patch :).
Alex
> -{
> - unsigned long i;
> - unsigned long j, npages;
> - void *linear;
> - struct page *pg;
> - const char *typestr;
> - struct kvmppc_linear_info *linear_info;
> -
> - if (!count)
> - return;
> -
> - typestr = (type == KVM_LINEAR_RMA) ? "RMA" : "HPT";
> -
> - npages = size>> PAGE_SHIFT;
> - linear_info = alloc_bootmem(count * sizeof(struct kvmppc_linear_info));
> - for (i = 0; i< count; ++i) {
> - linear = alloc_bootmem_align(size, size);
> - pr_debug("Allocated KVM %s at %p (%ld MB)\n", typestr, linear,
> - size>> 20);
> - linear_info[i].base_virt = linear;
> - linear_info[i].base_pfn = __pa(linear)>> PAGE_SHIFT;
> - linear_info[i].npages = npages;
> - linear_info[i].type = type;
> - list_add_tail(&linear_info[i].list,&free_linears);
> - atomic_set(&linear_info[i].use_count, 0);
> -
> - pg = pfn_to_page(linear_info[i].base_pfn);
> - for (j = 0; j< npages; ++j) {
> - atomic_inc(&pg->_count);
> - ++pg;
> - }
> - }
> -}
> -
> -static struct kvmppc_linear_info *kvm_alloc_linear(int type)
> -{
> - struct kvmppc_linear_info *ri, *ret;
> -
> - ret = NULL;
> - spin_lock(&linear_lock);
> - list_for_each_entry(ri,&free_linears, list) {
> - if (ri->type != type)
> - continue;
> -
> - list_del(&ri->list);
> - atomic_inc(&ri->use_count);
> - memset(ri->base_virt, 0, ri->npages<< PAGE_SHIFT);
> - ret = ri;
> - break;
> - }
> - spin_unlock(&linear_lock);
> - return ret;
> -}
> -
> -static void kvm_release_linear(struct kvmppc_linear_info *ri)
> -{
> - if (atomic_dec_and_test(&ri->use_count)) {
> - spin_lock(&linear_lock);
> - list_add_tail(&ri->list,&free_linears);
> - spin_unlock(&linear_lock);
> -
> - }
> -}
> -
> -/*
> - * Called at boot time while the bootmem allocator is active,
> - * to allocate contiguous physical memory for the hash page
> - * tables for guests.
> - */
> -void __init kvm_linear_init(void)
> -{
> - /* RMA */
> - /* Only do this on PPC970 in HV mode */
> - if (!cpu_has_feature(CPU_FTR_HVMODE) ||
> - !cpu_has_feature(CPU_FTR_ARCH_201))
> - return;
> -
> - if (!kvm_rma_size || !kvm_rma_count)
> - return;
> -
> - /* Check that the requested size is one supported in hardware */
> - if (lpcr_rmls(kvm_rma_size)< 0) {
> - pr_err("RMA size of 0x%lx not supported\n", kvm_rma_size);
> - return;
> - }
> -
> - kvm_linear_init_one(kvm_rma_size, kvm_rma_count, KVM_LINEAR_RMA);
> -}
> -
> /**
> * kvm_cma_reserve() - reserve area for kvm hash pagetable
> *
> @@ -265,6 +176,8 @@ void __init kvm_cma_reserve(void)
> align_size = __rounddown_pow_of_two(selected_size);
> else
> align_size = HPT_ALIGN_PAGES<< PAGE_SHIFT;
> +
> + align_size = max(kvm_rma_pages<< PAGE_SHIFT, align_size);
> kvm_cma_declare_contiguous(selected_size, align_size);
> }
> }
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