lkml.org 
[lkml]   [2022]   [Feb]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH v2] iommu/iova: Separate out rcache init
From
On 03/02/2022 11:34, Michael S. Tsirkin wrote:
> On Thu, Feb 03, 2022 at 05:59:20PM +0800, John Garry wrote:
>> Currently the rcache structures are allocated for all IOVA domains, even if
>> they do not use "fast" alloc+free interface. This is wasteful of memory.
>>
>> In addition, fails in init_iova_rcaches() are not handled safely, which is
>> less than ideal.
>>
>> Make "fast" users call a separate rcache init explicitly, which includes
>> error checking.
>>
>> Signed-off-by: John Garry <john.garry@huawei.com>
>
> virtio things:
>
> Acked-by: Michael S. Tsirkin <mst@redhat.com>

Cheers

Hi Robin,

Can you kindly give this your blessing if you are happy with it?

Thanks!

>
>> ---
>> Differences to v1:
>> - Drop stubs for iova_domain_init_rcaches() and iova_domain_free_rcaches()
>> - Use put_iova_domain() in vdpa code
>>
>> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
>> index d85d54f2b549..b22034975301 100644
>> --- a/drivers/iommu/dma-iommu.c
>> +++ b/drivers/iommu/dma-iommu.c
>> @@ -525,6 +525,7 @@ static int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,
>> struct iommu_dma_cookie *cookie = domain->iova_cookie;
>> unsigned long order, base_pfn;
>> struct iova_domain *iovad;
>> + int ret;
>>
>> if (!cookie || cookie->type != IOMMU_DMA_IOVA_COOKIE)
>> return -EINVAL;
>> @@ -559,6 +560,9 @@ static int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,
>> }
>>
>> init_iova_domain(iovad, 1UL << order, base_pfn);
>> + ret = iova_domain_init_rcaches(iovad);
>> + if (ret)
>> + return ret;
>>
>> /* If the FQ fails we can simply fall back to strict mode */
>> if (domain->type == IOMMU_DOMAIN_DMA_FQ && iommu_dma_init_fq(domain))
>> diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c
>> index b28c9435b898..7e9c3a97c040 100644
>> --- a/drivers/iommu/iova.c
>> +++ b/drivers/iommu/iova.c
>> @@ -15,13 +15,14 @@
>> /* The anchor node sits above the top of the usable address space */
>> #define IOVA_ANCHOR ~0UL
>>
>> +#define IOVA_RANGE_CACHE_MAX_SIZE 6 /* log of max cached IOVA range size (in pages) */
>> +
>> static bool iova_rcache_insert(struct iova_domain *iovad,
>> unsigned long pfn,
>> unsigned long size);
>> static unsigned long iova_rcache_get(struct iova_domain *iovad,
>> unsigned long size,
>> unsigned long limit_pfn);
>> -static void init_iova_rcaches(struct iova_domain *iovad);
>> static void free_cpu_cached_iovas(unsigned int cpu, struct iova_domain *iovad);
>> static void free_iova_rcaches(struct iova_domain *iovad);
>>
>> @@ -64,8 +65,6 @@ init_iova_domain(struct iova_domain *iovad, unsigned long granule,
>> iovad->anchor.pfn_lo = iovad->anchor.pfn_hi = IOVA_ANCHOR;
>> rb_link_node(&iovad->anchor.node, NULL, &iovad->rbroot.rb_node);
>> rb_insert_color(&iovad->anchor.node, &iovad->rbroot);
>> - cpuhp_state_add_instance_nocalls(CPUHP_IOMMU_IOVA_DEAD, &iovad->cpuhp_dead);
>> - init_iova_rcaches(iovad);
>> }
>> EXPORT_SYMBOL_GPL(init_iova_domain);
>>
>> @@ -488,6 +487,13 @@ free_iova_fast(struct iova_domain *iovad, unsigned long pfn, unsigned long size)
>> }
>> EXPORT_SYMBOL_GPL(free_iova_fast);
>>
>> +static void iova_domain_free_rcaches(struct iova_domain *iovad)
>> +{
>> + cpuhp_state_remove_instance_nocalls(CPUHP_IOMMU_IOVA_DEAD,
>> + &iovad->cpuhp_dead);
>> + free_iova_rcaches(iovad);
>> +}
>> +
>> /**
>> * put_iova_domain - destroys the iova domain
>> * @iovad: - iova domain in question.
>> @@ -497,9 +503,9 @@ void put_iova_domain(struct iova_domain *iovad)
>> {
>> struct iova *iova, *tmp;
>>
>> - cpuhp_state_remove_instance_nocalls(CPUHP_IOMMU_IOVA_DEAD,
>> - &iovad->cpuhp_dead);
>> - free_iova_rcaches(iovad);
>> + if (iovad->rcaches)
>> + iova_domain_free_rcaches(iovad);
>> +
>> rbtree_postorder_for_each_entry_safe(iova, tmp, &iovad->rbroot, node)
>> free_iova_mem(iova);
>> }
>> @@ -608,6 +614,7 @@ EXPORT_SYMBOL_GPL(reserve_iova);
>> */
>>
>> #define IOVA_MAG_SIZE 128
>> +#define MAX_GLOBAL_MAGS 32 /* magazines per bin */
>>
>> struct iova_magazine {
>> unsigned long size;
>> @@ -620,6 +627,13 @@ struct iova_cpu_rcache {
>> struct iova_magazine *prev;
>> };
>>
>> +struct iova_rcache {
>> + spinlock_t lock;
>> + unsigned long depot_size;
>> + struct iova_magazine *depot[MAX_GLOBAL_MAGS];
>> + struct iova_cpu_rcache __percpu *cpu_rcaches;
>> +};
>> +
>> static struct iova_magazine *iova_magazine_alloc(gfp_t flags)
>> {
>> return kzalloc(sizeof(struct iova_magazine), flags);
>> @@ -693,28 +707,54 @@ static void iova_magazine_push(struct iova_magazine *mag, unsigned long pfn)
>> mag->pfns[mag->size++] = pfn;
>> }
>>
>> -static void init_iova_rcaches(struct iova_domain *iovad)
>> +int iova_domain_init_rcaches(struct iova_domain *iovad)
>> {
>> - struct iova_cpu_rcache *cpu_rcache;
>> - struct iova_rcache *rcache;
>> unsigned int cpu;
>> - int i;
>> + int i, ret;
>> +
>> + iovad->rcaches = kcalloc(IOVA_RANGE_CACHE_MAX_SIZE,
>> + sizeof(struct iova_rcache),
>> + GFP_KERNEL);
>> + if (!iovad->rcaches)
>> + return -ENOMEM;
>>
>> for (i = 0; i < IOVA_RANGE_CACHE_MAX_SIZE; ++i) {
>> + struct iova_cpu_rcache *cpu_rcache;
>> + struct iova_rcache *rcache;
>> +
>> rcache = &iovad->rcaches[i];
>> spin_lock_init(&rcache->lock);
>> rcache->depot_size = 0;
>> - rcache->cpu_rcaches = __alloc_percpu(sizeof(*cpu_rcache), cache_line_size());
>> - if (WARN_ON(!rcache->cpu_rcaches))
>> - continue;
>> + rcache->cpu_rcaches = __alloc_percpu(sizeof(*cpu_rcache),
>> + cache_line_size());
>> + if (!rcache->cpu_rcaches) {
>> + ret = -ENOMEM;
>> + goto out_err;
>> + }
>> for_each_possible_cpu(cpu) {
>> cpu_rcache = per_cpu_ptr(rcache->cpu_rcaches, cpu);
>> +
>> spin_lock_init(&cpu_rcache->lock);
>> cpu_rcache->loaded = iova_magazine_alloc(GFP_KERNEL);
>> cpu_rcache->prev = iova_magazine_alloc(GFP_KERNEL);
>> + if (!cpu_rcache->loaded || !cpu_rcache->prev) {
>> + ret = -ENOMEM;
>> + goto out_err;
>> + }
>> }
>> }
>> +
>> + ret = cpuhp_state_add_instance_nocalls(CPUHP_IOMMU_IOVA_DEAD,
>> + &iovad->cpuhp_dead);
>> + if (ret)
>> + goto out_err;
>> + return 0;
>> +
>> +out_err:
>> + free_iova_rcaches(iovad);
>> + return ret;
>> }
>> +EXPORT_SYMBOL_GPL(iova_domain_init_rcaches);
>>
>> /*
>> * Try inserting IOVA range starting with 'iova_pfn' into 'rcache', and
>> @@ -831,7 +871,7 @@ static unsigned long iova_rcache_get(struct iova_domain *iovad,
>> {
>> unsigned int log_size = order_base_2(size);
>>
>> - if (log_size >= IOVA_RANGE_CACHE_MAX_SIZE)
>> + if (log_size >= IOVA_RANGE_CACHE_MAX_SIZE || !iovad->rcaches)
>> return 0;
>>
>> return __iova_rcache_get(&iovad->rcaches[log_size], limit_pfn - size);
>> @@ -849,6 +889,8 @@ static void free_iova_rcaches(struct iova_domain *iovad)
>>
>> for (i = 0; i < IOVA_RANGE_CACHE_MAX_SIZE; ++i) {
>> rcache = &iovad->rcaches[i];
>> + if (!rcache->cpu_rcaches)
>> + break;
>> for_each_possible_cpu(cpu) {
>> cpu_rcache = per_cpu_ptr(rcache->cpu_rcaches, cpu);
>> iova_magazine_free(cpu_rcache->loaded);
>> @@ -858,6 +900,9 @@ static void free_iova_rcaches(struct iova_domain *iovad)
>> for (j = 0; j < rcache->depot_size; ++j)
>> iova_magazine_free(rcache->depot[j]);
>> }
>> +
>> + kfree(iovad->rcaches);
>> + iovad->rcaches = NULL;
>> }
>>
>> /*
>> diff --git a/drivers/vdpa/vdpa_user/iova_domain.c b/drivers/vdpa/vdpa_user/iova_domain.c
>> index 2b1143f11d8f..22f7d43f8a68 100644
>> --- a/drivers/vdpa/vdpa_user/iova_domain.c
>> +++ b/drivers/vdpa/vdpa_user/iova_domain.c
>> @@ -480,6 +480,7 @@ vduse_domain_create(unsigned long iova_limit, size_t bounce_size)
>> struct file *file;
>> struct vduse_bounce_map *map;
>> unsigned long pfn, bounce_pfns;
>> + int ret;
>>
>> bounce_pfns = PAGE_ALIGN(bounce_size) >> PAGE_SHIFT;
>> if (iova_limit <= bounce_size)
>> @@ -513,10 +514,20 @@ vduse_domain_create(unsigned long iova_limit, size_t bounce_size)
>> spin_lock_init(&domain->iotlb_lock);
>> init_iova_domain(&domain->stream_iovad,
>> PAGE_SIZE, IOVA_START_PFN);
>> + ret = iova_domain_init_rcaches(&domain->stream_iovad);
>> + if (ret)
>> + goto err_iovad_stream;
>> init_iova_domain(&domain->consistent_iovad,
>> PAGE_SIZE, bounce_pfns);
>> + ret = iova_domain_init_rcaches(&domain->consistent_iovad);
>> + if (ret)
>> + goto err_iovad_consistent;
>>
>> return domain;
>> +err_iovad_consistent:
>> + put_iova_domain(&domain->stream_iovad);
>> +err_iovad_stream:
>> + fput(file);
>> err_file:
>> vfree(domain->bounce_maps);
>> err_map:
>> diff --git a/include/linux/iova.h b/include/linux/iova.h
>> index cea79cb9f26c..320a70e40233 100644
>> --- a/include/linux/iova.h
>> +++ b/include/linux/iova.h
>> @@ -21,18 +21,8 @@ struct iova {
>> unsigned long pfn_lo; /* Lowest allocated pfn */
>> };
>>
>> -struct iova_magazine;
>> -struct iova_cpu_rcache;
>>
>> -#define IOVA_RANGE_CACHE_MAX_SIZE 6 /* log of max cached IOVA range size (in pages) */
>> -#define MAX_GLOBAL_MAGS 32 /* magazines per bin */
>> -
>> -struct iova_rcache {
>> - spinlock_t lock;
>> - unsigned long depot_size;
>> - struct iova_magazine *depot[MAX_GLOBAL_MAGS];
>> - struct iova_cpu_rcache __percpu *cpu_rcaches;
>> -};
>> +struct iova_rcache;
>>
>> /* holds all the iova translations for a domain */
>> struct iova_domain {
>> @@ -46,7 +36,7 @@ struct iova_domain {
>> unsigned long max32_alloc_size; /* Size of last failed allocation */
>> struct iova anchor; /* rbtree lookup anchor */
>>
>> - struct iova_rcache rcaches[IOVA_RANGE_CACHE_MAX_SIZE]; /* IOVA range caches */
>> + struct iova_rcache *rcaches;
>> struct hlist_node cpuhp_dead;
>> };
>>
>> @@ -102,6 +92,7 @@ struct iova *reserve_iova(struct iova_domain *iovad, unsigned long pfn_lo,
>> unsigned long pfn_hi);
>> void init_iova_domain(struct iova_domain *iovad, unsigned long granule,
>> unsigned long start_pfn);
>> +int iova_domain_init_rcaches(struct iova_domain *iovad);
>> struct iova *find_iova(struct iova_domain *iovad, unsigned long pfn);
>> void put_iova_domain(struct iova_domain *iovad);
>> #else
>> --
>> 2.26.2
>
> .

\
 
 \ /
  Last update: 2022-02-14 14:27    [W:0.063 / U:0.908 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site