From: Keqian Zhu <zhukeqian1@huawei.com>
To: Alex Williamson <alex.williamson@redhat.com>
Cc: <linux-kernel@vger.kernel.org>,
<linux-arm-kernel@lists.infradead.org>,
<iommu@lists.linux-foundation.org>, <kvm@vger.kernel.org>,
<kvmarm@lists.cs.columbia.edu>, Cornelia Huck <cohuck@redhat.com>,
"Will Deacon" <will@kernel.org>, Marc Zyngier <maz@kernel.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Mark Rutland <mark.rutland@arm.com>,
James Morse <james.morse@arm.com>,
Robin Murphy <robin.murphy@arm.com>,
Joerg Roedel <joro@8bytes.org>,
Daniel Lezcano <daniel.lezcano@linaro.org>,
"Thomas Gleixner" <tglx@linutronix.de>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Julien Thierry <julien.thierry.kdev@gmail.com>,
Andrew Morton <akpm@linux-foundation.org>,
Alexios Zavras <alexios.zavras@intel.com>,
<wanghaibin.wang@huawei.com>, <jiangkunkun@huawei.com>
Subject: Re: [PATCH 3/6] vfio/iommu_type1: Initially set the pinned_page_dirty_scope
Date: Mon, 18 Jan 2021 21:34:36 +0800 [thread overview]
Message-ID: <bc343f12-e9be-7d67-f220-5da1d02038fa@huawei.com> (raw)
In-Reply-To: <20210115163041.704a4e9d@omen.home.shazbot.org>
On 2021/1/16 7:30, Alex Williamson wrote:
> On Thu, 7 Jan 2021 12:43:58 +0800
> Keqian Zhu <zhukeqian1@huawei.com> wrote:
>
>> For now there are 3 ways to promote the pinned_page_dirty_scope
>> status of vfio_iommu:
>>
>> 1. Through vfio pin interface.
>> 2. Detach a group without pinned_dirty_scope.
>> 3. Attach a group with pinned_dirty_scope.
>>
>> For point 3, the only chance to promote the pinned_page_dirty_scope
>> status is when vfio_iommu is newly created. As we can safely set
>> empty vfio_iommu to be at pinned status, then the point 3 can be
>> removed to reduce operations.
>>
>> Signed-off-by: Keqian Zhu <zhukeqian1@huawei.com>
>> ---
>> drivers/vfio/vfio_iommu_type1.c | 4 +---
>> 1 file changed, 1 insertion(+), 3 deletions(-)
>>
>> diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
>> index 110ada24ee91..b596c482487b 100644
>> --- a/drivers/vfio/vfio_iommu_type1.c
>> +++ b/drivers/vfio/vfio_iommu_type1.c
>> @@ -2045,11 +2045,8 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
>> * Non-iommu backed group cannot dirty memory directly,
>> * it can only use interfaces that provide dirty
>> * tracking.
>> - * The iommu scope can only be promoted with the
>> - * addition of a dirty tracking group.
>> */
>> group->pinned_page_dirty_scope = true;
>> - promote_pinned_page_dirty_scope(iommu);
>> mutex_unlock(&iommu->lock);
>>
>> return 0;
>> @@ -2436,6 +2433,7 @@ static void *vfio_iommu_type1_open(unsigned long arg)
>> INIT_LIST_HEAD(&iommu->iova_list);
>> iommu->dma_list = RB_ROOT;
>> iommu->dma_avail = dma_entry_limit;
>> + iommu->pinned_page_dirty_scope = true;
>> mutex_init(&iommu->lock);
>> BLOCKING_INIT_NOTIFIER_HEAD(&iommu->notifier);
>>
>
> This would be resolved automatically if we used the counter approach I
> mentioned on the previous patch, adding a pinned-page scope group simply
> wouldn't increment the iommu counter, which would initially be zero
> indicating no "all-dma" groups. Thanks,
>
Sure, I will do that, thanks.
Keqian.
> Alex
>
> .
>
next prev parent reply other threads:[~2021-01-18 14:01 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-07 4:43 [PATCH 0/6] vfio/iommu_type1: Some optimizations about dirty tracking Keqian Zhu
2021-01-07 4:43 ` [PATCH 1/6] vfio/iommu_type1: Make an explicit "promote" semantic Keqian Zhu
2021-01-15 22:42 ` Alex Williamson
2021-01-18 13:33 ` Keqian Zhu
2021-01-07 4:43 ` [PATCH 2/6] vfio/iommu_type1: Ignore external domain when promote pinned_scope Keqian Zhu
2021-01-15 23:23 ` Alex Williamson
2021-01-07 4:43 ` [PATCH 3/6] vfio/iommu_type1: Initially set the pinned_page_dirty_scope Keqian Zhu
2021-01-15 23:30 ` Alex Williamson
2021-01-18 13:34 ` Keqian Zhu [this message]
2021-01-07 4:43 ` [PATCH 4/6] vfio/iommu_type1: Drop parameter "pgsize" of vfio_dma_bitmap_alloc_all Keqian Zhu
2021-01-15 23:37 ` Alex Williamson
2021-01-07 4:44 ` [PATCH 5/6] vfio/iommu_type1: Drop parameter "pgsize" of vfio_iova_dirty_bitmap Keqian Zhu
2021-01-15 23:39 ` Alex Williamson
2021-01-07 4:44 ` [PATCH 6/6] vfio/iommu_type1: Drop parameter "pgsize" of update_user_bitmap Keqian Zhu
2021-01-15 23:44 ` Alex Williamson
2021-01-18 13:48 ` Keqian Zhu
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