From patchwork Fri Jul 9 01:34:38 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Xiao Guangrong X-Patchwork-Id: 110976 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter.kernel.org (8.14.4/8.14.3) with ESMTP id o691dCin005197 for ; Fri, 9 Jul 2010 01:39:12 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752366Ab0GIBie (ORCPT ); Thu, 8 Jul 2010 21:38:34 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:51800 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751281Ab0GIBie (ORCPT ); Thu, 8 Jul 2010 21:38:34 -0400 Received: from tang.cn.fujitsu.com (tang.cn.fujitsu.com [10.167.250.3]) by song.cn.fujitsu.com (Postfix) with ESMTP id 2F5D4170149; Fri, 9 Jul 2010 09:38:32 +0800 (CST) Received: from fnst.cn.fujitsu.com (tang.cn.fujitsu.com [127.0.0.1]) by tang.cn.fujitsu.com (8.14.3/8.13.1) with ESMTP id o691ZoCq028000; Fri, 9 Jul 2010 09:35:50 +0800 Received: from [10.167.141.99] (unknown [10.167.141.99]) by fnst.cn.fujitsu.com (Postfix) with ESMTPA id 7381C10C1A3; Fri, 9 Jul 2010 09:38:47 +0800 (CST) Message-ID: <4C367CAE.5070500@cn.fujitsu.com> Date: Fri, 09 Jul 2010 09:34:38 +0800 From: Xiao Guangrong User-Agent: Thunderbird 2.0.0.24 (Windows/20100228) MIME-Version: 1.0 To: Avi Kivity CC: Marcelo Tosatti , LKML , KVM list Subject: Re: [PATCH v5 4/9] KVM: MMU: introduce gfn_to_pfn_atomic() function References: <4C330918.6040709@cn.fujitsu.com> <4C3309D3.6010109@cn.fujitsu.com> In-Reply-To: <4C3309D3.6010109@cn.fujitsu.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.3 (demeter.kernel.org [140.211.167.41]); Fri, 09 Jul 2010 01:39:12 +0000 (UTC) Xiao Guangrong wrote: > + if (atomic) > + goto return_bad_page; > + > down_read(¤t->mm->mmap_sem); > if (is_hwpoison_address(addr)) { > up_read(¤t->mm->mmap_sem); > @@ -959,6 +965,7 @@ static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr) > if (vma == NULL || addr < vma->vm_start || > !(vma->vm_flags & VM_PFNMAP)) { > up_read(¤t->mm->mmap_sem); > +return_bad_page: > get_page(bad_page); > return page_to_pfn(bad_page); > } > @@ -972,7 +979,7 @@ static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr) > return pfn; This patch is broken caused by commit b4f8c24994, rebase it on next branch Subject: [PATCH v6 4/9] KVM: MMU: introduce gfn_to_pfn_atomic() function Introduce gfn_to_pfn_atomic(), it's the fast path and can used in atomic context, the later patch will use it Signed-off-by: Xiao Guangrong --- include/linux/kvm_host.h | 1 + virt/kvm/kvm_main.c | 32 +++++++++++++++++++++++++------- 2 files changed, 26 insertions(+), 7 deletions(-) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 8055067..bf20c97 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -296,6 +296,7 @@ void kvm_release_page_dirty(struct page *page); void kvm_set_page_dirty(struct page *page); void kvm_set_page_accessed(struct page *page); +pfn_t gfn_to_pfn_atomic(struct kvm *kvm, gfn_t gfn); pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn); pfn_t gfn_to_pfn_memslot(struct kvm *kvm, struct kvm_memory_slot *slot, gfn_t gfn); diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index b78b794..55a61b7 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -943,19 +943,25 @@ unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn) } EXPORT_SYMBOL_GPL(gfn_to_hva); -static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr) +static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr, bool atomic) { struct page *page[1]; int npages; pfn_t pfn; - might_sleep(); - - npages = get_user_pages_fast(addr, 1, 1, page); + if (atomic) + npages = __get_user_pages_fast(addr, 1, 1, page); + else { + might_sleep(); + npages = get_user_pages_fast(addr, 1, 1, page); + } if (unlikely(npages != 1)) { struct vm_area_struct *vma; + if (atomic) + goto return_fault_page; + down_read(¤t->mm->mmap_sem); if (is_hwpoison_address(addr)) { up_read(¤t->mm->mmap_sem); @@ -968,6 +974,7 @@ static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr) if (vma == NULL || addr < vma->vm_start || !(vma->vm_flags & VM_PFNMAP)) { up_read(¤t->mm->mmap_sem); +return_fault_page: get_page(fault_page); return page_to_pfn(fault_page); } @@ -981,7 +988,7 @@ static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr) return pfn; } -pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn) +pfn_t __gfn_to_pfn(struct kvm *kvm, gfn_t gfn, bool atomic) { unsigned long addr; @@ -991,7 +998,18 @@ pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn) return page_to_pfn(bad_page); } - return hva_to_pfn(kvm, addr); + return hva_to_pfn(kvm, addr, atomic); +} + +pfn_t gfn_to_pfn_atomic(struct kvm *kvm, gfn_t gfn) +{ + return __gfn_to_pfn(kvm, gfn, true); +} +EXPORT_SYMBOL_GPL(gfn_to_pfn_atomic); + +pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn) +{ + return __gfn_to_pfn(kvm, gfn, false); } EXPORT_SYMBOL_GPL(gfn_to_pfn); @@ -999,7 +1017,7 @@ pfn_t gfn_to_pfn_memslot(struct kvm *kvm, struct kvm_memory_slot *slot, gfn_t gfn) { unsigned long addr = gfn_to_hva_memslot(slot, gfn); - return hva_to_pfn(kvm, addr); + return hva_to_pfn(kvm, addr, false); } struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn)