From nobody Tue Sep 29 05:33:50 2026 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 4F94E4204E; Wed, 12 Aug 2026 00:05:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786493126; cv=none; b=iJmY4E0OfDvvHYLkKtU9ayDg+y6GKDZD1ghe159i4rSRlt7guGcBZO+4LOPrpsBX8XFJGakh/YRRgcyTQhjUyaR4MglO6kIN9toRmd9KfR9QNH8A8AqNoeXTvHoq3JS15UEzIE70ODmvzZRXJmsJ17O39IwGof4BcW2v/iXgY+U= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786493126; c=relaxed/simple; bh=1NgHFM2Vg0yBu2SLL+GefWAHrRdz78dFOui9uBucu3E=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=V+CjMUHcpx710kKiw/wkAWABm/RxHad+/zJsn9ljbUxiiI2Kw1ZiARbrFFxCvATASllu15VQA/yziZddTLs7ci9XO3KYn7moBoM71Y2xl8+HgxvkPdQC0nBl7xVIfU4YGNRvMsJCJNP2WG0zjqDnbg6ieExOJiZp1ofI6y2kDQM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=KqNGn01P; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="KqNGn01P" Received: from mrdev.corp.microsoft.com (unknown [40.86.181.13]) by linux.microsoft.com (Postfix) with ESMTPSA id 3CD9020B7168; Tue, 11 Aug 2026 17:04:55 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 3CD9020B7168 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1786493095; bh=U6vqpB/pHLHFQfy/VQj0XgJau/ZvOHIFmfxHxQMM40o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KqNGn01PY7jBeBy6ISxY5At9MdK5J8IDZBnBmIB1SuEVfrr9TqEdky8QnElI+8HpC HOSjT0Q+upy5f9eJQSJZJrsocQ7Jy0xFyYLDgugMrmm343IQbtFcNVTb78GGncRXTV eARFYBcCw1KIEk855uyy9w+/JjqK1TY59kySZNL4= From: Mukesh R To: linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org Cc: kys@microsoft.com, wei.liu@kernel.org, mhkelley58@gmail.com, mrathor@linux.microsoft.com Subject: [PATCH V0 1/2] mshv: Stub out deposit memory functions Date: Tue, 11 Aug 2026 17:05:06 -0700 Message-ID: <20260812000507.3809046-2-mrathor@linux.microsoft.com> X-Mailer: git-send-email 2.51.2.vfs.0.1 In-Reply-To: <20260812000507.3809046-1-mrathor@linux.microsoft.com> References: <20260812000507.3809046-1-mrathor@linux.microsoft.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Stub out deposit memory functions so adding of new redesigned functions is much eaiser to review. Signed-off-by: Mukesh R --- drivers/hv/hv_proc.c | 126 ++----------------------------------------- 1 file changed, 3 insertions(+), 123 deletions(-) diff --git a/drivers/hv/hv_proc.c b/drivers/hv/hv_proc.c index 57b2c64197cb..d5ce9a032e9c 100644 --- a/drivers/hv/hv_proc.c +++ b/drivers/hv/hv_proc.c @@ -9,135 +9,15 @@ #include #include =20 -/* - * See struct hv_deposit_memory. The first u64 is partition ID, the rest - * are GPAs. - */ -#define HV_DEPOSIT_MAX (HV_HYP_PAGE_SIZE / sizeof(u64) - 1) - -/* Deposits exact number of pages. Must be called with interrupts enabled.= */ int hv_call_deposit_pages(int node, u64 partition_id, u32 num_pages) { - struct page **pages, *page; - int *counts; - int num_allocations; - int i, j, page_count; - int order; - u64 status; - int ret; - u64 base_pfn; - struct hv_deposit_memory *input_page; - unsigned long flags; - - if (num_pages > HV_DEPOSIT_MAX) - return -E2BIG; - if (!num_pages) - return 0; - - /* One buffer for page pointers and counts */ - page =3D alloc_page(GFP_KERNEL); - if (!page) - return -ENOMEM; - pages =3D page_address(page); - - counts =3D kzalloc_objs(int, HV_DEPOSIT_MAX); - if (!counts) { - free_page((unsigned long)pages); - return -ENOMEM; - } - - /* Allocate all the pages before disabling interrupts */ - i =3D 0; - - while (num_pages) { - /* Find highest order we can actually allocate */ - order =3D 31 - __builtin_clz(num_pages); - - while (1) { - pages[i] =3D alloc_pages_node(node, GFP_KERNEL, order); - if (pages[i]) - break; - if (!order) { - ret =3D -ENOMEM; - num_allocations =3D i; - goto err_free_allocations; - } - --order; - } - - split_page(pages[i], order); - counts[i] =3D 1 << order; - num_pages -=3D counts[i]; - i++; - } - num_allocations =3D i; - - local_irq_save(flags); - - input_page =3D *this_cpu_ptr(hyperv_pcpu_input_arg); - - input_page->partition_id =3D partition_id; - - /* Populate gpa_page_list - these will fit on the input page */ - for (i =3D 0, page_count =3D 0; i < num_allocations; ++i) { - base_pfn =3D page_to_pfn(pages[i]); - for (j =3D 0; j < counts[i]; ++j, ++page_count) - input_page->gpa_page_list[page_count] =3D base_pfn + j; - } - status =3D hv_do_rep_hypercall(HVCALL_DEPOSIT_MEMORY, - page_count, 0, input_page, NULL); - local_irq_restore(flags); - if (!hv_result_success(status)) { - hv_status_err(status, "\n"); - ret =3D hv_result_to_errno(status); - goto err_free_allocations; - } - - ret =3D 0; - goto free_buf; - -err_free_allocations: - for (i =3D 0; i < num_allocations; ++i) { - base_pfn =3D page_to_pfn(pages[i]); - for (j =3D 0; j < counts[i]; ++j) - __free_page(pfn_to_page(base_pfn + j)); - } - -free_buf: - free_page((unsigned long)pages); - kfree(counts); - return ret; + return -ENOTSUPP; } EXPORT_SYMBOL_GPL(hv_call_deposit_pages); =20 -int hv_deposit_memory_node(int node, u64 partition_id, - u64 hv_status) +int hv_deposit_memory_node(int node, u64 partition_id, u64 hv_status) { - u32 num_pages =3D 1; - - switch (hv_result(hv_status)) { - case HV_STATUS_INSUFFICIENT_MEMORY: - break; - case HV_STATUS_INSUFFICIENT_CONTIGUOUS_MEMORY: - num_pages =3D HV_MAX_CONTIGUOUS_ALLOCATION_PAGES; - break; - - case HV_STATUS_INSUFFICIENT_CONTIGUOUS_ROOT_MEMORY: - num_pages =3D HV_MAX_CONTIGUOUS_ALLOCATION_PAGES; - fallthrough; - case HV_STATUS_INSUFFICIENT_ROOT_MEMORY: - if (!hv_root_partition()) { - hv_status_err(hv_status, "Unexpected root memory deposit\n"); - return -ENOMEM; - } - partition_id =3D HV_PARTITION_ID_SELF; - break; - - default: - hv_status_err(hv_status, "Unexpected!\n"); - return -ENOMEM; - } - return hv_call_deposit_pages(node, partition_id, num_pages); + return -ENOTSUPP; } EXPORT_SYMBOL_GPL(hv_deposit_memory_node); =20 --=20 2.51.2.vfs.0.1 From nobody Tue Sep 29 05:33:50 2026 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 5B90228DC4; Wed, 12 Aug 2026 00:05:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786493127; cv=none; b=OIEf7GpZm1vTqCymzTvG/iSCdNcJf9mg2htokbC3yLBqZghl/cifG1QCdgSnY/m36ULv6WIWX61C+9Z1RqIaPleLfQRITUtpdxzGxONhtDO3rt/TxuknrUHvuytlmJpKf671282kDjo2j8V4B5eJxfIcbjU6CmVGaHyNFsuGuao= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786493127; c=relaxed/simple; bh=70RWACNEyQn7+QJ+NYOurkIxzjut6EwsK/NE1M6a0aI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=CK485EQz3htyiiitKK1s/Fzh9fRRXzx9YwC6QXgHSBZ2//huczrQelMOI1oOs5wWV55o3rqDLwXzlyq/2ozjkMysNnB78q5gOiUPr0uOJ8Zw2Rv2l33UgbkC0wRnVCgnNvxYjqwncuWGo6iQ3kij6bxE8FnYgdmfnjBpARH56NE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=Ahg8JzKM; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="Ahg8JzKM" Received: from mrdev.corp.microsoft.com (unknown [40.86.181.13]) by linux.microsoft.com (Postfix) with ESMTPSA id EDC6020B710C; Tue, 11 Aug 2026 17:04:55 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com EDC6020B710C DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1786493096; bh=vFRVfFWdvf2mQshcVmmw5NSWr7/5EQ6ATsoLVpoGjjM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Ahg8JzKM6gFQmDisErC+LgvHdp1jmubHl4cyL7gdJJmoKe3LMVDJTBLRCYu07EuoP 5cZYZazKr1WtURbB+NulJYWiJMvFACyuuIwsN+xdcNcmohOj/Tt2YQdUoolKr3MSAn 3246B8ojaPaxnYCZ4RbR6C098lbiVlHOlbYRd3yk= From: Mukesh R To: linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org Cc: kys@microsoft.com, wei.liu@kernel.org, mhkelley58@gmail.com, mrathor@linux.microsoft.com Subject: [PATCH V0 2/2] mshv: Redesign hypervisor memory deposit logic Date: Tue, 11 Aug 2026 17:05:07 -0700 Message-ID: <20260812000507.3809046-3-mrathor@linux.microsoft.com> X-Mailer: git-send-email 2.51.2.vfs.0.1 In-Reply-To: <20260812000507.3809046-1-mrathor@linux.microsoft.com> References: <20260812000507.3809046-1-mrathor@linux.microsoft.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" There are few issues/bugs in the deposit memory implementation: o It is very slow o Contiguous range requirement is ignored, and is critical bug o An incorrect assumption is made that contiguous memory size would always be power of 2. o Two pages are allocated, only one is really needed. This adds to overhead. o For a 512 page deposit, the allocation is split into two: one for 511 and second for 1. Thus, an order 9 allocation never happens. A contiguous 2M range would significantly improve performance in the hypervisor. o Since a page is already allocated to collect the frames, there is not really a need to use per cpu input page, and hence avoid local irq disable. All of above is addressed by: o Start with a full 2M range alloc, thus getting contiguous if available. o Allocate only one page in the deposit function and collect 511 pfns there. Just use a local variable for last pfn. o Use the page as input to hypercall. Since this page is allocated, irq disable can be avoided helping speed up the deposit. o Fix the contiguous requirement by using kmalloc in such case. o A minimum deposit of 2M done universally to overcome bad performance=20 overheads. The hypervisor will always first reuse any unused memory=20 that was previously deposited before asking for more. Signed-off-by: Mukesh R --- drivers/hv/hv_proc.c | 180 +++++++++++++++++++++++++++++++-- drivers/hv/mshv_root_hv_call.c | 10 +- include/asm-generic/mshyperv.h | 5 - 3 files changed, 174 insertions(+), 21 deletions(-) diff --git a/drivers/hv/hv_proc.c b/drivers/hv/hv_proc.c index d5ce9a032e9c..fd74c286e612 100644 --- a/drivers/hv/hv_proc.c +++ b/drivers/hv/hv_proc.c @@ -9,15 +9,182 @@ #include #include =20 -int hv_call_deposit_pages(int node, u64 partition_id, u32 num_pages) +#define HV_DEPOSIT_MAX 512 +#define HV_DEPOSIT_INP_MAX ((HV_HYP_PAGE_SIZE - \ + offsetof(struct hv_deposit_memory, gpa_page_list)) / sizeof(u64)) + +static int hv_alloc_contig_pages(int node, u64 *pfna, u64 *lastpfnp, + int num_pages) +{ + void *p; + int i, tmp; + ulong pfn; + size_t size =3D num_pages * HV_HYP_PAGE_SIZE; + + if (num_pages > HV_DEPOSIT_MAX || + (num_pages =3D=3D HV_DEPOSIT_MAX && lastpfnp =3D=3D NULL)) + return -EINVAL; + + p =3D kmalloc_node(size, GFP_KERNEL, node); + if (p =3D=3D NULL) + return -ENOMEM; + + pfn =3D PFN_DOWN(virt_to_phys(p)); + tmp =3D min(num_pages, HV_DEPOSIT_INP_MAX); + + for (i =3D 0; i < tmp; i++, pfn++) + pfna[i] =3D pfn; + + if (num_pages =3D=3D HV_DEPOSIT_MAX) + *lastpfnp =3D pfn; + + return num_pages; +} + + +/* + * Allocate free pages for deposit to hypervisor. pfna[] must be large eno= ugh + * to hold HV_DEPOSIT_INP_MAX (511) pages. If num_pages is 512, return last + * pfn in lastpfn. + * + * Returns : -ENOMEM if zero allocated, else number of pages allocated + */ +static int hv_alloc_dep_pages(int node, u64 *pfna, u64 *lastpfnp, int num_= pages) +{ + struct page *page; + int num_allocd, count =3D 0; + + /* Published ABI, enforce its immutability. */ + BUILD_BUG_ON(HV_DEPOSIT_INP_MAX !=3D 511); + + if (num_pages > HV_DEPOSIT_MAX || + (num_pages =3D=3D HV_DEPOSIT_MAX && lastpfnp =3D=3D NULL)) + return -EINVAL; + + while (num_pages) { + /* Find highest order we can actually allocate */ + int order =3D 31 - __builtin_clz(num_pages); + + while (1) { + page =3D alloc_pages_node(node, GFP_KERNEL, order); + if (page || order =3D=3D 0) + break; + + order--; + } + + if (page =3D=3D NULL) + break; + + split_page(page, order); + num_allocd =3D 1 << order; + num_pages -=3D num_allocd; + + while (num_allocd && count < HV_DEPOSIT_INP_MAX) { + pfna[count++] =3D page_to_pfn(page++); + num_allocd--; + } + + if (num_allocd-- && count =3D=3D HV_DEPOSIT_INP_MAX) { + *lastpfnp =3D page_to_pfn(page); + count++; + break; + } + } + + return count ? count : -ENOMEM; +} + +/* + * Deposit memory in the hypervisor. A contiguous 2M worth of pfns is utmo= st + * desired, but short of that, we deposit whatever contiguous chunks we can + * get. + */ +static int hv_call_deposit_memory(int node, u64 partition_id, bool contigu= ous) { - return -ENOTSUPP; + struct hv_deposit_memory *hc_input; + int i, rc, num_pages; + u64 status, *pfna, lastpfn =3D 0; + + BUILD_BUG_ON(HV_MAX_CONTIGUOUS_ALLOCATION_PAGES > HV_DEPOSIT_MAX); + + if (contiguous) + num_pages =3D HV_MAX_CONTIGUOUS_ALLOCATION_PAGES; + else + num_pages =3D HV_DEPOSIT_MAX; + + hc_input =3D (struct hv_deposit_memory *)get_zeroed_page(GFP_KERNEL); + if (hc_input =3D=3D NULL) + return -ENOMEM; + + hc_input->partition_id =3D partition_id; + pfna =3D hc_input->gpa_page_list; + + if (contiguous) + rc =3D hv_alloc_contig_pages(node, pfna, &lastpfn, num_pages); + else + rc =3D hv_alloc_dep_pages(node, pfna, &lastpfn, num_pages); + if (rc < 0) + goto out_free; + + num_pages =3D rc; + if (num_pages > HV_DEPOSIT_INP_MAX) + num_pages =3D HV_DEPOSIT_INP_MAX; + + /* We are not using hyperv_pcpu_input_arg, so no need to disable */ + + status =3D hv_do_rep_hypercall(HVCALL_DEPOSIT_MEMORY, num_pages, + 0, hc_input, NULL); + if (!hv_result_success(status)) { + hv_status_err(status, "\n"); + rc =3D hv_result_to_errno(status); + goto out_free_dep_pages; + } + + if (lastpfn) { + hc_input->gpa_page_list[0] =3D lastpfn; + status =3D hv_do_rep_hypercall(HVCALL_DEPOSIT_MEMORY, 1, 0, + hc_input, NULL); + if (!hv_result_success(status)) + /* We deposited some earlier, so just free this */ + __free_page(pfn_to_page(lastpfn)); + } + + free_page((unsigned long)hc_input); + return 0; + +out_free_dep_pages: + for (i =3D 0; i < num_pages; i++) + __free_page(pfn_to_page(pfna[i])); + if (lastpfn) + __free_page(pfn_to_page(lastpfn)); + +out_free: + free_page((unsigned long)hc_input); + return rc; } -EXPORT_SYMBOL_GPL(hv_call_deposit_pages); =20 -int hv_deposit_memory_node(int node, u64 partition_id, u64 hv_status) +int hv_deposit_memory_node(int node, u64 pt_id, u64 hv_status) { - return -ENOTSUPP; + int result =3D hv_result(hv_status); + bool contiguous =3D false; + + if (result =3D=3D HV_STATUS_INSUFFICIENT_ROOT_MEMORY || + result =3D=3D HV_STATUS_INSUFFICIENT_CONTIGUOUS_ROOT_MEMORY) { + if (!hv_root_partition()) { + hv_status_err(hv_status, + "Unexpected root memory deposit\n"); + return -EINVAL; + } + + pt_id =3D HV_PARTITION_ID_SELF; + } + + if (result =3D=3D HV_STATUS_INSUFFICIENT_CONTIGUOUS_MEMORY || + result =3D=3D HV_STATUS_INSUFFICIENT_CONTIGUOUS_ROOT_MEMORY) + contiguous =3D true; + + return hv_call_deposit_memory(node, pt_id, contiguous); } EXPORT_SYMBOL_GPL(hv_deposit_memory_node); =20 @@ -85,8 +252,7 @@ int hv_call_create_vp(int node, u64 partition_id, u32 vp= _index, u32 flags) =20 /* Root VPs don't seem to need pages deposited */ if (partition_id !=3D hv_current_partition_id) { - /* The value 90 is empirically determined. It may change. */ - ret =3D hv_call_deposit_pages(node, partition_id, 90); + ret =3D hv_call_deposit_memory(node, partition_id, false); if (ret) return ret; } diff --git a/drivers/hv/mshv_root_hv_call.c b/drivers/hv/mshv_root_hv_call.c index cb55d4d4be2e..b8d199f95299 100644 --- a/drivers/hv/mshv_root_hv_call.c +++ b/drivers/hv/mshv_root_hv_call.c @@ -15,8 +15,6 @@ #include "mshv_root.h" =20 /* Determined empirically */ -#define HV_INIT_PARTITION_DEPOSIT_PAGES 208 -#define HV_MAP_GPA_DEPOSIT_PAGES 256 #define HV_UMAP_GPA_PAGES 512 =20 #define HV_PAGE_COUNT_2M_ALIGNED(pg_count) (!((pg_count) & (0x200 - 1))) @@ -140,11 +138,6 @@ int hv_call_initialize_partition(u64 partition_id) =20 input.partition_id =3D partition_id; =20 - ret =3D hv_call_deposit_pages(NUMA_NO_NODE, partition_id, - HV_INIT_PARTITION_DEPOSIT_PAGES); - if (ret) - return ret; - do { status =3D hv_do_fast_hypercall8(HVCALL_INITIALIZE_PARTITION, *(u64 *)&input); @@ -248,8 +241,7 @@ static int hv_do_map_gpa_hcall(u64 partition_id, u64 gf= n, u64 page_struct_count, completed =3D hv_repcomp(status); =20 if (hv_result_needs_memory(status)) { - ret =3D hv_call_deposit_pages(NUMA_NO_NODE, partition_id, - HV_MAP_GPA_DEPOSIT_PAGES); + ret =3D hv_deposit_memory(partition_id, status); if (ret) break; =20 diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h index bf601d67cecb..c16abaecb65e 100644 --- a/include/asm-generic/mshyperv.h +++ b/include/asm-generic/mshyperv.h @@ -345,7 +345,6 @@ static inline bool hv_parent_partition(void) =20 bool hv_result_needs_memory(u64 status); int hv_deposit_memory_node(int node, u64 partition_id, u64 status); -int hv_call_deposit_pages(int node, u64 partition_id, u32 num_pages); int hv_call_add_logical_proc(int node, u32 lp_index, u32 acpi_id); int hv_call_notify_all_processors_started(void); bool hv_lp_exists(u32 lp_index); @@ -360,10 +359,6 @@ static inline int hv_deposit_memory_node(int node, u64= partition_id, u64 status) { return -EOPNOTSUPP; } -static inline int hv_call_deposit_pages(int node, u64 partition_id, u32 nu= m_pages) -{ - return -EOPNOTSUPP; -} static inline int hv_call_add_logical_proc(int node, u32 lp_index, u32 acp= i_id) { return -EOPNOTSUPP; --=20 2.51.2.vfs.0.1