From: Chao Peng <chao.p.peng@linux.intel.com> To: Sean Christopherson <seanjc@google.com> Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org, qemu-devel@nongnu.org, Paolo Bonzini <pbonzini@redhat.com>, Jonathan Corbet <corbet@lwn.net>, Vitaly Kuznetsov <vkuznets@redhat.com>, Wanpeng Li <wanpengli@tencent.com>, Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>, Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>, x86@kernel.org, "H . Peter Anvin" <hpa@zytor.com>, Hugh Dickins <hughd@google.com>, Jeff Layton <jlayton@kernel.org>, "J . Bruce Fields" <bfields@fieldses.org>, Andrew Morton <akpm@linux-foundation.org>, Mike Rapoport <rppt@kernel.org>, Steven Price <steven.price@arm.com>, "Maciej S . Szmigiero" <mail@maciej.szmigiero.name>, Vlastimil Babka <vbabka@suse.cz>, Vishal Annapurve <vannapurve@google.com>, Yu Zhang <yu.c.zhang@linux.intel.com>, "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>, luto@kernel.org, jun.nakajima@intel.com, dave.hansen@intel.com, ak@linux.intel.com, david@redhat.com Subject: Re: [PATCH v5 05/13] KVM: Extend the memslot to support fd-based private memory Date: Fri, 8 Apr 2022 21:46:41 +0800 [thread overview] Message-ID: <20220408134641.GD57095@chaop.bj.intel.com> (raw) In-Reply-To: <YkIvEeC3/lgKTLPt@google.com> On Mon, Mar 28, 2022 at 09:56:33PM +0000, Sean Christopherson wrote: > On Thu, Mar 10, 2022, Chao Peng wrote: > > Extend the memslot definition to provide fd-based private memory support > > by adding two new fields (private_fd/private_offset). The memslot then > > can maintain memory for both shared pages and private pages in a single > > memslot. Shared pages are provided by existing userspace_addr(hva) field > > and private pages are provided through the new private_fd/private_offset > > fields. > > > > Since there is no 'hva' concept anymore for private memory so we cannot > > rely on get_user_pages() to get a pfn, instead we use the newly added > > memfile_notifier to complete the same job. > > > > This new extension is indicated by a new flag KVM_MEM_PRIVATE. > > > > Signed-off-by: Yu Zhang <yu.c.zhang@linux.intel.com> > > Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com> > > --- > > Documentation/virt/kvm/api.rst | 37 +++++++++++++++++++++++++++------- > > include/linux/kvm_host.h | 7 +++++++ > > include/uapi/linux/kvm.h | 8 ++++++++ > > 3 files changed, 45 insertions(+), 7 deletions(-) > > > > diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst > > index 3acbf4d263a5..f76ac598606c 100644 > > --- a/Documentation/virt/kvm/api.rst > > +++ b/Documentation/virt/kvm/api.rst > > @@ -1307,7 +1307,7 @@ yet and must be cleared on entry. > > :Capability: KVM_CAP_USER_MEMORY > > :Architectures: all > > :Type: vm ioctl > > -:Parameters: struct kvm_userspace_memory_region (in) > > +:Parameters: struct kvm_userspace_memory_region(_ext) (in) > > :Returns: 0 on success, -1 on error > > > > :: > > @@ -1320,9 +1320,17 @@ yet and must be cleared on entry. > > __u64 userspace_addr; /* start of the userspace allocated memory */ > > }; > > > > + struct kvm_userspace_memory_region_ext { > > + struct kvm_userspace_memory_region region; > > Peeking ahead, the partial switch to the _ext variant is rather gross. I would > prefer that KVM use an entirely different, but binary compatible, struct internally. > And once the kernel supports C11[*], I'm pretty sure we can make the "region" in > _ext an anonymous struct, and make KVM's internal struct a #define of _ext. That > should minimize the churn (no need to get the embedded "region" field), reduce > line lengths, and avoid confusion due to some flows taking the _ext but others > dealing with only the "base" struct. Will try that. > > Maybe kvm_user_memory_region or kvm_user_mem_region? Though it's tempting to be > evil and usurp the old kvm_memory_region :-) > > E.g. pre-C11 do > > struct kvm_userspace_memory_region_ext { > struct kvm_userspace_memory_region region; > __u64 private_offset; > __u32 private_fd; > __u32 padding[5]; > }; > > #ifdef __KERNEL__ > struct kvm_user_mem_region { > __u32 slot; > __u32 flags; > __u64 guest_phys_addr; > __u64 memory_size; /* bytes */ > __u64 userspace_addr; /* start of the userspace allocated memory */ > __u64 private_offset; > __u32 private_fd; > __u32 padding[5]; > }; > #endif > > and then post-C11 do > > struct kvm_userspace_memory_region_ext { > #ifdef __KERNEL__ Is this #ifndef? As I think anonymous struct is only for kernel? Thanks, Chao > struct kvm_userspace_memory_region region; > #else > struct kvm_userspace_memory_region; > #endif > __u64 private_offset; > __u32 private_fd; > __u32 padding[5]; > }; > > #ifdef __KERNEL__ > #define kvm_user_mem_region kvm_userspace_memory_region_ext > #endif > > [*] https://lore.kernel.org/all/20220301145233.3689119-1-arnd@kernel.org > > > + __u64 private_offset; > > + __u32 private_fd; > > + __u32 padding[5]; > > +};
WARNING: multiple messages have this Message-ID (diff)
From: Chao Peng <chao.p.peng@linux.intel.com> To: Sean Christopherson <seanjc@google.com> Cc: Wanpeng Li <wanpengli@tencent.com>, jun.nakajima@intel.com, kvm@vger.kernel.org, david@redhat.com, qemu-devel@nongnu.org, "J . Bruce Fields" <bfields@fieldses.org>, linux-mm@kvack.org, "H . Peter Anvin" <hpa@zytor.com>, ak@linux.intel.com, Jonathan Corbet <corbet@lwn.net>, Joerg Roedel <joro@8bytes.org>, x86@kernel.org, Hugh Dickins <hughd@google.com>, Steven Price <steven.price@arm.com>, Ingo Molnar <mingo@redhat.com>, "Maciej S . Szmigiero" <mail@maciej.szmigiero.name>, Borislav Petkov <bp@alien8.de>, luto@kernel.org, Thomas Gleixner <tglx@linutronix.de>, Vitaly Kuznetsov <vkuznets@redhat.com>, Vlastimil Babka <vbabka@suse.cz>, Jim Mattson <jmattson@google.com>, dave.hansen@intel.com, linux-api@vger.kernel.org, Jeff Layton <jlayton@kernel.org>, linux-kernel@vger.kernel.org, Yu Zhang <yu.c.zhang@linux.intel.com>, "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>, linux-fsdevel@vger.kernel.org, Paolo Bonzini <pbonzini@redhat.com>, Andrew Morton <akpm@linux-foundation.org>, Vishal Annapurve <vannapurve@google.com>, Mike Rapoport <rppt@kernel.org> Subject: Re: [PATCH v5 05/13] KVM: Extend the memslot to support fd-based private memory Date: Fri, 8 Apr 2022 21:46:41 +0800 [thread overview] Message-ID: <20220408134641.GD57095@chaop.bj.intel.com> (raw) In-Reply-To: <YkIvEeC3/lgKTLPt@google.com> On Mon, Mar 28, 2022 at 09:56:33PM +0000, Sean Christopherson wrote: > On Thu, Mar 10, 2022, Chao Peng wrote: > > Extend the memslot definition to provide fd-based private memory support > > by adding two new fields (private_fd/private_offset). The memslot then > > can maintain memory for both shared pages and private pages in a single > > memslot. Shared pages are provided by existing userspace_addr(hva) field > > and private pages are provided through the new private_fd/private_offset > > fields. > > > > Since there is no 'hva' concept anymore for private memory so we cannot > > rely on get_user_pages() to get a pfn, instead we use the newly added > > memfile_notifier to complete the same job. > > > > This new extension is indicated by a new flag KVM_MEM_PRIVATE. > > > > Signed-off-by: Yu Zhang <yu.c.zhang@linux.intel.com> > > Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com> > > --- > > Documentation/virt/kvm/api.rst | 37 +++++++++++++++++++++++++++------- > > include/linux/kvm_host.h | 7 +++++++ > > include/uapi/linux/kvm.h | 8 ++++++++ > > 3 files changed, 45 insertions(+), 7 deletions(-) > > > > diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst > > index 3acbf4d263a5..f76ac598606c 100644 > > --- a/Documentation/virt/kvm/api.rst > > +++ b/Documentation/virt/kvm/api.rst > > @@ -1307,7 +1307,7 @@ yet and must be cleared on entry. > > :Capability: KVM_CAP_USER_MEMORY > > :Architectures: all > > :Type: vm ioctl > > -:Parameters: struct kvm_userspace_memory_region (in) > > +:Parameters: struct kvm_userspace_memory_region(_ext) (in) > > :Returns: 0 on success, -1 on error > > > > :: > > @@ -1320,9 +1320,17 @@ yet and must be cleared on entry. > > __u64 userspace_addr; /* start of the userspace allocated memory */ > > }; > > > > + struct kvm_userspace_memory_region_ext { > > + struct kvm_userspace_memory_region region; > > Peeking ahead, the partial switch to the _ext variant is rather gross. I would > prefer that KVM use an entirely different, but binary compatible, struct internally. > And once the kernel supports C11[*], I'm pretty sure we can make the "region" in > _ext an anonymous struct, and make KVM's internal struct a #define of _ext. That > should minimize the churn (no need to get the embedded "region" field), reduce > line lengths, and avoid confusion due to some flows taking the _ext but others > dealing with only the "base" struct. Will try that. > > Maybe kvm_user_memory_region or kvm_user_mem_region? Though it's tempting to be > evil and usurp the old kvm_memory_region :-) > > E.g. pre-C11 do > > struct kvm_userspace_memory_region_ext { > struct kvm_userspace_memory_region region; > __u64 private_offset; > __u32 private_fd; > __u32 padding[5]; > }; > > #ifdef __KERNEL__ > struct kvm_user_mem_region { > __u32 slot; > __u32 flags; > __u64 guest_phys_addr; > __u64 memory_size; /* bytes */ > __u64 userspace_addr; /* start of the userspace allocated memory */ > __u64 private_offset; > __u32 private_fd; > __u32 padding[5]; > }; > #endif > > and then post-C11 do > > struct kvm_userspace_memory_region_ext { > #ifdef __KERNEL__ Is this #ifndef? As I think anonymous struct is only for kernel? Thanks, Chao > struct kvm_userspace_memory_region region; > #else > struct kvm_userspace_memory_region; > #endif > __u64 private_offset; > __u32 private_fd; > __u32 padding[5]; > }; > > #ifdef __KERNEL__ > #define kvm_user_mem_region kvm_userspace_memory_region_ext > #endif > > [*] https://lore.kernel.org/all/20220301145233.3689119-1-arnd@kernel.org > > > + __u64 private_offset; > > + __u32 private_fd; > > + __u32 padding[5]; > > +};
next prev parent reply other threads:[~2022-04-08 13:47 UTC|newest] Thread overview: 183+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-03-10 14:08 [PATCH v5 00/13] KVM: mm: fd-based approach for supporting KVM guest private memory Chao Peng 2022-03-10 14:08 ` Chao Peng 2022-03-10 14:08 ` [PATCH v5 01/13] mm/memfd: Introduce MFD_INACCESSIBLE flag Chao Peng 2022-03-10 14:08 ` Chao Peng 2022-04-11 15:10 ` Kirill A. Shutemov 2022-04-11 15:10 ` Kirill A. Shutemov 2022-04-12 13:11 ` Chao Peng 2022-04-12 13:11 ` Chao Peng 2022-04-23 5:43 ` Vishal Annapurve 2022-04-24 8:15 ` Chao Peng 2022-04-24 8:15 ` Chao Peng 2022-03-10 14:09 ` [PATCH v5 02/13] mm: Introduce memfile_notifier Chao Peng 2022-03-10 14:09 ` Chao Peng 2022-03-29 18:45 ` Sean Christopherson 2022-04-08 12:54 ` Chao Peng 2022-04-08 12:54 ` Chao Peng 2022-04-12 14:36 ` Hillf Danton 2022-04-13 6:47 ` Chao Peng 2022-03-10 14:09 ` [PATCH v5 03/13] mm/shmem: Support memfile_notifier Chao Peng 2022-03-10 14:09 ` Chao Peng 2022-03-10 23:08 ` Dave Chinner 2022-03-10 23:08 ` Dave Chinner 2022-03-11 8:42 ` Chao Peng 2022-03-11 8:42 ` Chao Peng 2022-04-11 15:26 ` Kirill A. Shutemov 2022-04-11 15:26 ` Kirill A. Shutemov 2022-04-12 13:12 ` Chao Peng 2022-04-12 13:12 ` Chao Peng 2022-04-19 22:40 ` Vishal Annapurve 2022-04-20 3:24 ` Chao Peng 2022-04-20 3:24 ` Chao Peng 2022-03-10 14:09 ` [PATCH v5 04/13] mm/shmem: Restrict MFD_INACCESSIBLE memory against RLIMIT_MEMLOCK Chao Peng 2022-03-10 14:09 ` Chao Peng 2022-04-07 16:05 ` Sean Christopherson 2022-04-07 17:09 ` Andy Lutomirski 2022-04-07 17:09 ` Andy Lutomirski 2022-04-08 17:56 ` Sean Christopherson 2022-04-08 18:54 ` David Hildenbrand 2022-04-08 18:54 ` David Hildenbrand 2022-04-12 14:36 ` Jason Gunthorpe 2022-04-12 14:36 ` Jason Gunthorpe 2022-04-12 21:27 ` Andy Lutomirski 2022-04-12 21:27 ` Andy Lutomirski 2022-04-13 16:30 ` David Hildenbrand 2022-04-13 16:30 ` David Hildenbrand 2022-04-13 16:24 ` David Hildenbrand 2022-04-13 16:24 ` David Hildenbrand 2022-04-13 17:52 ` Jason Gunthorpe 2022-04-13 17:52 ` Jason Gunthorpe 2022-04-25 14:07 ` David Hildenbrand 2022-04-25 14:07 ` David Hildenbrand 2022-04-08 13:02 ` Chao Peng 2022-04-08 13:02 ` Chao Peng 2022-04-11 15:34 ` Kirill A. Shutemov 2022-04-11 15:34 ` Kirill A. Shutemov 2022-04-12 5:14 ` Hugh Dickins 2022-04-11 15:32 ` Kirill A. Shutemov 2022-04-11 15:32 ` Kirill A. Shutemov 2022-04-12 13:39 ` Chao Peng 2022-04-12 13:39 ` Chao Peng 2022-04-12 19:28 ` Kirill A. Shutemov 2022-04-12 19:28 ` Kirill A. Shutemov 2022-04-13 9:15 ` Chao Peng 2022-04-13 9:15 ` Chao Peng 2022-03-10 14:09 ` [PATCH v5 05/13] KVM: Extend the memslot to support fd-based private memory Chao Peng 2022-03-10 14:09 ` Chao Peng 2022-03-28 21:27 ` Sean Christopherson 2022-04-08 13:21 ` Chao Peng 2022-04-08 13:21 ` Chao Peng 2022-03-28 21:56 ` Sean Christopherson 2022-04-08 13:46 ` Chao Peng [this message] 2022-04-08 13:46 ` Chao Peng 2022-04-08 17:45 ` Sean Christopherson 2022-03-10 14:09 ` [PATCH v5 06/13] KVM: Use kvm_userspace_memory_region_ext Chao Peng 2022-03-10 14:09 ` Chao Peng 2022-03-28 22:26 ` Sean Christopherson 2022-04-08 13:58 ` Chao Peng 2022-04-08 13:58 ` Chao Peng 2022-03-10 14:09 ` [PATCH v5 07/13] KVM: Add KVM_EXIT_MEMORY_ERROR exit Chao Peng 2022-03-10 14:09 ` Chao Peng 2022-03-28 22:33 ` Sean Christopherson 2022-04-08 13:59 ` Chao Peng 2022-04-08 13:59 ` Chao Peng 2022-03-10 14:09 ` [PATCH v5 08/13] KVM: Use memfile_pfn_ops to obtain pfn for private pages Chao Peng 2022-03-10 14:09 ` Chao Peng 2022-03-28 23:56 ` Sean Christopherson 2022-04-08 14:07 ` Chao Peng 2022-04-08 14:07 ` Chao Peng 2022-04-28 12:37 ` Chao Peng 2022-04-28 12:37 ` Chao Peng 2022-03-10 14:09 ` [PATCH v5 09/13] KVM: Handle page fault for private memory Chao Peng 2022-03-10 14:09 ` Chao Peng 2022-03-29 1:07 ` Sean Christopherson 2022-04-12 12:10 ` Chao Peng 2022-04-12 12:10 ` Chao Peng 2022-03-10 14:09 ` [PATCH v5 10/13] KVM: Register private memslot to memory backing store Chao Peng 2022-03-10 14:09 ` Chao Peng 2022-03-29 19:01 ` Sean Christopherson 2022-04-12 12:40 ` Chao Peng 2022-04-12 12:40 ` Chao Peng 2022-03-10 14:09 ` [PATCH v5 11/13] KVM: Zap existing KVM mappings when pages changed in the private fd Chao Peng 2022-03-10 14:09 ` Chao Peng 2022-03-29 19:23 ` Sean Christopherson 2022-04-12 12:43 ` Chao Peng 2022-04-12 12:43 ` Chao Peng 2022-04-05 23:45 ` Michael Roth 2022-04-08 3:06 ` Sean Christopherson 2022-04-19 22:43 ` Vishal Annapurve 2022-04-20 3:17 ` Chao Peng 2022-04-20 3:17 ` Chao Peng 2022-03-10 14:09 ` [PATCH v5 12/13] KVM: Expose KVM_MEM_PRIVATE Chao Peng 2022-03-10 14:09 ` Chao Peng 2022-03-29 19:13 ` Sean Christopherson 2022-04-12 12:56 ` Chao Peng 2022-04-12 12:56 ` Chao Peng 2022-03-10 14:09 ` [PATCH v5 13/13] memfd_create.2: Describe MFD_INACCESSIBLE flag Chao Peng 2022-03-10 14:09 ` Chao Peng 2022-03-24 15:51 ` [PATCH v5 00/13] KVM: mm: fd-based approach for supporting KVM guest private memory Quentin Perret 2022-03-28 17:13 ` Sean Christopherson 2022-03-28 18:00 ` Quentin Perret 2022-03-28 18:58 ` Sean Christopherson 2022-03-29 17:01 ` Quentin Perret 2022-03-30 8:58 ` Steven Price 2022-03-30 8:58 ` Steven Price 2022-03-30 10:39 ` Quentin Perret 2022-03-30 17:58 ` Sean Christopherson 2022-03-31 16:04 ` Andy Lutomirski 2022-03-31 16:04 ` Andy Lutomirski 2022-04-01 14:59 ` Quentin Perret 2022-04-01 17:14 ` Sean Christopherson 2022-04-01 18:03 ` Quentin Perret 2022-04-01 18:24 ` Sean Christopherson 2022-04-01 19:56 ` Andy Lutomirski 2022-04-01 19:56 ` Andy Lutomirski 2022-04-04 15:01 ` Quentin Perret 2022-04-04 17:06 ` Sean Christopherson 2022-04-04 22:04 ` Andy Lutomirski 2022-04-04 22:04 ` Andy Lutomirski 2022-04-05 10:36 ` Quentin Perret 2022-04-05 17:51 ` Andy Lutomirski 2022-04-05 17:51 ` Andy Lutomirski 2022-04-05 18:30 ` Sean Christopherson 2022-04-06 18:42 ` Andy Lutomirski 2022-04-06 18:42 ` Andy Lutomirski 2022-04-06 13:05 ` Quentin Perret 2022-04-05 18:03 ` Sean Christopherson 2022-04-06 10:34 ` Quentin Perret 2022-04-22 10:56 ` Chao Peng 2022-04-22 10:56 ` Chao Peng 2022-04-22 11:06 ` Paolo Bonzini 2022-04-22 11:06 ` Paolo Bonzini 2022-04-24 8:07 ` Chao Peng 2022-04-24 8:07 ` Chao Peng 2022-04-24 16:59 ` Andy Lutomirski 2022-04-24 16:59 ` Andy Lutomirski 2022-04-25 13:40 ` Chao Peng 2022-04-25 13:40 ` Chao Peng 2022-04-25 14:52 ` Andy Lutomirski 2022-04-25 14:52 ` Andy Lutomirski 2022-04-25 20:30 ` Sean Christopherson 2022-06-10 19:18 ` Andy Lutomirski 2022-06-10 19:27 ` Sean Christopherson 2022-04-28 12:29 ` Chao Peng 2022-04-28 12:29 ` Chao Peng 2022-05-03 11:12 ` Quentin Perret 2022-05-09 22:30 ` Michael Roth 2022-05-09 23:29 ` Sean Christopherson 2022-07-21 20:05 ` Gupta, Pankaj 2022-07-21 21:19 ` Sean Christopherson 2022-07-21 21:36 ` Gupta, Pankaj 2022-07-23 3:09 ` Andy Lutomirski 2022-07-25 9:19 ` Gupta, Pankaj 2022-03-30 16:18 ` Sean Christopherson 2022-03-28 20:16 ` Andy Lutomirski 2022-03-28 20:16 ` Andy Lutomirski 2022-03-28 22:48 ` Nakajima, Jun 2022-03-28 22:48 ` Nakajima, Jun 2022-03-29 0:04 ` Sean Christopherson 2022-04-08 21:35 ` Vishal Annapurve 2022-04-12 13:00 ` Chao Peng 2022-04-12 13:00 ` Chao Peng 2022-04-12 19:58 ` Kirill A. Shutemov 2022-04-12 19:58 ` Kirill A. Shutemov
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