search for: subblock_size

...> > can overflow. Rather than try to catch all instances of that, > > let's tweak block size to 64 bit. > > I fail to see where we could actually trigger an overflow. The reported > warning looked like a false positive to me. So const uint64_t size = count * vm->subblock_size; is it unreasonable for count to be 4K with subblock_size being 1M? > > > > It ripples through UAPI which is an ABI change, but it's not too late to > > make it, and it will allow supporting >4Gbyte blocks while might > > become necessary down the road. > >...

...> > can overflow. Rather than try to catch all instances of that, > > let's tweak block size to 64 bit. > > I fail to see where we could actually trigger an overflow. The reported > warning looked like a false positive to me. So const uint64_t size = count * vm->subblock_size; is it unreasonable for count to be 4K with subblock_size being 1M? > > > > It ripples through UAPI which is an ABI change, but it's not too late to > > make it, and it will allow supporting >4Gbyte blocks while might > > become necessary down the road. > >...

...). */ - uint32_t device_block_size; + uint64_t device_block_size; /* The translated node id. NUMA_NO_NODE in case not specified. */ int nid; /* Physical start address of the memory region. */ @@ -86,7 +86,7 @@ struct virtio_mem { uint64_t region_size; /* The subblock size. */ - uint32_t subblock_size; + uint64_t subblock_size; /* The number of subblocks per memory block. */ uint32_t nb_sb_per_mb; @@ -1698,9 +1698,9 @@ static int virtio_mem_init(struct virtio_mem *vm) * - At least the device block size. * In the worst case, a single subblock per memory block. */ - vm->subblock_...

...). */ - uint32_t device_block_size; + uint64_t device_block_size; /* The translated node id. NUMA_NO_NODE in case not specified. */ int nid; /* Physical start address of the memory region. */ @@ -86,7 +86,7 @@ struct virtio_mem { uint64_t region_size; /* The subblock size. */ - uint32_t subblock_size; + uint64_t subblock_size; /* The number of subblocks per memory block. */ uint32_t nb_sb_per_mb; @@ -1698,9 +1698,9 @@ static int virtio_mem_init(struct virtio_mem *vm) * - At least the device block size. * In the worst case, a single subblock per memory block. */ - vm->subblock_...

...nt64_t device_block_size; > /* The translated node id. NUMA_NO_NODE in case not specified. */ > int nid; > /* Physical start address of the memory region. */ > @@ -86,7 +86,7 @@ struct virtio_mem { > uint64_t region_size; > > /* The subblock size. */ > - uint32_t subblock_size; > + uint64_t subblock_size; > /* The number of subblocks per memory block. */ > uint32_t nb_sb_per_mb; > > @@ -1698,9 +1698,9 @@ static int virtio_mem_init(struct virtio_mem *vm) > * - At least the device block size. > * In the worst case, a single subblock per mem...

On Mon 02-03-20 14:49:37, David Hildenbrand wrote: [...] > +static void virtio_mem_notify_going_offline(struct virtio_mem *vm, > + unsigned long mb_id) > +{ > + const unsigned long nr_pages = PFN_DOWN(vm->subblock_size); > + unsigned long pfn; > + int sb_id, i; > + > + for (sb_id = 0; sb_id < vm->nb_sb_per_mb; sb_id++) { > + if (virtio_mem_mb_test_sb_plugged(vm, mb_id, sb_id, 1)) > + continue; > + /* > + * Drop our reference to the pages so the memory can get > + * offline...

On Mon 02-03-20 14:49:37, David Hildenbrand wrote: [...] > +static void virtio_mem_notify_going_offline(struct virtio_mem *vm, > + unsigned long mb_id) > +{ > + const unsigned long nr_pages = PFN_DOWN(vm->subblock_size); > + unsigned long pfn; > + int sb_id, i; > + > + for (sb_id = 0; sb_id < vm->nb_sb_per_mb; sb_id++) { > + if (virtio_mem_mb_test_sb_plugged(vm, mb_id, sb_id, 1)) > + continue; > + /* > + * Drop our reference to the pages so the memory can get > + * offline...

...y to catch all instances of that, >>> let's tweak block size to 64 bit. >> >> I fail to see where we could actually trigger an overflow. The reported >> warning looked like a false positive to me. > > > So > > const uint64_t size = count * vm->subblock_size; > > is it unreasonable for count to be 4K with subblock_size being 1M? virtio_mem_mb_plug_sb() and friends are only called on subblocks residing within a single Linux memory block. (currently, 128MB .. 2G on x86-64). A subblock on x86-64 is currently at least 4MB. So "count * vm->...

...+1717,8 @@ static int virtio_mem_init(struct virtio_mem *vm) (unsigned long long)vm->device_block_size); dev_info(&vm->vdev->dev, "memory block size: 0x%lx", memory_block_size_bytes()); - dev_info(&vm->vdev->dev, "subblock size: 0x%x", - vm->subblock_size); + dev_info(&vm->vdev->dev, "subblock size: 0x%llx", + (unsigned long long)vm->subblock_size); if (vm->nid != NUMA_NO_NODE) dev_info(&vm->vdev->dev, "nid: %d", vm->nid); -- MST

...al Hocko wrote: > > On Mon 02-03-20 14:49:37, David Hildenbrand wrote: > > [...] > >> +static void virtio_mem_notify_going_offline(struct virtio_mem *vm, > >> + unsigned long mb_id) > >> +{ > >> + const unsigned long nr_pages = PFN_DOWN(vm->subblock_size); > >> + unsigned long pfn; > >> + int sb_id, i; > >> + > >> + for (sb_id = 0; sb_id < vm->nb_sb_per_mb; sb_id++) { > >> + if (virtio_mem_mb_test_sb_plugged(vm, mb_id, sb_id, 1)) > >> + continue; > >> + /* > >> + *...

...tio/virtio_mem.c @@ -570,6 +570,53 @@ static void virtio_mem_notify_online(struct virtio_mem *vm, unsigned long mb_id, virtio_mem_retry(vm); } +static void virtio_mem_notify_going_offline(struct virtio_mem *vm, + unsigned long mb_id) +{ + const unsigned long nr_pages = PFN_DOWN(vm->subblock_size); + unsigned long pfn; + int sb_id, i; + + for (sb_id = 0; sb_id < vm->nb_sb_per_mb; sb_id++) { + if (virtio_mem_mb_test_sb_plugged(vm, mb_id, sb_id, 1)) + continue; + /* + * Drop our reference to the pages so the memory can get + * offlined and add the unplugged pages to the managed...

...ested_size; + + /* The device block size (for communicating with the device). */ + uint32_t device_block_size; + /* The translated node id. NUMA_NO_NODE in case not specified. */ + int nid; + /* Physical start address of the memory region. */ + uint64_t addr; + + /* The subblock size. */ + uint32_t subblock_size; + /* The number of subblocks per memory block. */ + uint32_t nb_sb_per_mb; + + /* Id of the first memory block of this device. */ + unsigned long first_mb_id; + /* Id of the last memory block of this device. */ + unsigned long last_mb_id; + /* Id of the last usable memory block of this device. */...

This series is based on v5.7-rc4. The patches are located at: https://github.com/davidhildenbrand/linux.git virtio-mem-v4 This is basically a resend of v3 [1], now based on v5.7-rc4 and restested. One patch was reshuffled and two ACKs I missed to add were added. The rebase did not require any modifications to patches. Details about virtio-mem can be found in the cover letter of v2 [2]. A

On 10.03.20 12:43, Michal Hocko wrote: > On Mon 02-03-20 14:49:37, David Hildenbrand wrote: > [...] >> +static void virtio_mem_notify_going_offline(struct virtio_mem *vm, >> + unsigned long mb_id) >> +{ >> + const unsigned long nr_pages = PFN_DOWN(vm->subblock_size); >> + unsigned long pfn; >> + int sb_id, i; >> + >> + for (sb_id = 0; sb_id < vm->nb_sb_per_mb; sb_id++) { >> + if (virtio_mem_mb_test_sb_plugged(vm, mb_id, sb_id, 1)) >> + continue; >> + /* >> + * Drop our reference to the pages so the m...

...used. rc = virtio_mem_init_vq(vm); ^ >> drivers/virtio/virtio_mem.c:801:22: warning: int result is assigned to long variable. If the variable is long to avoid loss of information, then you have loss of information. [truncLongCastAssignment] const uint64_t size = count * vm->subblock_size; ^ drivers/virtio/virtio_mem.c:822:22: warning: int result is assigned to long variable. If the variable is long to avoid loss of information, then you have loss of information. [truncLongCastAssignment] const uint64_t size = count * vm->subblock_size;...

This series is based on latest linux-next. The patches are located at: https://github.com/davidhildenbrand/linux.git virtio-mem-v3 Patch #1 - #10 where contained in v2 and only contain minor modifications (mostly smaller fixes). The remaining patches are new and contain smaller optimizations. Details about virtio-mem can be found in the cover letter of v2 [1]. A basic QEMU implementation was

This series is based on latest linux-next. The patches are located at: https://github.com/davidhildenbrand/linux.git virtio-mem-v3 Patch #1 - #10 where contained in v2 and only contain minor modifications (mostly smaller fixes). The remaining patches are new and contain smaller optimizations. Details about virtio-mem can be found in the cover letter of v2 [1]. A basic QEMU implementation was

This series is based on latest linux-next. The patches are located at: https://github.com/davidhildenbrand/linux.git virtio-mem-rfc-v4 The basic idea of virtio-mem is to provide a flexible, cross-architecture memory hot(un)plug solution that avoids many limitations imposed by existing technologies, architectures, and interfaces. More details can be found below and in linked material. This

This series is based on latest linux-next. The patches are located at: https://github.com/davidhildenbrand/linux.git virtio-mem-rfc-v4 The basic idea of virtio-mem is to provide a flexible, cross-architecture memory hot(un)plug solution that avoids many limitations imposed by existing technologies, architectures, and interfaces. More details can be found below and in linked material. This

This series is based on latest linux-next. The patches are located at: https://github.com/davidhildenbrand/linux.git virtio-mem-v2 I now have acks for all !virtio-mem changes. I'll be happy to get review feedback, testing reports, etc. for the virtio-mem changes. If there are no further comments, I guess this is good to go as a v1 soon. The basic idea of virtio-mem is to provide a