Messages in this thread Patch in this message | | | Date | Fri, 15 Oct 2021 16:33:32 +0300 | Subject | Re: [PATCH v3 1/4] nitro_enclaves: Merge contiguous physical memory regions | From | "Paraschiv, Andra-Irina" <> |
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On 09/10/2021 04:32, Longpeng(Mike) wrote: > > From: Longpeng <longpeng2@huawei.com> > > There can be cases when there are more memory regions that need to be > set for an enclave than the maximum supported number of memory regions > per enclave. One example can be when the memory regions are backed by 2 > MiB hugepages (the minimum supported hugepage size). > > Let's merge the adjacent regions if they are physical contiguous. This
physical contiguous => physically contiguous
> way the final number of memory regions is less than before merging and > could potentially avoid reaching maximum. > > Signed-off-by: Longpeng <longpeng2@huawei.com> > --- > Changes v2 -> v3: > - update the commit title and commit message. [Andra] > - use 'struct range' to instead of 'struct phys_mem_region'. [Andra, Greg KH] > - add comments before the function definition. [Andra] > - rename several variables, parameters and function. [Andra] > --- > drivers/virt/nitro_enclaves/ne_misc_dev.c | 79 +++++++++++++++++++++---------- > 1 file changed, 55 insertions(+), 24 deletions(-) > > diff --git a/drivers/virt/nitro_enclaves/ne_misc_dev.c b/drivers/virt/nitro_enclaves/ne_misc_dev.c > index e21e1e8..eea53e9 100644 > --- a/drivers/virt/nitro_enclaves/ne_misc_dev.c > +++ b/drivers/virt/nitro_enclaves/ne_misc_dev.c > @@ -26,6 +26,7 @@ > #include <linux/poll.h> > #include <linux/slab.h> > #include <linux/types.h> > +#include <linux/range.h>
Please keep the alphabetical order and move this before "#include <linux/slab.h>."
> #include <uapi/linux/vm_sockets.h> > > #include "ne_misc_dev.h" > @@ -126,6 +127,16 @@ struct ne_cpu_pool { > static struct ne_cpu_pool ne_cpu_pool; > > /** > + * struct phys_contig_mem_regions - Physical contiguous memory regions
Physical contiguous memory regions => Contiguous physical memory regions
> + * @num: The number of regions that currently has. > + * @region: The array of physical memory regions. > + */ > +struct phys_contig_mem_regions { > + unsigned long num; > + struct range region[0];
Should use "struct range *regions" instead, to keep a similar style with regard to arrays throughout the code.
Please align the fields name (e.g. [1]) so that it's easier to distinguish between fields type and name.
Let's also prefix with "ne" the data structure naming e.g. ne_phys_contig_mem_regions. So that is similar to other data structures defined in the NE kernel driver codebase.
[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/virt/nitro_enclaves/ne_misc_dev.c#n118
> +}; > + > +/** > * ne_check_enclaves_created() - Verify if at least one enclave has been created. > * @void: No parameters provided. > * > @@ -825,6 +836,33 @@ static int ne_sanity_check_user_mem_region_page(struct ne_enclave *ne_enclave, > } > > /** > + * ne_merge_phys_contig_memory_regions() - Add a memory region and merge the adjacent > + * regions if they are physical contiguous.
physical contiguous => physically contiguous
> + * @regions : Private data associated with the physical contiguous memory regions.
physical contiguous memory regions => contiguous physical memory regions
@regions => @phys_contig_regions
> + * @page_paddr: Physical start address of the region to be added. > + * @page_size : Length of the region to be added. > + * > + * Return: > + * * No return value.
Please add "Context: Process context. This function is called with the ne_enclave mutex held." before "Return", similar to other defined functions.
Can remove these lines, as for now there is no return value:
* Return: * * No return value.
And then can add this in the second patch in the series:
* Context: Process context. This function is called with the ne_enclave mutex held. (note: already available in the first patch) * Return: (note: added in the second patch) * * 0 ...
> + */ > +static void > +ne_merge_phys_contig_memory_regions(struct phys_contig_mem_regions *regions, > + u64 page_paddr, u64 page_size)
phys_contig_mem_regions => ne_phys_contig_mem_regions *regions => *phys_contig_regions
Can define something like this:
unsigned long num = phys_contig_regions->num;
and then use it inside the function, except the last line that increments the num.
> +{ > + /* Physical contiguous, just merge */
Physical contiguous => Physically contiguous
> + if (regions->num && > + (regions->region[regions->num - 1].end + 1) == page_paddr) {
e.g. phys_contig_regions->regions[num - 1]
> + regions->region[regions->num - 1].end += page_size; > + > + return; > + } > + > + regions->region[regions->num].start = page_paddr; > + regions->region[regions->num].end = page_paddr + page_size - 1; > + regions->num++; > +} > + > +/** > * ne_set_user_memory_region_ioctl() - Add user space memory region to the slot > * associated with the current enclave. > * @ne_enclave : Private data associated with the current enclave. > @@ -843,9 +881,9 @@ static int ne_set_user_memory_region_ioctl(struct ne_enclave *ne_enclave, > unsigned long max_nr_pages = 0; > unsigned long memory_size = 0; > struct ne_mem_region *ne_mem_region = NULL; > - unsigned long nr_phys_contig_mem_regions = 0; > struct pci_dev *pdev = ne_devs.ne_pci_dev->pdev; > - struct page **phys_contig_mem_regions = NULL; > + struct phys_contig_mem_regions *phys_contig_mem_regions = NULL;
struct phys_contig_mem_regions *phys_contig_mem_regions = NULL; => struct ne_phys_contig_mem_regions phys_contig_mem_regions = {};
> + size_t size_to_alloc = 0; > int rc = -EINVAL; > > rc = ne_sanity_check_user_mem_region(ne_enclave, mem_region); > @@ -866,8 +904,9 @@ static int ne_set_user_memory_region_ioctl(struct ne_enclave *ne_enclave, > goto free_mem_region; > } > > - phys_contig_mem_regions = kcalloc(max_nr_pages, sizeof(*phys_contig_mem_regions), > - GFP_KERNEL); > + size_to_alloc = sizeof(*phys_contig_mem_regions) + > + max_nr_pages * sizeof(struct range); > + phys_contig_mem_regions = kzalloc(size_to_alloc, GFP_KERNEL);
Then can alloc memory for the regions field.
phys_contig_mem_regions.regions = kcalloc(max_nr_pages, sizeof(*phys_contig_mem_regions.regions), GFP_KERNEL);
The "size_of_alloc" will not be needed in this case.
> if (!phys_contig_mem_regions) { > rc = -ENOMEM; > > @@ -901,26 +940,16 @@ static int ne_set_user_memory_region_ioctl(struct ne_enclave *ne_enclave, > if (rc < 0) > goto put_pages; > > - /* > - * TODO: Update once handled non-contiguous memory regions > - * received from user space or contiguous physical memory regions > - * larger than 2 MiB e.g. 8 MiB. > - */ > - phys_contig_mem_regions[i] = ne_mem_region->pages[i]; > + ne_merge_phys_contig_memory_regions(phys_contig_mem_regions,
And can pass it here like this: &phys_contig_mem_regions.
> + page_to_phys(ne_mem_region->pages[i]), > + page_size(ne_mem_region->pages[i])); > > memory_size += page_size(ne_mem_region->pages[i]); > > ne_mem_region->nr_pages++; > } while (memory_size < mem_region.memory_size); > > - /* > - * TODO: Update once handled non-contiguous memory regions received > - * from user space or contiguous physical memory regions larger than > - * 2 MiB e.g. 8 MiB. > - */ > - nr_phys_contig_mem_regions = ne_mem_region->nr_pages; > - > - if ((ne_enclave->nr_mem_regions + nr_phys_contig_mem_regions) > > + if ((ne_enclave->nr_mem_regions + phys_contig_mem_regions->num) > > ne_enclave->max_mem_regions) { > dev_err_ratelimited(ne_misc_dev.this_device, > "Reached max memory regions %lld\n", > @@ -931,9 +960,10 @@ static int ne_set_user_memory_region_ioctl(struct ne_enclave *ne_enclave, > goto put_pages; > } > > - for (i = 0; i < nr_phys_contig_mem_regions; i++) { > - u64 phys_region_addr = page_to_phys(phys_contig_mem_regions[i]); > - u64 phys_region_size = page_size(phys_contig_mem_regions[i]); > + for (i = 0; i < phys_contig_mem_regions->num; i++) { > + struct range *range = phys_contig_mem_regions->region + i; > + u64 phys_region_addr = range->start; > + u64 phys_region_size = range_len(range);
With the updated data structure field, could be:
u64 phys_region_addr = phys_contig_mem_regions.regions[i].start; u64 phys_region_size = range_len(&phys_contig_mem_regions.regions[i]);
> > if (phys_region_size & (NE_MIN_MEM_REGION_SIZE - 1)) { > dev_err_ratelimited(ne_misc_dev.this_device, > @@ -959,13 +989,14 @@ static int ne_set_user_memory_region_ioctl(struct ne_enclave *ne_enclave, > > list_add(&ne_mem_region->mem_region_list_entry, &ne_enclave->mem_regions_list); > > - for (i = 0; i < nr_phys_contig_mem_regions; i++) { > + for (i = 0; i < phys_contig_mem_regions->num; i++) { > struct ne_pci_dev_cmd_reply cmd_reply = {}; > struct slot_add_mem_req slot_add_mem_req = {}; > + struct range *range = phys_contig_mem_regions->region + i; > > slot_add_mem_req.slot_uid = ne_enclave->slot_uid; > - slot_add_mem_req.paddr = page_to_phys(phys_contig_mem_regions[i]); > - slot_add_mem_req.size = page_size(phys_contig_mem_regions[i]); > + slot_add_mem_req.paddr = range->start; > + slot_add_mem_req.size = range_len(range);
Similarly here:
slot_add_mem_req.paddr = phys_contig_mem_regions.regions[i].start; slot_add_mem_req.size = range_len(&phys_contig_mem_regions.regions[i]);
Then remain the kfree paths for "phys_contig_mem_regions.regions" instead of "phys_contig_mem_regions".
Thanks, Andra
> > rc = ne_do_request(pdev, SLOT_ADD_MEM, > &slot_add_mem_req, sizeof(slot_add_mem_req), > -- > 1.8.3.1 >
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