Messages in this thread | | | Date | Tue, 27 Jun 2023 12:51:24 +0300 | From | kirill.shutemov@linux ... | Subject | Re: [PATCH v12 08/22] x86/virt/tdx: Get information about TDX module and TDX-capable memory |
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On Tue, Jun 27, 2023 at 02:12:38AM +1200, Kai Huang wrote: > static int init_tdx_module(void) > { > + struct tdsysinfo_struct *sysinfo; > + struct cmr_info *cmr_array; > + int ret; > + > + /* > + * Get the TDSYSINFO_STRUCT and CMRs from the TDX module. > + * > + * The buffers of the TDSYSINFO_STRUCT and the CMR array passed > + * to the TDX module must be 1024-bytes and 512-bytes aligned > + * respectively. Allocate one page to accommodate them both and > + * also meet those alignment requirements. > + */ > + sysinfo = (struct tdsysinfo_struct *)__get_free_page(GFP_KERNEL); > + if (!sysinfo) > + return -ENOMEM; > + cmr_array = (struct cmr_info *)((unsigned long)sysinfo + PAGE_SIZE / 2); > + > + BUILD_BUG_ON(PAGE_SIZE / 2 < TDSYSINFO_STRUCT_SIZE); > + BUILD_BUG_ON(PAGE_SIZE / 2 < sizeof(struct cmr_info) * MAX_CMRS);
This works, but why not just use slab for this? kmalloc has 512 and 1024 pools already and you won't waste memory for rounding up.
Something like this:
sysinfo = kmalloc(TDSYSINFO_STRUCT_SIZE, GFP_KERNEL); if (!sysinfo) return -ENOMEM;
cmr_array_size = sizeof(struct cmr_info) * MAX_CMRS;
/* CMR array has to be 512-aligned */ cmr_array_size = round_up(cmr_array_size, 512);
cmr_array = kmalloc(cmr_array_size, GFP_KERNEL); if (!cmr_array) { kfree(sysinfo); return -ENOMEM; }
?
-- Kiryl Shutsemau / Kirill A. Shutemov
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