As the last step of constructing TDMRs, create reserved area information for the memory region holes in each TDMR. If any PAMT (or part of it) resides within a particular TDMR, also it as reserved. All reserved areas in each TDMR must be in address ascending order, required by TDX architecture. Signed-off-by: Kai Huang <kai.huang@xxxxxxxxx> --- arch/x86/virt/vmx/tdx.c | 148 +++++++++++++++++++++++++++++++++++++++- 1 file changed, 146 insertions(+), 2 deletions(-) diff --git a/arch/x86/virt/vmx/tdx.c b/arch/x86/virt/vmx/tdx.c index c58c99b94c72..f6345af29414 100644 --- a/arch/x86/virt/vmx/tdx.c +++ b/arch/x86/virt/vmx/tdx.c @@ -15,6 +15,7 @@ #include <linux/atomic.h> #include <linux/slab.h> #include <linux/math.h> +#include <linux/sort.h> #include <asm/msr-index.h> #include <asm/msr.h> #include <asm/cpufeature.h> @@ -1108,6 +1109,145 @@ static int tdmrs_setup_pamt_all(struct tdmr_info **tdmr_array, int tdmr_num) return -ENOMEM; } +static int tdmr_add_rsvd_area(struct tdmr_info *tdmr, int *p_idx, + u64 addr, u64 size) +{ + struct tdmr_reserved_area *rsvd_areas = tdmr->reserved_areas; + int idx = *p_idx; + + /* Reserved area must be 4K aligned in offset and size */ + if (WARN_ON(addr & ~PAGE_MASK || size & ~PAGE_MASK)) + return -EINVAL; + + /* Cannot exceed maximum reserved areas supported by TDX */ + if (idx >= tdx_sysinfo.max_reserved_per_tdmr) + return -E2BIG; + + rsvd_areas[idx].offset = addr - tdmr->base; + rsvd_areas[idx].size = size; + + *p_idx = idx + 1; + + return 0; +} + +/* Compare function called by sort() for TDMR reserved areas */ +static int rsvd_area_cmp_func(const void *a, const void *b) +{ + struct tdmr_reserved_area *r1 = (struct tdmr_reserved_area *)a; + struct tdmr_reserved_area *r2 = (struct tdmr_reserved_area *)b; + + if (r1->offset + r1->size <= r2->offset) + return -1; + if (r1->offset >= r2->offset + r2->size) + return 1; + + /* Reserved areas cannot overlap. Caller should guarantee. */ + WARN_ON(1); + return -1; +} + +/* Set up reserved areas for a TDMR, including memory holes and PAMTs */ +static int tdmr_setup_rsvd_areas(struct tdmr_info *tdmr, + struct tdmr_info **tdmr_array, + int tdmr_num) +{ + u64 start, end, prev_end; + int rsvd_idx, i, ret = 0; + + /* Mark holes between e820 RAM entries as reserved */ + rsvd_idx = 0; + prev_end = TDMR_START(tdmr); + e820_for_each_mem(i, start, end) { + /* Break if this entry is after the TDMR */ + if (start >= TDMR_END(tdmr)) + break; + + /* Exclude entries before this TDMR */ + if (end < TDMR_START(tdmr)) + continue; + + /* + * Skip if no hole exists before this entry. "<=" is + * used because one e820 entry might span two TDMRs. + * In that case the start address of this entry is + * smaller then the start address of the second TDMR. + */ + if (start <= prev_end) { + prev_end = end; + continue; + } + + /* Add the hole before this e820 entry */ + ret = tdmr_add_rsvd_area(tdmr, &rsvd_idx, prev_end, + start - prev_end); + if (ret) + return ret; + + prev_end = end; + } + + /* Add the hole after the last RAM entry if it exists. */ + if (prev_end < TDMR_END(tdmr)) { + ret = tdmr_add_rsvd_area(tdmr, &rsvd_idx, prev_end, + TDMR_END(tdmr) - prev_end); + if (ret) + return ret; + } + + /* + * Walk over all TDMRs to find out whether any PAMT falls into + * the given TDMR. If yes, mark it as reserved too. + */ + for (i = 0; i < tdmr_num; i++) { + struct tdmr_info *tmp = tdmr_array[i]; + u64 pamt_start, pamt_end; + + pamt_start = tmp->pamt_4k_base; + pamt_end = pamt_start + tmp->pamt_4k_size + + tmp->pamt_2m_size + tmp->pamt_1g_size; + + /* Skip PAMTs outside of the given TDMR */ + if ((pamt_end <= TDMR_START(tdmr)) || + (pamt_start >= TDMR_END(tdmr))) + continue; + + /* Only mark the part within the TDMR as reserved */ + if (pamt_start < TDMR_START(tdmr)) + pamt_start = TDMR_START(tdmr); + if (pamt_end > TDMR_END(tdmr)) + pamt_end = TDMR_END(tdmr); + + ret = tdmr_add_rsvd_area(tdmr, &rsvd_idx, pamt_start, + pamt_end - pamt_start); + if (ret) + return ret; + } + + /* TDX requires reserved areas listed in address ascending order */ + sort(tdmr->reserved_areas, rsvd_idx, sizeof(struct tdmr_reserved_area), + rsvd_area_cmp_func, NULL); + + return 0; +} + +static int tdmrs_setup_rsvd_areas_all(struct tdmr_info **tdmr_array, + int tdmr_num) +{ + int i; + + for (i = 0; i < tdmr_num; i++) { + int ret; + + ret = tdmr_setup_rsvd_areas(tdmr_array[i], tdmr_array, + tdmr_num); + if (ret) + return ret; + } + + return 0; +} + static int construct_tdmrs(struct tdmr_info **tdmr_array, int *tdmr_num) { int ret; @@ -1124,8 +1264,12 @@ static int construct_tdmrs(struct tdmr_info **tdmr_array, int *tdmr_num) if (ret) goto err_free_tdmrs; - /* Return -EFAULT until constructing TDMRs is done */ - ret = -EFAULT; + ret = tdmrs_setup_rsvd_areas_all(tdmr_array, *tdmr_num); + if (ret) + goto err_free_pamts; + + return 0; +err_free_pamts: tdmrs_free_pamt_all(tdmr_array, *tdmr_num); err_free_tdmrs: free_tdmrs(tdmr_array, *tdmr_num); -- 2.35.1