[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [xen master] xen/pdx: Standardize region validation wrt pdx compression
commit 63d077ede470ae7c5ca94eb1a1fc0e6a3621d811 Author: Alejandro Vallejo <alejandro.vallejo@xxxxxxxxx> AuthorDate: Tue Aug 8 14:02:18 2023 +0100 Commit: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> CommitDate: Fri Sep 22 18:26:22 2023 +0100 xen/pdx: Standardize region validation wrt pdx compression Regions must be occasionally validated for pdx compression validity. That is, whether any of the machine addresses spanning the region have a bit set in the pdx "hole" (which is expected to always contain zeroes). There are a few such tests through the code, and they all check for different things. This patch replaces all such occurrences with a call to a centralized function that checks a region for validity. Signed-off-by: Alejandro Vallejo <alejandro.vallejo@xxxxxxxxx> Reviewed-by: Julien Grall <jgrall@xxxxxxxxxx> Reviewed-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> --- xen/arch/x86/x86_64/mm.c | 6 ++++-- xen/common/efi/boot.c | 13 ++++++++++--- xen/common/pdx.c | 10 ++++++++-- xen/include/xen/pdx.h | 9 +++++++++ 4 files changed, 31 insertions(+), 7 deletions(-) diff --git a/xen/arch/x86/x86_64/mm.c b/xen/arch/x86/x86_64/mm.c index 15b36e332d..c3ebb77714 100644 --- a/xen/arch/x86/x86_64/mm.c +++ b/xen/arch/x86/x86_64/mm.c @@ -1158,6 +1158,8 @@ static int transfer_pages_to_heap(struct mem_hotadd_info *info) static int mem_hotadd_check(unsigned long spfn, unsigned long epfn) { unsigned long s, e, length, sidx, eidx; + paddr_t mem_base = pfn_to_paddr(spfn); + unsigned long mem_npages = epfn - spfn; if ( (spfn >= epfn) ) return 0; @@ -1168,7 +1170,7 @@ static int mem_hotadd_check(unsigned long spfn, unsigned long epfn) if ( (spfn | epfn) & ((1UL << PAGETABLE_ORDER) - 1) ) return 0; - if ( (spfn | epfn) & pfn_hole_mask ) + if ( !pdx_is_region_compressible(mem_base, mem_npages) ) return 0; /* Make sure the new range is not present now */ @@ -1207,7 +1209,7 @@ static int mem_hotadd_check(unsigned long spfn, unsigned long epfn) length += (e - s) * sizeof(struct page_info); - if ((length >> PAGE_SHIFT) > (epfn - spfn)) + if ( (length >> PAGE_SHIFT) > mem_npages ) return 0; return 1; diff --git a/xen/common/efi/boot.c b/xen/common/efi/boot.c index 99cb033e2a..a1bd4c3d60 100644 --- a/xen/common/efi/boot.c +++ b/xen/common/efi/boot.c @@ -14,6 +14,7 @@ #include <xen/multiboot.h> #include <xen/param.h> #include <xen/pci_regs.h> +#include <xen/pdx.h> #include <xen/pfn.h> #if EFI_PAGE_SIZE != PAGE_SIZE # error Cannot use xen/pfn.h here! @@ -1646,9 +1647,11 @@ static __init void copy_mapping(unsigned long mfn, unsigned long end, static bool __init cf_check ram_range_valid(unsigned long smfn, unsigned long emfn) { + paddr_t ram_base = pfn_to_paddr(smfn); + unsigned long ram_npages = emfn - smfn; unsigned long sz = pfn_to_pdx(emfn - 1) / PDX_GROUP_COUNT + 1; - return !(smfn & pfn_hole_mask) && + return pdx_is_region_compressible(ram_base, ram_npages) && find_next_bit(pdx_group_valid, sz, pfn_to_pdx(smfn) / PDX_GROUP_COUNT) < sz; } @@ -1682,6 +1685,8 @@ void __init efi_init_memory(void) u64 len = desc->NumberOfPages << EFI_PAGE_SHIFT; unsigned long smfn, emfn; unsigned int prot = PAGE_HYPERVISOR_RWX; + paddr_t mem_base; + unsigned long mem_npages; printk(XENLOG_INFO " %013" PRIx64 "-%013" PRIx64 " type=%u attr=%016" PRIx64 "\n", @@ -1733,6 +1738,9 @@ void __init efi_init_memory(void) smfn = PFN_DOWN(desc->PhysicalStart); emfn = PFN_UP(desc->PhysicalStart + len); + mem_base = pfn_to_paddr(smfn); + mem_npages = emfn - smfn; + if ( desc->Attribute & EFI_MEMORY_WB ) prot |= _PAGE_WB; else if ( desc->Attribute & EFI_MEMORY_WT ) @@ -1760,8 +1768,7 @@ void __init efi_init_memory(void) prot |= _PAGE_NX; if ( pfn_to_pdx(emfn - 1) < (DIRECTMAP_SIZE >> PAGE_SHIFT) && - !(smfn & pfn_hole_mask) && - !((smfn ^ (emfn - 1)) & ~pfn_pdx_bottom_mask) ) + pdx_is_region_compressible(mem_base, mem_npages) ) { if ( (unsigned long)mfn_to_virt(emfn - 1) >= HYPERVISOR_VIRT_END ) prot &= ~_PAGE_GLOBAL; diff --git a/xen/common/pdx.c b/xen/common/pdx.c index 99d4a90a50..3c88ceeb9c 100644 --- a/xen/common/pdx.c +++ b/xen/common/pdx.c @@ -88,7 +88,7 @@ bool __mfn_valid(unsigned long mfn) } /* Sets all bits from the most-significant 1-bit down to the LSB */ -static uint64_t __init fill_mask(uint64_t mask) +static uint64_t fill_mask(uint64_t mask) { while (mask & (mask + 1)) mask |= mask + 1; @@ -96,6 +96,12 @@ static uint64_t __init fill_mask(uint64_t mask) return mask; } +bool pdx_is_region_compressible(paddr_t base, unsigned long npages) +{ + return !(paddr_to_pfn(base) & pfn_hole_mask) && + !(pdx_region_mask(base, npages * PAGE_SIZE) & ~ma_va_bottom_mask); +} + /* We don't want to compress the low MAX_ORDER bits of the addresses. */ uint64_t __init pdx_init_mask(uint64_t base_addr) { @@ -103,7 +109,7 @@ uint64_t __init pdx_init_mask(uint64_t base_addr) (uint64_t)1 << (MAX_ORDER + PAGE_SHIFT)) - 1); } -uint64_t __init pdx_region_mask(uint64_t base, uint64_t len) +uint64_t pdx_region_mask(uint64_t base, uint64_t len) { /* * We say a bit "moves" in a range if there exist 2 addresses in that diff --git a/xen/include/xen/pdx.h b/xen/include/xen/pdx.h index 6276b685e2..c1b18a2138 100644 --- a/xen/include/xen/pdx.h +++ b/xen/include/xen/pdx.h @@ -79,6 +79,15 @@ extern unsigned long pfn_top_mask, ma_top_mask; (sizeof(*frame_table) & -sizeof(*frame_table))) extern unsigned long pdx_group_valid[]; +/** + * Validate a region's compatibility with the current compression runtime + * + * @param base Base address of the region + * @param npages Number of PAGE_SIZE-sized pages in the region + * @return True iff the region can be used with the current compression + */ +bool pdx_is_region_compressible(paddr_t base, unsigned long npages); + /** * Calculates a mask covering "moving" bits of all addresses of a region * -- generated by git-patchbot for /home/xen/git/xen.git#master
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