kernel.git/arch/s390/kernel/uv.c, branch linux-5.18.y

s390/uv: fix memblock virtual vs physical address confusion

2021-12-16T18:58:07Z

memblock_alloc_try_nid() returns a virtual address, however in error case the allocated memory is incorrectly freed with memblock_phys_free(). Properly use memblock_free() instead, and pass a physical address to uv_init() to fix this. Note: this doesn't fix a bug currently, since virtual and physical addresses are identical. Reviewed-by: Alexander Gordeev Signed-off-by: Heiko Carstens

Merge branch 'akpm' (patches from Andrew)

2021-11-06T21:08:17Z

Merge misc updates from Andrew Morton: "257 patches. Subsystems affected by this patch series: scripts, ocfs2, vfs, and mm (slab-generic, slab, slub, kconfig, dax, kasan, debug, pagecache, gup, swap, memcg, pagemap, mprotect, mremap, iomap, tracing, vmalloc, pagealloc, memory-failure, hugetlb, userfaultfd, vmscan, tools, memblock, oom-kill, hugetlbfs, migration, thp, readahead, nommu, ksm, vmstat, madvise, memory-hotplug, rmap, zsmalloc, highmem, zram, cleanups, kfence, and damon)" * emailed patches from Andrew Morton : (257 commits) mm/damon: remove return value from before_terminate callback mm/damon: fix a few spelling mistakes in comments and a pr_debug message mm/damon: simplify stop mechanism Docs/admin-guide/mm/pagemap: wordsmith page flags descriptions Docs/admin-guide/mm/damon/start: simplify the content Docs/admin-guide/mm/damon/start: fix a wrong link Docs/admin-guide/mm/damon/start: fix wrong example commands mm/damon/dbgfs: add adaptive_targets list check before enable monitor_on mm/damon: remove unnecessary variable initialization Documentation/admin-guide/mm/damon: add a document for DAMON_RECLAIM mm/damon: introduce DAMON-based Reclamation (DAMON_RECLAIM) selftests/damon: support watermarks mm/damon/dbgfs: support watermarks mm/damon/schemes: activate schemes based on a watermarks mechanism tools/selftests/damon: update for regions prioritization of schemes mm/damon/dbgfs: support prioritization weights mm/damon/vaddr,paddr: support pageout prioritization mm/damon/schemes: prioritize regions within the quotas mm/damon/selftests: support schemes quotas mm/damon/dbgfs: support quotas of schemes ...

memblock: rename memblock_free to memblock_phys_free

2021-11-06T20:30:41Z

Since memblock_free() operates on a physical range, make its name reflect it and rename it to memblock_phys_free(), so it will be a logical counterpart to memblock_phys_alloc(). The callers are updated with the below semantic patch: @@ expression addr; expression size; @@ - memblock_free(addr, size); + memblock_phys_free(addr, size); Link: https://lkml.kernel.org/r/20210930185031.18648-6-rppt@kernel.org Signed-off-by: Mike Rapoport Cc: Christophe Leroy Cc: Juergen Gross Cc: Shahab Vahedi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

KVM: s390: pv: properly handle page flags for protected guests

2021-10-27T05:55:53Z

Introduce variants of the convert and destroy page functions that also clear the PG_arch_1 bit used to mark them as secure pages. The PG_arch_1 flag is always allowed to overindicate; using the new functions introduced here allows to reduce the extent of overindication and thus improve performance. These new functions can only be called on pages for which a reference is already being held. Signed-off-by: Claudio Imbrenda Reviewed-by: Janosch Frank Reviewed-by: Christian Borntraeger Link: https://lore.kernel.org/r/20210920132502.36111-7-imbrenda@linux.ibm.com Signed-off-by: Christian Borntraeger

KVM: s390: pv: avoid stalls when making pages secure

2021-10-25T07:20:39Z

Improve make_secure_pte to avoid stalls when the system is heavily overcommitted. This was especially problematic in kvm_s390_pv_unpack, because of the loop over all pages that needed unpacking. Due to the locks being held, it was not possible to simply replace uv_call with uv_call_sched. A more complex approach was needed, in which uv_call is replaced with __uv_call, which does not loop. When the UVC needs to be executed again, -EAGAIN is returned, and the caller (or its caller) will try again. When -EAGAIN is returned, the path is the same as when the page is in writeback (and the writeback check is also performed, which is harmless). Fixes: 214d9bbcd3a672 ("s390/mm: provide memory management functions for protected KVM guests") Signed-off-by: Claudio Imbrenda Reviewed-by: Janosch Frank Reviewed-by: Christian Borntraeger Link: https://lore.kernel.org/r/20210920132502.36111-5-imbrenda@linux.ibm.com Signed-off-by: Christian Borntraeger

s390/uv: fully validate the VMA before calling follow_page()

2021-10-25T07:20:38Z

We should not walk/touch page tables outside of VMA boundaries when holding only the mmap sem in read mode. Evil user space can modify the VMA layout just before this function runs and e.g., trigger races with page table removal code since commit dd2283f2605e ("mm: mmap: zap pages with read mmap_sem in munmap"). find_vma() does not check if the address is >= the VMA start address; use vma_lookup() instead. Fixes: 214d9bbcd3a6 ("s390/mm: provide memory management functions for protected KVM guests") Signed-off-by: David Hildenbrand Reviewed-by: Claudio Imbrenda Acked-by: Heiko Carstens Reviewed-by: Liam R. Howlett Link: https://lore.kernel.org/r/20210909162248.14969-6-david@redhat.com Signed-off-by: Christian Borntraeger

s390/uv: de-duplicate checks for Protected Host Virtualization

2021-07-27T07:39:14Z

De-duplicate checks for Protected Host Virtualization in decompressor and kernel. Set prot_virt_host=0 in the decompressor in *any* of the following cases and hand it over to the decompressed kernel: * No explicit prot_virt=1 is given on the kernel command-line * Protected Guest Virtualization is enabled * Hardware support not present * kdump or stand-alone dump The decompressed kernel needs to use only is_prot_virt_host() instead of performing again all checks done by the decompressor. Signed-off-by: Alexander Egorenkov Reviewed-by: Vasily Gorbik Signed-off-by: Heiko Carstens

s390: mm: Fix secure storage access exception handling

2021-07-05T10:44:23Z

Turns out that the bit 61 in the TEID is not always 1 and if that's the case the address space ID and the address are unpredictable. Without an address and its address space ID we can't export memory and hence we can only send a SIGSEGV to the process or panic the kernel depending on who caused the exception. Unfortunately bit 61 is only reliable if we have the "misc" UV feature bit. Signed-off-by: Janosch Frank Reviewed-by: Christian Borntraeger Fixes: 084ea4d611a3d ("s390/mm: add (non)secure page access exceptions handlers") Cc: stable@vger.kernel.org Signed-off-by: Vasily Gorbik

s390: setup kernel memory layout early

2021-06-18T14:41:19Z

Currently there are two separate places where kernel memory layout has to be known and adjusted: 1. early kasan setup. 2. paging setup later. Those 2 places had to be kept in sync and adjusted to reflect peculiar technical details of one another. With additional factors which influence kernel memory layout like ultravisor secure storage limit, complexity of keeping two things in sync grew up even more. Besides that if we look forward towards creating identity mapping and enabling DAT before jumping into uncompressed kernel - that would also require full knowledge of and control over kernel memory layout. So, de-duplicate and move kernel memory layout setup logic into the decompressor. Reviewed-by: Alexander Gordeev Signed-off-by: Vasily Gorbik

s390/protvirt: fix error return code in uv_info_init()

2021-04-12T10:46:41Z

Fix to return a negative error code from the error handling case instead of 0, as done elsewhere in this function. Reported-by: Hulk Robot Signed-off-by: Baisong Zhong Fixes: 37564ed834ac ("s390/uv: add prot virt guest/host indication files") Link: https://lore.kernel.org/r/2f7d62a4-3e75-b2b4-951b-75ef8ef59d16@huawei.com Signed-off-by: Heiko Carstens