kernel.git/arch/s390/kernel/uv.c, branch linux-6.4.y

KVM: s390: fix race in gmap_make_secure()

2023-05-04T16:26:27Z

Fix a potential race in gmap_make_secure() and remove the last user of follow_page() without FOLL_GET. The old code is locking something it doesn't have a reference to, and as explained by Jason and David in this discussion: https://lore.kernel.org/linux-mm/Y9J4P%2FRNvY1Ztn0Q@nvidia.com/ it can lead to all kind of bad things, including the page getting unmapped (MADV_DONTNEED), freed, reallocated as a larger folio and the unlock_page() would target the wrong bit. There is also another race with the FOLL_WRITE, which could race between the follow_page() and the get_locked_pte(). The main point is to remove the last use of follow_page() without FOLL_GET or FOLL_PIN, removing the races can be considered a nice bonus. Link: https://lore.kernel.org/linux-mm/Y9J4P%2FRNvY1Ztn0Q@nvidia.com/ Suggested-by: Jason Gunthorpe Fixes: 214d9bbcd3a6 ("s390/mm: provide memory management functions for protected KVM guests") Reviewed-by: Jason Gunthorpe Signed-off-by: Claudio Imbrenda Message-Id: <20230428092753.27913-2-imbrenda@linux.ibm.com>

KVM: s390: pv: avoid export before import if possible

2022-11-23T09:06:50Z

If the appropriate UV feature bit is set, there is no need to perform an export before import. The misc feature indicates, among other things, that importing a shared page from a different protected VM will automatically also transfer its ownership. Signed-off-by: Claudio Imbrenda Reviewed-by: Nico Boehr Reviewed-by: Janosch Frank Reviewed-by: Steffen Eiden Link: https://lore.kernel.org/r/20221111170632.77622-5-imbrenda@linux.ibm.com Message-Id: <20221111170632.77622-5-imbrenda@linux.ibm.com> Signed-off-by: Janosch Frank

KVM: s390: pv: add export before import

2022-07-13T14:42:11Z

Due to upcoming changes, it will be possible to temporarily have multiple protected VMs in the same address space, although only one will be actually active. In that scenario, it is necessary to perform an export of every page that is to be imported, since the hardware does not allow a page belonging to a protected guest to be imported into a different protected guest. This also applies to pages that are shared, and thus accessible by the host. Signed-off-by: Claudio Imbrenda Reviewed-by: Janosch Frank Link: https://lore.kernel.org/r/20220628135619.32410-7-imbrenda@linux.ibm.com Message-Id: <20220628135619.32410-7-imbrenda@linux.ibm.com> Signed-off-by: Janosch Frank

KVM: s390: pv: handle secure storage violations for protected guests

2022-07-13T14:42:11Z

A secure storage violation is triggered when a protected guest tries to access secure memory that has been mapped erroneously, or that belongs to a different protected guest or to the ultravisor. With upcoming patches, protected guests will be able to trigger secure storage violations in normal operation. This happens for example if a protected guest is rebooted with deferred destroy enabled and the new guest is also protected. When the new protected guest touches pages that have not yet been destroyed, and thus are accounted to the previous protected guest, a secure storage violation is raised. This patch adds handling of secure storage violations for protected guests. This exception is handled by first trying to destroy the page, because it is expected to belong to a defunct protected guest where a destroy should be possible. Note that a secure page can only be destroyed if its protected VM does not have any CPUs, which only happens when the protected VM is being terminated. If that fails, a normal export of the page is attempted. This means that pages that trigger the exception will be made non-secure (in one way or another) before attempting to use them again for a different secure guest. Signed-off-by: Claudio Imbrenda Acked-by: Janosch Frank Link: https://lore.kernel.org/r/20220628135619.32410-3-imbrenda@linux.ibm.com Message-Id: <20220628135619.32410-3-imbrenda@linux.ibm.com> Signed-off-by: Janosch Frank

s390: Add attestation query information

2022-07-11T09:29:51Z

We have information about the supported attestation header version and plaintext attestation flag bits. Let's expose it via the sysfs files. Signed-off-by: Steffen Eiden Reviewed-by: Claudio Imbrenda Reviewed-by: Janosch Frank Link: https://lore.kernel.org/lkml/20220601100245.3189993-1-seiden@linux.ibm.com/ Signed-off-by: Janosch Frank

s390/uv: Add dump fields to query

2022-06-01T14:57:14Z

The new dump feature requires us to know how much memory is needed for the "dump storage state" and "dump finalize" ultravisor call. These values are reported via the UV query call. Signed-off-by: Janosch Frank Reviewed-by: Claudio Imbrenda Reviewed-by: Steffen Eiden Link: https://lore.kernel.org/r/20220517163629.3443-3-frankja@linux.ibm.com Message-Id: <20220517163629.3443-3-frankja@linux.ibm.com> Signed-off-by: Christian Borntraeger

s390/uv: Add SE hdr query information

2022-06-01T14:57:14Z

We have information about the supported se header version and pcf bits so let's expose it via the sysfs files. Signed-off-by: Janosch Frank Reviewed-by: Claudio Imbrenda Reviewed-by: Steffen Eiden Link: https://lore.kernel.org/r/20220517163629.3443-2-frankja@linux.ibm.com Message-Id: <20220517163629.3443-2-frankja@linux.ibm.com> Signed-off-by: Christian Borntraeger

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