Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm updates from Paolo Bonzini:
 "Generic:

   - Use memdup_array_user() to harden against overflow.

   - Unconditionally advertise KVM_CAP_DEVICE_CTRL for all
     architectures.

   - Clean up Kconfigs that all KVM architectures were selecting

   - New functionality around "guest_memfd", a new userspace API that
     creates an anonymous file and returns a file descriptor that refers
     to it. guest_memfd files are bound to their owning virtual machine,
     cannot be mapped, read, or written by userspace, and cannot be
     resized. guest_memfd files do however support PUNCH_HOLE, which can
     be used to switch a memory area between guest_memfd and regular
     anonymous memory.

   - New ioctl KVM_SET_MEMORY_ATTRIBUTES allowing userspace to specify
     per-page attributes for a given page of guest memory; right now the
     only attribute is whether the guest expects to access memory via
     guest_memfd or not, which in Confidential SVMs backed by SEV-SNP,
     TDX or ARM64 pKVM is checked by firmware or hypervisor that
     guarantees confidentiality (AMD PSP, Intel TDX module, or EL2 in
     the case of pKVM).

  x86:

   - Support for "software-protected VMs" that can use the new
     guest_memfd and page attributes infrastructure. This is mostly
     useful for testing, since there is no pKVM-like infrastructure to
     provide a meaningfully reduced TCB.

   - Fix a relatively benign off-by-one error when splitting huge pages
     during CLEAR_DIRTY_LOG.

   - Fix a bug where KVM could incorrectly test-and-clear dirty bits in
     non-leaf TDP MMU SPTEs if a racing thread replaces a huge SPTE with
     a non-huge SPTE.

   - Use more generic lockdep assertions in paths that don't actually
     care about whether the caller is a reader or a writer.

   - let Xen guests opt out of having PV clock reported as "based on a
     stable TSC", because some of them don't expect the "TSC stable" bit
     (added to the pvclock ABI by KVM, but never set by Xen) to be set.

   - Revert a bogus, made-up nested SVM consistency check for
     TLB_CONTROL.

   - Advertise flush-by-ASID support for nSVM unconditionally, as KVM
     always flushes on nested transitions, i.e. always satisfies flush
     requests. This allows running bleeding edge versions of VMware
     Workstation on top of KVM.

   - Sanity check that the CPU supports flush-by-ASID when enabling SEV
     support.

   - On AMD machines with vNMI, always rely on hardware instead of
     intercepting IRET in some cases to detect unmasking of NMIs

   - Support for virtualizing Linear Address Masking (LAM)

   - Fix a variety of vPMU bugs where KVM fail to stop/reset counters
     and other state prior to refreshing the vPMU model.

   - Fix a double-overflow PMU bug by tracking emulated counter events
     using a dedicated field instead of snapshotting the "previous"
     counter. If the hardware PMC count triggers overflow that is
     recognized in the same VM-Exit that KVM manually bumps an event
     count, KVM would pend PMIs for both the hardware-triggered overflow
     and for KVM-triggered overflow.

   - Turn off KVM_WERROR by default for all configs so that it's not
     inadvertantly enabled by non-KVM developers, which can be
     problematic for subsystems that require no regressions for W=1
     builds.

   - Advertise all of the host-supported CPUID bits that enumerate
     IA32_SPEC_CTRL "features".

   - Don't force a masterclock update when a vCPU synchronizes to the
     current TSC generation, as updating the masterclock can cause
     kvmclock's time to "jump" unexpectedly, e.g. when userspace
     hotplugs a pre-created vCPU.

   - Use RIP-relative address to read kvm_rebooting in the VM-Enter
     fault paths, partly as a super minor optimization, but mostly to
     make KVM play nice with position independent executable builds.

   - Guard KVM-on-HyperV's range-based TLB flush hooks with an #ifdef on
     CONFIG_HYPERV as a minor optimization, and to self-document the
     code.

   - Add CONFIG_KVM_HYPERV to allow disabling KVM support for HyperV
     "emulation" at build time.

  ARM64:

   - LPA2 support, adding 52bit IPA/PA capability for 4kB and 16kB base
     granule sizes. Branch shared with the arm64 tree.

   - Large Fine-Grained Trap rework, bringing some sanity to the
     feature, although there is more to come. This comes with a prefix
     branch shared with the arm64 tree.

   - Some additional Nested Virtualization groundwork, mostly
     introducing the NV2 VNCR support and retargetting the NV support to
     that version of the architecture.

   - A small set of vgic fixes and associated cleanups.

  Loongarch:

   - Optimization for memslot hugepage checking

   - Cleanup and fix some HW/SW timer issues

   - Add LSX/LASX (128bit/256bit SIMD) support

  RISC-V:

   - KVM_GET_REG_LIST improvement for vector registers

   - Generate ISA extension reg_list using macros in get-reg-list
     selftest

   - Support for reporting steal time along with selftest

  s390:

   - Bugfixes

  Selftests:

   - Fix an annoying goof where the NX hugepage test prints out garbage
     instead of the magic token needed to run the test.

   - Fix build errors when a header is delete/moved due to a missing
     flag in the Makefile.

   - Detect if KVM bugged/killed a selftest's VM and print out a helpful
     message instead of complaining that a random ioctl() failed.

   - Annotate the guest printf/assert helpers with __printf(), and fix
     the various bugs that were lurking due to lack of said annotation"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (185 commits)
  x86/kvm: Do not try to disable kvmclock if it was not enabled
  KVM: x86: add missing "depends on KVM"
  KVM: fix direction of dependency on MMU notifiers
  KVM: introduce CONFIG_KVM_COMMON
  KVM: arm64: Add missing memory barriers when switching to pKVM's hyp pgd
  KVM: arm64: vgic-its: Avoid potential UAF in LPI translation cache
  RISC-V: KVM: selftests: Add get-reg-list test for STA registers
  RISC-V: KVM: selftests: Add steal_time test support
  RISC-V: KVM: selftests: Add guest_sbi_probe_extension
  RISC-V: KVM: selftests: Move sbi_ecall to processor.c
  RISC-V: KVM: Implement SBI STA extension
  RISC-V: KVM: Add support for SBI STA registers
  RISC-V: KVM: Add support for SBI extension registers
  RISC-V: KVM: Add SBI STA info to vcpu_arch
  RISC-V: KVM: Add steal-update vcpu request
  RISC-V: KVM: Add SBI STA extension skeleton
  RISC-V: paravirt: Implement steal-time support
  RISC-V: Add SBI STA extension definitions
  RISC-V: paravirt: Add skeleton for pv-time support
  RISC-V: KVM: Fix indentation in kvm_riscv_vcpu_set_reg_csr()
  ...

2 files changed, 33 insertions, 12 deletions

diff --git a/mm/compaction.c b/mm/compaction.c
index 27ada42924d5..4add68d40e8d 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -882,6 +882,7 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn,
 
 	/* Time to isolate some pages for migration */
 	for (; low_pfn < end_pfn; low_pfn++) {
+		bool is_dirty, is_unevictable;
 
 		if (skip_on_failure && low_pfn >= next_skip_pfn) {
 			/*
@@ -1079,8 +1080,10 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn,
 		if (!folio_test_lru(folio))
 			goto isolate_fail_put;
 
+		is_unevictable = folio_test_unevictable(folio);
+
 		/* Compaction might skip unevictable pages but CMA takes them */
-		if (!(mode & ISOLATE_UNEVICTABLE) && folio_test_unevictable(folio))
+		if (!(mode & ISOLATE_UNEVICTABLE) && is_unevictable)
 			goto isolate_fail_put;
 
 		/*
@@ -1092,26 +1095,42 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn,
 		if ((mode & ISOLATE_ASYNC_MIGRATE) && folio_test_writeback(folio))
 			goto isolate_fail_put;
 
-		if ((mode & ISOLATE_ASYNC_MIGRATE) && folio_test_dirty(folio)) {
-			bool migrate_dirty;
+		is_dirty = folio_test_dirty(folio);
+
+		if (((mode & ISOLATE_ASYNC_MIGRATE) && is_dirty) ||
+		    (mapping && is_unevictable)) {
+			bool migrate_dirty = true;
+			bool is_unmovable;
 
 			/*
 			 * Only folios without mappings or that have
-			 * a ->migrate_folio callback are possible to
-			 * migrate without blocking.  However, we may
-			 * be racing with truncation, which can free
-			 * the mapping.  Truncation holds the folio lock
-			 * until after the folio is removed from the page
-			 * cache so holding it ourselves is sufficient.
+			 * a ->migrate_folio callback are possible to migrate
+			 * without blocking.
+			 *
+			 * Folios from unmovable mappings are not migratable.
+			 *
+			 * However, we can be racing with truncation, which can
+			 * free the mapping that we need to check. Truncation
+			 * holds the folio lock until after the folio is removed
+			 * from the page so holding it ourselves is sufficient.
+			 *
+			 * To avoid locking the folio just to check unmovable,
+			 * assume every unmovable folio is also unevictable,
+			 * which is a cheaper test.  If our assumption goes
+			 * wrong, it's not a correctness bug, just potentially
+			 * wasted cycles.
 			 */
 			if (!folio_trylock(folio))
 				goto isolate_fail_put;
 
 			mapping = folio_mapping(folio);
-			migrate_dirty = !mapping ||
-					mapping->a_ops->migrate_folio;
+			if ((mode & ISOLATE_ASYNC_MIGRATE) && is_dirty) {
+				migrate_dirty = !mapping ||
+						mapping->a_ops->migrate_folio;
+			}
+			is_unmovable = mapping && mapping_unmovable(mapping);
 			folio_unlock(folio);
-			if (!migrate_dirty)
+			if (!migrate_dirty || is_unmovable)
 				goto isolate_fail_put;
 		}
 
diff --git a/mm/migrate.c b/mm/migrate.c
index bde8273cf15b..cc9f2bcd73b4 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -962,6 +962,8 @@ static int move_to_new_folio(struct folio *dst, struct folio *src,
 
 		if (!mapping)
 			rc = migrate_folio(mapping, dst, src, mode);
+		else if (mapping_unmovable(mapping))
+			rc = -EOPNOTSUPP;
 		else if (mapping->a_ops->migrate_folio)
 			/*
 			 * Most folios have a mapping and most filesystems