Merge tag 'kvmarm-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 updates for 6.16

* New features:

  - Add large stage-2 mapping support for non-protected pKVM guests,
    clawing back some performance.

  - Add UBSAN support to the standalone EL2 object used in nVHE/hVHE and
    protected modes.

  - Enable nested virtualisation support on systems that support it
    (yes, it has been a long time coming), though it is disabled by
    default.

* Improvements, fixes and cleanups:

  - Large rework of the way KVM tracks architecture features and links
    them with the effects of control bits. This ensures correctness of
    emulation (the data is automatically extracted from the published
    JSON files), and helps dealing with the evolution of the
    architecture.

  - Significant changes to the way pKVM tracks ownership of pages,
    avoiding page table walks by storing the state in the hypervisor's
    vmemmap. This in turn enables the THP support described above.

  - New selftest checking the pKVM ownership transition rules

  - Fixes for FEAT_MTE_ASYNC being accidentally advertised to guests
    even if the host didn't have it.

  - Fixes for the address translation emulation, which happened to be
    rather buggy in some specific contexts.

  - Fixes for the PMU emulation in NV contexts, decoupling PMCR_EL0.N
    from the number of counters exposed to a guest and addressing a
    number of issues in the process.

  - Add a new selftest for the SVE host state being corrupted by a
    guest.

  - Keep HCR_EL2.xMO set at all times for systems running with the
    kernel at EL2, ensuring that the window for interrupts is slightly
    bigger, and avoiding a pretty bad erratum on the AmpereOne HW.

  - Add workaround for AmpereOne's erratum AC04_CPU_23, which suffers
    from a pretty bad case of TLB corruption unless accesses to HCR_EL2
    are heavily synchronised.

  - Add a per-VM, per-ITS debugfs entry to dump the state of the ITS
    tables in a human-friendly fashion.

  - and the usual random cleanups.

2 files changed, 14 insertions, 3 deletions

diff --git a/lib/Kconfig.ubsan b/lib/Kconfig.ubsan
index f6ea0c5b5da3..42ed41804644 100644
--- a/lib/Kconfig.ubsan
+++ b/lib/Kconfig.ubsan
@@ -165,4 +165,13 @@ config TEST_UBSAN
 	  This is a test module for UBSAN.
 	  It triggers various undefined behavior, and detect it.
 
+config UBSAN_KVM_EL2
+	bool "UBSAN for KVM code at EL2"
+	depends on ARM64
+	help
+	  Enable UBSAN when running on ARM64 with KVM in a split mode
+	  (nvhe/hvhe/protected) for the hypervisor code running in EL2.
+	  In this mode, any UBSAN violation in EL2 would panic the kernel
+	  and information similar to UBSAN_TRAP would be printed.
+
 endif	# if UBSAN
diff --git a/lib/ubsan.c b/lib/ubsan.c
index cdc1d31c3821..a6ca235dd714 100644
--- a/lib/ubsan.c
+++ b/lib/ubsan.c
@@ -19,13 +19,13 @@
 
 #include "ubsan.h"
 
-#ifdef CONFIG_UBSAN_TRAP
+#if defined(CONFIG_UBSAN_TRAP) || defined(CONFIG_UBSAN_KVM_EL2)
 /*
  * Only include matches for UBSAN checks that are actually compiled in.
  * The mappings of struct SanitizerKind (the -fsanitize=xxx args) to
  * enum SanitizerHandler (the traps) in Clang is in clang/lib/CodeGen/.
  */
-const char *report_ubsan_failure(struct pt_regs *regs, u32 check_type)
+const char *report_ubsan_failure(u32 check_type)
 {
 	switch (check_type) {
 #ifdef CONFIG_UBSAN_BOUNDS
@@ -97,7 +97,9 @@ const char *report_ubsan_failure(struct pt_regs *regs, u32 check_type)
 	}
 }
 
-#else
+#endif
+
+#ifndef CONFIG_UBSAN_TRAP
 static const char * const type_check_kinds[] = {
 	"load of",
 	"store to",