Merge tag 'kvmarm-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 updates for 6.12

* New features:

  - Add a Stage-2 page table dumper, reusing the main ptdump
    infrastructure, and allowing easier debugging of the our
    page-table infrastructure

  - Add FP8 support to the KVM/arm64 floating point handling.

  - Add NV support for the AT family of instructions, which mostly
    results in adding a page table walker that deals with most of the
    complexity of the architecture.

* Improvements, fixes and cleanups:

  - Add selftest checks for a bunch of timer emulation corner cases

  - Fix the multiple of cases where KVM/arm64 doesn't correctly handle
    the guest trying to use a GICv3 that isn't advertised

  - Remove REG_HIDDEN_USER from the sysreg infrastructure, making
    things little more simple

  - Prevent MTE tags being restored by userspace if we are actively
    logging writes, as that's a recipe for disaster

  - Correct the refcount on a page that is not considered for MTE tag
    copying (such as a device)

  - Relax the synchronisation when walking a page table to split block
    mappings, moving it at the end the walk, as there is no need to
    perform it on every store.

  - Fix boundary check when transfering memory using FFA

  - Fix pKVM TLB invalidation, only affecting currently out of tree
    code but worth addressing for peace of mind

1 files changed, 16 insertions, 1 deletions

diff --git a/tools/include/uapi/linux/kvm.h b/tools/include/uapi/linux/kvm.h
index e5af8c692dc0..637efc055145 100644
--- a/tools/include/uapi/linux/kvm.h
+++ b/tools/include/uapi/linux/kvm.h
@@ -192,11 +192,24 @@ struct kvm_xen_exit {
 /* Flags that describe what fields in emulation_failure hold valid data. */
 #define KVM_INTERNAL_ERROR_EMULATION_FLAG_INSTRUCTION_BYTES (1ULL << 0)
 
+/*
+ * struct kvm_run can be modified by userspace at any time, so KVM must be
+ * careful to avoid TOCTOU bugs. In order to protect KVM, HINT_UNSAFE_IN_KVM()
+ * renames fields in struct kvm_run from <symbol> to <symbol>__unsafe when
+ * compiled into the kernel, ensuring that any use within KVM is obvious and
+ * gets extra scrutiny.
+ */
+#ifdef __KERNEL__
+#define HINT_UNSAFE_IN_KVM(_symbol) _symbol##__unsafe
+#else
+#define HINT_UNSAFE_IN_KVM(_symbol) _symbol
+#endif
+
 /* for KVM_RUN, returned by mmap(vcpu_fd, offset=0) */
 struct kvm_run {
 	/* in */
 	__u8 request_interrupt_window;
-	__u8 immediate_exit;
+	__u8 HINT_UNSAFE_IN_KVM(immediate_exit);
 	__u8 padding1[6];
 
 	/* out */
@@ -918,6 +931,8 @@ struct kvm_enable_cap {
 #define KVM_CAP_GUEST_MEMFD 234
 #define KVM_CAP_VM_TYPES 235
 #define KVM_CAP_PRE_FAULT_MEMORY 236
+#define KVM_CAP_X86_APIC_BUS_CYCLES_NS 237
+#define KVM_CAP_X86_GUEST_MODE 238
 
 struct kvm_irq_routing_irqchip {
 	__u32 irqchip;