Merge tag 'kvm-x86-generic-6.12' of https://github.com/kvm-x86/linux into HEAD

KVK generic changes for 6.12:

 - Fix a bug that results in KVM prematurely exiting to userspace for coalesced
   MMIO/PIO in many cases, clean up the related code, and add a testcase.

 - Fix a bug in kvm_clear_guest() where it would trigger a buffer overflow _if_
   the gpa+len crosses a page boundary, which thankfully is guaranteed to not
   happen in the current code base.  Add WARNs in more helpers that read/write
   guest memory to detect similar bugs.

1 files changed, 26 insertions, 0 deletions

diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h
index 63c2aaae51f3..b297a84f7be5 100644
--- a/tools/testing/selftests/kvm/include/kvm_util.h
+++ b/tools/testing/selftests/kvm/include/kvm_util.h
@@ -460,6 +460,32 @@ static inline uint32_t kvm_vm_reset_dirty_ring(struct kvm_vm *vm)
 	return __vm_ioctl(vm, KVM_RESET_DIRTY_RINGS, NULL);
 }
 
+static inline void kvm_vm_register_coalesced_io(struct kvm_vm *vm,
+						uint64_t address,
+						uint64_t size, bool pio)
+{
+	struct kvm_coalesced_mmio_zone zone = {
+		.addr = address,
+		.size = size,
+		.pio  = pio,
+	};
+
+	vm_ioctl(vm, KVM_REGISTER_COALESCED_MMIO, &zone);
+}
+
+static inline void kvm_vm_unregister_coalesced_io(struct kvm_vm *vm,
+						  uint64_t address,
+						  uint64_t size, bool pio)
+{
+	struct kvm_coalesced_mmio_zone zone = {
+		.addr = address,
+		.size = size,
+		.pio  = pio,
+	};
+
+	vm_ioctl(vm, KVM_UNREGISTER_COALESCED_MMIO, &zone);
+}
+
 static inline int vm_get_stats_fd(struct kvm_vm *vm)
 {
 	int fd = __vm_ioctl(vm, KVM_GET_STATS_FD, NULL);