Merge tag 'kvm-x86-fixes-6.18-rc2' of https://github.com/kvm-x86/linux into HEAD

KVM x86 fixes for 6.18:

 - Expand the KVM_PRE_FAULT_MEMORY selftest to add a regression test for the
   bug fixed by commit 3ccbf6f47098 ("KVM: x86/mmu: Return -EAGAIN if userspace
   deletes/moves memslot during prefault")

 - Don't try to get PMU capabbilities from perf when running a CPU with hybrid
   CPUs/PMUs, as perf will rightly WARN.

 - Rework KVM_CAP_GUEST_MEMFD_MMAP (newly introduced in 6.18) into a more
   generic KVM_CAP_GUEST_MEMFD_FLAGS

 - Add a guest_memfd INIT_SHARED flag and require userspace to explicitly set
   said flag to initialize memory as SHARED, irrespective of MMAP.  The
   behavior merged in 6.18 is that enabling mmap() implicitly initializes
   memory as SHARED, which would result in an ABI collision for x86 CoCo VMs
   as their memory is currently always initialized PRIVATE.

 - Allow mmap() on guest_memfd for x86 CoCo VMs, i.e. on VMs with private
   memory, to enable testing such setups, i.e. to hopefully flush out any
   other lurking ABI issues before 6.18 is officially released.

 - Add testcases to the guest_memfd selftest to cover guest_memfd without MMAP,
   and host userspace accesses to mmap()'d private memory.

1 files changed, 25 insertions, 0 deletions

diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h
index 112d3f443a17..d3f3e455c031 100644
--- a/tools/testing/selftests/kvm/include/kvm_util.h
+++ b/tools/testing/selftests/kvm/include/kvm_util.h
@@ -286,6 +286,31 @@ static inline bool kvm_has_cap(long cap)
 #define __KVM_SYSCALL_ERROR(_name, _ret) \
 	"%s failed, rc: %i errno: %i (%s)", (_name), (_ret), errno, strerror(errno)
 
+static inline void *__kvm_mmap(size_t size, int prot, int flags, int fd,
+			       off_t offset)
+{
+	void *mem;
+
+	mem = mmap(NULL, size, prot, flags, fd, offset);
+	TEST_ASSERT(mem != MAP_FAILED, __KVM_SYSCALL_ERROR("mmap()",
+		    (int)(unsigned long)MAP_FAILED));
+
+	return mem;
+}
+
+static inline void *kvm_mmap(size_t size, int prot, int flags, int fd)
+{
+	return __kvm_mmap(size, prot, flags, fd, 0);
+}
+
+static inline void kvm_munmap(void *mem, size_t size)
+{
+	int ret;
+
+	ret = munmap(mem, size);
+	TEST_ASSERT(!ret, __KVM_SYSCALL_ERROR("munmap()", ret));
+}
+
 /*
  * Use the "inner", double-underscore macro when reporting errors from within
  * other macros so that the name of ioctl() and not its literal numeric value