[PATCH 1/1] tools headers UAPI: Sync linux/kvm.h with the kernel sources

Arnaldo Carvalho de Melo
2025-11-03T14:40:51Z

tldr; Just FYI, I'm carrying this on the perf tools tree.

Full explanation:

There used to be no copies, with tools/ code using kernel headers
directly. From time to time tools/perf/ broke due to legitimate kernel
hacking. At some point Linus complained about such direct usage. Then we
adopted the current model.

See further details at:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/tools/include/uapi/README

To pick the changes in:

fe2bf6234e947bf5 ("KVM: guest_memfd: Add INIT_SHARED flag, reject user page faults if not set")
d2042d8f96ddefde ("KVM: Rework KVM_CAP_GUEST_MEMFD_MMAP into KVM_CAP_GUEST_MEMFD_FLAGS")
3d3a04fad25a6621 ("KVM: Allow and advertise support for host mmap() on guest_memfd files")

That just rebuilds perf, as these patches don't add any new KVM ioctl to
be harvested for the the 'perf trace' ioctl syscall argument
beautifiers.

This addresses this perf build warning:

Warning: Kernel ABI header differences:
diff -u tools/include/uapi/linux/kvm.h include/uapi/linux/kvm.h

Please see tools/include/uapi/README for further details.

Cc: Sean Christopherson <seanjc@google.com>
Cc: Fuad Tabba <tabba@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/include/uapi/linux/kvm.h | 3 +++
1 file changed, 3 insertions(+)

diff --git a/tools/include/uapi/linux/kvm.h b/tools/include/uapi/linux/kvm.h
index f0f0d49d25443552..52f6000ab020840e 100644
--- a/tools/include/uapi/linux/kvm.h
+++ b/tools/include/uapi/linux/kvm.h
@@ -962,6 +962,7 @@ struct kvm_enable_cap {
#define KVM_CAP_ARM_EL2_E2H0 241
#define KVM_CAP_RISCV_MP_STATE_RESET 242
#define KVM_CAP_ARM_CACHEABLE_PFNMAP_SUPPORTED 243
+#define KVM_CAP_GUEST_MEMFD_FLAGS 244

struct kvm_irq_routing_irqchip {
__u32 irqchip;
@@ -1598,6 +1599,8 @@ struct kvm_memory_attributes {
#define KVM_MEMORY_ATTRIBUTE_PRIVATE (1ULL << 3)

#define KVM_CREATE_GUEST_MEMFD _IOWR(KVMIO, 0xd4, struct kvm_create_guest_memfd)
+#define GUEST_MEMFD_FLAG_MMAP (1ULL << 0)
+#define GUEST_MEMFD_FLAG_INIT_SHARED (1ULL << 1)

struct kvm_create_guest_memfd {
__u64 size;
--
2.51.1