[PATCH 1/1] tools headers UAPI: Sync x86's asm/kvm.h with the kernel sources

From: Arnaldo Carvalho de Melo
Date: Mon Nov 03 2025 - 11:15:09 EST


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:

fddd07626baa419c ("KVM: x86: Define AMD's #HV, #VC, and #SX exception vectors")
f2f5519aa4e3ec4e ("KVM: x86: Define Control Protection Exception (#CP) vector")
9d6812d415358372 ("KVM: x86: Enable guest SSP read/write interface with new uAPIs")
06f2969c6a1237f0 ("KVM: x86: Introduce KVM_{G,S}ET_ONE_REG uAPIs support")

That just rebuilds kvm-stat.c on x86, no change in functionality.

This silences these perf build warning:

Warning: Kernel ABI header differences:
diff -u tools/arch/x86/include/uapi/asm/kvm.h arch/x86/include/uapi/asm/kvm.h

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

Cc: Sean Christopherson <seanjc@xxxxxxxxxx>
Cc: Yang Weijiang <weijiang.yang@xxxxxxxxx>
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/arch/x86/include/uapi/asm/kvm.h | 34 +++++++++++++++++++++++++++
1 file changed, 34 insertions(+)

diff --git a/tools/arch/x86/include/uapi/asm/kvm.h b/tools/arch/x86/include/uapi/asm/kvm.h
index 0f15d683817d6a77..d420c9c066d48c98 100644
--- a/tools/arch/x86/include/uapi/asm/kvm.h
+++ b/tools/arch/x86/include/uapi/asm/kvm.h
@@ -35,6 +35,11 @@
#define MC_VECTOR 18
#define XM_VECTOR 19
#define VE_VECTOR 20
+#define CP_VECTOR 21
+
+#define HV_VECTOR 28
+#define VC_VECTOR 29
+#define SX_VECTOR 30

/* Select x86 specific features in <linux/kvm.h> */
#define __KVM_HAVE_PIT
@@ -411,6 +416,35 @@ struct kvm_xcrs {
__u64 padding[16];
};

+#define KVM_X86_REG_TYPE_MSR 2
+#define KVM_X86_REG_TYPE_KVM 3
+
+#define KVM_X86_KVM_REG_SIZE(reg) \
+({ \
+ reg == KVM_REG_GUEST_SSP ? KVM_REG_SIZE_U64 : 0; \
+})
+
+#define KVM_X86_REG_TYPE_SIZE(type, reg) \
+({ \
+ __u64 type_size = (__u64)type << 32; \
+ \
+ type_size |= type == KVM_X86_REG_TYPE_MSR ? KVM_REG_SIZE_U64 : \
+ type == KVM_X86_REG_TYPE_KVM ? KVM_X86_KVM_REG_SIZE(reg) : \
+ 0; \
+ type_size; \
+})
+
+#define KVM_X86_REG_ID(type, index) \
+ (KVM_REG_X86 | KVM_X86_REG_TYPE_SIZE(type, index) | index)
+
+#define KVM_X86_REG_MSR(index) \
+ KVM_X86_REG_ID(KVM_X86_REG_TYPE_MSR, index)
+#define KVM_X86_REG_KVM(index) \
+ KVM_X86_REG_ID(KVM_X86_REG_TYPE_KVM, index)
+
+/* KVM-defined registers starting from 0 */
+#define KVM_REG_GUEST_SSP 0
+
#define KVM_SYNC_X86_REGS (1UL << 0)
#define KVM_SYNC_X86_SREGS (1UL << 1)
#define KVM_SYNC_X86_EVENTS (1UL << 2)
--
2.51.1