sys/linux: rework ioctl$KVM_SET_GUEST_DEBUG

This ioctl accepts an arch-specific struct as an argument, so better split it
into several arch-specific ioctls.

To avoid compilation errors on exotic arches like MIPS, this patch also adds
sys/linux/dev_kvm_extra.txt that takes care of them.

While at it, also define KVM_GUESTDBG_USE_HW.

5 files changed, 30 insertions, 5 deletions

diff --git a/sys/linux/dev_kvm.txt b/sys/linux/dev_kvm.txt
index 919fcc3aa..ec342b320 100644
--- a/sys/linux/dev_kvm.txt
+++ b/sys/linux/dev_kvm.txt
@@ -78,8 +78,6 @@ ioctl$KVM_GET_ONE_REG(fd fd_kvmcpu, cmd const[KVM_GET_ONE_REG], arg ptr[in, kvm_
 ioctl$KVM_KVMCLOCK_CTRL(fd fd_kvmcpu, cmd const[KVM_KVMCLOCK_CTRL])
 ioctl$KVM_S390_INTERRUPT_CPU(fd fd_kvmcpu, cmd const[KVM_S390_INTERRUPT], arg ptr[in, kvm_s390_interrupt])
 ioctl$KVM_GET_REG_LIST(fd fd_kvmcpu, cmd const[KVM_GET_REG_LIST], arg ptr[inout, kvm_reg_list])
-ioctl$KVM_SET_GUEST_DEBUG(fd fd_kvmcpu, cmd const[KVM_SET_GUEST_DEBUG], arg ptr[in, kvm_guest_debug])
-
 ioctl$KVM_SET_DEVICE_ATTR(fd fd_kvmdev, cmd const[KVM_SET_DEVICE_ATTR], arg ptr[in, kvm_device_attr])
 ioctl$KVM_GET_DEVICE_ATTR(fd fd_kvmdev, cmd const[KVM_GET_DEVICE_ATTR], arg ptr[in, kvm_device_attr])
 ioctl$KVM_HAS_DEVICE_ATTR(fd fd_kvmdev, cmd const[KVM_HAS_DEVICE_ATTR], arg ptr[in, kvm_device_attr])
@@ -108,7 +106,7 @@ kvm_ioeventfd_flags = KVM_IOEVENTFD_FLAG_DATAMATCH, KVM_IOEVENTFD_FLAG_PIO, KVM_
 kvm_ioeventfd_len = 0, 1, 2, 4, 8
 kvm_device_type = KVM_DEV_TYPE_FSL_MPIC_20, KVM_DEV_TYPE_FSL_MPIC_42, KVM_DEV_TYPE_XICS, KVM_DEV_TYPE_VFIO, KVM_DEV_TYPE_ARM_VGIC_V2, KVM_DEV_TYPE_FLIC, KVM_DEV_TYPE_ARM_VGIC_V3, KVM_DEV_TYPE_ARM_VGIC_ITS, KVM_DEV_TYPE_XIVE, KVM_DEV_TYPE_ARM_PV_TIME, KVM_DEV_TYPE_RISCV_AIA
 kvm_device_flags = 0, KVM_CREATE_DEVICE_TEST
-kvm_guest_debug_flags = KVM_GUESTDBG_ENABLE, KVM_GUESTDBG_SINGLESTEP, KVM_GUESTDBG_USE_SW_BP, KVM_GUESTDBG_USE_HW_BP, KVM_GUESTDBG_INJECT_DB, KVM_GUESTDBG_INJECT_BP, KVM_GUESTDBG_EXIT_PENDING, KVM_GUESTDBG_BLOCKIRQ
+kvm_guest_debug_flags = KVM_GUESTDBG_ENABLE, KVM_GUESTDBG_SINGLESTEP, KVM_GUESTDBG_USE_SW_BP, KVM_GUESTDBG_USE_HW_BP, KVM_GUESTDBG_USE_HW, KVM_GUESTDBG_INJECT_DB, KVM_GUESTDBG_INJECT_BP, KVM_GUESTDBG_EXIT_PENDING, KVM_GUESTDBG_BLOCKIRQ
 kvm_guest_selector = 0, 3, 4, 8, 9, 10, 11, 12, 13, 14, 15, 16
 kvm_dirty_log_protect = KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE, KVM_DIRTY_LOG_INITIALLY_SET
 kvm_dirty_log_sizes = 4096, 8192, 16384, 32768, 65536
@@ -166,10 +164,10 @@ define KVM_SETUP_PPC64_PR	(1<<3)
 # Set PID=1 i.e. not kernel's PID
 define KVM_SETUP_PPC64_PID1	(1<<4)
 
-kvm_guest_debug {
+type kvm_guest_debug[ARCH] {
 	ctrl	flags[kvm_guest_debug_flags, int32]
 	pad	const[0, int32]
-	reg	array[int64, 8]
+	arch	ARCH
 }
 
 kvm_reg_list {
diff --git a/sys/linux/dev_kvm.txt.const b/sys/linux/dev_kvm.txt.const
index 7f313efdb..b43af3832 100644
--- a/sys/linux/dev_kvm.txt.const
+++ b/sys/linux/dev_kvm.txt.const
@@ -84,6 +84,7 @@ KVM_GUESTDBG_EXIT_PENDING = 386:amd64:arm64:mips64le:ppc64le:???, s390x:26843545
 KVM_GUESTDBG_INJECT_BP = 524288, arm64:mips64le:ppc64le:s390x:???
 KVM_GUESTDBG_INJECT_DB = 262144, arm64:mips64le:ppc64le:s390x:???
 KVM_GUESTDBG_SINGLESTEP = 2
+KVM_GUESTDBG_USE_HW = 386:amd64:mips64le:ppc64le:s390x:???, arm64:131072
 KVM_GUESTDBG_USE_HW_BP = 131072, arm64:mips64le:???, s390x:65536
 KVM_GUESTDBG_USE_SW_BP = 65536, mips64le:s390x:???
 KVM_HAS_DEVICE_ATTR = 1075359459, mips64le:ppc64le:2149101283
diff --git a/sys/linux/dev_kvm_amd64.txt b/sys/linux/dev_kvm_amd64.txt
index 41fb947cd..43474f9f6 100644
--- a/sys/linux/dev_kvm_amd64.txt
+++ b/sys/linux/dev_kvm_amd64.txt
@@ -483,6 +483,7 @@ ioctl$KVM_GET_FPU(fd fd_kvmcpu, cmd const[KVM_GET_FPU], arg ptr[out, kvm_fpu])
 ioctl$KVM_SET_FPU(fd fd_kvmcpu, cmd const[KVM_SET_FPU], arg ptr[in, kvm_fpu])
 ioctl$KVM_GET_DEBUGREGS(fd fd_kvmcpu, cmd const[KVM_GET_DEBUGREGS], arg ptr[out, kvm_debugregs])
 ioctl$KVM_SET_DEBUGREGS(fd fd_kvmcpu, cmd const[KVM_SET_DEBUGREGS], arg ptr[in, kvm_debugregs])
+ioctl$KVM_SET_GUEST_DEBUG_x86(fd fd_kvmcpu, cmd const[KVM_SET_GUEST_DEBUG], arg ptr[in, kvm_guest_debug[kvm_guest_debug_arch_x86]])
 ioctl$KVM_GET_XCRS(fd fd_kvmcpu, cmd const[KVM_GET_XCRS], arg ptr[out, kvm_xcrs])
 ioctl$KVM_SET_XCRS(fd fd_kvmcpu, cmd const[KVM_SET_XCRS], arg ptr[in, kvm_xcrs])
 ioctl$KVM_GET_XSAVE(fd fd_kvmcpu, cmd const[KVM_GET_XSAVE], arg ptr[out, kvm_xsave])
@@ -519,6 +520,10 @@ ioctl$KVM_GET_XSAVE2(fd fd_kvmcpu, cmd const[KVM_GET_XSAVE2], arg vma)
 ioctl$KVM_GET_SREGS2(fd fd_kvmcpu, cmd const[KVM_GET_SREGS2], arg ptr[out, kvm_sregs2])
 ioctl$KVM_SET_SREGS2(fd fd_kvmcpu, cmd const[KVM_SET_SREGS2], arg ptr[in, kvm_sregs2])
 
+kvm_guest_debug_arch_x86 {
+	reg	array[int64, 8]
+}
+
 kvm_nested_state {
 	flags	flags[kvm_nested_state_flags, int16]
 	format	const[0, int16]
diff --git a/sys/linux/dev_kvm_arm64.txt b/sys/linux/dev_kvm_arm64.txt
index 53e2d71e8..f4c724606 100644
--- a/sys/linux/dev_kvm_arm64.txt
+++ b/sys/linux/dev_kvm_arm64.txt
@@ -58,6 +58,15 @@ kvm_arm_device_addr {
 	addr	flags[kvm_guest_addrs, int64]
 }
 
+kvm_guest_debug_arch_arm64 {
+	dbg_bcr	array[int64, 16]
+	dbg_bvr	array[int64, 16]
+	dbg_wcr	array[int64, 16]
+	dbg_wvr	array[int64, 16]
+}
+
+ioctl$KVM_SET_GUEST_DEBUG_arm64(fd fd_kvmcpu, cmd const[KVM_SET_GUEST_DEBUG], arg ptr[in, kvm_guest_debug[kvm_guest_debug_arch_arm64]])
+
 ioctl$KVM_ARM_VCPU_INIT(fd fd_kvmcpu, cmd const[KVM_ARM_VCPU_INIT], arg ptr[in, kvm_vcpu_init])
 ioctl$KVM_ARM_PREFERRED_TARGET(fd fd_kvmcpu, cmd const[KVM_ARM_PREFERRED_TARGET], arg ptr[out, kvm_vcpu_init])
 # KVM_ARM_VCPU_FINALIZE accepts a single CPU feature encoded as a bit number: https://docs.kernel.org/virt/kvm/api.html#kvm-arm-vcpu-finalize.
diff --git a/sys/linux/dev_kvm_extra.txt b/sys/linux/dev_kvm_extra.txt
new file mode 100644
index 000000000..395ce577d
--- /dev/null
+++ b/sys/linux/dev_kvm_extra.txt
@@ -0,0 +1,12 @@
+# Copyright 2025 syzkaller project authors. All rights reserved.
+# Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
+
+# This file is used for non-x86, non-ARM definitions.
+
+meta arches["mips64le", "ppc64le", "s390x"]
+
+ioctl$KVM_SET_GUEST_DEBUG_generic(fd fd_kvmcpu, cmd const[KVM_SET_GUEST_DEBUG], arg ptr[in, kvm_guest_debug[kvm_guest_debug_arch_generic]])
+
+kvm_guest_debug_arch_generic {
+	reg	array[int64, 8]
+}