On Thu, Apr 25, 2019 at 09:44:18AM +0200, Pavel Hrdina wrote:
In order to implement devices controller with cgroup v2 we need to add support for BPF programs, cgroup v2 doesn't have devices controller. This introduces required helpers wrapping linux syscalls. Signed-off-by: Pavel Hrdina <phrdina@xxxxxxxxxx> --- configure.ac | 5 + include/libvirt/virterror.h | 2 + src/libvirt_private.syms | 16 ++ src/util/Makefile.inc.am | 2 + src/util/virbpf.c | 438 ++++++++++++++++++++++++++++++++++++ src/util/virbpf.h | 259 +++++++++++++++++++++ src/util/virerror.c | 2 + 7 files changed, 724 insertions(+) create mode 100644 src/util/virbpf.c create mode 100644 src/util/virbpf.h diff --git a/src/util/virbpf.h b/src/util/virbpf.h new file mode 100644 index 0000000000..b5874e1e8d --- /dev/null +++ b/src/util/virbpf.h @@ -0,0 +1,259 @@ +/* + * virbpf.h: methods for eBPF + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library. If not, see + * <http://www.gnu.org/licenses/>. + */ +
+#ifndef LIBVIRT_VIRBPF_H +# define LIBVIRT_VIRBPF_H
#pragma once is the new avocado toast.
+
+# if HAVE_DECL_BPF_PROG_QUERY
+
+# include <linux/bpf.h>
+
+/* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */
+
+# define VIR_BPF_ALU64_REG(op, dst, src) \
+ ((struct bpf_insn) { \
+ .code = BPF_ALU64 | BPF_OP(op) | BPF_X, \
+ .dst_reg = dst, \
+ .src_reg = src, \
+ .off = 0, \
+ .imm = 0, \
+ })
+
+/* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */
+
+# define VIR_BPF_ALU64_IMM(op, dst, immval) \
+ ((struct bpf_insn) { \
+ .code = BPF_ALU64 | BPF_OP(op) | BPF_K, \
+ .dst_reg = dst, \
+ .src_reg = 0, \
+ .off = 0, \
+ .imm = immval, \
+ })
+
+/* mov of registers, dst_reg = src_reg */
+
+# define VIR_BPF_MOV64_REG(dst, src) \
+ ((struct bpf_insn) { \
+ .code = BPF_ALU64 | BPF_MOV | BPF_X, \
+ .dst_reg = dst, \
+ .src_reg = src, \
+ .off = 0, \
+ .imm = 0, \
+ })
+
+/* mov of immediates, dst_reg = imm32 */
+
+# define VIR_BPF_MOV64_IMM(dst, immval) \
+ ((struct bpf_insn) { \
+ .code = BPF_ALU64 | BPF_MOV | BPF_K, \
+ .dst_reg = dst, \
+ .src_reg = 0, \
+ .off = 0, \
+ .imm = immval, \
+ })
+
+/* helper to encode 16 byte instruction */
+
+# define _VIR_BPF_LD_IMM64_RAW(dst, src, immval) \
+ ((struct bpf_insn) { \
+ .code = BPF_LD | BPF_DW | BPF_IMM, \
+ .dst_reg = dst, \
+ .src_reg = src, \
+ .off = 0, \
+ .imm = (uint32_t)immval, \
+ }), \
+ ((struct bpf_insn) { \
+ .code = 0, \
+ .dst_reg = 0, \
+ .src_reg = 0, \
+ .off = 0, \
+ .imm = ((uint64_t)immval) >> 32, \
+ })
+
Trust, yada, yada.. Reviewed-by: Ján Tomko <jtomko@xxxxxxxxxx> Jano
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