[PATCH v2 1/3] kvm: decode the argument of KVM_SET_CPUID2 and KVM_GET_*_CPUID ioctl command

[Pierre Marsais]

* configure.ac (AC_CHECK_TYPES): Add struct kvm_cpuid2.
* kvm.c [HAVE_STRUCT_KVM_CPUID2]: Include "xlat/kvm_cpuid_flags.h".
[HAVE_STRUCT_KVM_CPUID2] (print_kvm_cpuid_entry, kvm_ioctl_decode_cpuid2):
New functions.
(kvm_ioctl) [HAVE_STRUCT_KVM_CPUID2]: Use kvm_ioctl_decode_cpuid2.
* xlat/kvm_cpuid_flags.in: New file.

Signed-off-by: Pierre Marsais <pierre.marsais at lse.epita.fr>
---
Changes in v2:
* Follow the GNU ChangeLog style for commit message
* Improve code style in kvm.c

 configure.ac            |  1 +
 kvm.c                   | 61 +++++++++++++++++++++++++++++++++++++++++
 xlat/kvm_cpuid_flags.in |  3 ++
 3 files changed, 65 insertions(+)
 create mode 100644 xlat/kvm_cpuid_flags.in

diff --git a/configure.ac b/configure.ac
index 9dec1b23..c1eeb578 100644
--- a/configure.ac
+++ b/configure.ac
@@ -575,6 +575,7 @@ AC_CHECK_TYPES(m4_normalize([
 ]),,, [#include <linux/ptp_clock.h>])
 
 AC_CHECK_TYPES(m4_normalize([
+	struct kvm_cpuid2,
 	struct kvm_regs,
 	struct kvm_sregs,
 	struct kvm_userspace_memory_region
diff --git a/kvm.c b/kvm.c
index 86fd9e50..15beedca 100644
--- a/kvm.c
+++ b/kvm.c
@@ -85,6 +85,60 @@ kvm_ioctl_decode_regs(struct tcb *const tcp, const unsigned int code,
 }
 # endif /* HAVE_STRUCT_KVM_REGS */
 
+# ifdef HAVE_STRUCT_KVM_CPUID2
+#  include "xlat/kvm_cpuid_flags.h"
+static bool
+print_kvm_cpuid_entry(struct tcb *const tcp,
+		      void* elem_buf, size_t elem_size, void* data)
+{
+	const struct kvm_cpuid_entry2 *entry = elem_buf;
+	PRINT_FIELD_X("{", *entry, function);
+	PRINT_FIELD_X(", ", *entry, index);
+	PRINT_FIELD_FLAGS(", ", *entry, flags, kvm_cpuid_flags,
+			  "KVM_CPUID_FLAG_???");
+	PRINT_FIELD_X(", ", *entry, eax);
+	PRINT_FIELD_X(", ", *entry, ebx);
+	PRINT_FIELD_X(", ", *entry, ecx);
+	PRINT_FIELD_X(", ", *entry, edx);
+	tprints("}");
+
+	return true;
+}
+
+static int
+kvm_ioctl_decode_cpuid2(struct tcb *const tcp, const unsigned int code,
+			const kernel_ulong_t arg)
+{
+	struct kvm_cpuid2 cpuid;
+
+	if ((code == KVM_GET_EMULATED_CPUID ||
+	     code == KVM_GET_SUPPORTED_CPUID) && entering(tcp))
+		return 0;
+
+	tprints(", ");
+	if (!umove_or_printaddr(tcp, arg, &cpuid)) {
+		PRINT_FIELD_U("{", cpuid, nent);
+
+		tprints(", entries=");
+		if (abbrev(tcp)) {
+			tprints("[");
+			if (cpuid.nent)
+				tprints("...");
+			tprints("]");
+
+		} else {
+			struct kvm_cpuid_entry2 entry;
+			print_array(tcp, arg + sizeof(cpuid), cpuid.nent,
+				    &entry, sizeof(entry), tfetch_mem,
+				    print_kvm_cpuid_entry, NULL);
+		}
+		tprints("}");
+	}
+
+	return RVAL_IOCTL_DECODED;
+}
+# endif /* HAVE_STRUCT_KVM_CPUID2 */
+
 # ifdef HAVE_STRUCT_KVM_SREGS
 static int
 kvm_ioctl_decode_sregs(struct tcb *const tcp, const unsigned int code,
@@ -127,6 +181,13 @@ kvm_ioctl(struct tcb *const tcp, const unsigned int code, const kernel_ulong_t a
 		return kvm_ioctl_decode_sregs(tcp, code, arg);
 # endif
 
+# ifdef HAVE_STRUCT_KVM_CPUID2
+       case KVM_SET_CPUID2:
+       case KVM_GET_SUPPORTED_CPUID:
+       case KVM_GET_EMULATED_CPUID:
+               return kvm_ioctl_decode_cpuid2(tcp, code, arg);
+# endif
+
 	case KVM_CREATE_VM:
 		return RVAL_DECODED | RVAL_FD;
 	case KVM_RUN:
diff --git a/xlat/kvm_cpuid_flags.in b/xlat/kvm_cpuid_flags.in
new file mode 100644
index 00000000..d80ce734
--- /dev/null
+++ b/xlat/kvm_cpuid_flags.in
@@ -0,0 +1,3 @@
+KVM_CPUID_FLAG_SIGNIFCANT_INDEX
+KVM_CPUID_FLAG_STATEFUL_FUNC
+KVM_CPUID_FLAG_STATE_READ_NEXT
-- 
2.18.0