[PATCH 4/5] lscpu: improve vmware detection

Ruediger Meier
2014-05-20T15:43:08Z

From: Ruediger Meier <ruediger.meier@ga-group.nl>

This patch comes from openSUSE / SLE. Original author was probably
Petr Uzel.
Internal SUSE references: fate310255, sr226509

CC: Stanislav Brabec <sbrabec@suse.cz>
CC: Petr Uzel <petr.uzel@suse.cz>
Signed-off-by: Ruediger Meier <ruediger.meier@ga-group.nl>
---
sys-utils/lscpu.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 68 insertions(+)

diff --git a/sys-utils/lscpu.c b/sys-utils/lscpu.c
index b9e07e6..ee3ad19 100644
--- a/sys-utils/lscpu.c
+++ b/sys-utils/lscpu.c
@@ -32,6 +32,15 @@
#include <stdarg.h>
#include <sys/types.h>
#include <sys/stat.h>
+#include <stdint.h>
+#include <signal.h>
+#include <strings.h>
+#include <setjmp.h>
+#if defined(__x86_64__) || defined(__i386__)
+#ifdef HAVE_sys_io_h
+#include <sys/io.h>
+#endif
+#endif

#include <libsmartcols.h>

@@ -573,6 +582,57 @@ read_hypervisor_cpuid(struct lscpu_desc *desc)
desc->hyper = HYPER_VMWARE;
}

+#define VMWARE_BDOOR_MAGIC 0x564D5868
+#define VMWARE_BDOOR_PORT 0x5658
+#define VMWARE_BDOOR_CMD_GETVERSION 10
+
+#define VMWARE_BDOOR(eax, ebx, ecx, edx) \
+ __asm__("inl (%%dx)" : \
+ "=a"(eax), "=c"(ecx), "=d"(edx), "=b"(ebx) : \
+ "0"(VMWARE_BDOOR_MAGIC), "1"(VMWARE_BDOOR_CMD_GETVERSION), \
+ "2"(VMWARE_BDOOR_PORT), "3"(0) : \
+ "memory");
+
+static jmp_buf segv_handler_env;
+
+static void
+segv_handler(int sig, siginfo_t *info, void *ignored)
+{
+ siglongjmp(segv_handler_env, 1);
+}
+
+static int
+is_vmware_platform(void)
+{
+ uint32_t eax, ebx, ecx, edx;
+ struct sigaction act, oact;
+
+ /*
+ * The assembly routine for vmware detection works
+ * fine under vmware, even if ran as regular user. But
+ * on real HW or under other hypervisors, it segfaults (which is
+ * expected). So we temporarily install SIGSEGV handler to catch
+ * the signal. All this magic is needed because lscpu
+ * isn't supposed to require root privileges.
+ */
+ if (sigsetjmp(segv_handler_env, 1))
+ return 0;
+
+ bzero(&act, sizeof(act));
+ act.sa_sigaction = segv_handler;
+ act.sa_flags = SA_SIGINFO;
+
+ if (sigaction(SIGSEGV, &act, &oact))
+ err(EXIT_FAILURE, _("error: can not set signal handler"));
+
+ VMWARE_BDOOR(eax, ebx, ecx, edx);
+
+ if (sigaction(SIGSEGV, &oact, NULL))
+ err(EXIT_FAILURE, _("error: can not restore signal handler"));
+
+ return eax != (uint32_t)-1 && ebx == VMWARE_BDOOR_MAGIC;
+}
+
#else /* ! __x86_64__ */
static void
read_hypervisor_cpuid(struct lscpu_desc *desc __attribute__((__unused__)))
@@ -623,6 +683,11 @@ read_hypervisor_cpuid(struct lscpu_desc *desc __attribute__((__unused__)))
}
#endif
}
+
+static int is_vmware_platform(void)
+{
+ return 0;
+}
#endif

static void
@@ -659,6 +724,9 @@ read_hypervisor(struct lscpu_desc *desc, struct lscpu_modifier *mod)
} else if (has_pci_device( hv_vendor_pci[HYPER_XEN], hv_graphics_pci[HYPER_XEN])) {
desc->hyper = HYPER_XEN;
desc->virtype = VIRT_FULL;
+ } else if (is_vmware_platform()) {
+ desc->hyper = HYPER_VMWARE;
+ desc->virtype = VIRT_FULL;
} else if (has_pci_device( hv_vendor_pci[HYPER_VMWARE], hv_graphics_pci[HYPER_VMWARE])) {
desc->hyper = HYPER_VMWARE;
desc->virtype = VIRT_FULL;
--
1.8.4.5