[Xen-changelog] Avoid xen crash if there is no VMX support. If a platform

[Xen patchbot -unstable <patchbot-unstable@xxxxxxxxxxxxxxxxxxx>]

# HG changeset patch
# User kaf24@xxxxxxxxxxxxxxxxxxxx
# Node ID 02cfa3beabba1de2b6dc864a71d10f0776c7aa99
# Parent  4299f983e8fe19187873062e1e2da32933f88292
Avoid xen crash if there is no VMX support. If a platform
doesn't support VMX, creating VMX domain will crash xen
HV.

Signed-off-by: Xin Li <xin.b.li@xxxxxxxxx>

diff -r 4299f983e8fe -r 02cfa3beabba tools/libxc/xc_vmx_build.c
--- a/tools/libxc/xc_vmx_build.c        Fri Dec 30 16:02:30 2005
+++ b/tools/libxc/xc_vmx_build.c        Fri Dec 30 16:07:34 2005
@@ -574,29 +574,6 @@
     return -1;
 }
 
-#define VMX_FEATURE_FLAG 0x20
-
-static int vmx_identify(void)
-{
-    int eax, ecx;
-
-    __asm__ __volatile__ (
-#if defined(__i386__)
-                          "push %%ebx; cpuid; pop %%ebx"
-#elif defined(__x86_64__)
-                          "push %%rbx; cpuid; pop %%rbx"
-#endif
-                          : "=a" (eax), "=c" (ecx)
-                          : "0" (1)
-                          : "dx");
-
-    if (!(ecx & VMX_FEATURE_FLAG)) {
-        return -1;
-    }
-
-    return 0;
-}
-
 int xc_vmx_build(int xc_handle,
                  uint32_t domid,
                  int memsize,
@@ -613,10 +590,18 @@
     unsigned long nr_pages;
     char         *image = NULL;
     unsigned long image_size;
-
-    if ( vmx_identify() < 0 )
-    {
-        PERROR("CPU doesn't support VMX Extensions");
+    xen_capabilities_info_t xen_caps;
+
+    if ( (rc = xc_version(xc_handle, XENVER_capabilities, &xen_caps)) != 0 )
+    {
+        PERROR("Failed to get xen version info");
+        goto error_out;
+    }
+
+    if ( !strstr(xen_caps, "hvm") )
+    {
+        PERROR("CPU doesn't support VMX Extensions or "
+               "CPU VMX Extensions are not turned on");
         goto error_out;
     }
 
diff -r 4299f983e8fe -r 02cfa3beabba tools/python/xen/xend/image.py
--- a/tools/python/xen/xend/image.py    Fri Dec 30 16:02:30 2005
+++ b/tools/python/xen/xend/image.py    Fri Dec 30 16:07:34 2005
@@ -188,6 +188,10 @@
 
     def configure(self, imageConfig, deviceConfig):
         ImageHandler.configure(self, imageConfig, deviceConfig)
+
+        info = xc.xeninfo()
+        if not 'hvm' in info['xen_caps']:
+            raise VmError("vmx: not an Intel VT platform, we stop creating!")
 
         self.dmargs = self.parseDeviceModelArgs(imageConfig, deviceConfig)
         self.device_model = sxp.child_value(imageConfig, 'device_model')
diff -r 4299f983e8fe -r 02cfa3beabba xen/arch/x86/domain.c
--- a/xen/arch/x86/domain.c     Fri Dec 30 16:02:30 2005
+++ b/xen/arch/x86/domain.c     Fri Dec 30 16:07:34 2005
@@ -35,7 +35,6 @@
 #include <xen/console.h>
 #include <xen/elf.h>
 #include <asm/vmx.h>
-#include <asm/vmx_vmcs.h>
 #include <asm/msr.h>
 #include <asm/physdev.h>
 #include <xen/kernel.h>
@@ -348,6 +347,8 @@
              ((c->user_regs.ss & 3) == 0) )
             return -EINVAL;
     }
+    else if ( !hvm_enabled )
+        return -EINVAL;
 
     clear_bit(_VCPUF_fpu_initialised, &v->vcpu_flags);
     if ( c->flags & VGCF_I387_VALID )

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