x86/vvmx: correctly report vvmcs size

The size of Xen's virtual vmcs region is 4096 bytes (see comment about
Virtual VMCS layout in include/asm-x86/hvm/vmx/vvmx.h). Correctly report
it to the guest in case when VMCS shadowing is not available instead of
providing H/W value (which is usually smaller).

Signed-off-by: Sergey Dyasli <sergey.dyasli@citrix.com>
Acked-by: Kevin Tian <kevin.tian@intel.com>

diff --git a/xen/arch/x86/hvm/vmx/vvmx.c b/xen/arch/x86/hvm/vmx/vvmx.c
index 1cb4af51138ae5101b867ce8d2c6f269e1305289..610236e3f2f8a300ff9ec6ae432ce2a4235ea692 100644 (file)
--- a/xen/arch/x86/hvm/vmx/vvmx.c
+++ b/xen/arch/x86/hvm/vmx/vvmx.c
@@ -2091,6 +2091,14 @@ int nvmx_msr_read_intercept(unsigned int msr, u64 *msr_content)
         data = (host_data & (~0ul << 32)) |
                (vmcs->vmcs_revision_id & 0x7fffffff);
         unmap_domain_page(vmcs);
+
+        if ( !cpu_has_vmx_vmcs_shadowing )
+        {
+            /* Report vmcs_region_size as 4096 */
+            data &= ~VMX_BASIC_VMCS_SIZE_MASK;
+            data |= 1ULL << 44;
+        }
+
         break;
     }
     case MSR_IA32_VMX_PINBASED_CTLS: