From: Haiwei Li <lihaiwei@xxxxxxxxxxx>
Add compile-time assertions in vmcs_check32() to disallow accesses to
64-bit and 64-bit high fields via vmcs_{read,write}32(). Upper level KVM
code should never do partial accesses to VMCS fields. KVM handles the
split accesses automatically in vmcs_{read,write}64() when running as a
32-bit kernel.
Reviewed-and-tested-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Signed-off-by: Haiwei Li <lihaiwei@xxxxxxxxxxx>
---
v1 -> v2:
* Improve the changelog
arch/x86/kvm/vmx/vmx_ops.h | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arch/x86/kvm/vmx/vmx_ops.h b/arch/x86/kvm/vmx/vmx_ops.h
index 692b0c3..164b64f 100644
--- a/arch/x86/kvm/vmx/vmx_ops.h
+++ b/arch/x86/kvm/vmx/vmx_ops.h
@@ -37,6 +37,10 @@ static __always_inline void vmcs_check32(unsigned long field)
{
BUILD_BUG_ON_MSG(__builtin_constant_p(field) && ((field) & 0x6000) == 0,
"32-bit accessor invalid for 16-bit field");
+ BUILD_BUG_ON_MSG(__builtin_constant_p(field) && ((field) & 0x6001) == 0x2000,
+ "32-bit accessor invalid for 64-bit field");
+ BUILD_BUG_ON_MSG(__builtin_constant_p(field) && ((field) & 0x6001) == 0x2001,
+ "32-bit accessor invalid for 64-bit high field");
BUILD_BUG_ON_MSG(__builtin_constant_p(field) && ((field) & 0x6000) == 0x6000,
"32-bit accessor invalid for natural width field");
}
--
1.8.3.1
